Government of India

CENTRAL INSTITUTE OF PSYCHIATRY SEMINAR

DISORDERS OF MEMORYChairperson : Dr.A.K. Bakhla Presenter : Dr. Archana Singh Discussant : Dr. Sathishkumar S V 1. 2. 3. 4. 5. Introduction Classification Of Memory Processes Of Memory Formation Models Of Memory Processing Clinical Assessment of Memory 6. Types Of Memeory Disorders A. Amnesia B.Paramnesia C. Hyperamnesia 7. Conclusion

INTRODUCTIONThe ability to store and recall information is one of the most amazing capacities of higher organisms. As human adults, we can remember events that happened in our earliest childhood. We can recall skills learned far in the past. Our memories encapsulate our sense of personal identity, our cultural identities, and the meaning of our lives. We can even be influenced by memories that we cannot explicitly remember. However, we all remember of that there can be no doubt. Whether we remember accurately or inaccurately, in detail or in abstract, are questions that researchers have investigated for many years. Disturbance of memory is always of significance for the sufferers; sometimes, however, forgetting is equally important and is an active process. The memory disturbance was a specific feature following head injury and other conditions was recognised in various writings in mid 19th century. The earliest detailed study of disordered memory from a psychological perspective was by Ribot (1882). Korsakov (1890) subsequently described his eponymous condition, pointing out that gross disorder of memory may occur in patients in whom other intellectual functions and judgement are preserved (Oyebode, 2008).

CLASSIFICATIONS OF MEMORY BASED ON DURATION y SENSORY MEMORY y SHORT TERM MEMORY y LONG TERM MEMORY WORKING MEMORY BASED ON INTEGRITY OF INFORMATION y IMMEDIATE MEMORY y RECENT MEMORY y REMOTE MEMORYBASED ON DURATION SENSORY MEMORY SHORT TERM MEMORY LONG TERM MEMORY WORKING MEMORY BASED ON INTEGRITY OF INFORMATION IMMEDIATE MEMORY

RECENT MEMORY REMOTE MEMORY

SENSORY MEMORYSensory memory is the ability to retain impressions of sensory information after the original stimulus has ceased. It refers to items detected by the sensory receptors which are retained temporarily in the sensory registers and which have a large capacity for unprocessed information but are only able to hold accurate images of sensory information momentarily. Sensory memory corresponds approximately to the initial 200 500 milliseconds after an item is perceived (Morgan et al., 1993). The two types of sensory memory that have been most explored are iconic memory and echoic memory. Visual sensory memory is more commonly referred to as iconic memory and auditory sensory memory is known as echoic memory. This type of memory cannot

be prolonged via rehearsal.

SHORT TERM MEMORYShort-term memory (or "primary" or "active memory") is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of

short-term memory is believed to be in the order of seconds. Estimates of short-term memory capacity are 7 plus or minus 2 units. Short term memory is memory that holds information received from sensory register for up to about 30 seconds. Baddeley, (1986) defined working memory as "A system for the temporary holding and manipulation of information during the performance of cognitive task such as comprehension, learning and reasoning (Sims, 2003). Short-term memory is believed to rely mostly on an acoustic code for storing information, and to a lesser extent a visual code.

LONG TERM MEMORY (LTM)When memories have been MEMORY rehearsed in short term memory, they SHORT are encoded into SENSORY MEMORY TERM LONG TERM MEMORY MEMORY long term memory. Long Term Memory (LTM), provides DECLARATIVE NON-DECLARATIVE ICONIC ECHOIC lasting retention of MEMORY MEMORY information and SIMPLE skills from minutes SEMANTIC EPISODIC PROCEDURAL CLASSICAL PRIMING to a lifetime and CONDITIONING has a limitless capacity. Encoding is the process of placing information into what is believed to be a limitless memory reservoir or LTM, can occur for specific stimuli as well as for the general memory (Casey and Kelly, 2007). ). The storage of material in long-term memory allows for recall of events from the past and for the utilization of information learned throughout life.

Divisions Of Long Term MemoryLong-term memory is commonly divided into two major types -'declarative' and 'non-declarative (Oyebode, 2008).

y Declarative memory also termed as explicit memory, encompasses all the information that we can consciously describe or report. . It has been further subcategorized into: (a) Semantic memory which concerns memory for meaning, the storage of abstracts and general facts. (b) Episodic memory or autobiographical memory is memories based upon a personal experience relating to self and is linked to a particular time and place in life. y Non Declarative memory refers to skills, habits or other manifestation of learning that can be expressed without an awareness of what has been learned. It is heterogeneous collection of nonconscious or implicit memory abilities. Subtypes Procedural Simple classical conditioning Priming Procedural memory, also known as implicit memory, is memory system that retains information we cannot readily express verbally-for example, information necessary to perform skilled motor activities like riding a bicycle (Baron, 2005). Although we retain these skills and abilities we are often completely unable to introspect upon or describe how we do them. Procedural memory is very resistant to forgetting and is also resistant to brain damage that eradicates other forms of memory like seen in anterograde amnesic patients who forget simple events or verbal instructions after a few moments. Simple Classical Conditioning is another type of non-declarative memory that generally occurs in the presence of conscious awareness of conditioned stimulus (CS) and unconditioned stimulus (UCS) contingency, but can occur without awareness also (Budson,2001). Priming When an object has just been perceived or processed, there is a tendency for that object to be perceived more easily the next time, a temporary facilitation that is something like a warm-up effect. Such priming operates across a wide range of sensory and motor systems, occurring at a range of different processing levels. For example, presenting a picture of an airplane will make it easier for a subject to identify a highly fragmented version of the picture as an airplane when it is presented shortly afterwards. In general, priming tends to be very specific, as though some aspect of the perceptual system has been facilitated by being used recently. As mentioned earlier, priming is usually preserved in amnesic patients good explicit learning do not influence implicit learning,

and vice versa. Another feature of implicit learning is the way in which it appears to bypass conscious awareness.

The diagram indicates various neural structures thought to be important for different types of declarative and non declarative memory.SEMANTIC MEMORY Semantic memory refers to a person s conceptual knowledge about the world. It includes knowledge of the meaning of words, objects and other stimuli perceived through the senses, as well as a rich abundance of facts and associated information. Semantic memory is immensely important because it constitutes the knowledge base that allows us to communicate, use objects, recognize foods, react to environmental stimuli and function appropriately in the world. Semantic memory does not break down in an all-or-none fashion. Patients may know some words but not others, may recognize one exemplar of an object but not another, and may retain partial information about a concept while other information is lost(Snowden, 2002). WORKING MEMORY The concept of working memory (WM) was initially proposed by Baddeley and Hitch (1974) and developed by Baddeley (1986), and is characterised by the assumption that short-term storage of information must be considered as part of a more complex system involved in the execution of a specific task. The information is stored in the WM as long as necessary, and the structure need not be defined only in terms of the dichotomy between short- and longterm information storage. On the contrary, this system has the ability to store and process information simultaneously (Cornoldi & Vecchi 2003).

CLINICAL CLASSIFICATION For clinical descriptive purposes, memory is often subdivided into three basic types immediate, recent, and remote distinguished by the time interval between presentation of the stimuli and retrieval. Immediate memory may refer to the registration of information as a memory trace for several seconds or more, corresponding to both sensory and sometimes short-term memory described earlier. Recent memory assumes some period of memory storage, and might include a person s recall of day-to-day events, and may refer to information learned hours, days, or even weeks ago. Remote memories typically include memories of events or knowledge learned years ago, usually premorbidly or before a brain injury (Strub and Black, 2000 ).

PROCESSES OF MEMORY FORMATION

Description of the requirement for memory is chiefly referable to long term memory and can be subdivided phenomenologically into the following five functions (Oyebode, 2008).y y y y y

Registration or encoding is the capacity to add new information to the memory store. Retention or storage is the ability to maintain knowledge that can subsequently be returned to consciousness. Retrieval is the capacity to access stored information from memory by recognition, recall or by demonstrating that a relevant task is performed more efficiently as a result of prior experience.Recall is the effortful retrieval of stored information into consciousness at a chosen moment. It requires an active complex search process. It is influenced by primacy and recency effects. Recognition is the retrieval of stored information that depends on the identification of items previously learned and is based on either remembering (effortful recollection) or knowing (familiarity based recollection).

Seven stages in memory: Following Welford, memory can be isolated in seven stages (Hamilton, 1984). These are 1. Adequate perception, comprehension and response to the material to be learned. 2. Short-term storage mechanism. 3. Formation of a durable trace. 4. Consolidation in which traces are often modified or simplified by subsequent learning. 5. Recognition that certain material needs to be recalled. 6. Isolation of the relevant memory. 7. Using the recalled material in new situation.

MODELS OF MEMORY PROCESSING1) Atkinson-Shiffrin model

Atkinson and Shiffrin considered memory to have three major constituents. In the Atkinson-Shiffrin theory, memory starts with a sensory input from the environment which is held for a very brief period in the sensory register associated with the sensory channels like vision, hearing and touch etc. information that is attended to and recognized in the sensory register is passed on to short term memory where it is held for about 20-30 seconds. Some of the information reaching short term memory is processed by being rehearsed and may then be passed along to long term memory; information that is not processed is lost. When items of information are placed in long term memory they are organized into categories. It was assumed that the longer an item is held in the short term memory, the more likely it is to go into long-term memory (Morgan et al., 1993).

2)

Working memory model- Baddeley and Hitch

In 1974 Baddeley and Hitch proposed a working memory model which replaced the concept of general short term memory with specific, active components. In this model, working memory consists of three basic stores: the central executive, the phonological loop and the visuo-spatial sketchpad. In 2000 this model was expanded with the multimodal episodic buffer. The central executive essentially acts as attention. It channels information to the three component processes: the phonological loop, the visuo-spatial sketchpad, and the episodic buffer. The phonological loop stores auditory information by silently rehearsing sounds or words in a continuous loop: the articulatory process. The visuospatial sketchpad stores visual and spatial information. The episodic buffer is dedicated to linking information across domains to form integrated units of visual, spatial, and verbal information and chronological ordering. The episodic buffer is also assumed to have links to long-term memory and semantical meaning. The working memory model explains many practical observations, such as why it is easier to do two different tasks (one verbal and one visual) than two similar tasks (e.g., two visual).

3)

Levels of processing model- Craik and Lockharts

Craik and Lockhart (1972) argued that the previous view of a short-term memory store relying on speech coding and feeding a long-term memory store was inappropriate. They suggested that the more deeply information is processed; the more likely it is to be retained (Baron , 2005). They argued that all of these processes would lead to some long-term learning, but that the amount of learning depended on the type of processing, with "deep" processing in terms of meaning leading to much better retention than "shallow" processing. Maintenance rehearsal might keep material available, but would not enhance long-term learning. Memory DisordersMemory disorders may affect the ability to recall both past events (retrospective memory) and future events and intentions (prospective memory) The two major brain regions that have generally been implicated in human memory dysfunction include the diencephalon and the hippocampi (Emilien et al., 2005). The dysmnesic syndromes that involve these structures include impairment of long-term data storage, disruption of the encoding of short-term into long-term storage, or a loss of decoding or access to the long-term data storage. Dysmnesia is the preferred term describing a partial memory loss, in contrast to the term amnesia, which implies a total memory loss. Amnesia may be viewed as an extreme on a broad continuum of dysmnesic syndromes where mild dysmnesic illnesses occur more commonly than total amnesia. There can be varied presentation of memory impairments. A patient can have memory impairment in single memory domain, e.g. working memory, or can have deficit in different domains simultaneously (Lishman, 2004). Memory disorders can be broadly classified into AMNESIAS (loss of memory) PARAAMNESIAS (distortions of memory) HYPERAMNESIAS THE AMNESIAS Amnesia is a general term meaning temporary or permanent impairment of some part of the memory system. The term amnesia is typically applied to a deficit of long-term episodic memory, involving an impaired capacity for new learning (anterograde amnesia), and/or a deficit in access to old memories (retrograde amnesia). The classic amnesic syndrome involves impaired episodic memory, but with preserved intellect, normal working memory and access to semantic memory, although new semantic learning is likely to be impaired. Implicit memory is likely to be preserved, with patients able to acquire motor and perceptual skills, to show perceptual priming, to be capable of classical conditioning, and of non-associative learning.

Its origin may be organic or psychogenic.y

Psychogenic Amnesias:Psychogenic amnesias may appear without any organic disease present but the presentation of organic brain disease is always modified by psychogenic factors, (Oyebode, 2008).

Childhood amnesia- Freud used the concept of repression to account for childhood amnesia. He said that we are unable to retrieve childhood memories because they are associated with the forbidden, guilt arousing sexual and aggressive urges. These urges and their associations are repressed and cannot be retrieved; they are forgotten because being aware of them would result in strong feeling of guilt or anxiety. Another interpretation of childhood amnesia stresses over difference in the ways young children and older people encode and store information (Morgan et al., 1993). Dream amnesia-Freud s interpretation of dreams was based on repression. He considered dreams to be expression of forbidden sexual and aggressive urges. Other interpretation stress the differences in the symbol system used in dreaming and waking, the memory-symbol network in waking life are different from those of dreaming so it is difficult to retrieve dreams in waking state (Morgan et al., 1993). Defensive amnesia-This form of amnesia is usually considered to be a way of protecting oneself from the guilt or anxiety that can result from intense, intolerable life situations or conflicts. People with this form of amnesia may forget their names, place of living, occupation and many other important details of their past life. Amnesic episode can last for weeks, months, or years (Morgan et al., 1993). Anxiety amnesias- Anxiety amnesia occurs when there is anxious preoccupation or poor concentration in disorders such as depressive illness or generalized anxiety. More severe forms of amnesia in depressive disorders resemble dementia and are known as depressive pseudo dementia.

Amnesias in anxiety and depressive disorders are generally caused by impaired concentration and resolve once the underlying disorder is treated (Casey and Kelly, 2007).Katathymic amnesia- also known as motivated forgetting. It is the inability to recall specific painful memories and is believed to occur due to defense mechanism of repression. Though the term is often used interchangeably with dissociative amnesia, katathymic amnesia is more persistent and circumscribed than dissociation in that there is no loss of personal identity (Casey and Kelly, 2007). Dissociative or hysterical amnesia- is a sudden amnesia that occurs during periods of extreme trauma

and may be concerned about the stressful or traumatic life events that may last for hours or even days. The amnesia will be for personal identity such as name, address and history as well as for personal events, while at the same time the ability to perform complex behaviors is maintained (Casey and Kelly, 2007). Dissociation may be associated with a fugue or wandering state in which the subject travels to another town or country, and is often found wandering and lost. Four types of amnesia are been described. y y y y Localized amnesia being the commonest type, have inability to recall the events over circumscribed period of time corresponding to stressor. Selective amnesia related to only selective events of a particular period related to stressful life event without impairment of memory in other events of same time period. Continuous amnesia, inability to recall all the personal events from the time of stressful situation till present time. Generalized amnesia, rarest inability to recall whole life in face of stressful life event (Ahuja, 1999).

Organic amnesiasOrganic impairment of memory is referred to as true amnesia and can affect different functions of memory. There can be impairment of registration, retention, retrieval or recall, or recognition. y Acute brain disease -In these conditions memory is poor owing to disorders of perception and attention. Hence there is a failure to encode material in long-term memory. In acute head injury there is amnesia, known as retrograde amnesia that embraces the events just before the injury. Anterograde amnesia is amnesia for events occurring after the injury; these occurred most commonly following accidents and are indicative of failure to encode events into long-term memory. Blackouts are circumscribed periods of anterograde amnesia experienced particularly by those who are alcohol dependent during and following bouts of drinking. They indicate reversible brain damage and vary in length but can span many hours. They also occur in acute confusional states (delirium) due to infections or epilepsy (Casey and Kelly, 2007). Subacute coarse brain disease- The characteristic feature of this disorder, is an amnestic state in which the patient is unable to register new memories leading to inability to learn new information (anterograde amnesia),and the inability to recall previously learned material (retrograde amnesia). However, memories from the remote past remain intact, as does recall of over learned material from the past and immediate recall. As improvement occurs, the amnestic period may shrink and recovery may sometimes be total (Casey and Kelly, 2007). Chronic coarse brain disease- Patients with a progressive chronic brain disease have an amnesia extending over many years, though the memory for recent events is lost before that for remote events. This was pointed out by Ribot and is known as Ribot's law of memory regression (Casey and Kelly, 2007).

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THE AMNESIC SYNDROMES Korsakoff s syndromeKorsakoff s syndrome results from prolonged and excessive alcohol intake. The thiamine (B1) deficiency has a direct effect on the brain, specifically on the medial thalamus and possibly on the mammillary bodies of the hypothalamus (Victor et al., 1989).The most common symptoms associated with this syndrome include anterograde as well as retrograde amnesia, confabulations, and a general sense of apathy. Korsakoff s syndrome has long been recognized the prototype of diencephalic amnesia, although it is now recognised that Korsakoff s syndrome commonly involves cortical atrophy, especially the frontal lobes and damage to other brain regions (Parkin, 1991 ). In addition to their Anterograde memory deficit, Korsakoff s syndrome patients have severely impaired retrograde memory. In Korsakoff s syndrome memory for events in the more distant past preserved relative to memory for more recent events (Butters & Granholm, 1987; Parkin, 1991). Patients with Korsakoff s syndrome have a striking anterograde and retrograde amnesia, often with marked confabulation but preserved attention, personality, social functioning, STM, and nondeclarative memory. Korsakoff patients, like other amnesics, exhibit severe impairments in the ability to learn new information.

Transient global amnesiaIn most cases of amnesia, the severity of the memory deficit remains stable over a period of years, but there are conditions such as transient global amnesia where recovery occurs. Global amnesia is characterized by a relatively circumscribed deficit in LTM for new information. It appears that transient global amnesia may be caused by temporary bilateral dysfunction of medial temporal lobe structures, including the hippocampus, entorrhinal cortex, and parahippocampal gyrus (Fisher, 1982). This dysfunction is most likely due to ischaemia, perhaps caused by vertebrobasilar hypoperfusion or migrainous vasospasm of vertebrobasilar vessels (Caplan et al., 1981; Crowell et al., 1984). This type of amnesia is characterised by a patient s inability to learn new material, by their repeated asking of questions that have been answered and being able to recall events that antedate the onset of the episode. Transient global amnesia occurs in middle aged and elderly men more commonly than women (Fisher and Adams, 1964). The condition, which is still not clearly understood, can emerge in times of severe stress, pain, or emotion, and has been attributed to migraine, epilepsy, drug use, hypoglycaemia, stroke, and neoplasms but is still not clearly understood. Fortunately, these patients normally improve spontaneously, within a few hours, and are neurologically normal the following day. In the clinic, transient global amnesia is typically assessed by means of recall and recognition tests that require retrieval of recently learned information. Patients with global amnesia also manifest retrograde amnesia. Frequently, remote memories are better preserved than memories for events that occurred shortly before brain injury.

Visual memory-deficit amnesiaVision and visual imagery play a central role in a variety of memory tasks (Rubin, 1995). Biographical memory appears to rely on visual imagery to a much greater extent than other sensory modalities. A form of amnesia called visual memory deficit amnesia, caused by damage to areas of the visual system that store visual information, has been described (Rubin & Greenberg, 1998). Because it is caused by a deficit in access to stored visual material and not by an impaired ability to encode or retrieve new material, it has the otherwise infrequent properties of a more severe retrograde than anterograde amnesia with no temporal gradient in the retrograde amnesia.

Paramnesia (Distortions of memory)This term was coined by Emil Kraepelin (1887) in analogy of terms such as paranoia, paraphasia, and paraphrenia, as a general term to explain illusions and hallucinations of memory (Burnham, 1889). This is the falsification of memory by distortion. This can occur in normal subjects due to the process of normal forgetting or due to proactive and retroactive interference from newly acquired material and is also seen in persons suffering from emotional problems or other organic states. It can be divided into Distortions of recall Distortions of recognition

Distortions of recallRetrospective falsification Retrospective falsification refers to the unintentional distortion of memory that occurs when it is filtered through a person's current emotional, experiential and cognitive state (Casey and Kelly, 2007).Though it can occur in any psychiatric illnesses, it is often found in those suffering from depressive illness and hysterical personality and is invariably related to the insight of the patient as well as to suggestibility. Retrospective delusions Retrospective delusions are found in some patients with psychoses who backdate their delusions in spite of the clear evidence that the illness is of recent origin (Casey and Kelly, 2007). Thus, the person will say that they have always been persecuted or that they have always been evil.

Delusional memoriesPrimary delusional experiences may take the form of memories and these are known as delusional memories, consisting of sudden delusional ideas and delusional perceptions. Delusional memories are variously defined, some authorities believing them to be delusional interpretations of real memories (Pawar & Spence, 2003), while others such as the Present State Examination (PSE) suggest that they are experiences of past events that did not occur but which the subject clearly remembers. There are two components to a delusional memory, i.e. the perception (either real or imagined) and the memory. Confabulation

Confabulation is the falsification of memory occurring in clear consciousness in association with organic pathology. It manifests itself as the filling-in of gaps in memory by imagined or untrue experiences that have no basis in fact. There are two broad patterns (Bonhoeffer, 1901), the embarrassed type in which the patient tries to fill in gaps in memory as a result of an awareness of a deficit and fantastic type in which the lacunae are filled in by details exceeding the need of the memory impairment. The confabulation diminishes as the impairment worsens. Some related disorders include Pseudologia fantastica Pseudologia fantastica or fluent plausible lying (pathological lying) is the term used to describe the confabulation that occurs in those without organic brain pathology such as personality disorder of antisocial or hysterical type. Typically the subject describes various major events and traumas or makes grandiose claims and these often present at a time of personal crisis, such as facing legal proceedings. Although it seems that the person with pseudologia believes their own stories and there is a blurring of the boundary between fantasy and reality, when confronted with incontrovertible evidence these individuals will admit their lying (Casey and Kelly, 2007). Minor varieties of this occur in those who falsify or exaggerate the past in order to impress others. Vorbeireden or approximate answers Vorbeireden or approximate answers is seen in patients with hysterical pseudodementia, named after Ganser who, in 1898 described four criminals showing several common features (Casey and Kelly, 2007). Prominent features present in such patients include: clouding of consciousness with disorientation, auditory and visual hallucinations (or pseudo-hallucinations), amnesia for the period during which the symptoms were manifest, conversion symptoms and recent head injury, infection or severe emotional stress. Approximate answers suggest that the patient understands the questions but appears to be deliberately avoiding the correct answer, for instance, to avoid a court appearance .It is distinguished from pseudodementia in which consciousness is clear. Many now believe that the Ganser syndrome is indicative of either an organic or a psychotic state rather than hysteria as originally believed .Ganser syndrome and malingering/factitious disorder are often confused in spite of the conscious basis for the latter. Vorbeireden is also found in acute schizophrenia, usually the hebephrenic type. Munchausen's syndrome It is a variant of pathological lying in which the individual presents to hospitals with bogus illnesses, complex medical histories and often multiple surgical scars. A proxy form of this condition has been described in which the individual, usually a parent, produces a factitious illness in somebody else, generally their child. The

diagnosis of Munchausen s by proxy is itself a controversial diagnosis.y False memory False memory is the recollection of an event (or events) that did not occur but which the individual subsequently strongly believes did take place (Brandon et al, 1998). The syndrome refers not to distortion of true memories, as in normal forgetting, but to the actual construction of memories around events that never took place (Casey and Kelly, 2007). Memory distrust syndrome is a type of false memory which originates from the person's own fundamental distrust of their memory known as 'source amnesia'. This source amnesia arises because of difficulty remembering the source from which the information was acquired, whether from one's own recall or from some external source as recounted by others. y Screen memory This is a recollection that is partially true and partially false; the affected individual only recalls part of the true memory because the entirety of the true memory is too painful to recall (Casey and Kelly, 2007). It is difficult to find out precisely which elements of such memories are true and which is false.

y Multiple personality disorder (W .H .0,1992 ; Oyebode,2008) This disorder is rare, remains controversial due to lack of reliable information, unclear prevalence, selection bias and psychopathological imprecisions (Oyebode, 2008). The essential feature is the apparent existence of two or more distinct personalities within an individual, with only one of them being evident at a time. Each personality is complete, with its own memories, behaviour, and preferences: these may be in marked contrast to the single premorbid personality. In the common form with two personalities, one personality is usually dominant but neither has access to the memories of the other and the two are almost always unaware of each other's existence. Change from one personality to another in the first instance is usually sudden and closely associated with traumatic events.

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Cryptamnesia

Cryptamnesia is described as 'the experience of not remembering that one is remembering, (Oyebode,2008).For example a person writes a witty passage and does not realize that they are quoting from some passage they have seen elsewhere rather than writing something original. There is no indication as to whether this is a common phenomenon or whether it is associated with any specific psychiatric disorder (Casey and Kelly, 2007).

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State-dependent memory

State dependent memory is the recall of events or learned material only when the person is in the same drug or medication-induced state under which the event was experienced or the material learned. Patients with psychosis or severe mood disorder experience this phenomenon and, when well, will not recall dramatic experiences that occurred when ill. When ill again, the memories are again accessible and recalled (MurphyEberenz et al. 2006).

Distortions of recognitionDj vu is not strictly a disturbance of memory, but a problem with the familiarity of places and events. It comprises the feeling of having experienced a current event in the past, although it has no basis in fact. Jamais vous is the knowledge that an event has been experienced before but is not presently associated with the appropriate feelings of familiarity.

Dj entendu, the feeling of auditory recognition.Dj pense, a new thought recognized as having previously occurred, is related to dj vu, being different only in the modality of experience. These experiences occur occasionally in normal persons but they may

become excessive in temporal lobe lesions. Misidentification This may occur in confusion psychosis and in acute and chronic schizophrenia. Misidentification may be Positive misidentification Negative misidentification y Positive misidentification:

The patient recognizes strangers as his friends and relatives. Some patients assert that all of the people whom they meet are doubles of real people. In acute schizophrenia, it can be based on a delusional perception. y Negative misidentification:

The patient denies that his friends and relatives are people whom they say they are and insists that they are strangers in disguise. Leonhard has suggested that negative identification could result from an excessive concretization of memory images, so that the patient retains all the minute details of the characteristics of the people whom he encounters. When he sees the same person again he compares the new perception with the exact memory image.

The Basic Misidentification Syndromes Capgras Syndrome It was first described by capgras and Reboul-Lachaux in 1923. The essential feature of this syndrome is hypoidentification. Patients insists that a particular person (or persons), usually somebody with whom the patients is emotionally linked, is not the person he claims to be but is really a double; is often accompanied by depersonalization and occurs in a paranoid setting. The commonest cause of capgras syndrome is schizophrenia and less common causes include involutional depression and hysteria. Amphitryon illusion: in this patients believe that their spouses are doubles. Sosias illusion: In this patients believe that other people as well as the spouse are doubles (Hamilton 1984) . Fregoli syndrome It was first described by courbon and Fail in 1927. In fregoli syndrome hyperidentification takes place. The patient identifies a familiar person (usually his persecutor) in various strangers, who are therefore fundamentally the same individual. Syndrome of Subjective Doubles It is characterized by delusions of doubles exclusively of the patient s own self. The misidentification can be either hallucinatory or delusional. Syndrome of Intermetamorphosis In this syndrome patient believes that others have changed their physical appearance. Reduplicative paramnesia In reduplicative paramnesia, patients believe that a physical location has been duplicated.

HyperamnesiaThe opposite of amnesia and paramnesia can also occur and is termed hyperamnesia, or exaggerated registration, retention and recall. Flashbulb memories are those memories that are associated with intense emotion. They are unusually vivid, detailed and long-lasting. Flashbacks are sudden intrusive memories that are associated with the cognitive and emotional experiences of a traumatic event such as an accident. It may lead to acting and/or feeling that the event is recurring. It is regarded as one of the characteristic symptoms of posttraumatic stress disorder but is also associated with substance misuse disorders and emotional events (McGee, 1984). It is also likely to be a term that is used inaccurately and should not be confused with intrusive recollections, which lack the emotional familiarity of flashbacks. Flashbacks involving hallucinogenic experiences can occur in association with hallucinogenic drugs and possibly cannabis use after the short-term effects have worn off. These incorporate visual distortions, false perceptions of movement in peripheral fields, flashes of color, trails of images from moving objects, after-images and halos, as well as classical hallucinations. Eidetic images represent visual memories of almost hallucinatory vividness that are found in disorders due to substance misuse, especially hallucinogenic agents.

CLINICAL ASSESSMENT OF MEMORY Tests for memory (Strub & Black, 2000)Valid memory testing presumes that the patient is reasonably attentive, can relate to and cooperate with the examiner, and has no defect that impairs language comprehension or expression.

Immediate recall (short term memory) Immediate memory usually tested by digit repetition. Recent memory: Tested for constantly changing facts. Indian adaptation (max score=5): 1. ? 2. ? 3. ?4. - ? 5. - ?

Remote memoryThese evaluate the patient s ability to recall personal and historic events. Personal events must be verified from a reliable source other than the patient, and performance on the recall of historic information must be interpreted in light of the patient s premorbid intelligence, education, and social experience.

Indian adaptation: The following items to be enquired1. 2. 3. 4. 5. 6. ? ? ?/ ?/ - ? ? ? ?

Each correct answer to be scored one thus a maximum score of 6. (Pershad & Wig, 1988) Four unrelated wordsInstructions: Tell the patient, I am going to tell you four words that I would like you to remember. In a few minutes, I will ask you to recall these words . To ensure that the patient has heard, understood, and initially retained the four words, have him or her to repeat the words immediately and to correct any errors. Older patients may require several trials to learn the words.

Then he is asked to recall the words at 5, 10 and 30 minutes. To eliminate possible mental rehearsal, interference should be used between presentation and recall of words.

Scoring: Normal persons accurately recall 3-4 words after a 10-minute delay. In some, after being reminded of the correct words i.e., by verbal cues, whether he/she recognizes the appropriate word from the series of words and improve their performance after 10 and 30 minutes may be seen, but patients with dementia cannot improve even on subsequent trials. Indian adaptation: (Pershad & Wig, 1988) Set 1 , , , , Set 2 , , , ,

Verbal story for immediate recall Instructions: tell the patient, I am going to read you a short paragraph. Listen carefully, because when I finish reading, I want you to tell me everything that I told you. A short paragraph is read out to the patient which he is required to reproduce immediately. As the patient retells the story the number of items recalled is indicated. The normal individual is expected to produce at least 10 of these items, though this number decreases with age. If recall is good then he may be asked for another recall after 30 minutes. Indian adaptation: There are three sentences of increasing length. First sentence is read slowly, distinctly and at a uniform rate and note down the recalled sentence verbatim or each of the correctly recalled clauses. One mark for each clause correctly reproduced. (Pershad & Wig, 1988) 1. , 2. , , 3. , , ,

Visual memory (hidden objects) (Strub & Black, 2000) Five small, commonly used, easily recognizable objects are hidden in the patient s vicinity while he is watching. Each item is named while being hidden. Then interfering stimuli is provided for 5 minutes. After this period he is asked to name and indicate the location of each hidden object. Finding out fewer than three objects indicates impaired visual memory. Paired associate learning Instructions: Tell the patient, I am going to read you a list of words, two at a time. Listen carefully because I will expect you to remember the words that go together. When the patient understands the directions, continue as follows: Now listen carefully to the words as I read them. The patient is read out a list of paired words at the rate of one pair every 2 seconds. Then he is given the first words from the pairs, one after another and given 5 seconds for each response. After completion of the first recall list the second presentation list is provided after a 10 second interval and proceeded in the same way. A normal person under 70 years is expected to recall the two easy paired associates and at least one of the hard associates of the first recall trial and to recall all paired associates on second trial. Some patients can learn the paired words with strong natural associations but cannot learn the pairs without such associations which indicate an inability to learn new material that cannot be associated with memories already in storage. Indian adaptation: (Pershad & Wig, 1988) Retention for similar pairs For dissimilar pairs

CONCLUSION Our memories reflect the accumulation of a lifetime of experience and, in this sense, our memories are who we are. We learn to walk, to dance, to drive a car, to throw a ball, and to play a video game a myriad of acquired skills we come to take for granted. We learn to fear dangerous situations, to appreciate particular types of music and styles of art a broad range of aversions and enjoyments we have assumed as elements of our preferences and personality. We learn world history, and we learn our own family tree and personal autobiography all of these, and much, much more, compose the vast contents and intricate, complex organization of memories that make each of us a unique human being. Disorders of memory may present as discrete dysfunction or as part of psychiatric syndrome. There are various clinical and neuropsychological tools to assess these and hence early interventions to manage these can be used. DISCUSSION Discussion will be covered under following headings:TYPES OF MEMORY: ARE THEY REPRESENTING SEPERATE SYSTEMS? MODELS OF MEMORY: A BRIEF CRITICAL APPRAISAL NEUROBIOLOGY OF MEMORY EPISODIC LEARNING, REMEMBERING, FORGETTING AND KNOWING AMNESIA IN THE CURRENT NOSOLOGY AGING, MILD COGNITIVE IMPAIRMENT AND DEMENTIA MEMORY DYSFUNCTION IN PSYCHIATRIC DISORDERS MEMORY DISORDERS IN EPILEPSY DRUG INDUCED MEMORY ALTERATION MEMORY DISTURBANCES AND ECT AGING AND MEMORY IMPAIRMENT EMOTIONAL AND SOCIAL CONSEQUENCES OF MEMORY DISORDERS MEMORY REHABILITATION CONCLUSION

TYPES OF MEMORY: ARE THEY REPRESENTING SEPERATE SYSTEMS? Memory researchers have hypothesized a range of separate memories that deal in different ways with the incoming information from the external world. The oldest division hypothesized was between primary and secondary memory, which was proposed by William James (1890). He distinguished between what one remembered from current consciousness which he called primary memory and secondary memory which involved the knowledge about what had been absent from consciousness. This can be considered as the beginning of the working memory / long term memory distinction. During 1960s this distinction was elaborated into a theory of short term and long-term memory (Atkinson and Shiffrin, 1968) and later modified into a theory of working memory model (Baddeley, 1986) in which an account of the mechanism and support system for processing was given. Working memory model introduced several subdivision of short term memory. There is a central executive, responsible for the processing of the incoming information, the articulatory loop that can hold a couple of seconds of speech like information, temporarily freeing the central executive of their load and the visuo-spatial sketchpad that can similarly retain spatial information for a short time. Prior even to the central executive, other very short-term, sensory memories have been postulated on the basis of the ability for apparently large amounts of visual and acoustic information to be held briefly. A visual iconic memory store was initially postulated by Sperling (1960) and later a related acoustic memory was proposed by crowder and morton

(1969). Though there are robust demonstration of the accessibility of much that has been presented visually or verbally for brief intervals. Usually less than 1 second, there have been disputes over their interpretation (Haber, 1983;Coltheart, 1983). Beyond the short intervals covered by sensory and working memories, the possible subdivisions of longer-term memory have been controversial. However, the distinction between explicit and implicit memory has been generally incorporated into the accepted conceptual anatomy of memory research. The implicit/explicit memory distinction is justified by data that fit the defined distinction, but argument continues over whether the phenomena of implicit and explicit memory implies that there are two separate memory systems. Similar disputes occur-over the other major divisions of longer-term memory. The terms episodic, semantic, autobiographical, prospective, declarative, propositional and procedural memories provide useful concepts to aid the understanding of memory even if they do not, necessarily, represent structurally separate parts of the cognitive system (Morris and Gruneberg, 1994). The episodic- semantic distinction was introduced by Tulving (1972) and can be useful in describing the detailed content of losses from the long term memory store. A further distinction is made between declarative and procedural memory and has particular relevance to the classic amnesic syndrome. The phenomenon of priming probably also falls within the domain of procedural memory i.e., the capacity to profit from prior exposure to cues such as previously perceived or partially completed words in the execution of a task. Again this represents unconscious memory manifested in behavior. Thus there appear to be several independent memory systems possibly tied to different neural networks within the brain (Lishman, 2004). Tulving proposed (Cohen, 2008) a number of criteria whereby separate systems could be distinguished: 1.Different memory systems have different functions and handle different types of information. 2. Different systems may employ different processes but need not necessarily do so. 3. Different systems are mediated by different brain structures or mechanisms. 4 Different systems have developed at different evolutionary stages. 5 Different systems may have different forms of representation. Applying these criteria Tulving identified five separate but interacting memory systems: 1. Procedural memory, which is involved in skills, actions, and simple conditioning. 2. The Perceptual Representation System, which is involved in perceptual priming of the identification of objects - 3. Short-term memory, which includes working memory. 4. Semantic memory, for general knowledge of the world. 5 Episodic memory, for conscious recollection of personal experiences. Each of these fine major systems includes multiple subsystems, as yet not fully identified however, although there is a general agreement that memory includes different systems and subsystems, there is no consensus about what these are and how they are related to and interact with each other. For the purpose of clinical description a somewhat arbitrary division is made into immediate, recent and remote memory. The immediate memory span (or ultra short-term memory) is reflected in the reproduction of material such as brief digit sequences which fall within the span of attention. Clinically it provides evidence that registration is intact. Recent memory is reflected in ability to acquire and retain new knowledge (current memorizing. new learning) and requires a process of consolidation in addition to registration. Remote memory is reflected in the ability to recall information acquired after a considerable distance in time, and certainly before the onset of the memory difficulties, it therefore represents a process of retrieval of material which has been held in long term storage. In every day clinical practice it is convenient to employ the terms- immediate, recent and

remote. Unfortunately however, considerable confusion can arise over some of the terms used in referring to memory mechanisms, particularly when attempting to translate the experimental literature to clinical practice. Short term for example is often used by psychologists as synonymous with immediate, and often in medical practice as broadly congruent with recent memory (Lishman, 2004). MODELS OF MEMORY: A BRIEF CRITICAL APPRAISAL Atkinson and ShiffrinS Model (1968): The model by Atkinson and Shiffrin (1968) was criticized as being too rigid and simplistic as information must flow in both the directions since there is good deal of interaction between various stores, for example we tend to pay attention to relevant information from the sensory register but this relevance must be stored in a long term way. It also does not take into account the types of information taken into memory as some items seemed to flow into Long Term Memory (LTM) far more readily than others. It also ignores factors such as the effort and strategy subjects may show while remembering and why information changes in coding from one memory store to another (Hill, 1998). Craik and Lockharts Model:In the ensuing years researchers while analyzing Craik and Lockharts deep processing model found out that the complex semantic processing produced better cued recall than simple semantic processing and called this mechanism as elaboration. Eyesenck and Eyesenck (1980) found even words processed phonetically were better recalled if they were distinctive or usually labelled and termed it as distinctiveness. Tyler et al. (1979) found better recall for words presented as difficult anagrams like OCDTRO than simple anagrams like DOCTRO and termed it effort. Rogers et al. (1977) found better recall for those questions which have personnel relevance (e.g. describes you) than general semantic ones (e.g. means) (Hill, 1998). Baddeley and Hitch Model (1974): There remain problems in defining deep processing and further clarifying as to why it is so effective as semantic processing does not always lead to better retrieval. It was the working memory model of Baddeley and Hitch (1974) which then gave further insights into the memory processing and its revised model of 1990 is currently the most accepted models in memory processing (Hill, 1998). Miyake and Shah Model (1999): In their recent comprehensive review of working memory models, Miyake and Shah (1999) proposed that working memory is those mechanisms or processes that are involved in the service of complex cognition, including novel as well as familiar, skilled tasks. This definition differentiates working memory from short-term memory because it suggests that working memory goes beyond simply keeping information in mind; rather working memory brings or keeps information online in a goaldirected fashion (Kay and Tasman, 2006), though both the term (STM and working memory) are used interchangeably. NEUROBIOLOGY OF MEMORY According to current views, information from the senses is temporarilly stored in various areas of the prefrontal cortex as working memory. It is also passed to the medial temporal lobe, and specifically to the parahippocampal gyrus. From there, it enters the hippocampus and is processed in a way that is not yet fully understood. From the hippocampus it leaves via the subiculum and the entorhinal cortex and somehow binds together and strengthens circuits in many different neocortical areas, forming over time stable remote memories that can now be accessed by many different cues (Ganong, 2005). Figure below shows the brain regions thought to be critical for the formation and storage of declarative memory. The entorhinal cortex in the major source of projections to the hippocampus, and nearly two-thirds of the cortical input to the entorhinal cortex originates in the perirhinal and parahippocampal cortex. The entorhinal cortex also receives direct connections from the cingulate, insula, orbitofrontal, and superior temporal cortices. (Ken and Larry, 2005).

midline thalamic nuclei dorsomedial thalamus anterior thalamus mammillary nuclei

hippocampal region entorhinal cortex perirhinal parahippocampal cortex cortex

frontal association areas

sensory association areas

EPISODIC LEARNING

Stage1 Sensory, motor and other information, comprising the episode/event-to-beremembered,activate a number of nodes in the trace system (filled circles). Stage 2 Through the trace system a set of link nodes is activated, possibly within less than a second. If the episode is sufficiently new or interesting, the modulatory system will be activated. This will allow strengthening of connections between activated link nodes and trace nodes shown by the thickening of the connections. Stage 3 This stage represents the initial consolidation process. Repeated activation takes place, leading to the gradual formation of tracetrace connections. These are initially weak, but grow in strength with each consolidation episode. The repeated reactivation of already learned representations is a random process that is initiated by randomly activating a number of nodes in the link system. Consolidation occurs by further strengthening of the tracetrace connections (tracelink connections are not strengthened further at this time; this follows one the model of cholinergic processes in the hippocampus.( Hasselmo,1995, 1999). Stage 4 In the final stage of consolidation, tracetrace connections have become very strong and retrieval has become independent of the link system. In both the link and trace system, the learning of new memory representations will result in the gradual overwriting of older representations (i.e. forgetting). This interference process is more evident in the link system compared to the trace system, however, because the link system has a lower capacity and higher plasticity. REMEMBERING, FORGETTING AND KNOWING Gardiner and Richardson-Klavhen (2000) defined remembering as intensely personal experiences of the past ,those in which we seem to recreate previous events and experience with the awareness and experiences mentally. The process of remembering has four partsregistration, retention, retrieval and recall.

Knowing is referred to experience of the past in which we are aware of knowledge that we process but in a more impersonal way without awareness of reliving them mentally or familiarity of facts (Kopelman, 2002). Forgetting refers to the apparent loss of information already learned and stored in long term memory. Much is forgotten but enough enters so that we have a sketchy record of our lives. Much of what we think we have forgotten does not really qualify as forgotten because it was never encoded and stored in the first place. (Morgan et al. 2007) . Intereference theory Forgetting is a result of some memories interfering with others. Proactive interference: Old memories interfere with ability to remember new memories. Retroactive interference : New memories interfere with ability to remember old memories. Intereference is stronger when material is similar . AMNESIA IN THE CURRENT NOSOLOGY Amnesia forms the core component or a part of symptomatology of a number of psychiatric disorders in the current nosological system. The diagnostic categories in the current nosological systems with amnesia as the core component of the diagnosis include: ICD-10: The ICD-10(World Health Organization ,1992), provides two diagnostic categories for describing amnesic disorder depending on the etiology of the disorders rather than the symptomatology. The lCD-10 differentiates amnesia due to organic conditions from amnesia due to use of substance single or multiple. The diagnostic categories are: F 04: Organic Amnesic Syndrome not induced by alcohol and other psychoactive substances F1x.6: Mental and Behavioral disorder dun to use of psychoactive substances Amnesic Syndrome. DSM-IV-TR: The DSM-lV-TR (American Psychiatric Association,1994) categorization of amnesic disorders bears resemblance to the lCD-10 except for the fact that the two diagnostic categories are clubbed under one roof as Amnestic disorders with further categorization into that due to general medical condition, substance induced end unspecified. The amnestic disorders are labelled under axis-I disorders with a description of the underlying medical condition to be provided under the axis-Ill category wherever applicable. The diagnostic categories are: 294.0: Amnestic disorder due to a general medical condition Substance induced persisting amnestic disorder (Specific substances to be coded as 291.1 Alcohol induced persisting amnesic disorder, 292.83 Secobarbital induced persisting amnestic disorder and the likewise) 294.8 Amnestic disorder not otherwise specified. AGING AND MEMORY IMPAIRMENT Both physical and cognitive functions change as we get older. Fluid intelligence and the capacity to respond rapidly end flexibly gradually diminishes, while crystallised intelligence, the residue of prior learning, continues to show a small but steady increase. In general, memory deteriorates, but is to some extent compensated by the increased use of knowledge, memory aids, and strategies. In the case of working memory, the phonological loop is reasonably robust, the visuo-spatial sketch pad somewhat less so, while at least some executive processes tend to decline. In the case of long-term memory, episodic memory shows a slow but steady decline from the twenties onwards, with memory for names being particularly sensitive to the effects of ageing. Semantic memory continues to grow, but speed and reliability of access declines. Implicit learning shows a mixed pattern, with some types of learning being relatively preserved, but others deteriorating. As age advances, we find it harder to maintain performance against distraction, particularly under levels of high arousal. Nutritional factors may also influence the elderly more, as they are less able to maintain blood glucose leave during the gaps between meals, resulting in poorer memory performance (Baddeley, 1999). MILD COGNITIVE IMPAIRMENT

A large group of elderly cognitively impaired subjects do not meet the criteria for dementia or other specific neurological and psychiatric disorders. Several descriptors including MCI, incipient dementia, and isolated memory impairment have been used. The terminology mild cognitive impairment refers to subjective memory disturbances verified by objective deficits of memory at testing. DEMENTIA The Clinical features related to the three symptomatic domains that characterize dementia is as follows Neuropsychological impairment Psychiatric symptoms/ Behavioral disturbance y Amnesia-loss of memory y Aphasia-impairment of language, most commonly apparent on direct questioning, when asking a person to name objects; a nominal aphasia. y Agnosia- inability to recognize or associate meaning to a sensory perception y Executive dysfunctiondisturbances in judgment, planning and abstraction. Other deficits y Acalculia- inability arithmetic calculations to perform Psychiatric symptoms y Depression y Anxiety y Hallucinations y Delusions y Euphoria y Misidentifications Behavioural disturbances y Agitation y Aggression y Aberrant motor behavior (pacing,wandering,irritability) Apathy y Sexual disinhibition y Sleep abnormalities y Increased appetite/ Change in eating habits Inability to perform activities of daily life Deficits in instrumental activities y Handling money y Shopping y Driving y Using the telephone y Doing the laundry y Preparing meals y Managing medication Deficits in basic activities, e.g. y y y y Dressing Eating Using the toilet Personal hygiene

y Agraphia- inability to write y Alexia-inability to read

Dementia was initially thought of as a unitary behavioural syndrome, characterised by a homogeneous decline in intellectual functions, regardless of aetiology. Dementia is defined as decline of memory and other cognitive functions in comparison with the patients previous level of function, implying a change between two or more assessment points (McKhann et al., 1984). ALZHEIMERS DISEASE The dementia of AD typically includes anterograde and retrograde amnesia early in its course. Deficits in recent memory are typically the first symptoms of AD and may be clinically reported as misplacing objects, repeating questions and statements, and forgetting names. Impairments in visuospatial memory are often experienced as getting lost. This anterograde amnesia reflects impaired encoding and consolidation of the material. (Greene et al., 1995; Sagar et al., 1988). Several hypotheses have been proposed to account for this impairment of episodic memory in AD, which might affect both encoding and retrieval of information, and would result from attentional deficiencies, working memory dysfunction, semantic difficulties, or neglect of contextual information (Van der Linden, 1994). It has also been suggested that recent memories are more vulnerable than remote memory especially in dementia(Ribot law). In general, remote memory remains relatively intact early in the course of AD. With disease progression, a slight temporal gradient becomes evident. The remote memory impairment in AD is a temporal gradient, with recall of recent events being more severely impaired than recall of more remote events (Beatty & Salmon, 1991). In moderate to severe AD, the temporal gradient disappears and patients show marked retrograde amnesia for all decades of life (Butters et al., 1995). This general pattern of impairment has been demonstrated for memory for famous faces and public events, visuospatial information, and autobiographical information. Semantic memory Naming

A naming disturbance has been recognised as one of the core clinical features of AD (Wilkins & Brody, 1969). The anomia tends to be a relatively early manifestation of the disease. It progressively worsens over the disease course and is strongly correlated with overall dementia severity (Chertkow & Bub, 1990). SEMANTIC DEMENTIA Semantic dementia is a recently documented syndrome associated with non-Alzheimer degenerative pathology of the polar and inferolateral temporal neocortex with relative sparing (at least in the early stages) of the hippocampal complex (Hodges et al., 1992). Core features of semantic dementia 1. Selective impairment of semantic memory causing severe anomia, impaired spoken and written single-word comprehension, reduced generation of exemplars on category fluency tests, and an impoverished fund of general knowledge about objects, persons, and the meaning of words. 2. Relative sparing of other components of language output and comprehension, notably syntax and phonology. 3. Normal visuo-perceptual and spatial skills, working memory, and non-verbal problemsolving abilities. 4. Relatively preserved autobiographical and day-to-day (episodic) memory. (Hodges et al., 1992). Meta-memory Meta-memory is the subjective judgment about ones own memory capabilities. It is influenced by the present state of emotion. Patients who are depressed subjectively experience their performance to be worse than in fact, while those in manias or with the frontal lobe disinhibited syndrome experience their performance to be better than in fact. Patients with temporal lobe epilepsy overestimate their memory capacities and their selfmonitoring is less accurate for verbal or non-verbal recall depending on the side of the seizure focus. MEMORY DYSFUNCTION IN PSYCHIATRIC DISORDERS The most common psychiatric disorders in which memory impairment may be seen are schizophrenia, depression, and anxiety. The objective cognitive impairment is often mild with alterations in such functions as attention, STM, and speed of processing. SCHIZOPHRENIA Memory deficits observed in schizophrenia are not restricted to a single element of memory but strike different systems, such as declarative memory, short term, and working memory (Goldberg et al., 1993).There are deficits in long-term memory, including evidence of impaired retrieval in both recall and recognition. There is also evidence of impaired short term memory. Furthermore, there is evidence of impairment of working memory and semantic memory but procedural or implicit memory remains intact (McKenna et al., 2002). Cognitive impairment is a central manifestation of the schizophrenic illness that impacts on the quality of life of the patient. ANXIETY The presence of distracting, task-irrelevant thoughts is a common feature of anxiety. As worry occupies some of the limited capacity available to the working memory system, this negatively impacts tasks that rely heavily on the working memory system. The adverse effects of anxiety will be evident on tasks carried out in conjunction with a task treated as more primary, as this reduces the capacity available for further tasks. DEPRESSION STM or the retention of small amounts of information over very short durations has been found to be unaffected among depressive patients (Austin et al., 1992; LTM seems to be more prone to impairment. Depression is associated with a number of deficits in episodic memory and learning. There is involvement of both explicit verbal and visual memory in patients with both melancholic (endogenous) and non-melancholic (nonendogenous) depression (Austin et al., 1999).Impaired delayed memory as opposed to preserved immediate recall has also been found among depressive patients (Cohen et al., 1982).People with major depressive disorder, including those who have recently attempted suicide, have difficulty retrieving specific autobiographical memories in response to cue words (Williams, 1996). Obsessive compulsive disorder Obsessive compulsive disorder (OCD) is characterized by recurrent unwanted thoughts and repetitive, ritualistic behaviors that lead to severe impairments in daily functioning. There are

deficits in learning and memory, especially for non verbal information in OCD patients (Dirson et al., 1996). The difficulty in retrieving specific autobiographical memories exhibited by OCD patients might reflect excessive cognitive capacity consumption due to preoccupation with intrusive thoughts typical of major depression. Panic disorder Patients with panic disorder have a defect in fear-relevant episodic memory, and their panic attacks arise from automaticity in recollecting fear-relevant emotionalautomatic clusters. The cluster as a component of fear appears to have been dissociated from cognitive structure, episodic or informative memory trace, or from information structures. Post-traumatic stress disorder Post-traumatic stress disorder (PTSD) is a specific anxiety disorder of significant prevalence and morbidity that develops following exposure to extreme emotional trauma. Three symptoms clusters characterise the disorder, all of which represent direct or indirect effects of memory processes: (1) persistent re-experience of the traumatic event, (2) persistent symptoms of increased arousal, (3) persistent avoidance of stimuli associated with the trauma that may include amnesia for an important aspect of the traumatic event. Adult PTSD patients often report a wide range of cognitive problems in memory, concentration, attention, planning, and judgment. PTSD may be conceived as a clinical condition that involves both memory intensification for the core traumatic event and memory impairment for the context surrounding the trauma. The latter comprises dissociation of the experience from ordinary autobiographical memory. MEMORY DISORDERS IN EPILEPSY Patients with epilepsy frequently complain of memory difficulties.In some cases this is secondary to problems of concentration and attention and may therefore not be a memory defect per se. For patients with temporal lobe abnormalities,memory may be selectively affected. Seizures may have an acute effect on memory but this is usually transient and does not affect prospective memory .But poor memory of patients with temporal lobe epilepsy does not correlate with seizure frequency. In patients who are undergoing temporal lobectomy careful testing of memory function prior to surgery is mandatory,and deficits may occur following removal of offending lobe. DRUG INDUCED MEMORY ALTERATION Some drugs that may impair or improve memoryDrugs IMPAIRED MEMORY Lorazepam and diazepam Methylenedioxymethamphetamine (MDMA or Ecstasy) Ethanol and temazepam IMPROVED MEMORY Citicoline Facilitates recovery of function and cognition after traumatic brain injury Type of memory impaired/improved Explicit and Implicit Memory Verbal and visual Memory LTM

Over the past three or four decades,there has been increasing interest in neuropharmocological regulation of memory.Some drugs have been identified as cognitive enhancing agents or SMART DRUGS.these group of drugs have displayed memoryenhansing effects in experimental settings through diverse mechanism of actions.important

mechanisms includes cholinergic agonists at the muscarinic and nicotinic receptors,cholinesterase inhibitors such as physostigmine,CCBs like nimodipine,neurotransmitters such as norepinaphrine,GABA-B receptor blockers,peptides like vasopressin corticotropin,glucose etc.(Beversdorf et al.,1998). Lithium usually causes mind slowing(bradyphrenia) and cognitive deficits are more when used along with ECT. Anticholinergics mainly affects short term memory information. especially encoding and storage of

Ethanol acute ingestion induces BLACKOUT AMNESIA which refers to profound STM deficits and it may be associated with hypoglycemia, hypomagnesemia etc.chronic ingestion causes korsakoffs psychosis where we can see the memory deficits as confabulation as the patient tries to fill the memory gaps with unnecessary details. Beta blockers may produce information(Cahill et al.,1994). poor memory particularly for emotionally valent

Corticosteroids causes memory impairment mainly by its deleterious hippocampus.(Sapolsky et al 1990).

effects on

Barbiturates tend to impair acquisition and interfere with retention of learned behavior. Antiepileptic drugs may exacerbate pre existing memory problem by affecting concentration,attention and psychomotor abilities.Phenyton and primodone are associated with cognitive decline. Topiramate causes word finding difficulties. Cognitive enhancers(cerebroactive drugs).There are various drugs claimed to be having cognitive enhansing property.But as per the Cochrane review there is no definitive evidence. Cholinergic activators:Donepezil,Rivastigmine,Galantamine,Tacrine. Glutamate(NMDA) antagonist:Memantine Miscellaneous cerebroactive drugs:Piracetam,Pyritinol,Dihydroergotoxine,Piribedil, Ginkgo biloba . MEMORY DISTURBANCES AND ECT Memory disturbances are seen occurring immediately after ECT and includes short lived impaired learning ability, defective retrievals along with permanent loss of memories of events (especially autobiographical memories) preceding immediately to ECT treatment. These deficits are proportional to strength of current ,duration of electrical stimulus, number of sessions given to the individual, the area of the brain where the current pulse is given (dominant or non-dominant area of the brain) and finally bilaterality of ECT. Therefore ECT if applied unilaterally, in non-dominant side of the brain not only hastens recovery but also causes less post ictal amnesia, confusion and memory disturbances. However amidst various ongoing controversies regarding the ECT generated memory deficits the effects do not seem to last more than six months and some researchers currently have pointed out that ECT does not cause more than a temporary disturbance in memory (Oyebode, 2008). EMOTIONAL AND SOCIAL CONSEQUENCES OF MEMORY DISORDERS These are acquired neuropsychological disorders fall within the domain of psychosocial functioning.Emotional responses occur within the context of an individuals personality structure and their environment underlying stable traits, and transient fluctuations in emotional affective and mood states, which occur in response to day to day events. Those with fairly circumscribed memory disorders are well placed to harness their intelligence and other neuropsychological strengths and implement compensatory strategies to circumvent the memory disorders. This enables them to access a range of life otherwise it will be difficult to achieveproductive work, independent lifestyles and a regular social life in the presence of other neuropsychological impairments in addition to memory disorder makes it difficult to attribute any emotional or social disturbance to the memory disorder itself, as opposed to some concomitant neuropsychological problem that the person may experience, such as aphasia, executive impairment, attention deficit and so forth.The literature regarding emotional and social consequences for people with a range of neuropsychological problems is relevant and important, given that, as Wilson (1991) observes, the majority of adults who experience acquired memory disorder also have additional neuropsychological impairments. (Prigatano, 1992).

MEMORY REHABILITATION How are the memory difficulties manifested in everyday life? What problems cause most concern to the family and the memoryimpaired person? What do we know about the cultural background and level of support available? What coping strategies are used? Are the problems exacerbated by depression or anxiety? Is this person likely to be able to return to work (or school)? Can this person live independently? What kind of compensatory aids did this person use premorbidly? What kind of memory compensation strategies are being used now? What is the best way for this person to learn new information? Ten Key Memory Tips Take it easy 1. Try not to do too many things at once. 2. Anxiety and tiredness can affect memory, so try to avoid stressful situations. Be positive and have regular breaks. 3. If you do forget something, dont get too upset about it. Stay calm and think of connections that may jog your memory. Be well organized 4. Keep to a fixed routine, with set things at set times of the day and on set days of the week. 5. Be systematic: Have a place for everything and put everything back in its place. Put labels on drawers and files. Concentrate better 6. If you have to do something, do it now rather than later: Do it or lose it. 7. Try not to let your mind wander: Keep on track. 8. If you have to remember something such as a message or a name, go over it in your mind at regular intervals. 9. Try to find meaning in things you have to remember (e.g., by making associations or linking things together). (from Narinder Kapur). 10. Use memory aids External memory aids are effective in improving everyday memory functioning, and this benefit is particularly evident in the area of prospective memory. 1. An electronic diary to keep a record of appointments. 2. An alarm which provides auditory cues, with or without text information, at preset, regular or irregular times. 3. A temporary store for items such as shopping lists, messages, etc. 4. A more permanent store for information such as addresses, telephone numbers, etc. 5. In more expensive models, a communication device that can receive and send information, such as reminders and factual knowledge. CONCLUSION Memory is not a unitary phenomenon. Capacities to remember vary for the different senses and perceptions. When individuals with extraordinary memories complain of memory loss, ordinary memory tests may be inadequate to detect their deficits, as their relative memory loss may have reduced their capacities to a point within the range of most normal people. REFERENCES American Psychiatric Association(1994) Diagnostic and Statistical Manual of Mental Disorder(4th ed)(DSM-IV).Washington DC ,APA.. Sims,A.. (2003). Disturbance of memory.In Symptoms in the Mind :An Introduction to Descriptive Psychopathology,3rd ed,pp.63-76.Philadelphia,Saunders. Baddeley, A., Emslie, H., Nimmo-Smith, I. (1996). The door and people test. Bury St. Edumuinds: Thames Valley Test Company, Suffolk As cited in Mayes AR. The Assessment of memory disorder. In Baddeley AD, Wilson BA, Wattas FN, 1st eds. Handbook of Memory Disorders. New York: John Wiley & Sons Inc. Baddeley, A.D. (1999). Aging and memory. In essential of human memory. Taylor and Franscis Routledge, pp251-272.

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Budson, E.A., Price, B.H. (2001). Memory: Clinical Disorders. ENCYCLOPEDIA OF LIFE SCIENCES, Macmillan Publishers Ltd. / www.els.net