Lecture 24 Mammalian Sensory Systems and Agnosias Sensory systems end up in the cortex- neocortex is made of 6 layers Frontal lobe- Prefrontal, olfactory Motor- Movement- in front of somatosensory

Somatosensory- Audition( inner ear through the brainstem primary auditory cortex Visual cortex- Huge primary visual cortex( input comes from below in the primary visual cortexBroadmanns area 17 Certain regions of the neocortex expanded in primates- large expansion of visual cortex and prefrontal cortex

Gustatory is in the old cortex

Mapping- autopsy of brain damaged patientssee where hearing loss was from in the brain

See what brain area lights up when you give certain stimuli.

If there are certain areas that are not sensory nor motor, they are called associative.

Prefrontal is associative!

M1 is the mirror image of S1 along the central sulcus

S2 is gets response from pressure sensors in the skin

Rat has a smooth cortex- ratunculous

No prefrontal

Retina- back of the eyeball and leads to the optic nerve to the brain. Embryologically, retina is an extension of the brain. Retinal ganglion cells that extend into the brain.

Fovea- area where optic nerve leaves to go to the brain- has a TON of myelinated axons and therefore you have a blind spot.

Rods and cones transform signals- cones- color and fine vision, rods- low light, movement, peripheral vision.

Light hits receptors and uses EC signal and gets picked up by bipolar cells, which send signal to the ganglion cells which send little action potentials out.

Lots of random light is picked up and comes in to the retinal cells that fix the resolution.

Horizontal cells- clean up the image by connecting to bipolar cells

Amacrine cells- clean up the image by connecting the ganglion

Lateral inhibition- retina ganglion cells are activated by light. If you have a strongly stimulated area, the area next to it is strongly inhibited.

Take a tiny beam of light and it falls on ganglion cell it fires lots. If you stimulate a nearby cell and record the same ganglion cell that will fire less due to lateral inhibition. Receptive field- sensory receptors surface linked to other neurons- stimulation will change this surrounding firing in SOME way aka must be a receptive field- on center and off surround.

Hubel and Wiesel- firing of neurons in visual system of rats.

Area 17 was where they recorded from.

They had a glass slide with a crack and slipped it in the projector- the firing occurred

Neurons in one column will respond to a bar in a particular orientation! Same receptive field.

These are called simple cells In the retina we have circular receptive fields with an on center and off surround- if it were off center and on surround- if it were the latter case it would be a world made of dots!

Hubel and Wiesel found that cats VC respond to bars in a particular orientation specific to that neuronal column.

3 ganglion cells project to the PVC

A bar makes it fire because all three need to be activated with a bar of light that lay on top of the ganglion cells. Vertical orientation. Orientation of bar in a particular column depends on the wiring of the ganglion cells.

Say we have 6- 3x2 column- V1 linked to 3 and another V1 cell linked to another 3 ganglion cells. If the bar Is MOVING across A then to B, the V2 cell can fire since both V1 cells are firing simultaneously. Complex cells are the ganglion cells that respond to moving bars of light.

Usually there will be V3 and V4 etc until the time where these cells get so specialized that they only fire when you see a certain persons face.

Auditory levels of reactivity is based on tone or signal.

Commonalities of sensory systems

Receptors that transduce stimuli

Lateral inhibition- clean up of signal

Thalamic relay (lateral geniculate for vision) medial geniculate audition

Hierarchical organization (more complex information at each level)

Both serial and parallel- more on this next (think physics resistors)

Visual Protheses- put a sensor in the persons eyeball in replacement of damaged retina.

Dorsal and Ventral pathways

Analysis is done at the same time- done through a parallel system

System is wired in series which means that it does one thing then the next then the next over and over.

BOTH SYSTEMS ARE WORKING! That is why human brain is made of neuron which only fires 1000 times a second but since its in parallel too, it does things a gajillion times faster.

Dorsal- where- parietal- wheres something/ someone in space?

Ventral- what- faces, objects and color

Agnosia- not knowing- an outcome of damage within a serially connected system Mistaking various people or objects for something else.

A doctor writes a book and his patient cant recognize objects and is super interested in art too.

Could identify a rose by scent but not visual system.

His art changes as his agnosia develops.

Simultagnosia- inability to recognize a whole image although individual details are recognized

Prosopagnosia- cant recognize faces

Amusia- cant recognize sounds.

Human cortices- primary zones and secondary and tertiary secondary and tertiary are association cortices? If you measure recording ins from prefrontal- neurons respond to numerous kinds of inputs or none at all. Found primary by looking at damaged brain patients

Association- multiple senses come together. Tone and Footshock for example. If you record at V1 you only get response to vision. Fuzzy to define what is associationV2 and V3.

Within the ventral path its serial processing and within dorsal its serial too. But since there are two simultaneous processes running side by side, it means that its PARALLEL!

Brain and Language

Brocas area- brain damaged patients couldnt produce speech

Not about vocal cord but about the damage to brain cortex.

Speech output reduced- agrammatical

Limited to short utterances

Repetition ability is poor

Speech is laborious and clumsy

Vocab is poor

Writing may be affected but comprehension is ok.

Wernickes area- aphasia causes problems in understanding language

Can produce normal language but cant understand it well.

Chief impairment is comprehension of spoken words

Speech although not effortful often includes superfluous words.

Sentences dont hang together. Poor repetition, reading and writing is impaired.

Anatomical reflection of language- left cerebral hemisphere

Wernicke- Geshwind model- Brocas- 44/45, Wernickes-22, Angular cortex- 39. Arcuate fasciculus connects the posterior language comprehension area with anterior language production regions.

Angular cortex- connects sensory cortex (what you hear) to motor (what you speak)

Sensory language (hear) to Wernickes area to arcuate fasciculus to Brocas to motor. This allows you to repeat a word

Read a written word- it hands off to Angular gyrus which transforms the word into an auditory code.

When you first learn to read- visual cortex hands off word to angular cortex. Angular gyrus C makes it into auditory code then hands it off to Brocas through Arcuate Fasciculus.

People with damaged Wernickes hve problems with spoken language but not written language.

Brocas damage- have problems with written language not spoken.

Ear to primary auditory cortex to wernickes to auditory comprehension

Eye to V1 to Angular cortex to wernickes to auditory comprehension

Damage to Angular cortex means less reading and writing comprehension

Damage to Wernickes means less reading and spoken Damage to Brocas means less speaking- no damage to comprehension

Petscan- language lateralization in humans R handed people have language in left hemisphere 98% of time

L handed people have language in right hemisphere 30% of time

Area 22- Wernickes- takes out ability to read and comprehend spoken language. Area 39- Angular gyrus- takes out ability to read but CAN comprehend spoken language.

Thus, it must be 39 that converts a written form to an internally spoken form. 39 functions as a converter to hand off to 22 which is really good at comprehension.

Conduction Aphasia/ Global Aphasia

Alexia- cant read at all

Dyslexia- can read but not at a normal level

Agraphia- cant write language at all

Language is lateralized- R handed, 95% of language center is in the L hemisphere. L handed, 70% of language center is in the L hemisphere.

Early L hemisphere damage can cause the R hemisphere to become dominant for speech ad left hand to be preferred.

Either L or R- CANT HAVE BOTH! Must be lateralized.

Tests of Language Laterality

Sodium amytal test- inject it into the carotid artery- heart to brain is how it travels. WADA test- Inject into the right carotid- right hemisphere is hit first and the left hemisphere wont be anesthetized until a delay of a few seconds. If language is in the R hemisphere they stop talking right away. If language is in L hemisphere they dont stop talking until a few min later.

Dichotic Listening

Look at the ability to repeat back digits

Which ear does sound come from?

Dominant hemisphere does the talking- crosses over- R ear processed at L hemisphere

If R ear is stronger, auditory cortex is in the L cortex.

Ape Language Project- GSU- Dr. Sue Savage-Rumbaugh

Yerkish is an idiographic language- graphics presented to an animal and each represents something but the image doesnt look like it at all.

Lana, the monkey learned grammar and syntax.

Koko and All- Ball

Sign language- signs that shes sad when all ball dies.

Bonobos are chimps that are highly endangered- stand up straight like australepithecines- argument still goes on- huge cognitive ability and conscience! Face to face sex. Baby can watch and learn. Language is what sets us apart.

Gene Pepperberg- had an African Grey Parrot named Alex- 35 year life span- can speak!

Have a different brain than primates

Look at behavior and gene expression

Bird song region of brain during breeding season grows!

Dyslexia

Comes from a disorder of phonological aspects of words- what a word sounds like when you read it

Orthographic- what the word looks like

The problem with dyslexia is the mapping of each other- phonological

Rumsey- phonological pronunciation and phonological decision making.

You have nonsense words-

With non sense- there are GREATER error differences between dyslexic patients and controls. When it is non words- there is a smaller difference in errors

Dyslexic has trouble translating what it looks like to what it sounds like.

Specific vs. general learning disability

Clear evidence of genetic transmission

Problem seems to be with neural network- does comprehension of written and spoken words

General

ADD/ADHD- difficulty in learning across the board.

Shayqitz shows increase in activation during phonologic compared to orthographic coding in different brain regions- there is less activation in dyslexic readers.

Hemispheric Lateralization Anterior commissure- by NAcc- connects subcortical area

Hippocampal commissure- connects two hippocampi

Posterior commissure- back in midbrain

Left hand- R hemisphere. Right hand- L hemisphere.

Nasal portion of retina crosses over and temporal portion of retina goes straight back.

Pirate cat experiment- Cat learns with eye patch on. Right eye (nasal) to L hemi and temporal to right.

If you turn on light and press lever you get milk with a split collosum. They learn with left eye patch on. IF you switch to the eye patch to the right eye they STILL HAVE LEARNING. This is because both hemispheres learned from the right eye when the left eye patch was on.

If you cut the optic nerve at the optic chiasm, then do the left and right eye patch thing, left eye patch moved to right eye they have NO idea that if you press lever you get sweet milk. They still learn when the eye patch is on the left eye but the right hemisphere has done NONE of this learning so when its moved to the right eye its all new to the right hemisphere! Information from right eye goes only to the right hemisphere so when the right eye is covered, the left hemisphere hasnt learned anything! Cant respond push lever.

Normal monkey- reaches through solid wall on right side and learns on the left side. Corpus Collosum lesion- monkey reaches through using right hand and close that hole, then force them to use left hand. When you train with right hand, left hemi learns. Now left hand needed to be used and right hemi doesnt know what to do.

If you do it with a clear plexiglass wall. Collosum cut means that they can they can STILL use their left hand. This is because the right hemi was watching the whole thing through vision and observationally learning.

Sperrys experiment with split collosum and chiasm- that eye would learn but other hemi wouldnt learn it.

Split collosum surgery leads to epilepsy fixing- confined to one hemisphere or less in frequency

Subject asked to fixate vision on screen where x is.

Baseball hits the left side of each retina from right side.

Flash the image for ms and light rays go only to left hemisphere- left eye temporal and right eye- nasal

If you cut chiasm you dont get nasal portion of eyeball.

Right handed people have language in a left hemispherethis is the speaking hemisphere.

Subject asked to fixate on X again

Hammer on left side goes to right side of brain which cant talk- the left hemi answers that they cant see anything.

If asked to pick up what they saw, they still grab the hammer

L hemi does reading, writing and math

R hemi doesnt talk, BUT can comprehend simple sentencescan comprehend but cant respond verbally.

The two hemis can become more aware of each other- this is NOT schizo. Both hemisphere in operation at once in a split brain subject

The left brain says ring- key is picked up by right brain through (left hand)

Verbal and non verbal responses to olfactory stimulus in a split brain subject

Right hemisphere is smelling, not left. Speaking person doesnt smell anything. Smell ISNT CROSSED. Left nostril is plugged.

Start cheating- yes/ no questions that allow someone to answer differently

Left handed before surgery- but come out right handed/ lose function. Both are more balanced.

Right hemisphere is better at some things like visuospatial tasks

Left hemisphere is better at some things like linear thining/ analytical. Tests of visuospatial ability- guys have a stronger L hemi

Right hemisphere is usually running the show even when youre drawing when youre right handed. R hand gets lost when you lose the collosum.

Male with L or R hemisphere damage- IQ drops more in L- better visuospatial- more split between two hemis than in women.

Female with L or R hemi damage- IQ drops same amount- have more bilateral representation of language.

Females have a back up plan!

Cognitive differences may be set up by hormones in utero since masculinized women have better spatial skills

Einstein had a huge parietal- prob on R hemi.

Sleep and Dreaming

Electroencephalogram- read out of brain activity

Alpha- relaxed, asleep 8-12 cycles per second

Beta- awake and attentive 13 and above During beginning of sleep, EEG shows slower waves- theta waves 4-8

As you become more sleepy, even slower frequency in waves

Flat out sleep becomes delta waves 1-3 per second.

Suprachiasmatic nucleus- SCN- above optic chiasm and its in the hypothalamus- clock in basic sleep active rhythm Deep sleep- two pathways were found to influence the cortical EEG- through the basal forebrain (does the heavy lifting)

And through the dorsal midbrain to the thalamus

Put humans in a low light cave- you cant tell if its day or night

There is no external stimulus to tell you when it was night or day

Means that there is a biological clock called SCN that controls this.

This drifts if you leave them in a cage for months.

This means that it isnt light that tells you night and day

Zeitgeber- any external signal cues that syncs the clock (light for example) Retinohypothalamic tract- ganglion cells project to lateral geniculate.

Another branch goes from the ganglion cells to the hypothalamus- this keeps track of when its light and dark Moruzzi and Magoum

EEG in cats- stimulate brainstem and it makes EEG beta

Beta is low amplitude high frequency and occurs when youre awake and attentive

Delta has high amplitude low frequency

Places in the brainstem that woke up brain wasnt in sensory tract but rather in the MRF- midbrain reticular formation.

Animal goes from delta to beta when stimulated.

Must turn off MRF in order to sleep.

Lesion MRF and you go into a coma

THIS VIEW HAS CHANGED! Its not just the MRF, but multiple systems axons pass through the MRF thus if you lesion the MRF you mess up multiple systems

Locus Coeruleus- LC releases NE into the cortex (located in the forebrain) Raphe- 5HT nucleus goes to the forebrain (Located in forebrain) Tuberomammillary nucleus- histamine is the transmitter

Antihistamines make you drowsy because they block a transmitter that keeps you awake

Basal forebrain- projects acetylcholine and GABA

Pedunculopontine tegmentum- PPT- project to thalamus not cortex

Lateral dorsal tegmental- LDT- project to the thalamus

These both use volume conduction through varicosities to release NT into a region not one area.

BUT what was recently found- you can get rid of the entire thalamus and not do anything to the EEG

Bottom part of projections are most important in controlling wakefulness.

LH is in orexin (food intake people) and hypocreitin (sleep people)neurons that make orexin/ hypocretin project in the lateral hypothalamus and projections go all over the forebrain. O and H are the SAME SUBSTANCE!

All of these systems are involved in wakefulness

Aserinsky and Kleitmann- watches human infants sleep with EEG monitor

EEG sometimes goes into desynchronized form- eyes flit back and forth REM SLEEP and beta

Looks like awake state

Normally, deep sleep means slow waves and synchrony

Awake state means desynchrony and fast waves

Major markers of REM sleep

Desynchronized EEG

Rapid eye movement

Loss of muscle tones

PGO spikes in EEG

Record from occipital cortex geniculate and pons

Starts in pons and goes to geniculate and occipital cortex

Sleep stages- across the right inhumans

Non rem sleep becomes REM after one hour them non REM and REM at 3 hours etc.

As you head towards morning, REM episodes occur for longer periods of time- the periods occur every 90 minutes

If an individual is depressed REM shows up way earlier Why do we have REM?

Brain activity and breathing goes down in non REM

REM is a kicker to wake your body up

There are DEACTIVATING systems that put you to sleep

Ventrolateral preoptic area VLPO (projects to the PeF)

Kind of like the MPOA but it is LATERAL

PeF- axonal bundle from the hippocampus to the hypothalamus to LH to the fornix

Surgery to remove the fornix- fornicotomy

Area near the fornix is the perifornicla hypothalamus (PeF) orexin releasing. It is found in a region of the LH

If you damage the VLPO and insert an excitotoxin, the cats cant sleep.

If you stimulate it, he goes to sleep

Flip flop of control of sleep of wakefulness

VLPO winning, it suppresses orexin which makes you sleepy

LC, TMN and raphe winning, orexin activates it and VLPO is inhibited

As time goes by, the VLPO influence decreases and arousal system comes back and you wake up again. Kind of like REM?

Aserinsky and Kleitman- If brain is awake during REM, why arent you abe to move? You are paralyzed by REM by an axon that goes through Pons down to spinal cord which inhibits motor neurons!

Cats with lesions of this pontine area more aboutduring REM and act out during sleep.

People with REM sleep disorder also move about during REM- this makes them do strange things like destroy a room or kill a person.

The reason this occurs is because certain forebrain areas are normally active during REM sleep.

During non REM frontal regions turn off

During REM- limbic regions concerned with emotion are very active. They are not countered by the frontal lobe like normal since you are still suppressing the frontal lobe.

Stage 4 is the deepest most restful sleep

Dont dream only in REM

REM dream is a widescreen, Technicolor, bizaare state

Non REM dream- rolling along, day dream type Narcolepsy

Transition from wakefulness to REM takes minutes

Emotional excitement can also trigger a narcoleptic attack

A common treatment is ingestion of arousing drugs (amphetamine)

Narcoleptics in the lab get nervous and cant sleep but as soon as electrodes are removed, they pass out. Add electrodes again and its DEF REM.

Sometimes paralysis mechanisms are still on (all parts of REM are independent. Youre waking up but the pons is still paralyzed (hypnopompic)

Subcoeruleus- inhibits movement in pons. It gets turned on in narcolepsy. Memories are consolidated during REM and non-REM sleep!

Most dont make it into permanent memory

Place cells fire when a rat is in a particular area of the maze

Spatial cognition is from the hippocampal cells

This is played back in real time in their sleep

If you do a lot of learning during the day- you see tons of REM dring the night.

But if you are deprived of REM you dont learn as well

REM pressure builds- if deprived, it is harder to wake you up out of REM because the body craves it.

REM is needed for consolidation

Neuropsychology of Memory

Its not a problem in short term memory formation but the problem is in forming long term memory

If you learn something you can recall it for a while then you forget it. You have it only temporarily- short term memory.

Then you also have long term memory- this is when it turns into a permanent form- CONSOLIDATION

Most events of your day dont stick- when you get older you cant consolidate memories

Savante syndrome- one area of expertise- your brain only has room for so much stuff so one other area may suffer.

One area of expertise- your brain only has room for so much stuff so social capabilities or other brain areas may suffer.

How are memories

Formed- encoding

Retained- storage

Recalled- retrieval

Memories can be reconstructions- can be changed by misinformation by post event questions. You can implant information into peoples minds depending on how you ask a question to them.

If a question gets asked- violent memories from childhood that are repressed may come back!

Susceptible to errors in source monitoring which is memory for where something came from. Typically shows up as depression at middle age Cues can help with retrieval Amnesias

Retrograde- loss of memory from one point back in time

Anterograde- loss of memory from one point forward in time

Post traumatic amnesia- following traumatic brain injury

Transient global amnesia- brief cerebral ischemia- loss of blood flow- produces sudden loss of memory (minutes or days; retrograde)

Place rat on rectangle raised platform with a metal grid floor around it that is electrified.

Next day he doesnt step onto the grid floor.

If you did ECS right after he steps onto the floor on the first day, on the second day hell step off onto the floor again. Short term memory is blown away. After ECS you find a curve called a gradient

Using time points you see how far along short term gets consolidated

Doing ECS after 3 hours only show amnesia

After 2 hours show amnesia

After 6 hours no amnesia This tells us that memory is consolidated before 6 hours time mark is reached and ECS can do no damage to the STM since it has already been consolidated. Initial ECS treatment extends back a few years

After a series of treatments it goes back a few years but it slowly recovers. First part of recovery starts from farthest time point away from when damage occurred. Slowly they decrease from 2 years to 6 months to 2 weeks to only forgetting a few hours before the traumatic events this is called shrinking OR you can recover with islands of information. You may remember a single memory in between

Bilaterally temporal lobectomy- take out both parts of temporal lobe and you saw that the person had no memories. Brenda Milner Short term memory- if you dont rehearse it it is lost after 20-30 seconds

Will last as long as rehearsal continues

Limited to about 7 items + or 2

Can chunk to help remember- materials held in units.

Consolidation- process of STM to LTM

HM has severe anterograde amnesia and intact STM

Task to trace line in between 2 stars- must draw line while looking in the mirror

If HM does it, he makes errors on the first day

Second day he needs someone to explain the task again and he makes less errors! Motor memory is intact but the short term memory is gone/ anterograde amnesia

Can improve procedural memory even though he has no conscious memory of it (declarative memory)

Last night I went out and ate dinner is declarative

Learning to ride a bike is procedural

Different kinds of memory

Explicit- consciously recollected

Declarative- memory of material is available to conscious mind

Implicit- not deliberate but shows evidence of prior learning

Procedural- unconscious skills and procedures

Semantic- general knowledge

Episodic- tied to a specific experience

Larry Squire-

Look at multiple memory systems slide for layout of his tree

Priming- have you read a story about flowers and then ask you to recall a list of words later- You recall words that have to do with flowers that you normally wouldnt. Unconscious sort of thing. If you havent been primed, it wouldnt happen.

Where youre given information that facilitates your ability to form information about that type.

Conditioning- Pavlov or skinner boxes Declarative depends on the hippocampus, MTL and procedural depends on everything else.

If rats hippocampus is removed- there are no learning problems! HOW?!?

David Olton at JHU says that they do have memory problems but only on spatial memory tests

8 arm radial maze- put food pellet next to each arm

Run an arm and receive a food pellet- dont do 1 arm twice. If you use the turn right strategy you wont use same arm twice- same thing when they jump aroundno visiting the same arm.

They use spatial cues in the room to orient themselves.

If the hippo is removed- it runs down the arm and goes down the same arm a few minutes later.

Does NOT have an image of itself in space.

If people recorded from the CA3- fires 1 neuron when it runs down a particular arm- place cells!!!!

Species that hide food stuff in one area during the fall and need to find it later in the winterthey have larger hippocampus.

If you do spatial reasoning/ recognition stuff your hippocampus grows!

Spatial memory is a type of declarative memory for rats?

Novel object recognition test- Manns lab NB gets fencing foil in the nostril and it damages the medial thalamus- no declarative memory formed since then HENCE the diencephalon is where declarative memory is formed.

There is no place in the brain for memories

Hippocampus is needed for formation and retrieval of memory Memories are stored in area that controls that ability/ memory

Systems compete with one another and if you (for example) remove the hippocampus and it competes with the striatal learning task, the striatal learning task gets better.

Declarative is memory that is accessible to consciousness.

Karl Lashley searched for the engram which is the physical memory trace in the brain.

When you take out skull you see neocortex- he tried to see what would happen when he removed the neocortex. There was no particular area that stored memories but there WAS a noticeable change in behavior when more cortex was removed.

MEMORY IS DISTRIBUTED but most important node for specific kind of memory are listed in the memory tree.

Individual Differences and a Just Society

Size change in V1 cortex is what causes differences in magnitude of Ebbinghaus illusion.

How do you get cable properties signal to pass on

In dendrites the electrical signal is passed on passively so you want a larger diameter.

Small V1 means you have a small visual field of neuron relative to the whole visual field than if you have a large V1

Reaction time to a visual stimulus correlates with integrity of the optic radiations.

You see a light and push a button- measure reaction time

Fractional anisotropy which looks at the amount of H20 in a brain area. It helps us measure the degree of connection between area A and area B in the brain.

More myelination in thalamus to V2-the faster the reaction time, the less water. And anisotropy score decreases.

The ability to adjust speed vs. accuracy in a reaction time task correlates with the degree of axonal connection between the pre-supplemental motor area and dorsal striatum. Able to get an idea of connection strength and connected to speed vs. accuracy!

Individual differences between people!

Grey matter volume of specific brain regions correlates with four of five individual components f Big Five personality model

Extraversion- OFC, conscientiousness- mid frontal gyrus, agreeableness, have a positive correlation with grey matter volume. There is a negative correlation with neuroticismthe larger the volume the more anxiety.

Openness has no correlation found

Assumption- a lot of this is genetically set

Success in contemporary industrial information society depends on separate personality traits

Differences between individuals brains dont give everyone equal opportunity

IQ is general intelligence- g for general intelligence

Psychomatricians develop IQ tests and measure the psyche

Measure verbal comprehension, perceptual organization, working memory, processing speed- lowest correlation with g. ALL OF THESE ARE MEASURE BY IQ TESTS. Each has subtests

The Pi inspection time task- a warning cue comes on followed by a brief presentation of the stimulus, followed by mask stimulus. Subjects task is to identify which leg of pi stimulus is shorter (processing speed)

Vary the amount of time the stimulus is flashed

Event related potential spike in pi task and correlation of ERP slope with inspection time and IQ.

Steeper the slope the better that person will do on a particular task

Duncan and Owen common cortical regions activated by different cognitive tasks- evidence for g?

Thought that maybe brain areas common for solving general cognitive tasks

fMRI- did auditory discrimination and saw what areas lit up.

Refute that g exists

Concluded that certain areas of PFC relate to g since its involved in every task

Volue of cortical areas correlates between monozygotic (identical) and dizygotic (DZ) twins have less correlation.

Frontal, wernickes area and brocas area correlate highly in MZ twins- this is genetically based

MRI study with twins showing presumable superior frontal lobe thinning

Another ability needed in contemporary industrial information society is language skills

Dyslexics

Another skill is memory

Savante

Hyperlexia- kid has immense vocab and reads earl. At the price of social intelligence

People with bilateral amygdala damage cant judge trustworthiness of a face.