Cortical Structure and Function

FRONTAL LOBE

Anatomy of the Frontal Lobes

Functions of the Frontal Lobe

• Execution of motor movements (primary motor cortex)

• Selection of motor movements (premotor cortex)

• Executive Functions: planning, task persistence, ignoring distracting stimuli, working memory (prefrontal cortex)

Functions of the Motor and Premotor Cortex

• Motor: – Executes motor movements

• Premotor: – Selects movements to be executed– Chooses motor behavior in response to

external cues (e.g. mom calls name) or internal cues (e.g. hungry) NOTE: internal more tied to supplementary premotor

– Activates when cues become associated with movement (e.g. red light)

Motor System

Motor System

Functions of the Prefrontal Cortex

• Controls cognitive processes so that appropriate movements are selected at the correct time

• Executive Functioning: planning, task persistence, ignoring distracting stimuli, working memory, etc.

• Self knowledge

Asymmetry of the Frontal Lobes

• Left – Language– Encoding memories

• Right – Nonverbal movements, facial expression– Retrieving memories

Symptoms of Frontal Lobe Lesions

Visual Search

www.gocognitive.net/demo/visual-search

The Wisconsin Card Sorting Test

http://ertslab.com/web/portfolio/card-sorting-test/

The Stroop Test

http://ertslab.com/web/portfolio/color-naming-task-stroop/gallery/library/

Other tasks

• Verbal fluency (DKEFS)

• Design fluency (DKEFS)

• Tower task (DKEFS)

• Spatial working memory (WRAML)

TEMPORAL LOBE

Rey Complex Figure

• Instructions: “I’m going to show a card on which there is a design that I’d like you to copy on this paper. Please copy as carefully as you can.”

• Max of 5 minutes; Min of 2.5 minutes. • Tell to hurry up or to check for errors to make

sure falls within this window. • Record total time to complete.• 3 minute and 30 minute delays (we’ll do 30

minute delay)

Rey Complex Figure

Anatomy of the Temporal Lobe

Temporal Lobe Function

• Processing auditory input – sends ventral and dorsal streams (object

identification and for movement planning)

• Visual object recognition– Ventral visual stream

• Biological motion perception– Superior Temporal Sulcus

• Long-term storage of information– Memory (limbic system, hippocampus)

Temporal Lobe Function

• Sensory Processes– Identification and Categorization of Stimuli– Cross-Modal Matching

• Process of matching visual and auditory information

• Affective Responses– Emotional response is associated with a particular

stimulus

• Spatial Navigation– Hippocampus – Spatial Memory

•

Faces

Special face processing pathway

Thatcher Illusion

Thatcher Illusion

Which picture most looks like Ben?

Auditory Processing in the Temporal Lobe

• Speech perception

• Music Perception

• Left role in temporal grouping for rhythm, whereas right role in meter

• Right lobe special function in extracting pitch from sound (both speech or music)

• Prosody - “tone of voice” or pitch in speech

•

Asymmetry of Temporal Lobe Function

• Left temporal lobe– Verbal memory – Speech processing

• Right temporal lobe– Nonverbal memory– Musical processing– Facial processing

Primary auditory cortex

• Visual cortex (BA 17/18) or somatosensory cortex (BA 1/2/3) lead to loss of conscious sensation.

• Not so with Auditory cortex (BA 41/42/22), result is auditory hallucinations.

Symptoms of Temporal-Lobe Lesions

Rey Complex Figure

• “Do you remember the design I had you copy a while ago? Now I would like you to draw the figure from memory as carefully as you can on this sheet of paper. If you make a mistake do not erase, just correct whatever you think is wrong.”

• Don’t cheat!

Dichotic listening task

• “You are going to hear some words that will come into both ears at the same time. I want you to repeat all the words that you here. You will hear 3 sets of words and when I stop the tape, you must start repeating the words immediately, as many as you can remember.”

• Headphone and taped stimuli administration• http://www.linguistics.ucla.edu/people/schuh/

lx001/Dichotic/dichotic.html

California Verbal Learning Test (CVLT)

• Shopping List format tests:– Total recall and recognition

– Semantic and serial learning strategies

– Serial position effects

– Learning rate across trials

– Recall consistency

– Vulnerability to interference

– Retention over short and long periods

– Enhancement by category cueing and recognition

– Perseverations and intrusions

– False positives in recognition

• Immediate and Delayed (20 minute) recall

CVLT

CVLT

Rey Complex Figure

Rey Complex

Figure

Actual Ben

Actual Phil