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

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

The Wisconsin Card Sorting Test

The Stroop Test 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

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 x001/Dichotic/dichotic.htmlhttp:// x001/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

Rey Complex Figure

Actual Ben

Actual Phil