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