Cerebral Cortex

Layers• Most incoming

sensory signals: IV• Most output signals

leave cortex: V & VI• To brain stem and

SC: V• Fibers to thalamus:

VI• Intracortical

association functions: I,II,III

Functional AreasStuttering & Laughter !

Association Areas

• PRT Association area:

– Continous info about body spatial coordinates

– Language comprehension

– Initial processing of visual language (reading)

– Are for naming objects

Specific Functional Areas

Face Recognition

Wernicke’s Area

• Plays the greatest single role of any part of the cerebral cortex for the higher comprehension levels of brain function that we call intelligence

Cerebral Dominance?

• Dominant & nondominant hemispheres

• Categorical hemisphere • Sequential-analytic processes

– Language – Analytical reasoning

• Representational hemisphere • Visuospatial relations

– Identification of objects by their form– Recognition of faces– Recognition of musical themes

Lesions of Representational & Categorical Hemispheres 

• Lesions of categorical hemisphere: • Language disorders• Disturbed about their disability and often depressed

• Lesions of representational hemisphere:• No language disorders• Sometimes unconcerned and even euphoric!• Astereognosis—the inability to identify objects by feeling

them• Lesions of inferior parietal lobule cause unilateral

inattention and neglect • Inability to tell a story or make a joke

Language

• Language is one of the fundamental bases of human intelligence and a key part of human culture

• Areas concerned:• Wernicke's area connected via Arcuate fasciculus to

Broca's area

• 2nd language• Broca’s area concerned is different from that

associated with native language• Children learning 2 languages simultaneously have the

same Broca’s area dealing with both languages

• Two aspects:• Sensory

– Auditory input– Visual input

• Motor

Language Disorders

• Aphasias• Abnormalities of language functions that are not due

to defects of vision or hearing or to motor paralysis• Caused by lesions in categorical hemisphere

» Most common cause is embolism or thrombosis of a cerebral blood vessel

– Wernicke’s Aphasia• Global Aphasia

– Motor Aphasia– Dysarthria

• Receptive and expressive aphasia*

Language – Chair!

Type of Aphasia and Site of Lesion

Characteristic Naming Errors

Nonfluent (Broca’s area) "Tssair"

Fluent (Wernicke’s area) "Stool" or "choss" (neologism)

Fluent (areas 40, 41, and 42; conduction aphasia)

"Flair . . . no, swair . . . tair."

Anomic (angular gyrus) "I know what it is . . . I have a lot of them."

Thoughts

• A “pattern” of stimulation of many parts of the nervous system at the same time, probably involving most importantly the cerebral cortex, thalamus, limbic system, and upper reticular formation of the brain stem. (Holistic theory)

Memory

• Stored in brain by changing basic sensitivity of synaptic transmission b/w neurons as a result of previous neural activity

• New (facilitated) pathways - memory traces

• Once traces are established - they can be selectively activated by the thinking mind to reproduce the memories

Classification

• Time-wise• Short-term

» Presynaptic ++ or --

• Intermediate long-term» Reversible chemical/structural changes (pre- or

postsynaptic)

• Long-term» Actual structural changes

• Functional • Declarative• Skill

Classification

• Explicit or declarative memory • Associated with consciousness/awareness

• Implicit or nondeclarative memory • Does not involve awareness

Hippocampus

• Storage of memories

• Lesion causes: • Anterograde & • Retrograde amnesia• Cannot establish new declarative memories• Can establish skill (reflexive) memories

Strangeness & Familiarity

• Some parts of temporal lobes causes a change in interpretation of one's surroundings

• déjà vu phenomenon!