CORTEX

CEREBRAL CORTEX

• Wrinkled

• Thin

• Layered

• Interconnected• Plastic ( consider vs brainstem)

Layered

Many ways to organize the cortex

We will adopt the most traditional and simplest:

Cortical hemispheres

Corpus collosum

Hemispheres-Corpus collusomectomy

The Roger

Testing hemispheric functional asymmetries

Tachistoscopic studiesDichotic listening tasksSodium amytal tests

T-scope approach

A setup sometimes used in split-brain studies The participant fixates a center dot and then sees a picture or a word on the right or left side of the dot. He may be asked to respond verbally, by reading the word or naming the picture. He may also be asked to respond without words, for example, by picking out a named object from among a group spread out on a table and hidden from view, so that it can only be identified by touch. (After Gazzaniga, 1967) Bottom of Form

Functional asymmetries?Roughly 90% of right handers, and 70% of left handers

Popularized Ideas probably go too far-Left vs Right

• Prefer Classical Music • Your Left-Brain controls the right side of your body • Prefer things like instructions to be done verbally • Good at math • Like to read • Follow Western Thought* • Very Logical • Dog lovers • Don't enjoy clowning around • Can't be hypnotized • Usually remember things only specifically studied • Need total quiet to read or study • Like to read realistic stories • Like to write non-fiction • Prefer individual counseling • Enjoy copying or tracing pictures and filling in details • Also like to read action stories • Usually rational • Usually do things in a planned orderly way • If you have to answer someone's question, you won't let your

peronal feelings get in the way • Good at algebra • Can remember verbal material • Almost never absent minded • Like to tell stories but not act them out • Can think better sitting down • Like to be a music critic • Attentive during long verbal explanations • Prefer well structured assignments over open ended ones • Read for specific details and facts • Skilled at sequencing ideas • Likes to be Organized

• Prefer rock music • Right brain controls left side of body • Prefer visual instructions with examples • Good at sports • Good at art • Follow Eastern thought* • Cat lovers • Enjoy clowning around • Can be hypnotized • Like to read fantasy and mystery stories • Can listen to music or TV while studying • Like to write fiction • Prefer group • Fun to dream about things that will probably never happen • Enjoy making up own drawings and images • Good at geometry • Like organizing things to show relation • Can memorize music • Occasionally absentminded • Like to act out stories • Enjoy interacting affectively with others • Think better when lying down • Become restless during long verbal explanations • Enjoy creative storytelling • Prefer to learn through free exploration • Good at recalling spatial imagery • Read for main details • Skilled in showing relationships between ideas • Preference for summarizing over outlining • Solve problems intuitively • Very Spontaneous and unpredictable

More reasonable assertions based on data

Left hemisphere- analytical, rational, verbal, reading, writing ,mathRight Hemisphere- Intuitive, feeling, spatial processing, nonverbal, music

Videos of interest- Gazzaniga-1 Gazzaniga-2

LOBES- gyri and sulci

OCCIPITAL LOBEprimary visual processing-more later

Temporal Lobes

Primary auditory cortex Hearing Understanding language (receptive

language) Higher visual processing

TEMPORAL LOBES-superior temporal gyri

Almost like a sound recorder-highly

organized neural responses to sound

Temporal lobe and speech-Werniche’s area

Interesting video links one two

Werniche’s area appears to mediate the logical requirement for the brain to bring meaning and speech together…damage to this area produces

Werniche’s Aphasia

Speech sounds fluent, but is largely devoid of meaning

Parietal Lobes

Parietal Lobes

Primary somatosensory cortex Visuo-spatial processing

Primary Somatosensory CtxThe sensory homunculus

The “post central gyrus”

The Phantom limb Phenomenon

- awareness arises from cortex independently of reality.

Loss of limb, but not loss of the perception that the limb is there

RX for Phantom limb- awareness arises from cortex independently of reality.

Phantom limb video

Damage to the Primary Somatosensory Cortex?

-perception of reality depends on CTX

Asomatognosias- a loss of Knowledge about part of body represented by area of cortex that was damaged..pg 176

Anosagnosias- failure to recognize the deficit

AGNOSIA- A loss of knowledge

FRONTAL LOBES

Primary motor cortex-precentral gyrus

more later

Speech ccts

Speech ccts- Brocas area and Broca’s apahsia

Broca’s aphasia video interview

What about the rest of the frontal lobe?-Phineas Gage

rod

Brain-Based Theory of Emotions• Frontal lobes

– influence people’s conscious emotional feelings and ability to act in planned ways based on feelings (e.g., effects of prefrontal lobotomy)

– Some scientists contend that the prefrontal cortex normally acts as a brake that can suppress urges or impulses by communicating with other brain areas that mediate fear and aggression, such as the amygdala.

left frontal lobe may be most involved in processing positive emotionsright frontal lobe involved with negative emotions

ParietalFrontal

Occipital

Temporal

General frontal Lobe functionsSpeech

Organization and mental flexibility

Attention and concentration

Working memory

Copying

Awareness/self-awareness/self-monitoring

Conscious emotions

Personality

Goal setting/ Judgment , planning and anticipation

Self-control/ resistance to temptations

Intentional Initiation and inhibition of behavior

Testing frontal lobe Health-the Wisconsin Card Sorting Task (WCST)

HYPOFRONTALITY?

• Perseveration- a lack of mental flexibility

WHY?- the unfortunate story of Egas Moniz and Walter Freeman

The Prefrontal lobotomy and the trans-orbital leucotomy

Can you believe it?