Lateralization and Localization in Cognitive Science

Lateralization

Division of cognitive functions between hemispheres.

Localization

Specific brain areas control distinct functions.

Decussation

Crossing of nerve fibers between hemispheres.

Split-brain patients

Individuals with severed corpus callosum.

Left Hemisphere

LANGUAGE B&W areas: Associated with logical, calculative, and linguistic tasks.

Right Hemisphere

FACES & visual motor tasks, Associated with emotional, intuitive, and holistic processing.

Broca's area

Region responsible for language production.

Wernicke's area

Region responsible for language comprehension.

Contralateral control

Opposite hemisphere controls body side.

Selective amnesia

Loss of memory for specific events.

Aperceptive agnosia

Impaired shape recognition despite intact vision.

- disruption in perceiving the object (ex: corners)

- non verbal motion to facilitate recognition (pointing)

- diffuse and widespread damage (posterior regions of cerebral hemispheres

Associative agnosia

Inability to connect visual perception with meaning.

- can't label or name object --> damage to ventral visual stream "what" pathway

no nonverbal recognition or motion

Dyscalculia

Inability to perform simple mathematical calculations.

Alexia

Inability to read despite intact vision.

Agraphia

Inability to write despite intact motor skills.

Broca's aphasia

Difficulty in language production and speech.

Wernicke's aphasia

Difficulty in understanding spoken language.

Anosognosia

Unawareness of one's own disabilities.

Visual motor tasks

Activities requiring coordination of vision and movement.

Cerebral hemispheres

Two halves of the brain with specialized functions.

Left Damage

Right hemisphere is dominant:

Pessimistic, overly emotional, over noticing of even nonserious problems

Right Damage

Left hemisphere is dominant:

Optimistic, unemotional, oblivious to serious injury and disability(anosognosia)

Alien Hand Syndrome

Would try to strangle herself with her left hand. Would fight off her left hand with her right.

Right hemisphere (more emotional?) tried to

commit suicide - left hemisphere not aware of

this intention