Brain and Cognition

The brain

• weighs e pounds

• Has 86 billion neurons

Antonio Damasio

"The mind is the activity of the brain, not a thing but a process"

Cerebral cortex

• outermost layer of the brain

• 2 hemispheres and 4 lobes

Frontal lobe

Involved in executive functions (decision-making, problem-solving).

Responsible for movement.

Parietal lobe

Involved in spatial information (determining location in space).

Integrates sensory information.

Plays a role in creating a united, cohesive sense of self.

Damage can disrupt sensory integration (e.g., Body Integration Identity Disorder where patients feel a body part doesn't belong)

Temporal lobe

Involved in memory.

Responsible for language comprehension.

Contains Wernicke’s area – crucial for speech comprehension.

Occipital lobe

Primarily involved in vision.

Processes visual information from the left visual field (to the right visual cortex) and right visual field (to the left visual cortex) via the Optic Chiasm

Amygdala

Primarily involved in emotional appraisal (e.g., fear learning).

Jamal's neurodegenerative disorder (in the example) affecting fear, recognition of fear in others, and aggression would likely be due to this deterioration

Case Study: Patient S.M.

Had both hippocampi removed, leading to an inability to form new memories (anterograde amnesia).

Hypothalamus

Regulates vital functions: feeding, fighting, fleeing, and sexual activity

Thalamus

The sensory relay station of the brain.

"The gateway to the cortex" - information enters here and is then sent to appropriate processing areas.

Medulla (brain stem)

Base of the brain stem.

Controls fundamental life-sustaining functions: breathing and blood circulation.

Pons (brain stem)

Involved in attentiveness, sleep, and dreaming.

Connects the brain to the cerebellum.

Cerebellum

"Little brain".

Contains 10% of the brain's volume but 80% of its total neurons.

Primary functions: balance and coordination, learning new motor movements.

Language areas

• Broca’s area

• Wernicke’s area

Broca’s area

Involved in speech production

Wernicke’s area

Involved in speech comprehension

Corpus Callosum

Connects the left and right hemispheres, allowing them to communicate.

In certain cases of severe epilepsy, this structure has been severed to prevent seizures from crossing hemispheres.

Split-brain patients

have hemispheres that cannot communicate, leading to:

Different perceptions, emotions, situational goals, long-term goals, and religious beliefs

Capgras syndrome

A syndrome where a person recognizes someone but believes they are an imposter ("You are not my father!").

Capgras syndrome involves 2 systems:

• cognitive appraisal

• emotional appraisal

Cognitive appraisal

"You resemble my father" (intact intellectual recognition).

Emotional appraisal

"You feel familiar to me" (disrupted emotional familiarity).