The Brian (2_19_25)

The Brain Overview

Cerebrum: Major part of the brain responsible for higher brain functions.
Cerebral Cortex: Outer layer of the cerebrum involved in complex functions.
Thalamus: Sensory relay station.
Corpus Callosum: Connects left and right hemispheres, facilitating communication.
Hypothalamus: Regulates bodily functions (thirst, hunger, emotions).
Pituitary Gland: Endocrine gland controlled by the hypothalamus, involved in hormone regulation.
Pons: Key structure in sleep and arousal.
Cerebellum: Coordinates voluntary movements and motor learning.
Reticular Activating System: Regulates wakefulness and sleep-wake transitions.
Medulla: Controls basic life functions (heart rate, breathing).

Proposed by Franz Gall: bumps on the skull correlated with mental abilities.
While the theory was incorrect, it introduced the idea of brain localization, suggesting specific brain areas are linked to psychological traits.

Definition: Areas of brain tissue that have been destroyed.
Experimental Use: Lesions applied in animals to understand specific brain functions.
Human Studies: Observing behaviors after brain injuries (e.g., TBI, stroke, surgeries).
Notable Areas:
- Lesion to Wernicke’s Area: Affects language comprehension.
- Lesion in rats modeled Tourette Syndrome.
- Lesion to Broca’s Area: Alters speech production.

Measures electrical activity in the brain via scalp electrodes.
Pros: Excellent for timing brain activity.
Cons: Poor at pinpointing the location of activity; primarily measures surface activity.
Useful for examining neural processes related to evolving stimuli like language.

Utilizes powerful magnets to align hydrogen protons in body tissues.
Advantages: Produces high-quality structural images with excellent spatial resolution.

Measures blood flow to active brain regions.
Strengths: High spatial resolution for identifying active regions during tasks.
Limitations: Poor temporal resolution; data are correlational, thus not definitive about causation.

Description: Outer layer of the brain with approximately 14-16 billion neurons; consists of gray and white matter.
Functionality of Wrinkling: Increases surface area, allowing for a greater number of connections without enlarging the skull.

Role: Responsible for complex cognitive functions and behaviors.
Comprised of the Prefrontal Cortex (30% of the cortex) for decision-making, attention regulation, and planning.
Stress can impair its function.

Located at the back of the frontal lobes, controls voluntary movements.
Body parts needing precision occupy larger cortical space (mapped through Wilder Penfield’s electrical stimulation in surgeries).

Found at the front of the parietal lobe; processes tactile sensations and body movements.
Greater sensitivity corresponds to more cortical space dedicated to that body part's control.

Involved in taste perception, disgust, and bodily sensations linked to emotions.

A network that coordinates motor signals, influencing actions, motivation, habits, and reward processing.

Thalamus: Sensory switchboard directing input to respective cortical areas (excluding smell).
Hypothalamus: Regulates bodily functions (hunger, thirst, aggression, sex).
Hippocampus: Important for long-term memory formation; associated with damage in conditions like Clive Wearing.
Amygdala: Critical for emotional processing, especially related to fear and threat, enhancing memory formation for significant events.

Medulla: Controls vital functions such as heart rate and respiration.
Pons: Regulates sleep and arousal levels.
Cerebellum: Coordinates motor control, timing, and learning.
Substantia Nigra: Involved in voluntary movement and serves as a sensorimotor relay station.