Surgeons map out the somatosensory cortex and motor strip in the brain.
The somatosensory cortex is associated with sensory information from the body.
The motor strip governs movement.
Increased cortical area may relate to survival and reproductive functions, showcasing an adaptive phenomenon.
Key areas of focus: frontal lobe, parietal lobe, occipital lobe.
Functional Imaging: fMRI
fMRI (Functional Magnetic Resonance Imaging) allows assessment of brain structure and function.
Example of fMRI use: A subject experiences increased metabolic activity in the occipital lobe when exposed to visual stimuli.
Occipital lobe: Primarily associated with vision.
Similar fMRI activation patterns noted in the temporal lobe when exposed to auditory stimuli, linking it to speech comprehension.
Frontal Lobe Functions
Executive functions reside in the frontal lobe, which includes:
Planning for the future
Making moral judgments
Curbing impulsive behavior
Personality traits (e.g., extroversion, openness to experiences)
Technologies like fMRI help illustrate these functions through metabolic activity indicators.
Phineas Gage Case Study
Phineas Gage's accident involved a tamping iron that penetrated his frontal lobe, leading to a drastic personality change.
He went from being responsible and moral to impulsive and irresponsible post-accident.
His case provides insights into the correlation between brain regions and personality functions.
The accident illustrated how specific brain damage can affect distinct cognitive functions.
Plasticity of the Brain
Brain plasticity: The malleability of the brain to regain functions after injury.
Neurogenesis: The process of generating new neurons.
Brain plasticity is markedly better in younger individuals following damaging events.
Constraint-induced therapy: A rehabilitation method emphasizing use of the damaged body part to encourage neural recovery.
Corpus Callosum
The corpus callosum is a critical structure containing white matter, facilitating communication between the left and right brain hemispheres.
Severing the corpus callosum in patients (split-brain procedure) may treat severe epilepsy but leads to independent, often bizarre functioning of hemispheres.
Behavioral experiments have shown split-brain patients can have visual processing and speech processing influenced by the severance of this connection.
Consciousness Overview
Consciousness: Awareness of oneself and the environment; includes altered states, synchronized brain activity, and attention.
Different methods of exploring consciousness:
Sensory deprivation
Psychoactive drugs
Hypnosis
Dual processing in consciousness:
Explicit (conscious) and implicit (unconscious) activity observed in psychological phenomena.
Blind Sight
Blind sight occurs when individuals respond to stimuli without conscious visual awareness.
Researchers encountered patients who, although blind, could avoid obstacles in their path, highlighting implicit processing.
The phenomenon emphasizes the brain's capability to function beyond conscious awareness, impacting behaviors without explicit knowledge.
Conclusion
This discussion revolves around understanding the relationship between brain areas, functions, and consciousness.
Future explorations include sleep, dreams, and drug influences on consciousness through modules 7, 8, and 9.