Mass of jelly (3 pounds) capable of complex thought and self-awareness (recursive quality).
Holy grail of neuroscience: Understanding how self-awareness happens.
100 billion nerve cells essential for human nature and consciousness.
Approach to Studying the Brain
Methods: Observe patients with localized brain damage to study function loss and association with specific brain regions.
Aim: Map function onto structure and understand neural circuits.
Example 1: Capgras Syndrome
Brain Anatomy
Temporal lobes, frontal lobes, parietal lobes – main lobes of the brain.
Fusiform gyrus: Face recognition area.
Condition Description
Capgras delusion: Patient believes a familiar person (e.g., mother) is an impostor.
Standard Freudian explanation: Based on suppressed sexual urges (Oedipus complex).
Criticism: Does not make sense with non-human objects (e.g., pet poodle).
Alternative Explanation
Visual signals processed in visual areas then fusiform gyrus.
Message transferred to amygdala (gauges emotional significance).
In patients with Capgras, the connection to the emotional center (amygdala) is severed, resulting in a lack of emotional response which leads to the impostor delusion.
Evidence: Normal galvanic skin response to emotionally significant images except recognition of mother’s face.
Example 2: Phantom Limb
Description
Sensation of a limb after its amputation.
Certain patients feel they can move the phantom; others feel it as paralyzed.
Paralyzed phantom limb often linked to previous paralysis before amputation.
Treatment strategy
Concept of Learned Paralysis: Repetitive failed commands to move the paralyzed limb enforce the paralysis in the brain.
Introduction of the Mirror Box: Visual feedback used to give an illusion of movement to alleviate pain and paralysis.
Example 3: Synesthesia
Description
Synesthesia: Condition where stimulation of one sensory pathway leads to involuntary experiences in another pathway (e.g., numbers evoking colors).
Higher occurrences among artists, poets, and creative individuals.
Explanation
Cross-wiring in the brain: Adjacent areas in the fusiform gyrus (e.g., numbers, and colors) result in synesthesia.
Genetic Basis: Runs in families, suggesting a genetic mutation affecting neuronal trimming.
Link to Creativity: Enhanced cross-wiring might facilitate metaphorical thinking and abstract ideas.
Experimental Demonstration
Bouba-Kiki effect: Visual representation of abstract shapes (sharp/jagged vs. round) mapped onto auditory cues (Kiki vs. Bouba).