Topic: Discussion of the brain and its functions in the context of Psychology.
The Astonishing Hypothesis (Francis Crick)
Hypothesis: All aspects of human experience (joys, sorrows, memories, ambitions, personal identity, and free will) are the result of nerve cells and associated molecules.
Quote: “You’re nothing but a pack of neurons.”
View: This view is contrary to common belief and is described as “astonishing.”
Dualism vs. Materialism
Dualism: Historically prominent view found in every religion and most philosophical systems.
Key Proponent: Rene Descartes
Descartes's View: Humans are immaterial souls that possess physical bodies.
Arguments for Dualism:
Human Actions: Humans perform intentional, creative acts unlike machines (e.g., use of language).
Method of Doubt: Descartes’s process of doubting everything except the existence of his own thoughts (cogito, ergo sum).
The Common Sense of Dualism
Language: Use of possession to describe body parts (e.g., “my brain”).
Identity and Transformation: Popular culture examples (e.g., reincarnation, transformation stories like in Kafka's work).
Survival Beyond Physical Destruction: Beliefs across cultures in life after death.
Survey: Many people, irrespective of religion, believe in an afterlife.
Scientific Consensus: Modern neuroscience largely rejects dualism. The mind is an outcome of brain activities.
Materialism and Neuroscience
Challenges with Dualism:
It’s unscientific as it ignores physical explanations.
Difficulty explaining the interaction between immaterial soul and physical body.
Advances in Neuroscience: Physical objects (brains) can perform complex tasks (e.g., playing chess).
Brain-Mind Correlation: Brain activity maps directly to mental activities (e.g., imaging techniques showing brain activity during different tasks).
Structure and Function of the Brain
Neurons
Basic Building Block: Neuron
Components:
Dendrites: Receive signals.
Cell Body: Sums up signals.
Axon: Transmits the signal.
Myelin Sheath: Insulation for faster transmission.
Neuronal Communication: Happens chemically through neurotransmitters across synapses.
Types of Neurons: Sensory, Motor, and Interneurons.
Neurotransmitters and Drugs
Agonists: Increase effects of neurotransmitters.
Antagonists: Decrease effects of neurotransmitters.
Examples:
Curare: An antagonist that blocks motor neurons.
Alcohol: Inhibits inhibitory parts of the brain.
Amphetamines: Increase arousal via norepinephrine.
Prozac: Works on serotonin to alleviate depression.
L-DOPA: Increases dopamine to treat Parkinson’s disease.
Cortex: The outer layer responsible for complex mental functions (e.g., language, reasoning).
Topological Maps: Representations of body parts in the brain.
Methodologies and Neuropsychology
Imaging Techniques: CAT, PET, fMRI
Study of Damage: Understanding brain function through injury or disorders (e.g., apraxia, agnosia, sensory neglect, aphasia, acquired psychopathy).
Hemispheric Specialization
Lateralization: Certain functions are more dominant in one hemisphere (e.g., language in the left hemisphere for right-handed people).
Corpus Callosum: Connects the two hemispheres.
Conclusion and Reflection
Scientific Conception vs. Humanist Values: Tension between mechanistic view of the mind and notions of free will, moral responsibility, and spiritual value.
Options: Reject science, reject humanist values, or reconcile the two views.
Ongoing Question: How brain processes give rise to subjective experience and consciousness.
Next Class
Continuation of discussing the brain and its role in mental life.
Exploration of neurons, neurotransmitters, brain structures, and psychological processes.