Introduction to The Brain in Psychology

May 24, 2024

Introduction to Psychology Lecture: The Brain

Introduction

  • Professor: Paul Bloom
  • 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:
      1. Human Actions: Humans perform intentional, creative acts unlike machines (e.g., use of language).
      2. 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.

Brain Functions and Resilience

  • Parallel Processing: Brain operates through distributed, parallel networks unlike conventional computers.
  • Damage Compensation: The brain can adapt and preserve functions even after damage.

Brain Structure and Maps

  • Subcortical Structures: Medulla (heart rate), Cerebellum (balance), Hypothalamus (basic drives).
  • 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.