Physiological Psychology - Chapter 1 Notes

Introduction to Physiological Psychology

The Mind-Body Problem

  • Dualism:

    • Belief in the dual nature of reality.

    • Mind and body are separate entities.

    • Body is made of ordinary matter.

    • Mind is not physical or tangible.

  • Monism:

    • Belief that everything in the universe consists of matter and energy.

    • The mind is a phenomenon produced by the workings of the nervous system.

Understanding Consciousness

  • Consciousness:

    • Awareness of our thoughts, perceptions, memories, and feelings.

    • The ability to think and be aware of our own existence.

Blindsight

  • Definition: A neuropsychological condition where individuals respond to visual stimuli without conscious awareness.

  • Cause: Damage to the primary visual cortex (V1) in the brain.

  • Mechanism:

    • Secondary visual pathways process information without conscious awareness.

    • These pathways include parts of the frontal lobe, midbrain, and occipital lobe.

    • The brain still processes information even without conscious awareness.

  • Example:

    • A person correctly guesses the orientation of a line despite reporting seeing nothing.

  • Explanation of the Blindsight Phenomenon:

    • Primitive Visual System: Eye → Primitive behavioral mechanisms (eye and head movements, reaching movements with hands) → Other simple behaviors.

    • Mammalian Visual System: Damage abolishes perception and awareness of visual stimuli → More recently evolved behavioral mechanisms (speech and thinking in words (and consciousness), other complex behaviors).

  • Visual information can control behavior without producing a conscious sensation.

  • Blindsight suggests that consciousness is not a general property of all parts of the brain; some parts play a special role in consciousness.

Split Brains

  • Corpus Callosum: A large bundle of nerve fibers connecting corresponding parts of the two brain hemispheres.

  • Split-Brain Operation: Cutting the corpus callosum to reduce the frequency of epileptic seizures.

  • Brain Hemispheres:

    • The brain consists of two symmetrical parts.

    • Left hemisphere controls the right side of the body; right hemisphere controls the left side.

    • Left hemisphere: Dominant for analytical and verbal tasks.

    • Right hemisphere: Dominant for spatial tasks and music.

  • Olfactory System Exception:

    • Sensory information typically crosses to the opposite side of the brain.

    • Olfactory information is an exception: the left nostril sends information to the left brain.

  • Consciousness requires information to reach the parts of the brain responsible for verbal communication (located in the left hemisphere).

Unilateral Neglect

  • Definition: A syndrome in which people ignore objects located toward their left and the left sides of objects; caused by damage to the right parietal lobe.

  • Parietal Lobe Function: Receives information from skin, muscles, joints, internal organs, and inner ear (balance).

    • Integrates information about body movement/location and the location of objects in space.

Perception of Self

  • Rubber Hand Phenomenon:

    • Feeling of ownership of our own body results from brain mechanisms.

    • Studied using neuroscience methods.

    • Increased activity in the parietal lobe, later in the premotor cortex (planning movements).

    • Premotor cortex activation only occurs when subjects experience the rubber hand as their own.

Nature of Behavioral Neuroscience

  • Perception informs us of our environment.

  • Perception allows our behaviors to be adaptive and useful.

  • Perception without the ability to act would be useless.

  • Reflexes:

    • Descartes (dualist).

  • Doctrine of Specific Nerve Energies:

    • Muller's idea that all nerves send the same basic type of signal.

    • The way we experience a sensation depends on which nerves are activated.

  • Broca's Area:

    • In 1861, Broca performed an autopsy on a man who lost the ability to speak after a stroke.

    • Broca concluded that a portion of the cerebral cortex on the front part of the left side of the brain performs functions necessary for speech.

Natural Selection and Evolution

  • Functionalism:

    • Understanding a biological phenomenon (behavior or physiological structure) by understanding its useful functions for the organism.

  • Natural Selection:

    • Inherited traits conferring a selective advantage (increased likelihood to live and reproduce) become more prevalent in a population.