Brains and Function

Key Concepts of Brain Structure and Function

  • Phrenology

    • Originated from Joseph Gall in the late 1700s.

    • Studied the shape of the cranium to infer character traits; widely considered a pseudoscience.

    • Proposed that different brain regions correspond to different mental faculties.

  • Three Layers of the Brain

    • Hindbrain:

    • Composed of Pons, Medulla, Cerebellum.

    • Regulates vital functions like heart rate and digestion.

    • Midbrain:

    • Connects hindbrain and forebrain, involved in movement, sight, and hearing.

    • Forebrain:

    • Comprises Cerebrum and Limbic system, responsible for reasoning, emotions, and voluntary movement.

  • Brainstem and Cerebellum

    • Brainstem:

    • Controls automatic functions (heartbeat, breathing).

    • Pons: coordinates sleep and dreaming.

    • Medulla: regulates automatic functions.

    • Reticular Formation: filters sensory information and maintains alertness.

    • Cerebellum: Coordinates movement and balance, contains a large number of neurons.

  • Limbic System

    • Includes Amygdala, Hypothalamus, Hippocampus; crucial for emotions and memory.

    • Hypothalamus: Monitors body conditions and regulates basic bodily functions.

    • Amygdala: Plays a role in processing fear and aggression.

    • Hippocampus: Essential for forming long-term memories.

  • Cerebrum

    • Largest part of the brain, involved in higher cognitive functions.

    • Divided into cerebral hemispheres connected by the corpus callosum.

  • Cerebral Lobes

    • Frontal Lobe: Higher mental functions; planning and decision making.

    • Parietal Lobe: Processes sensory information; spatial awareness.

    • Temporal Lobe: Involved in memory and auditory processing.

    • Occipital Lobe: Processes visual information.

  • Language Centers

    • Broca’s Area (Left frontal lobe): Involved in speech production, difficulties result in Broca's Aphasia.

    • Wernicke’s Area (Left temporal lobe): Involved in understanding language, issues lead to Wernicke's Aphasia.

  • Split Brain Research

    • Roger Sperry’s experiments on split-brain patients showed hemispheric specialization after cutting the corpus callosum.

    • Right hemisphere: non-verbal tasks (drawing); left hemisphere: verbal tasks.

  • Reciprocal Relationship of Brain and Behavior

    • Plasticity: The brain's ability to adapt to experiences, including trauma.

    • Various cases illustrate how touch and environment influence development and functioning of the brain (e.g., psychosocial dwarfism).