In-depth Psychological Science Notes

Introduction to Psychology

• Course Overview: PSYC1020 - Introduction to Psychology
• Offered in 2009 at Wollongong
• Part of Psychological Science curriculum

Structure of the Brain

• The brain consists of two asymmetrical hemispheres connected by the corpus callosum.
• Gross Structure Components:
  • Lateral Sulcus: A significant groove in the brain, delineating regions.
  • Brodmann Areas: Cytoarchitectonics map developed by Korbinian Brodmann which categorizes brain areas based on tissue structures.

Brain Composition

• Brain Cells: Two main types of cells comprise the brain.
  • Neurons:
  • Estimated ~100 billion in the adult brain.
  • Form over 100 trillion neuronal connections, processing all information.
  • Glial Cells:
  • Provide support, nutrition, and physical structure to the brain.

Neuronal Structure

• Basic Neuronal Components:
  • Multipolar Neuron: Characterized by having one axon and multiple dendrites.
  • Soma (Cell Body): Contains the nucleus and all essential structures for neuron functioning.
  • Dendrites: Specialized structures that receive incoming signals.
  • Axons: Specialized for transmitting outgoing signals.

Neuron Communication

1. Resting Membrane Potential:
   • Neurons maintain a voltage difference of approximately -70 millivolts across their membrane, similar to a tiny battery.
2. Depolarization:
   • Reception of excitatory/inhibitory signals that alter the resting potential; threshold around -55 mv.
3. Action Potential Generation:
   • Initiated through rapid depolarization at the axon hillock, resulting in a current traveling down the axon.
4. Myelination:
   • Oligodendrocytes create a myelin sheath that influences how the action potential travels.
5. Synaptic Transmission:
   • Arrival of action potential triggers neurotransmitter release into the synaptic cleft.
6. Postsynaptic Effects:
   • Depending on the neurotransmitter type, EPSPs can depolarize or IPSPs can repolarize the postsynaptic neuron.

Brain Functionality

• Executive Functions (Prefrontal Cortex):
  • Involves cognitive processes such as planning, inhibition, and working memory.
• Motor Functions (Motor Cortex):
  • Primary Motor Cortex: Responsible for planning voluntary movements.
  • Premotor Cortex & Supplementary Motor Area: Involved in selecting and coordinating movements.
• Somatosensory Processing (Somatosensory Cortex):
  • Processes sensations such as pressure, pain, and temperature.
• Visual Processing (Visual Cortex):
  • Handles form, color, object identity, and motion perception.
  • Neuronal activity encodes a spatial map of the visual world, although details degrade with complexity.
• Auditory Processing (Auditory Cortex):
  • Processes sound frequency, localization, language, and music.
• Limbic System:
  • Often referred to as the “older mammalian brain,” regulates emotional responses and memory.
• Cerebellum (Hindbrain):
  • Coordinates complex movements and stores procedural memories.
• Medulla, Pons, Reticular Formation (Hindbrain):
  • Manage basic autonomic functions such as breathing, sleep, and wakefulness.