Review of Chapter 58: Cerebral Cortex - Learning and Memory

Introduction

• Review of the cerebral cortex and its role in learning and memory
• Anatomy of the cerebral cortex
  • Column-like structure: outer (row 1) to deep layer (row 6)
  • Three primary types of neurons: granular, fusiform, pyramidal
  • Function of neurons
    • Granular: interneurons, excitatory (glutamate) or inhibitory (GABA)
    • Pyramidal and fusiform: output fibers

Information Processing

• Inputs usually enter at row 4
  • Information may connect to other columns or go to rows 5 or 6 for output
  • Layer 5: Output to brainstem
  • Row 6: Output to thalamus
• Thalamocortical system
  • Interconnections between thalamus and cortex
  • Removal of part of the thalamus affects corresponding cerebral cortex

Functions of Specific Areas

• Primary areas: direct connections to muscles, movements, and senses
• Secondary areas: make sense of inputs and outputs
• Association areas:
  • Parietal-occipital-temporal: visual processing of words, spatial coordinates, naming objects
  • Limbic: behavior, emotions, motivation
  • Prefrontal: planning complex movements, elaboration of thoughts, working memory
• Facial recognition area: located on the medial aspect of the bottom of the brain

Wernicke's Area

• Connects auditory, visual, somatic areas
• Processes information and converts it into thought
• Essential for language comprehension
• Angular gyrus: processes visual information and sends it to Wernicke's area
  • Damage leads to dyslexia or word blindness
• Dominant hemisphere: usually the left side, can develop dominant characteristics if early damage occurs

Prefrontal Association Area

• Involved in working memory and complex problem-solving
• Prefrontal lobectomy: results in loss of problem-solving ability, inappropriate social responses

Communication Process

• Sensory input (hearing/seeing words) processed by Wernicke's area
• Motor output planned by Broca's area and executed by motor cortex

Corpus Callosum and Anterior Commissure

• Corpus callosum: connects left and right hemispheres
• Anterior commissure: connects with other brain areas like the amygdala

Thoughts, Consciousness, and Memory

• Thought: pattern of stimulation from multiple brain parts
• Consciousness: awareness of surroundings and thoughts
• Memory: changes in synaptic transmission sensitivity
  • Memory trace: new or facilitated pathway

Types of Memory

• Negative memory: inhibition of remembering certain stimuli
• Positive memory: forming memory trace
• Three types of positive memories:
  • Short-term: seconds to minutes
  • Intermediate long-term: days to weeks
  • Long-term: years to lifetime
• Working memory: short-term memory for problem-solving
• Declarative vs. Skill memory:
  • Declarative: personal experiences, sensations
  • Skill: performing skills like sports

Physiology of Memory

• Short-term: reverberating neuronal circuits, presynaptic facilitation/inhibition
• Intermediate long-term: chemical/physical changes in synapse
• Long-term: structural changes in neurons, increased vesicle release sites, more vesicles, etc.
• Consolidation: converting short-term to long-term memory, requires repetition
• Codification: storing memories near similar memories

Role of the Hippocampus

• Part of the limbic system, involved in memory processing
• Stores long-term memories preferentially based on reward or punishment
• Damage can cause:
  • Anterograde amnesia: inability to form new memories
  • Retrograde amnesia: inability to recall past experiences

Conclusion

• Link to downloadable audio files in the description
• Encouragement to engage with the content and subscribe for more