Lecture Notes on Motion Perception and Neuroanatomy

Key Concepts

• Importance of motion perception in daily life and survival
  • Precision throwing as a uniquely human ability
  • Visual motion shared with other animals
• Challenges with understanding motion through stop motion
  • Difficulty in lip reading when audio quality is poor
  • Nuances in facial expressions and micro-expressions

Motion Processing in the Brain

• Special brain machinery allocated for processing motion
• Speculation on survival in a "strobe world"
  • Difficulty in navigating everyday life without motion perception

Neuroanatomy Overview

• Human Brain Structure
  • Contains approximately 100 billion neurons
  • Neurons consist of:
    • Cell body, nucleus, axon, and dendrites
    • Myelin sheath for faster signal conduction
  • Brain operates on approximately 20 watts (very energy efficient)

Major Components of the Brain

1. Cortex - outer layer, responsible for higher brain functions
2. Brain Stem - controls basic bodily functions (breathing, consciousness)
3. Cerebellum - involved in motor coordination, possibly cognition
4. Limbic System - includes structures like the thalamus, hippocampus, and amygdala

Thalamus

• Acts as a relay station for sensory information
  • Most sensory information passes through here before reaching the cortex
  • Exception: Olfactory signals go directly to the olfactory cortex
• Increasing evidence that thalamus is involved in high-level cognitive functions

Hippocampus

• Key role in long-term episodic memory and navigation
• Famous case: H.M. who lost his ability to form new memories after hippocampus removal
• Other case: Lonni Sue Johnson, who lost all autobiographical memory but retained personality

Amygdala

• Involved in emotional processing, particularly fear
  • Patient SM: unable to recognize or experience fear
  • Functions associated with the four F's: Fighting, Fleeing, Feeding, Mating

White Matter

• Composed of myelinated axons connecting different brain regions
• Important for understanding brain connectivity and functioning
  • Distinct connectivity fingerprints for different cortical areas

Primary Sensory Regions of the Cortex

• Different regions correspond to different senses (visual, auditory, somatosensory)
• Each region has a map (e.g., retinotopic map in visual cortex)
• Receptive Fields: specific regions in space that cause a neuron to fire

Visual Area MT

• Specialized for processing motion
  • Direction-selective neurons respond to specific motion directions
  • Evidence from monkey studies showing functional specialization
  • Human studies using fMRI confirm area MT's response to motion

Conclusion

• Understanding the brain's structure and function is crucial for insights into perception and cognition
• Emphasis on connectivity and distinct functionalities across different cortical areas
• Continued exploration in upcoming lectures to deepen understanding of neuroanatomy and sensory processing.