Importance of understanding animal motion to avoid/approach them.
Unique human ability: Precision throwing.
Visual motion detection is shared among many animals.
Lip Reading and Facial Expressions
Difficulty in lip reading with poor audio quality.
Facial expressions convey nuanced emotions, often detected through fleeting micro-expressions.
Brain and Motion Processing
Allocation of Brain Machinery for Motion
Speculation on whether special brain machinery exists for processing motion due to its biological and ecological importance.
Neuroanatomy Basics
Overview of Human Brain
Contains approximately 100 billion neurons.
Distinctive features of neurons: axon, dendrites, myelin sheath.
Brain operates at 20 watts, compared to IBM's Watson (20,000 watts).
Major Components of the Brain
Cortex: Outer layer, responsible for complex functions.
Brain Stem: Controls basic life functions (breathing, consciousness).
Cerebellum: Involved in motor coordination; potential role in higher cognitive functions debated.
Limbic System: Includes the thalamus, hippocampus, and amygdala.
Thalamus
Acts as a relay for most sensory information (except olfactory).
Involved in high-level cognitive functions, not just passive relaying.
Hippocampus
Involved in long-term memory and navigation.
Example case: H.M. who lost episodic memory after hippocampus removal.
Amygdala
Associated with emotions, particularly fear.
Patient SM had amygdala loss and could not experience or recognize fear.
White Matter
Comprises axons connecting different brain regions.
Critical for understanding brain connectivity and functionality.
Cortex Overview
Primary Sensory Regions:
Visual, auditory, somatosensory, gustatory, and motor cortex.
Each region has maps specific to their functions: retinotopic for visual, somatosensory for touch, frequency maps for auditory.
Visual Cortex and Maps
Receptive Fields: Specific areas in the visual field that activate certain neurons.
Retinotopy: Nearby visual fields correspond to adjacent parts of the visual cortex.
Functional Evidence of Area MT
Area MT: Specialized for processing motion.
Evidence through:
Recording neuron responses in monkeys, showing direction selectivity.
Functional MRI in humans indicating higher responses to moving stimuli.
Neuronal Behavior and Direction Selectivity
Aftereffects show how neurons tuned for specific directions influence perception.
Criteria for Cortical Areas
Distinct function, connectivity, and physical differences.
Visual area MT meets all criteria, demonstrating unique function in motion processing.
Key Terms to Understand
Neurons, synapses, thalamus, hippocampus, amygdala, white matter, retinotopy, receptive fields, area MT, akinetopsia.
Conclusion
The lecture covered essential neuroanatomical components and their relevance to motion perception, setting the stage for future discussions on cognition and connectivity in the brain.