Lecture 13: Sensory Modalities Flashcards
What enables colour vision, and under what conditions does it function?
Colour vision occurs only in bright light and depends on three cone types in the retina, which express either S, M, or L opsin sensitive to different wavelength ranges.
How do colour-sensitive neurons contribute to colour perception and constancy?
Neurons in the P pathway and ventral stream (ganglion cells, LGN, V1, V2, V4) generate conscious colour perception and mediate colour constancy to adjust for changes in the spectral composition of sunlight.
What are the different types of colour vision found in animals?
Animals can have no colour vision, dichromatic (mammals), trichromatic, or tetrachromatic colour vision.
How does human trichromatic colour vision sometimes vary?
If one opsin is missing or has a shifted spectral sensitivity, it results in severe to mild colour deficiencies.
What are colour deficiencies more common in males?
They arise from defective opsin genes, most frequently on the X chromosome (coding for M or L opsin). Since males have only one X chromosome, they are more affected.
How do light and sound differ in their propagation?
Light propagates as absorbed quanta by photoreceptors, while sound propagates as waves that vibrate internal ear structures.
How do animals locate sound sources?
They compare sound information processed by both ears
How do hair cells in the inner ear process sound?
Hair cells have stereocilia and ion channels that open via mechanical forces. Inner hair cells release glutamate to excite afferent first-order auditory interneurons, transmitting signals to the cochlear nucleus and brainstem.
What role do outer hair cells and efferent interneurons play in auditory processing?
They modulate signal coding via top-down control
How is the auditory pathway similar to the visual pathway?
It has both parallel and serial connections
What do audiograms help determine?
They allow comparisons between species to see how hearing adapts to different tasks and ecological needs
How do difference brain areas process sensory input?
Various brain areas receive input from multiple sensory modalities
What is the multimodal integration, and what is its effect?
It combines different sensory inputs to generate unique perceptual qualities of diversify a salient cue
How does attention affect sensory processing?
It helps the brain select relevant information based on task and context
