BIOL 031 Lecture Notes - Lecture 12: Stimulus Modality, Receptive Field, Reticular Formation
17 Sep 2020
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Lec describe how the location of a stimulus can be identified; understand how size and density of receptive fields, convergence, and overlap affect spatial acuity. Size: spatial acuity is improved with smaller receptive fields. Density of receptive field: spatial acuity is improved with higher receptive field density. Convergence: spatial acuity is decreased with increased convergence; doesn"t matter how many signals we chat differentiate. All receptive fields converge, and we are unable to differentiate where signal has come from. Overlap: spatial acuity is improved with increased receptive field overlap. Describe the phenomenon of lateral inhibition and how it sharpens sensory acuity. Lateral inhibition: each axon inhibits the one next to it; lateral inhibition enhances the contrast between the center and periphery of a stimulated region, thereby increasing the brain"s ability to localize sensory input. It can occur at different levels in the sensory pathway. Describe the general characteristics of the specific and nonspecific ascending pathways of the afferent nervous system.
