FUNCTIONS OF VISUAL ANALYSER (RECEPTORS, NERVE SYSTEM) Talk for engineers Doc. MUDr. Jan Mares, CSc. Fyziologicky ustav 1. lekarske fakulty Karlovy Univerzity Visual system detects and interprets photic stimuli. In vertebrates, effective photic stimuli are electromagnertic waves between 400 and 750 nm long; such wavelengths constitute visible light. The eye can by specialized sensory epithelium - retina distinguish two aspect of the light brightness and its wavelength. Information processing within the retina is performed by retinal interneurons, and the output signals are carried to the brain by the axons of retina ganglion cells. The main visual pathway in humans is through the thalamic nuclei to the optic radiation to the primary visual cortex. The pattern recognition is based on processing of information about activation of visual fields (groups of receptors) and subsequent activation of specific neuron in the cortex followed by activation of associative visual cortex. The secondary visual areas are crucial for recognition of colors, visual motion, recognition and analysis of fine spatial details, motion analysis and the relative location of objects in visual space. (The overview talk is expected at the beginning. The speaker is willing do devote substantial part of the seminar to discussion according to audience interest.)