PSYC 100 Lecture Notes - Lecture 43: Thalamus, David H. Hubel, Retina

• School: McGill University
• Department: Psychology
• Course: PSYC 100
• Professor: Daniel Levitin

Document Summary

A+color+is+determined+by+the+mixture+of+the+wavelengths+from+a+stimulus. +any+given+color+may+ be+ produced+ in+ either+ 2+ ways,+ depending+ on+ the+ stimuli:+ subtractive+ and+ additive+ mixture+ of+ wavelengths. ++ Subtractive:+ a+ way+ to+ produce+ a+ given+ spectral+ pattern+ in+ which+ the+ mixture+ occurs+ within+ the+ stimulus+itself+and+is+actually+a+physical+process+ Paint+ is+ determined+ by+ pigments+ that+ absorb+ wavelengths+ and+ reflect+ the+ wavelength+ that+ corresponds+to+the+color+we+perceive. +red,+yellow+and+blue+are+subtractive+primary+colors. + Additive:+a+way+to+produce+a+given+spectral+pattern+in+which+different+wavelengths+of+light+are+ mixed. +the+percept+is+determined+by+the+interaction+of+these+wavelengths+with+receptors+in+the+ eye+ and+ is+ psychological. + primary+ additive+ colors+ are+ red,+ green+ and+ blue. + when+ added,+ they+ yield+white+light. ++ Color+is+a+property+of+our+visual+system;+it+doesn"t+exist+in+the+physical+world. +one+type+of+cone+is+ more+ sensitive+ to+ green+ light+ (medium+ wl),+ another+ to+ red+ light+ (long+ wl)+ and+ another+ to+ blue+ light+(short+wl). +the+cones+are+named+s,m,l. +yellow+looks+yellow+because+it+stimulate+the+l+and+ M+ cones+ and+ barely+ the+ s. + our+ perception+ of+ different+ colors+ is+ determined+ by+ the+ ratio+ of+ activity+among+the+3+types+of+receptors. ++ Simultaneous+ contrast:+ an+ optical+ illusion+ in+ which+ identical+ stimuli+ appear+ different+ when+ presented+against+different+backgrounds. +there+is+lateral+inhibition+in+the+retina+that+emphasises+ the+difference+between+an+object+and+its+background. + Vestibular+ sense:+ perception+ of+ balance+ and+ uses+ data+ from+ the+ receptors+ in+ the+ semi+ circular+ canals+ of+ the+ inner+ ear+ which+ contains+ a+ liquid+ that+ moves+ when+ the+ head+ moves,+ generating+ nerve+impulses+that+inform+us+of+the+head"s+position. +