Introduction to Cognitive Psychology - Department of Psychological ...

Prof. Greg Francis 1/2/12!! For a Reichardt detector toindicate motion, the signal fromthe second area must follow thesignal from the first by just theright length of time!! Vary the Interstimulus Interval(ISI) between the stimuli!! The time between offset of thefirst stimulus and onset of thesecond stimulusTimingISI too short"ISI about right"Korte’s laws!! Apparent motion was highly studied at the turn of the 20th century!! Korte (1915) noted that to get good motion, you needed to increasethe ISI between the stimuli as the distance between them increased!! CogLab data!! (169 participants- from class, 12,824 from global)ISI too long"Purdue UniversityPurdue UniversityMotion representation!! One conclusion of studies of apparent motionis that motion is a fundamental percept!! It has an explicit representation in the visual system!! You could imagine otherwise, we can be aware ofsomething moving withoutactually seeing the movement!! Apparent motion is the sourceof motion for all movies andanimationPurdue University!! Just like for color andorientation, we mightexpect an aftereffect ofmotion!! competition betweenopposite directions ofmotion!! Left-right!! Up-down!! habituating gate!! offset of one direction leads torebound in otherMotion aftereffectPurdue UniversityAfter effect!! Motion can be adopted by non-moving stimuli!! http://www.michaelbach.de/ot/mot_adapt/index.html!! Dynamic vision!! flicker!! persistence!! network dynamics!! Masking!! Reichardt detectors!! Apparent motion!! Motion aftereffectConclusions!! Also used to investigate other areas of cognitionand types of mental problemsPurdue UniversityPurdue UniversityPSY 200: Intro. to Cognitive Psychology 5