title: Effects of contrast, spatial frequency, and stimulus duration on reaction time in rats.
abstract: Early visual processing in rats is mediated by several pre-cortical pathways as well as multiple retinal ganglion cell types that vary in response characteristics. Discrete processing is thereby optimized for select ranges of stimulus parameters. In order to explore variation in response characteristics at a perceptual level, visual detection in rats was measured across a range of contrasts, spatial frequencies, and durations. Rats responded to the onset of Gabor patches. Onset time occurred after a random delay, and reaction time (RT) frequency distribution served to index target visibility. It was found that lower spatial frequency produced shorter RTs, as well as increased RT equivalent of contrast gain. Brief stimulus presentation reduced target visibility, slowed RTs, and reduced contrast gain at higher spatial frequencies. However, brief stimuli shortened RTs at low contrasts and low spatial frequencies, suggesting transient stimuli are more efficiently processed under these conditions. Collectively, perceptual characteristics appear to reflect distinctions in neural responses at early stages of processing. The RT characteristics found here may thereby reflect the contribution of multiple channels, and suggest a progressive shift in relative involvement across parameter levels.
authors.affiliation: Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States. Electronic address: dkurylo@brooklyn.cuny.edu.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Kurylo
authors.affiliation: Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States.
authors.forename: Caroline
authors.initials: C
authors.lastname: Chung
authors.affiliation: Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States.
authors.forename: Sowmya
authors.initials: S
authors.lastname: Yeturo
authors.affiliation: Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lanza
authors.affiliation: Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States.
authors.forename: Arina
authors.initials: A
authors.lastname: Gorskaya
authors.affiliation: Department of Computer Science, The Graduate Center CUNY, New York, NY 10016, United States.
authors.forename: Farhan
authors.initials: F
authors.lastname: Bukhari
mesh_terms: D000818:Animals; D015350:Contrast Sensitivity / Q000502:physiology*; D008297:Male; D011601:Psychophysics; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors; D014795:Visual Pathways / Q000502:physiology
keywords: Animal psychophysics; Pre-cortical channels; Rodent vision