Event
Can Contrast Response Functions (CRFs) Reveal Visual Processing Levels?| Title of the event | Can Contrast Response Functions (CRFs) Reveal Visual Processing Levels? |
| Series | Forschungskolloquium Experimentelle Psychologie |
| Organizer | Prof. Dr. Uwe Mattler |
| Speaker | Prof. Bruno G. Breitmeyer, Ph.D. |
| Speaker institution | Department of Psychology, University of Houston |
| Type of event | Vortrag |
| Category | Forschung |
| Registration required | Nein |
| Details | Can Contrast Response Functions (CRFs) Reveal Visual Processing Levels? Past physiological recordings from monkey and human cortex indicate that the contrast response function (CRF) of ensembles of neurons in V1 are characterized by a nearly linear increase of response magnitude as contrast increases. However, at progressively higher cortical levels (V2, V4, inferotemporal cortex) the response tends toward increasing nonlinearity, characterized by steep amplification of the contrast response for lower contrasts ranging from 0.0 to about 0.3. This property relates nicely to natural image statistics showing that roughly 70% of local contrasts in natural images are ≤ 0.3. The progressive increase in the nonlinearity of CRFs as one proceeds to higher levels of cortical processing therefor increases the contrast sensitivity within this low contrast range, thus allowing for optimal extraction of perceptual information. Moreover, using various experimental paradigms, past and more recent research has revealed that differences in the linearity/nonlinearity of CRFs can been used to indicate relative and absolute levels of visual cortical processing. By investigating variations of psychophysical CRFs, future research can indicate at least the relative levels of visual processing involved in many visual phenomena. |
| Date | Start: 05.02.2018, 17:15 Uhr Ende: 05.02.2018 , 18:45 Uhr |
| Location |
Georg-Elias-Müller-Institut für Psychologie (Goßlerstraße 14) GEMI Raum 1.136 |
| Contact |
0551 39 33613 sekretariat.experimentelle.psychologie@uni-goettingen.de |
| External link | https://www.psych.uni-goettingen.de/de/experime... |