The008th KARC Colloquium
The008th KARC Colloquium was ended. Thank you for the participation.
| Date&Time | Tuesday 8th January 2:00pm - 3:30pm |
| Place | KARC, Small-Meeting Room in the building No. 1 (2F) |
| Lecturer | "Perceptual plasticity, memory, and long-range interaction in early visual processing" |
| Speaker | Mr.Yasuto TANAKA |
| Abstract | Recent psychophysical and physiological studies have revealed dynamic interaction in early visual processing that induces neural plasticity (Karni and Sagi, 1991; Kapadia, Westheimer and Gilbert、1991).To study the plastic nature of spatial lateral interaction (Polat and Sagi, 1993, 1994; Ishai and Sagi, 1995) a forward masking paradigm was used to measure contrast sensitivity of Gabor signals for human observers. A brief presentation (90msec.) of low-contrast (near threshold) Gabor stimuli is found to produce a long-lasting memory trace, lowering target detection thresholds over 16.3 seconds, far beyond perceptual integration time (200msec.) The perceptual memory is specific to both global configurations (collinear; Tanaka and Sagi, 1998 Proc. Natl. Acad. Sci. 95:12729-33). The memory trace depends on dynamic interactions between low-level stimulus properties such as orientation and contrast, and a higher-level gating process produced by temporal cues maximal at cue-lead time at 300 to 500msec. (Tanaka and Sagi, 2000 Vision Research 40:1089-1100). The gating process also improves contrast discrimination (Tanaka and Sagi, 1999) and strengthens long-range interaction achieved by lateral Gabor flankers (Polat and Sagi, 1993). Recently, we were able to specify long-term plasticity that persists over months by use of repetition of the memory gating consolidation of improved efficacy activating lateral interaction. |
| Language | Japanese |
| Admission | Free |
| Organizer | Miyauchi or Shibahara |