The psychophysical mechanisms underlying the transfer of perceptual learning enabled by double training
23.3011, Saturday, 16-May, 8:30 am - 12:30 pm, Banyan Breezeway
Xin-Yu Xie1, Jun-Yun Zhang1, Cong Yu1; 1Department of Psychology and Peking-Tsinghua Center for Life Sciences, Peking University
Although visual perceptual learning is often location specific, learning can transfer to a new location/hemisphere if the new location/hemisphere is additionally trained with an irrelevant task (Xiao et al., 2008). Here we characterized the impact of this double training on Vernier learning and its transfer at various levels of external noise. The 2-Gabor Vernier was imbedded in five levels of white noise (rms contrast 0%～29%) and centered in a visual quadrant at 5o eccentricity. When training was at zero noise, Vernier thresholds were reduced at all noise levels at the trained location, and at high noise at the diagonal quadrant location. However, if orientation discrimination with a Gabor at zero noise was also practiced at the diagonal location, Vernier thresholds were improved at all noise levels at the same location. The pre- and post-training TvC functions were similar across trained and untrained locations. When training was at high noise, Vernier thresholds were only reduced at high noise at both trained and untrained locations. Interestingly, if Gabor orientation discrimination at zero noise was also practiced at the diagonal location, Vernier thresholds at lower noise levels were improved at both trained and untrained locations. Again the pre- and post-training TvC functions were similar across trained and untrained locations. Fitting TvC functions of Vernier learning revealed that: After double training the reduction of equivalent internal noise transferred from trained to untrained location when Vernier training was at zero noise. Double training also reduced equivalent internal noise at both trained and untrained locations when Vernier training was at high noise. These improvements at both trained and untrained locations due to training of an irrelevant task at the diagonal location suggest that equivalent internal noise reduction is realized through a high-level process.