Stiel Ben, Clifford Colin W G, Mareschal Isabelle
School of Psychology & Australian Centre of Excellence in Vision Science, The University of Sydney, Sydney, Australia.
J Vis. 2014 Jan 16;14(1):15. doi: 10.1167/14.1.15.
Previous adaptation studies have revealed the tuning properties of mechanisms coding left-right averted gaze. Here, Experiment 1 used an adaptation procedure to investigate the mechanisms that encode vergent eye gaze. Following prolonged exposure to convergent or divergent gaze, observers were more likely to categorize smaller gaze deviations in the adapted direction as parallel (i.e., nonvergent). We then examined whether adaptation was occurring to the eyes independently (monocular gaze direction) as opposed to the two eyes as a unitary stimulus (binocular gaze direction). In Experiment 2, we interleaved presentations of convergent and divergent adaptors and tested with either congruent (vergent) or incongruent (left-right) stimuli. Similarly, we interleaved presentations of leftward- and rightward-averted adaptors and tested with congruent (left-right) and incongruent (vergent) stimuli. If adaptation were driven solely by monocular gaze direction, congruent and incongruent adaptation would be similar because, at the level of an individual eye, the stimuli are identical. We find considerable adaptation in the incongruent conditions, consistent with adaptation to individual eye directions. However, we also find greater adaptation in congruent conditions, implicating the involvement of mechanisms that encode binocular gaze direction.
先前的适应性研究已经揭示了编码左右偏斜注视的机制的调谐特性。在这里，实验1使用了一种适应程序来研究编码辐辏眼注视的机制。在长时间暴露于辐辏或发散注视之后，观察者更有可能将适应方向上较小的注视偏差归类为平行（即非辐辏）。然后，我们研究了适应是独立发生在眼睛上（单眼注视方向），还是将两只眼睛作为一个整体刺激（双眼注视方向）发生。在实验2中，我们交替呈现辐辏和发散适应刺激，并使用一致（辐辏）或不一致（左右）刺激进行测试。同样，我们交替呈现向左和向右偏斜的适应刺激，并使用一致（左右）和不一致（辐辏）刺激进行测试。如果适应仅仅由单眼注视方向驱动，那么一致和不一致适应将是相似的，因为在单只眼睛的层面上，刺激是相同的。我们发现在不一致条件下有相当大的适应性，这与对单眼方向的适应一致。然而，我们也发现在一致条件下有更大的适应性，这意味着编码双眼注视方向的机制也参与其中。
