Abstract
Adaptation of saccadic amplitude is induced by displacing the target during eye movements (McLaughlin, 1967) and saccade amplitude matches the post-saccadic target location. This oculomotor plasticity is specific to the adapted saccade motor vector and transfer to other vectors is proportional to their proximity to the adapted vector (Watanabe, Noto, & Fuchs, 2000; Collins, Dore-Mazars, & Lappe, 2007). The aim of this study was to see how the temporal window of transfers to other saccades evolves over time. We adapted horizontal saccades of 12 or 16 dva (15 per condition). Observers were instructed to follow a dot which could appear 4,6,8,10,12,14,16,18 or 20 dva to the left or right in the Amplitude Test condition. In one condition, we adapted the 12 dva saccade by stepping the dot backwards with 3 dva and in another the 16 dva saccade by stepping back with 4 dva. In the Direction Test condition, the dot always appeared at 12 dva but in an angle of 0, 45, 90, 135, 180, 225, 270 or 315 degrees . In the pre- and post-adaptation stages, the dots disappeared upon saccade detection. In the adaptation stages, the dots disappeared except for the adapted vector. The adaptation stimulus was presented about 8 times more frequently as the other stimuli. We show that adaptation transfers to other vectors as a function of the difference between adapted and tested vectors both in amplitude (Figures 1 and 2) and direction (Figure 3). Current analyses, aimed at these early stages, reveal differences in time courses of separate vectors (e.g., the time course for the 12 dva Amplitude Test condition was less steep as the 12 dva in the Direction Test which was, in turn, correlating with the 16 dva Amplitude Test. We aim to distinct between the transferability of information stored in motor maps.
Meeting abstract presented at VSS 2018