Fig 1.
Panel A shows the adapting grating, a 2 cycle per degree Gabor pattern. Panel B shows the test stimulus used for the tilt aftereffect (TAE) task. Two orthogonal oblique sinusoidal gratings are combined to form a plaid of checks. In the TAE Task, participants adjusted the tilt of the oblique gratings, which changed the aspect ratio of the squares of the plaid, with the goal of making the checks appear square. Panel C shows the secondary test stimuli used for the secondary tasks. Two low contrast Gabors were displayed that differed in spatial frequency between the two images. A dot was displayed within a circular window at the center of each image, and the luminance of the dot differed between images. In the Grating task, participants judged which image had higher spatial frequency, and in the Fixation Task participants judged which dot had higher luminance.
Fig 2.
In the main testing sessions, a secondary task trial was immediately followed by a TAE Task trial. For the secondary task, the two stimuli were each displayed for 100 msec with a 200 msec gap between and an 1100 msec response period. For the TAE Task a 100 msec test presentation was followed by a 1400 msec response period.
Fig 3.
Design of experiments 1 and 2.
Panel A shows the sequence and duration of blocks in the main sessions of Experiment 1. A 2 min block of practice was followed by a 2 min block of trials prior to adaptation (Baseline). Then 3 minutes of viewing the adapter stimulus was followed by an additional 2 min of trials (Test). Panel B shows the sequence of blocks for Experiment 2. Prior to adaptation, 30 sec practice blocks alternated with 1 min Baseline blocks. Twelve blocks of each were performed with the secondary task switching after each Baseline block. Next, during adaptation, 30 sec practice blocks alternated with 1 min blocks of trials (Test) with 1 min of the adapting grating presented in between. Again, twelve blocks of each were performed, with the secondary task switching after each Test block. (see text for details).
Fig 4.
The left panel shows results of the TAE Task, when interleaved with the Grating Task (red) and with the Fixation Task (blue), during baseline (before adaptation., dotted) and following adaptation (solid). The right panel shows effects of adaptation computed by subtracting the baseline TAE from TAE after adaptation, for each secondary task, separately. Lines plot means across participants and error ribbons indicate +/- one standard error of the mean.
Fig 5.
Results of experiment 1 by session.
The left and right panels show raw results and effects with baseline subtracted, as in Fig 5. Panel A shows results for the first session, and panel B for the second session. Plotting conventions are as in Fig 4.
Fig 6.
Performance on secondary tasks.
Mean performance on the Grating Task and the Fixation Task shown during baseline (before adaptation) and following adaptation. Bars represent three 40-sec time bins over which performance was computed. Error bars represent +/- one SEM.
Fig 7.
The left panel shows results of the TAE Task, when interleaved with the Grating Task (red) and with the Fixation Task (blue), before (dotted) and after adaptation (solid). The right panel shows effects of adaptation computed by subtracting baseline TAE from TAE after adaptation, for each secondary task, separately. Lines plot means across participants and error ribbons indicate +/- one standard error of the mean.
Fig 8.
Results of experiment 2 divided by session.
The top and bottom panels show results for the first and second session, respectively. Plotting conventions are as in Fig 7.
Fig 9.
Performance on secondary tasks.
Mean performance on the Grating Task and the Fixation Task in Exp. 2 is shown. Plotting conventions are as in Fig 6.
Fig 10.
Pooled secondary task performance.
Mean change in performance between baseline and adaptation conditions for the Grating Task and the Fixation Task is shown, pooled across both experiments. Other plotting conventions are as in Fig 9.