Letters were presented for 375 ms, centred in a 500-ms DRD. In the exposure stage, subjects witnessed DRDs with 5% coherent motion while carrying out the identification task 1 on dimmed letters to prevent their attention from disengaging. In the tests 1, subjects reported direction of coherent motion of DRDs of 5% and 10% their performance in the tests was at chance at 5% coherence and better than chance at 10%. Red arrows indicate the 'designated direction' for the motion of the DRD that was presented at the same time as the task targets (two white letters) black arrows indicate the other directions of the DRD, which were paired with the task distractors (six black letters). But if learning occurs only for features to which attention is directed, no improvement should be found for any presented direction.Ī, Exposure stage, showing the letters used in the main identification task and the direction of motion of background dynamic random-dot displays (DRDs, arrows). If perceptual learning were due only to passive exposure, motion direction thresholds should improve equally for all of the presented directions. To test this idea, we presented four different directions of motion an equal number of times during the exposure stage of the experiment, with a 'designated direction' always being 'paired' with the targets of the letter-identification task and the other directions being randomly associated with the letter-task distractors ( Fig. This raises the question of whether subliminal learning occurs only as a result of passive exposure to a stimulus. This showed that perceptual learning occurs unconsciously as a result of frequent exposure to an irrelevant feature. Repetitive exposure improved subjects' performance in specifically identifying the direction of this subthreshold motion when tested in a subsequent above-threshold test 1. In our previous study 1, subjects carried out an attentionally demanding letter-identification task 7 in the fovea while a coherently moving, random-dot display that was below the visibility threshold was presented in the periphery.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |