Spatial Frequency Tuning and Transfer of Perceptual Learning for Motion Coherence Reflects the Tuning Properties of Global Motion Processing.

Jordi Asher,Paul Hibbard,Vincenzo Romei

doi:10.3390/vision3030044

Jordi Asher, Paul Hibbard + Show 1 more

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https://doi.org/10.3390/vision3030044

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Abstract

Perceptual learning is typically highly specific to the stimuli and task used during training. However, recently, it has been shown that training on global motion can transfer to untrained tasks, reflecting the generalising properties of mechanisms at this level of processing. We investigated (i) if feedback was required for learning in a motion coherence task, (ii) the transfer across the spatial frequency of training on a global motion coherence task and (iii) the transfer of this training to a measure of contrast sensitivity. For our first experiment, two groups, with and without feedback, trained for ten days on a broadband motion coherence task. Results indicated that feedback was a requirement for robust learning. For the second experiment, training consisted of five days of direction discrimination using one of three motion coherence stimuli (where individual elements were comprised of either broadband Gaussian blobs or low- or high-frequency random-dot Gabor patches), with trial-by-trial auditory feedback. A pre- and post-training assessment was conducted for each of the three types of global motion coherence conditions and high and low spatial frequency contrast sensitivity (both without feedback). Our training paradigm was successful at eliciting improvement in the trained tasks over the five days. Post-training assessments found evidence of transfer for the motion coherence task exclusively for the group trained on low spatial frequency elements. For the contrast sensitivity tasks, improved performance was observed for low- and high-frequency stimuli, following motion coherence training with broadband stimuli, and for low-frequency stimuli, following low-frequency training. Our findings are consistent with perceptual learning, which depends on the global stage of motion processing in higher cortical areas, which is broadly tuned for spatial frequency, with a preference for low frequencies.

Highlights

Perceptual learning has attracted much attention as a potential tool to aid recovery of lost visual function for clinical populations [1]
These results suggest that the inclusion of easy and difficult trials is not sufficient to ensure robust perceptual learning
We assessed the transfer of learning from training on a motion coherence task across spatial frequency and to a static contrast sensitivity task

Summary

Introduction

Perceptual learning has attracted much attention as a potential tool to aid recovery of lost visual function for clinical populations [1]. Perceptual training (with or without non-invasive brain stimulation) has been successfully used with optical defects such as myopia [2,3,4,5], amblyopia [6,7,8], presbyopia [8] and cortical damage [9,10,11]. This demonstrates the potential for sensory plasticity in adulthood and suggests that sensory development is not restricted to a critical period early in life [12,13]. We do this by evaluating the spatial frequency tuning of improvements in performance for trained and untrained stimuli and tasks

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