Perceptual learning in autism: over-specificity and possible remedies

Abstract

Inflexible behavior is a core characteristic of autism spectrum disorder (ASD), but its underlying cause is unknown. Using a perceptual learning protocol, we observed initially efficient learning in ASD that was followed by anomalously poor learning when the location of the target was changed (over-specificity). Reducing stimulus repetition eliminated over-specificity. Our results indicate that inflexible behavior may be evident ubiquitously in ASD, even in sensory learning, but can be circumvented by specifically designed stimulation protocols.

Response: Commentary: Perceptual learning in autism: over-specificity and possible remedies

“…Typical observers improve their performance (show reduced thresholds) with training across 3–4 days, but need to relearn the task when the target is moved to a different location in the visual field, showing specificity. We (Harris et al, 2015) reported similar results with observers with ASD, but unlike the typical observers who showed faster learning at the second location (Sagi, 2011), ASD observers showed difficulty in relearning the task at the second location, suggesting that the training with the target at the first location might have interfered with the training at the new, second location. We termed this anomalous poor learning “over-specificity” (OS) to reflect the narrowness of the learning and the failure to generalize, and quantified OS as the average threshold difference between the second and the first learning curves (for generalization OS < 0; specificity, OS = 0; over-specificity, OS > 0).…”

“…Mercado and coauthors (Mercado et al, 2016) have claimed that our results showing OS of learning in individuals with ASD, when using the standard training method (Harris et al, 2015), is explained by the higher initial thresholds of the ASD group relative to the other groups (standard typically developing controls (labeled TD); dummy ASD and dummy TD; Figure 2 in Harris et al (2015). To evaluate the validity of this claim, here, we analyzed the dependence of OS on the initial threshold (measured on day 1), using measurements derived from each participant individually.…”

“…In a recent study, we tested perceptual learning in adults with autism spectrum disorder (ASD) (Harris et al, 2015), employing the standard and well-established texture-learning paradigm [TDT; (Karni and Sagi, 1991; Sagi, 1995; Harris et al, 2012)]. In this paradigm, observers learn to discriminate an oriented texture target embedded at a fixed location in a background of elements having a different orientation.…”

“…We termed this anomalous poor learning “over-specificity” (OS) to reflect the narrowness of the learning and the failure to generalize, and quantified OS as the average threshold difference between the second and the first learning curves (for generalization OS < 0; specificity, OS = 0; over-specificity, OS > 0). A modified learning paradigm, where standard target trials were interleaved with no-target trials (“dummy” trials) during training, showed generalization of learning (OS < 0) across trained target locations, that is, non-specific, and generalizable learning, in both typical and ASD groups (Harris et al, 2015). When this newly defined OS measure is applied to previous studies with the experimental paradigm discussed here (Harris et al, 2012), and with other perceptual learning paradigms (Sagi, 2011), the results show mostly negative values, indicating some transfer of learning to the untrained stimulus.…”

Beyond Autism: Introducing the Dialectical Misattunement Hypothesis and a Bayesian Account of Intersubjectivity

“…Finally, it was considered that a different learning style, namely one resembling overfitting in machine learning, and differences in adaptation can also be explained by this hypothesis [cf. [64]].…”