The evidence concerning the level at which learned CP effects occur is complex. The goal of this study was to use a different approach to this question by manipulating the abstractness of the information available for distinguishing pairs of items in an XAB task, and the presence or absence of a short task-filled delay between X and AB. Participants engaged in XAB trials containing a mixture of trials with and without the delay task before and after standard training to classify visual texture stimuli into two categories. Training improved discrimination of pairs differing on the category-relevant dimension whether within- or betweencategory, but not on pairs differing only on non-category relevant low level features. In addition, only successful learners in the post-training trials avoided decreased discrimination accuracy due to the delay task, suggesting that they formed more stable representations. However, this effect was not limited to pairs varying in category-relevant ways.

We present evidence that successful chunk formation during a statistical learning task depends on how well the perceiver is able to parse the information that is presented between successive presentations of the to-be-learned chunk. First, we show that learners acquire a chunk better when the surrounding information is also chunk-able in a visual statistical learning task. We tested three process models of chunk formation, TRACX, PARSER, and MDLChunker, on our two different experimental conditions, and found that only PARSER and MDLChunker matched the observed result. These two models share the common principle of a memory capacity that is expanded as a result of learning. Though implemented in very different ways, both models effectively remember more individual items (the atomic components of a sequence) as additional chunks are formed. The ability to remember more information directly impacts learning in the models, suggesting that there is a positive-feedback loop in chunk learning.

A preliminary meta-analysis using the p-curve method(Simonsohn, Nelson, & Simmons, 2014) was performed on asubset of the learned categorical perception literature toexplore the robustness of the phenomenon. Only studies usingnovel visual categories and behavioral measures wereincluded. The results strongly suggest that the phenomenon isrobust but that the studies are somewhat underpowered. Weargue that this is problematic because it renders bothstatistically significant and nonsignificant results verydifficult to interpret, which impedes progress inunderstanding the learned CP phenomenon, for example, whyexpansion vs. compression is observed, or boundary vs.dimensional effects. Fortunately, there is a clear solution:conduct studies with greater statistical power.

A novel experimental method is motivated and applied in aneffort to test for effects of category learning on perceptualdiscrimination so as to clearly distinguish category boundaryeffects of expansion and compression from changes insensitivity to stimulus dimensions. The method includes acontrol group performing a task that, like category learning,requires attention to one systematically varying stimulusdimension rather than another. Discrimination accuracy istracked over time and measured using a psychophysicalstaircase procedure tailored to individual participants thatdoesn’t rely on memory. Initial results suggest improvementin discrimination accuracy over time, particularly on thedimension relevant to the categorization or control task, butno evidence of category boundary effects or effects ofcategory learning on dimension perception stronger than thoseof the control task. Possible reasons for this and directions forfurther research are briefly discussed .

This full-day workshop focuses on Massive Online Experiments (MOEs). MOEs have transformative potential, as they effectively allow researchers to run hundreds of experiments simultaneously (cf. Hartshorne & Germine, 2015; Reinecke & Gajos, 2014). The goal of the workshop is to help a broad cross-section of cognitive scientists begin to incorporate MOEs into their research.

Study sequence can have a profound impact on learning. Previous research has often shown advantages for interleaved over blocked study, though the reverse has also been found. Learners typically prefer blocking even in situations for which interleaving is superior. The present study investigated learner regulation of study sequence, and its effects on learning in an ecologically valid context – university students using an online tutorial relevant to an exam that counted toward their course grades. The majority of participants blocked study by problem category, and this tendency was positively associated with subsequent exam performance. The results suggest that preference for blocked study may be adaptive under some circumstances, and highlight the importance of identifying task environments under which different study sequences are most effective.