Integrating Novel Dimensions to Eliminate Category Exceptions: When More Is Less

Learning-induced changes in attentional allocation during categorization: a sizable catalog of attention change as measured by eye movements

Learning how to allocate attention properly is essential for success at many categorization tasks. Advances in our understanding of learned attention are stymied by a chicken-and-egg problem: there are no theoretical accounts of learned attention that predict patterns of eye movements, making data collection difficult to justify, and there are not enough datasets to support the development of a rich theory of learned attention. The present work addresses this by reporting five measures relating to the overt allocation of attention across 10 category learning experiments: accuracy, probability of fixating irrelevant information, number of fixations to category features, the amount of change in the allocation of attention (using a new measure called Time Proportion Shift - TIPS), and a measure of the relationship between attention change and erroneous responses. Using these measures, the data suggest that eye-movements are not substantially connected to error in most cases and that aggregate trial-by-trial attention change is generally stable across a number of changing task variables. The data presented here provide a target for computational models that aim to account for changes in overt attentional behaviors across learning.

The importance of differentiation in young children's acquisition of expertise

In a short-term longitudinal study, stories told about novel creatures conveyed information varying in its capability for differentiating. Depending on the context, a bodily feature could be functionally undifferentiated (FUF), meaning that its subtypes (e.g., eyes of two forms) shared a generic function ("seeing"), or functionally differentiated (FDF), meaning that each subtype's function was unique to it (e.g., only a "hooded eye" could "see in a sandstorm"). 5- to 6-year-olds who heard 8 stories, but not those who heard only 4, cited FDFs more than FUFs in a pair-justification test of judged similarity; and their delayed recall of specific story events was greater when FDFs rather than FUFs were involved. In the absence of direct instruction, young children show sensitivity to the degree of differentiation afforded by feature-function relations.