Abstract
Previous research suggests that intentional encoding instructions may lead to improved performance on recognition memory tests via generic-attentional mechanisms rather than encoding-specific mechanisms (Varakin & Hale, 2014, SageOpen). Since attention is limited in capacity, the benefits of intentional encoding instructions should be too. The current experiment was designed to test for such capacity limits. During a study phase, participants (N = 472) were shown a series of objects from different categories (e.g. birds, cars, chairs, etc.), displayed one at a time at the center of a computer display. Participants were instructed to perform one of two tasks: memorizing the appearance of certain categories, or keeping a running count of certain categories. To examine capacity limits, the number of categories relevant to the task was 1, 3, or 5. On a subsequent yes/no recognition test, participants were presented with objects from two categories, one that was relevant during study and one that was irrelevant during study. Two findings reinforce the idea that intentional encoding instructions operate via generic attentional mechanisms. First, the effect of task (memorize vs. count) was not significant, despite the large sample size. Second, the interaction between the number of relevant categories during study, and object relevance at test was significant (p < .01). Participants who memorized/counted either 1 or 3 object categories were better at recognizing previously task-relevant objects than task-irrelevant objects. However, when 5 object categories were relevant at study, there was no effect of task relevance at test. This result is consistent with the idea that the limit of attentional selection is about 3 or 4 (Cowan, 2000, Behavioral and Brain Sciences), as the benefits of task-relevance diminished when participants were asked to count or memorize 5 object categories.
Meeting abstract presented at VSS 2018