When does object familiarity lead to a task advantage?

Poster Presentation: Tuesday, May 21, 2024, 8:30 am – 12:30 pm, Banyan Breezeway
Session: Plasticity and Learning: Properties

JHILIK DAS1 (), SP Arun1; 1Indian Institute of Science

While it is well known that humans quickly become familiar with items that are repeatedly viewed, it is unclear whether this familiarity confers any task advantage. With extreme familiarity, such as in the case of reading, readers discriminate between letters of their own scripts better than those of unknown scripts. However, it is unclear at what time scales such effects develop, and whether these effects are dependent on the nature of experience with letters. Here, we investigated whether short-term familiarity with novel shapes can lead to improved shape discrimination. We performed five experiments. In each experiment, we trained two groups of naïve participants on letters or bigrams of two novel scripts. We also conducted familiarity tests with varying difficulty, at various time points, to assess their familiarity to the viewed items. All participants were highly accurate on the familiarity test (with even as few as 100 exposures), even when they had to identify a familiar letter compared to a slight modification of the letter, and even when tested two months after training. Thus, familiarity was quick, robust, and long-lasting. However, does this familiarization produce a task advantage? In Experiments 1 & 2, participants discriminated familiar letters faster only on hard trials of a visual search task. By contrast, in Experiments 3 & 4, when letters were dissimilar to each other, familiarizing them did not produce such a task advantage. In Experiment 5, when we created hard visual search trials by embedding familiarized letters against slightly modified distractors, participants were more accurate on familiar compared to unfamiliar letters both in a visual search task as well as a same-different task. Taken together, our results show that, while the effects of familiarity are fast and robust, this familiarity leads to a task advantage only for highly similar shapes.

Acknowledgements: This research was funded through a Senior Fellowship from the DBT-Wellcome India Alliance (Grant # IA/S/17/1/503081) and the DBT-IISc partnership programme (both to SPA).