Poster #7 - Overt Attention Enhances Visual Short-Term Memory Performance during Early Infancy

• In Event: 3-206 - Poster Session 13
  In Poster Session: PS 13 Section - Attention, Learning, Memory

Integrative Statement

Studies employing change detection tasks to measure infants’ ability to rapidly encode items in visual short-term memory (VSTM) reveal developmental changes during the first postnatal year. Infants 8 months and older detect changes in arrays containing multiple items, whereas infants 6 months and younger seem to only encode information when presented with arrays containing a single isolated item. Ross-Sheehy et al. (2011) showed that young infants’ limitation in change detection can be overcome by making one item in the array highly salient by rotating it. In this case, infants seemed to focus only on the rotating item, detecting when it changed.

We asked here if 6-month-old infants remember any overtly attended item in a change-detection task. That is, young infants’ failure to detect changes may reflect difficulty in selecting and attending to individual items in multiple-item arrays rather than an inability to encode information in VSTM. To assess this, we collected eye-tracking data while infants participated in two one-shot change detection tasks. In these tasks, infants are first presented with a brief sample array containing two differently colored items (500 ms); next, the screen is blank for a brief retention period (300 ms); finally, the two items reappear for 2000 ms for a test period in which one item has changed color and the other item has not (see Figure 1). If infants encode the color of the items in the sample array, they should prefer (i.e., look longer at) the novel color during test, a pattern shown by 8-month-old infants but not 6-month-old infants (Oakes et al., 2013).

We used cluster-based permutation analysis to assess infants’ moment-to-moment looking behavior to determine 1) what item infants overtly attended to during the sample period and 2) how infants’ looking towards that item differed during the test period as a function of whether it changed or remained the same color from sample to test. In both experiments, all items were the same shape on each trial, differing only in color. Thus, infants could only use color to individuate the items, which may make it difficult for them to select and attend to only one item. In Experiment 1 (N = 20) all items were squares on all trials and in Experiment 2 (N = 25) the shapes varied from trial to trial (e.g., triangles on trial 1, circles on trial 2). We defined infants’ attention to an item as overt if they looked longer at that item than the other item and if they looked at it for at least 100 ms during the sample and delay periods. Our results indicate that when infants’ overt attention was directed towards an item, they appeared to remember it, looking at changed items but not unchanged items more than expected by chance across both Experiments (see Figure 2). Together, these findings indicate that young infants’ difficulty in detecting changes in multiple-item arrays may reflect difficulty in selecting and attending to individual items.

Authors

• Aaron G Beckner, UC Davis Center for Mind and Brain
  Presenting Author

• Lisa Cantrell, California State University, Sacramento
  Non-Presenting Author

• Lisa Oakes, University of California, Davis
  Non-Presenting Author