Delayed Match Retrieval: a novel anticipation‐based visual working memory paradigm

Abstract

We tested 8- and 10-month-old infants’ Visual Working Memory (VWM) for object-location bindings — what is where — with a novel paradigm, Delayed Match Retrieval, that measured infants’ anticipatory gaze responses (using a Tobii T120 eye tracker). In an inversion of Delayed-Match-to-Sample tasks and with inspiration from the game Memory, in test trials, three face-down virtual ‘cards’ were presented. Two flipped over sequentially (revealing, e.g., a swirl pattern and then a star), and then flipped back face-down. Next, the third card was flipped to reveal a match (e.g. a star) to one of the previously seen, now-face-down cards. If infants looked to the location where the (now face-down) matching card had been shown, this was coded as a correct response. To encourage anticipatory looks, infants subsequently received a reward (a brief, engaging animation) presented at that location. 10-month-old infants performed significantly above chance, showing that their VWM could hold object-location information for the two cards. Overall, 8-month-olds’ performance was at chance, but they showed a robust learning trend. These results corroborate previous findings (Kaldy & Leslie, 2005; Oakes, Ross-Sheehy, & Luck, 2006) and point to rapid development of VWM for object-location bindings. However, compared to previous paradigms that measure passive gaze responses to novelty, this paradigm presents a more challenging, ecologically relevant test of VWM, as it measures the ability to make online predictions and actively localize objects based on VWM. As well, this paradigm can be readily scaled-up to test toddlers or older children without significant modification.

Infants’ representations of same and different in match- and non-match-to-sample

“…Following Kaldy et al (2015), infants were shown a series of animated videos on the screen of an eye-tracker, each consisting of three cards with various pictures on them. The left and right cards always had different pictures on them, while the middle card (the sample) displayed the same picture as one of the other cards.…”

“…First, although separate studies have found that 10-month-old infants can succeed at MTS with 2 pairs of stimuli (Kaldy et al, 2015) and at delayed NMTS generalizing to novel stimuli (Diamond, 2006), these studies used very different paradigms from one another. We tested infants on both MTS and NMTS, allowing us to compare performance on the two rules.…”

“…We asked both whether infants improved as the experiment progressed, to account for any baseline preferences, and whether they eventually performed better than chance. The 12-trial block size was chosen in advance based on previous infant and animal MTS studies (e.g., Giurfa et al, 2001; Kaldy et al, 2015). …”

“…In this paradigm, like in Kaldy and colleagues’ (2015), participants see a small number of pairs of stimuli (so they certainly could be learning specific associative rules), and are trained to select either specific matching stimuli, or specific non-matching oddity stimuli. For example, in a 1-pair match/oddity task with stimuli A and B, the rules in the Match condition would be: if A, pick A , and if B, pick B.…”

“…A recent study by Kaldy, Guillory and Blaser (2015) provides initial evidence that infants might indeed succeed on MTS much younger than 3 years of age in such a paradigm. Inspired by the card game Memory, their Delayed Match Retrieval paradigm involves a series of videos where three cards are presented.…”