Memory constraints on infants’ cross-situational statistical learning

Abstract

Infants are able to map linguistic labels to referents in the world by tracking co-occurrence probabilities across learning events, a behavior often termed cross-situational statistical learning. This study builds upon existing research by examining infants’ developing ability to aggregate and retrieve word-referent pairings over time. 16- and 20-month-old infants (N = 32) were presented with a cross-situational statistical learning task in which half of the object-label pairings were presented in immediate succession (massed) and half were distributed across time (interleaved). Results revealed striking developmental differences in word mapping performance; infants in both age groups were able to learn pairings presented in immediate succession, but only 20-month-old infants were able to correctly infer pairings distributed over time. This work reveals significant constraints on infants’ ability to aggregate and retrieve object-label pairings across time and challenges theories of cross-situational statistical learning that rest on retrieval processes as successful and automatic.

Finding meaning in a noisy world: exploring the effects of referential ambiguity and competition on 2·5-year-olds’ cross-situational word learning

“…In the dining room example described above, the child is confronted with dozens of potential referents for a new word. In contrast, in prior experiments, a novel word was accompanied by a maximum of two candidate object-or event-referents in each trial (e.g., Smith & Yu, 2008;Scott & Fisher, 2012;Vlach & Johnson, 2013). These simple test scenes may have been critical to children's success: recent evidence suggests that as the number of potential referents in a scene increases, even adults have difficulty using cross-situational information to identify the referents of words (e.g., Medina, Snedeker, Trueswell & Gleitman, 2011;Smith et al, 2011).…”

“…In addition, these four observations of the novel noun occurred without any other novel words interleaved between them. Recent evidence suggests that both children and adults have greater difficulty aggregating cross-situational information across observations of a given word when those observations are interleaved with observations of other novel words (e.g., Smith et al, 2011;Vlach & Johnson, 2013), in part because of the greater memory burden imposed by encoding, retrieving, and comparing multiple sets of candidate referents. The fact that children in the long-competition condition failed even with consecutive observations that occurred close together in time indicates that the burden imposed by the high-probability competitor referents was substantial.…”

“…In addition to presenting a limited number of potential referents, many prior crosssituational learning studies also involved exhaustive labeling: children encountered two potential referents on each trial and both of these referents were labeled with a novel word (e.g., Scott & Fisher, 2012;Smith & Yu, 2008;Suanda, Mugwanya, & Namy, 2014;Vlach & Johnson, 2013;Yu & Smith, 2011). Labeling both of the candidate referents present on each trial might have further reduced the referential ambiguity of the task in several ways.…”

“…Given that younger learners' less-developed memory capacities constrain their ability to encode, retrieve, and aggregate information about potential referents across observations (e.g., Vlach & Johnson, 2013), it is likely their cross-situational learning would be more easily disrupted by the presence of a high-probability competitor. Moreover, the order of learning observations might be especially important for younger children: if they repeatedly encounter the word with both the target and high-probability competitor, then they might be unable to identify the correct referent when they eventually encounter it in the absence of the competitor.…”

A communicative approach to early word learning

“…While infants demonstrate sensitivity to the co-occurrence information between words and objects, their memory for this information is quite fragile even under low levels of ambiguity (Vlach & Johnson, 2013;Vouloumanos & Werker, 2009). Even for adults, this process of statistical inference appears to be highly constrained 90 by limits on memory and attention (Smith et al, 2011;Trueswell et al, 2013;Yurovsky & Frank, 2015).…”