Memory Dynamics in Cross-Situational Statistical Learning

A central pursuit in cognitive science and developmental psychology has been to characterize how humans encode a seemingly infinite amount of information, interpret this information, and use the information at later points in time. For example, in the domain of language learning and development, researchers have long sought to determine how infants and adults are able to determine word-referent pairings, despite the infinite number of possibilities (Quine, 1960). More recent research has suggested that learners are able to determine word-referent pairings by tracking co-occurrence probabilities across time, a behavior commonly termed cross-situational statistical learning. The current series of experiments built upon research on cross-situational statistical learning by examining learning over varying timescales, from a matter of seconds to up to one week. In particular, this work examined the mechanisms underlying learning that promoted and/or deterred the learning and long-term retention of cross-situational statistics. Experiments 1 - 3 presented adult learners with a cross-situational learning task and then presented learners with a forced-choice inference test immediately or one week later. Experiments 2-3 examined how retrieval dynamics, the ease and/or difficulty of retrieving information while learning, was related to long-term retention and inference performance. Experiment 4 presented infant learners with a cross-situational learning task that manipulated the timing at which word-referent pairings were presented, requiring infants to retrieve prior potential pairings from long-term memory. The results of the these studies indicate that adult learners are able to retain cross-situational statistics for up to one week later and that the amount of retention is related to ease and/or difficulty of retrieval during the learning process. However, young infants demonstrated constraints on their ability to retrieve information over short timescales, indicating that memory development in retrieval abilities may be critical to acquiring word-referent pairings. This work challenges broad theories of cognition and development that rest on retrieval processes as successful and automatic. Indeed, retrieving the past is a dynamic process, which undergoes dramatic developments over the lifespan, and should be incorporated into theoretical and computational accounts of learning