Visual statistical learning in children and young adults: how implicit?

Abstract

Visual statistical learning (VSL) is the ability to extract the joint and conditional probabilities of shapes co-occurring during passive viewing of complex visual configurations. Evidence indicates that even infants are sensitive to these regularities (e.g., Kirkham et al., 2002). However, there is continuing debate as to whether VSL is accompanied by conscious awareness of the statistical regularities between sequence elements. Bertels et al. (2012) addressed this question in young adults. Here, we adapted their paradigm to investigate VSL and conscious awareness in children. Using the same version of the paradigm, we also tested young adults so as to directly compare results from both age groups. Fifth graders and undergraduates were exposed to a stream of visual shapes arranged in triplets. Learning of these sequences was then assessed using both direct and indirect measures. In order to assess the extent to which learning occurred explicitly, we also measured confidence through subjective measures in the direct task (i.e., binary confidence judgments). Results revealed that both children and young adults learned the statistical regularities between shapes. In both age groups, participants who performed above chance in the completion task had conscious access to their knowledge. Nevertheless, although adults performed above chance even when they claimed to guess, there was no evidence of implicit knowledge in children. These results suggest that the role of implicit and explicit influences in VSL may follow a developmental trajectory.

Investigating implicit statistical learning mechanisms through contextual cueing

“…In this respect, recent findings provide interesting insights. The use of both subjective and objective criteria of awareness suggests that participants are, at least in part, aware of their knowledge in visual SL [106,117]. Congruently, the MTL is not only involved but also required for such SL [46].…”

Measuring individual differences in statistical learning: Current pitfalls and possible solutions

“…In recent years this popular task was borrowed with little modifications to serve as an individual measure of one’s visual SL ability, mainly to predict other cognitive functions such L1 literacy (Arciuli & Simpson, 2012), L2 literacy (Frost et al, 2013), implicit RT-based measures (Bertels et al, 2012, 2014), auditory SL abilities (Siegelman & Frost, 2015), etc. Given these objectives, we will now consider this task from a psychometric perspective, and outline its critical shortcomings for studying individual differences.…”

“…The test phase in most existing SL tasks includes a few dozen 2AFC trials (but see, for example, Bertels et al, 2012, 2014, for a test with 4AFC trials only), each contrasting a “real” triplet from the learning phase (TPs of shapes typically set to 1.0), and a foil (TPs of shapes typically set to 0.0). Thus, the test phase comprises multiple items measuring the same type of knowledge, with the same level of difficulty.…”

“…A second approach to the study of individual differences stems from the assumption that understanding the source of individual differences in SL holds the promise of revealing critical insight regarding the cognitive operations underlying its mechanisms, leading to deeper comprehension of what SL capacity could predict and why (see Frost, Armstrong, Siegelman, & Christiansen, 2015, for a theoretical discussion). For example, researchers have recently investigated individual performance in SL to examine the role of explicit versus implicit knowledge in SL (Batterink, Reber, Neville, & Paller, 2015; Bertels, Boursain, Destrebecqz, & Gaillard, 2014; Bertels, Franco, & Destrebecqz, 2012; Kim, Seitz, Feenstra, & Shams, 2009), the relation between different types of computations in SL (Romberg & Saffran, 2013), the impact of input modality (Siegelman & Frost, 2015), and also to pinpoint the neurocircuitry involved in detection of regularities (Karuza et al, 2013; Turk-Browne, Scholl, Chun, & Johnson, 2009). …”

“…Although these studies have targeted individual differences as their main interest, they all employed the original tasks which were designed for group-level explorations with little to no modifications (but see Bertels et al, 2014, 2012, for task modification). Note that this same trend is revealed across other types of implicit learning paradigms, so that the tasks designed to show learning at the group level are used to probe individual capacities (i.e., AGL, Conway et al, 2010; Serial Reaction Time (SRT) task, Kaufman et al, 2010; Hebb repetition learning, Mosse & Jarrold, 2008).…”