The effect of delayed responding on Stroop-like task performance among preschoolers

Why are some inhibitory tasks easy for preschool children when most are difficult? Testing two hypotheses

Understanding the processes that create inhibitory demands is central to understanding the role of inhibitory control in all aspects of development. The processes that create inhibitory demands on most developmental tasks seem clear and well understood. However, there is one inhibitory task that appears substantially easier than the others: the Reverse Categorization task, in which children are asked to "reverse sort" items (e.g., put large items in a small box and put small items in a large box). This finding is both surprising and problematic because it cannot be explained by any existing account of inhibitory development. Four experiments with 3- and 4-year-olds sought to explain why the Reverse Categorization task is easy. Two experiments (N = 64) investigated the hypothesis that children conceptualize the task in a way that reduces its inhibitory demands; and two experiments (N = 56) tested the hypothesis that the task is easier because children sort items slowly. The data indicate that children spontaneously respond more slowly on the Reverse Categorization task than on other inhibitory tasks and that this slowing reduces the task's cognitive demands. The way in which slowed responding works, and its relation to other inhibition-reducing interventions, is discussed.

Can We Boost Preschoolers' Inhibitory Performance Just by Changing the Way They Respond?

Changing the way children make their response appears to sometimes, but not always, boost their inhibitory control-though interpreting existing findings is hampered by inconsistent methods and results. This study investigated the effects of delaying, and changing, the means of responding. Ninety-six preschoolers (M_age 46 months) completed tasks assessing inhibitory control, counterfactual reasoning, strategic reasoning, and false belief understanding. Children responded either immediately or after a delay, and either by pointing with their finger, or with a hand-held arrow. Delaying boosted performance on all tasks except false belief understanding; arrow-pointing only improved strategic reasoning. It is suggested that delay helps children work out the correct response; it is unlikely to help on tasks where this requirement is absent.

Early Executive Function: The Influence of Culture and Bilingualism

Evidence suggests that cultural experiences and learning multiple languages have measurable effects on children's cognitive development (EF). However, the precise impact of how bilingualism and culture contribute to observed effects remains inconclusive. The present study aims to investigate how these factors shape the development of early EF constructs longitudinally, between monolingual and bilingual children at ages 3, 3 ½ and 4 years, with a set of EF tasks that are uniquely relevant to the effects of bilingualism and cultural practices. We hypothesize that the effects of bilingualism and cultural backgrounds (i.e., Eastern) are based on different, though related, cognitive control processes associated with different EF constructs. Results revealed a significant bilingualism effect on cognitive control processes measuring selective attention, switching, and inhibition; while an effect of culture was most pronounced on behavioral regulation/response inhibition. Contributions of bilingualism and cultural experiences on individual EF constructs across development are discussed.

Conflict processing in kindergarten children: New evidence from distribution analyses reveals the dynamics of incorrect response activation and suppression

The development of cognitive control is known to follow a long and protracted development. However, whether the interference effect in conflict tasks in children would entail the same core processes as in adults, namely an automatic activation of incorrect response and its subsequent suppression, remains an open question. We applied distributional analyses to reaction times and accuracy of 5- and 6-year-old children performing three conflict tasks (flanker, Simon, and Stroop) in a within-participants design. This revealed both strong commonalities and differences between children and adults. As in adults, fast responses were more error prone than slow ones on incompatible trials, indicating a fast "automatic" activation of the incorrect response. In addition, the strength of this activation differed across tasks, following a pattern similar to that of adults. Moreover, modeling the data with a drift diffusion model adapted for conflict tasks allowed one to better assess the origin of the typical slowing down observed in children. Besides showing that advanced distribution analyses can be successfully applied to children, the current results support the notion that interference effects in 5- and 6-year-olds are driven by mechanisms very similar to the ones at play in adults but with different time courses.

Decision-making under risk of gain in young children and mangabey monkeys

In contrast to human adults, risk proneness in the gain domain is usually observed in both young children and non-human primates. It is currently unclear what mechanism might be underlying such economic preferences. We investigated decision-making under risk of gain in toddlers and monkeys. The choices of 2.5-year-old children and red-capped mangabeys (Cercocebus torquatus torquatus) were examined in a gambling task for food reward in which participants have to choose between two options, a secure option and a risky option. In contrast to monkeys, toddlers showed a strong preference for the risky option over the safe option. In order to test the hypothesis that risky choices in participants reflect inhibitory control difficulties, toddlers and mangabeys were presented in Experiment 2 with a situation analogous to that used in Experiment 1 except for the fact that the opaque cover under which was placed the secure option was replaced by a transparent cover. In this second experiment, toddlers continued to show a preference for the risky option over the safe option. In contrast, mangabeys showed a preference for the safe option over the risky option in Trial 1 but they shifted their economic preferences in Trial 2. We argue that decision-making strategies under risk of gain in both toddlers and mangabeys (a) do not reflect poor behavioral control and (b) are not reducible to perception-action couplings.

Explicit and Implicit Verbal Response Inhibition in Preschool-Age Children Who Stutter

PURPOSE

The purpose of this study was to examine (a) explicit and implicit verbal response inhibition in preschool children who do stutter (CWS) and do not stutter (CWNS) and (b) the relationship between response inhibition and language skills.

METHOD

Participants were 41 CWS and 41 CWNS between the ages of 3;1 and 6;1 (years;months). Explicit verbal response inhibition was measured using a computerized version of the grass-snow task (Carlson & Moses, 2001), and implicit verbal response inhibition was measured using the baa-meow task. Main dependent variables were reaction time and accuracy.

RESULTS

The CWS were significantly less accurate than the CWNS on the implicit task, but not the explicit task. The CWS also exhibited slower reaction times than the CWNS on both tasks. Between-group differences in performance could not be attributed to working memory demands. Overall, children's performance on the inhibition tasks corresponded with parents' perceptions of their children's inhibition skills in daily life.

CONCLUSIONS

CWS are less effective and efficient than CWNS in suppressing a dominant response while executing a conflicting response in the verbal domain.

Do children need reminders on the Day-Night task, or simply some way to prevent them from responding too quickly?

We previously reported better performance on the Day-Night task when a ditty was chanted between stimulus presentation and when children could respond (Diamond, Kirkham, & Amso, 2002). Here we investigated competing hypotheses about why the ditty helps. Does it help because it imposes a brief waiting time (the child waits while the ditty is chanted before responding)? Or, does the ditty help because of its content, providing information helpful to performing the task? One-third of the 72 children (age 4) were tested with the ditty previously used which reminds them: "Think about the answer; don't tell me." Another 24 children were tested with a ditty with no task-relevant content: "I hope you have a nice time; I like you." One-third received the standard condition. Performance in both ditty conditions was comparable and better than in the standard condition. That indicates that a factor common to both ditties (that chanting them took time, allowing the prepotent response to subside and the more-considered answer to reach response threshold) likely accounts for their benefit. Whether a ditty reminded children what to do or not did not affect the results. The challenge of the Day-Night task for preschoolers is not its working memory demands but the need to inhibit a dominant response, making a different response instead.