Age-related differentiation in verbal and visuospatial working memory processing in childhood.

Working memory (WM), a key feature of the cognitive system, allows for maintaining and processing information simultaneously and in a controlled manner. WM processing continuously develops across childhood, with significant increases both in verbal and visuospatial WM. Verbal and visuospatial WM may show different developmental trajectories, as verbal (but not visuospatial) WM relies on internal verbal rehearsal, which is less developed in younger children. We examined complex VWM and VSWM performance in 125 younger (age 4-6 years) and 101 older (age 8-10 years) children. Latent multi-group modeling showed that (1) older children performed better on both verbal and visuospatial WM span tasks than younger children, (2) both age groups performed better on verbal than visuospatial WM, and (3) a model with two factors representing verbal and visuospatial WM fit the data better than a one-factor model. Importantly, the correlation between the two factors was significantly higher in younger than in older children, suggesting an age-related differentiation of verbal and spatial WM processing in middle childhood. Age-related differentiation is an important characteristic of cognitive functioning and thus the findings contribute to our general understanding of WM processing.

14-Month-olds anticipate others' actions based on their belief about an object's identity.

Past research has accumulated evidence regarding infants' false-belief understanding, measuring their gaze patterns or active helping behaviors. However, the underlying mechanisms are still debated, specifically, whether young infants can compute that others represent the world under a certain aspect. Such performance requires holding in mind two representations about the same object simultaneously and attributing only one to another person. While 14-month-olds can encode an object under different aspects when forming first-person representations, it is unclear whether infants at this very age could also predict others' behavior based on their beliefs about an object's identity. Here, we investigate this question in a novel eye-tracking-based unexpected-identity task. We measured 14-month-olds' anticipatory looks combined with their looking time, using a violation-of-expectation paradigm. Results show that 14-month-olds look longer to an actor's reach that is incongruent with her false belief about the identity of an object compared to a congruent reach. Furthermore, infants correctly anticipated the actor's reach based on her false belief. Thus, as soon as infants represent dual identities they can integrate them in belief attributions and use them for consequent behavioral predictions. Such data provide evidence for the flexibility of false-belief attributions and support proposals arguing for infants' rich theory-of-mind abilities.

The effects of verbal and spatial memory load on children's processing speed.

Examining the impact of maintenance on processing speed allows us to test whether storage and processing resources are shared. Comparing these relationships in children of different ages allows further insight into whether one or multiple resources for these operations must be assumed and whether remembering is proactive throughout childhood. We tested 185 4- to 6- and 8- to 10-year-old children using adaptive complex span tasks, in which simple judgments were interleaved between to-be-remembered items. The adaptiveness of our tasks ensured that all participants frequently correctly recalled the items. If storage and processing require a single resource, and if participants serially reactivate the memoranda between processing episodes, processing response times should increase with serial position of the processing judgment within lists. We observed different within-list dynamics for each age group. Older children's processing judgments slowed gradually when more than two memory items were maintained. By contrast, younger children showed no evidence of slower processing with increasing memory load. Our results support models of working memory that assume that some common resource is responsible for verbal and spatial storage and processing. They also support the notion that remembering becomes more proactive as children mature.

Development and Plasticity of Cognitive Flexibility in Early and Middle Childhood.

Cognitive flexibility, the ability to flexibly switch between tasks, is a core dimension of executive functions (EFs) allowing to control actions and to adapt flexibly to changing environments. It supports the management of multiple tasks, the development of novel, adaptive behavior and is associated with various life outcomes. Cognitive flexibility develops rapidly in preschool and continuously increases well into adolescence, mirroring the growth of neural networks involving the prefrontal cortex. Over the past decade, there has been increasing interest in interventions designed to improve cognitive flexibility in children in order to support the many developmental outcomes associated with cognitive flexibility. This article provides a brief review of the development and plasticity of cognitive flexibility across early and middle childhood (i.e., from preschool to elementary school age). Focusing on interventions designed to improve cognitive flexibility in typically developing children, we report evidence for significant training and transfer effects while acknowledging that current findings on transfer are heterogeneous. Finally, we introduce metacognitive training as a promising new approach to promote cognitive flexibility and to support transfer of training.

Great apes distinguish true from false beliefs in an interactive helping task.

Understanding the behavior of others in a wide variety of circumstances requires an understanding of their psychological states. Humans' nearest primate relatives, the great apes, understand many psychological states of others, for example, perceptions, goals, and desires. However, so far there is little evidence that they possess the key marker of advanced human social cognition: an understanding of false beliefs. Here we demonstrate that in a nonverbal (implicit) false-belief test which is passed by human 1-year-old infants, great apes as a group, including chimpanzees (Pan troglodytes), bonobos (Pan paniscus), and orangutans (Pongo abelii), distinguish between true and false beliefs in their helping behavior. Great apes thus may possess at least some basic understanding that an agent's actions are based on her beliefs about reality. Hence, such understanding might not be the exclusive province of the human species.

The influence of a bystander agent's beliefs on children's and adults' decision-making process.

The ability to attribute and represent others' mental states (e.g., beliefs; so-called "theory of mind") is essential for participation in human social interaction. Despite a considerable body of research using tasks in which protagonists in the participants' attentional focus held false or true beliefs, the question of automatic belief attribution to bystander agents has received little attention. In the current study, we presented adults and 6-year-olds (N=92) with an implicit computer-based avoidance false-belief task in which participants were asked to place an object into one of three boxes. While doing so, we manipulated the beliefs of an irrelevant human-like or non-human-like bystander agent who was visible on the screen. Importantly, the bystander agent's beliefs were irrelevant for solving the task. Still, children's decision making was significantly influenced by the bystander agent's beliefs even if this was a non-human-like self-propelled object. Such an influence did not become obvious in adults' deliberate decisions but occurred only in their reaction times, which suggests that they also processed the bystander agent's beliefs but were able to suppress the influence of such beliefs on their behavior regulation. The results of a control study (N=53) ruled out low-level explanations and confirmed that self-propelledness of agents is a necessary factor for belief attribution to occur. Thus, not only do humans spontaneously ascribe beliefs to self-propelled bystander agents, but those beliefs even influence meaningful decisions in children.

What you get is what you believe: eighteen-month-olds demonstrate belief understanding in an unexpected-identity task.

Based on recent findings of implicit studies, researchers have claimed that even infants can understand others' false beliefs. However, it is unclear whether infants are able to understand others' belief about an object's identity when this object can be represented in different ways. In a novel interactive unexpected-identity task derived from the appearance-reality paradigm, 18-month-olds helped an adult to achieve her goal based on the adult's belief about an object's identity. To do so, they needed to understand how this adult represented this object--according to its appearance or its real identity--and to generalize these representations to a category of objects. The results suggest that infants' false-belief understanding is as sophisticated as that of preschool children.