Categorical flexibility in children: Distinguishing response flexibility from conceptual flexibility; the protracted development of taxonomic representations

This research explored the development of children's use of multiple conceptual organizations (thematic, taxonomic) in sorting sets of pictures. Experiment 1 revealed that between 5 and 9 years, two forms of categorical flexibility can be distinguished: response and conceptual flexibility. It appeared that children's multiple sorts do not necessarily reflect the use of different conceptual organizations. Such a lag was mainly due to a difficulty in accessing taxonomic representations, specifically in the younger age groups. Therefore, Experiment 2 investigated the development of taxonomic representations using an original approach requiring participants to decide whether new items could be included into an existing taxonomic sort. This approach showed that taxonomic representations were only gradually differentiated from thematic and perceptual ones over the 5 to 10 years period. The discussion raises new hypotheses about the interaction between developing executive control (specifically, increasing resistance to interference of irrelevant information) and increasing conceptual knowledge in accounting for the development of conceptual flexibility.     

Cortico-subcortical contributions to executive control

The term "executive functions" refers to a range of cognitive processes, their common feature being the coordination of information processing and action control. Cortico-subcortical circuits which connect the prefrontal cortex (PFC), the basal ganglia and the cerebellum via the thalamus are believed to serve as neuroanatomical substrates of executive processing. This paper focuses on information processing related to executive functions by the PFC and related subcortical regions. Findings are mainly derived from neuropsychological investigations of brain-damaged patients but also from imaging studies in healthy subjects. There is evidence for subtle differences between these regions with respect to the cognitive mechanisms contributing to inhibition of habitual responses, task management/multitasking and set shifting, although the data base is sparse so far.     

Relations among conceptual knowledge, procedural knowledge, and procedural flexibility in two samples differing in prior knowledge

Competence in many domains rests on children developing conceptual and procedural knowledge, as well as procedural flexibility. However, research on the developmental relations between these different types of knowledge has yielded unclear results, in part because little attention has been paid to the validity of the measures or to the effects of prior knowledge on the relations. To overcome these problems, we modeled the three constructs in the domain of equation solving as latent factors and tested (a) whether the predictive relations between conceptual and procedural knowledge were bidirectional, (b) whether these interrelations were moderated by prior knowledge, and (c) how both constructs contributed to procedural flexibility. We analyzed data from 2 measurement points each from two samples (Ns = 228 and 304) of middle school students who differed in prior knowledge. Conceptual and procedural knowledge had stable bidirectional relations that were not moderated by prior knowledge. Both kinds of knowledge contributed independently to procedural flexibility. The results demonstrate how changes in complex knowledge structures contribute to competence development.     

Categorical perception of emotional facial expressions in preschoolers

Adults perceive emotional facial expressions categorically. In this study, we explored categorical perception in 3.5-year-olds by creating a morphed continuum of emotional faces and tested preschoolers’ discrimination and identification of them. In the discrimination task, participants indicated whether two examples from the continuum “felt the same” or “felt different.” In the identification task, images were presented individually and participants were asked to label the emotion displayed on the face (e.g., “Does she look happy or sad?”). Results suggest that 3.5-year-olds have the same category boundary as adults. They were more likely to report that the image pairs felt “different” at the image pair that crossed the category boundary. These results suggest that 3.5-year-olds perceive happy and sad emotional facial expressions categorically as adults do. Categorizing emotional expressions is advantageous for children if it allows them to use social information faster and more efficiently.     

Sorting between dimensions: conditions of cognitive flexibility in preschoolers

The Dimensional Change Card Sorting task frequently is used to measure extradimensional shifting abilities in preschool children. In two studies, we investigated what makes this extradimensional shifting task difficult. In Study 1 with 61 2- to 4-year-olds, we showed that extradimensional shifts from one dimension to another are more difficult than reversal shifts within a dimension (even with irrelevant variation on a second dimension). Study 2 with 77 3- and 4-year-olds further confirmed this finding using a computerized paradigm and showed that sorting instructions are critical for 3-year-olds' difficulties with extradimensional shifts. This finding is taken to suggest that 3-year-olds have particular problems with spontaneously classifying one object in two different ways.     

Mood and flexibility in categorization: a conceptual replication

The present study tested the hypothesis that positive mood facilitates cognitive flexibility in categorization, i.e., positive mood enhances the ability to categorize flexibly at broad and narrow levels contingent on task requirement. The study was a conceptual replication of the 1990 work by Murray, Sujan, Hirt, and Sujan. Unlike the original study, it was carried out on the WWW with some modifications in the procedure. Participants were 29 women and 132 men whose average age was 29 yr. They were put into a positive, negative, or neutral mood using the Velten technique. Mood was measured with standard mood scales. Subjects then listed similarities differences between two entertainment TV shows. Contrary to the prediction, participants in a positive mood did not list a higher number, more diverse, or more unusual similarities and differences between the shows, and they were not faster than participants with neutral or negative moods. It is concluded that the influence of mood on cognitive flexibility needs to be reconsidered. In research, temporal aspects of categorization performance as well as a wider range of mood valences should be taken into account.     

Cognitive flexibility in preschoolers: the role of representation activation and maintenance

Preschoolers' lack of cognitive flexibility has often been attributed to perseverative processing. This study investigates alternative potential sources of difficulty such as deficits in activating previously ignored information and in maintaining currently relevant information. In Experiment 1, a new task tapping attentional switching was designed to isolate the difficulty of overriding an initial representation, that is, perseverative processing ('Perseveration' version), and the difficulty of activating a previously ignored representation, that is, activation deficit ('Activation-deficit' version). Three-year-olds' performance suggested that inflexibility may primarily stem from an activation deficit. Control experiments confirmed that the difficulty of the 'Activation-deficit' version could not be attributed to the effect of attraction to novelty. In Experiment 2, 'distraction' errors, alleged to reflect a failure to maintain a relevant representation, and 'perseverative' errors were distinguished. The results highlighted the important role of representation maintenance in flexibility. The present study indicates that preschoolers' lack of cognitive flexibility is multi-determined and prompts us to reconsider the role of perseveration.     

Complementary assessments of executive function in preterm and full-term preschoolers

Executive functions (EFs) are interrelated cognitive processes that have been studied in relation to behavior, attention, academic achievement, and developmental disorders. Studies of EF skills assessed through parent report and performance-based measures show correlations between them ranging from none to modest. Few studies have examined the relationship between EF skills measured through parent report and performance-based measures in relation to adaptive function. The present study included preschool children born preterm as a population at high risk for EF impairments. Preschool children (N = 149) completed a battery of EF tasks that assess working memory, response inhibition, idea generation, and attention shifting or cognitive flexibility. Parents reported on children’s EF and adaptive skills. Preterm children showed more parent-rated and performance-based EF impairments than did full-term children. The combined use of either parent report or performance-based measures resulted in the identification of a large number of children at risk for EF impairment, especially in the preterm group. Both parent report and performance-based EF measures were associated with children’s adaptive function. EF skills are measurable in young child'ren, and we suggest that EF skills may serve as targets for intervention to improve functional outcomes. We recommend the use of both parent report and performance-based measures to characterize children’s EF profiles and to customize treatment.     

ANS acuity and mathematics ability in preschoolers from low‐income homes: contributions of inhibitory control

Recent findings by Libertus, Feigenson, and Halberda (2011) suggest that there is an association between the acuity of young children's approximate number system (ANS) and their mathematics ability before exposure to instruction in formal schooling. The present study examined the generalizability and validity of these findings in a sample of preschoolers from low‐income homes. Children attending Head Start (N = 103) completed measures to assess ANS acuity, mathematics ability, receptive vocabulary, and inhibitory control. Results showed only a weak association between ANS acuity and mathematics ability that was reduced to non‐significance when controlling for a direct measure of receptive vocabulary. Results also revealed that inhibitory control plays an important role in the relation between ANS acuity and mathematics ability. Specifically, ANS acuity accounted for significant variance in mathematics ability over and above receptive vocabulary, but only for ANS acuity trials in which surface area conflicted with numerosity. Moreover, this association became non‐significant when controlling for inhibitory control. These results suggest that early mathematical experiences prior to formal schooling may influence the strength of the association between ANS acuity and mathematics ability and that inhibitory control may drive that association in young children.     

Verbal ability and executive functioning development in preschoolers at head start

Research suggests that executive functioning skills may enhance the school readiness of children from disadvantaged homes. Questions remain, however, concerning both the structure and the stability of executive functioning among preschoolers. In addition, there is a lack of research addressing potential predictors of longitudinal change in executive functioning during early childhood. This study examined the structure of executive functioning from fall to spring of the preschool year using a multimethod battery of measures. Confirmatory factor analyses revealed a unidimensional model fit the data well at both time points, and tests of measurement invariance across time points indicated that children's mean latent executive functioning scores significantly improved over time. Verbal ability was a significant predictor of longitudinal change in executive functioning. Theoretical implications and directions for future research are discussed.     

Reduced autobiographical memory specificity and posttraumatic stress: exploring the contributions of impaired executive control and affect regulation

Reduced specificity of autobiographical memories retrieved to word cues on the Autobiographical Memory Test (AMT) is associated with increased posttraumatic stress in traumatized samples. Theoretical debates concerning the dominant influences on this effect have focused on affect regulation, whereby specific personal information is avoided more by those experiencing greater distress, versus compromised executive control, whereby increased distress is associated with an inability to set aside inappropriately general responses on the AMT. The present study compared these 2 views in a correlational design using a reversed version of the AMT (the AMT-R) for which trauma-exposed participants (N=36) had to generate general memories from the past and avoid specific memories. An emphasis on the role of affect regulation would predict that distress would be associated with reduced specificity (as in the standard AMT), whereas emphasis on the role of executive control would predict that this relationship would be reversed. The data supported the affect regulation account, with greater posttraumatic stress being associated with reduced memory specificity.     

Training in family therapy: perceptual, conceptual and executive skills.

This paper presents a comprehensive and detailed outline of family therapy skills to aid in providing a more precise focus in the training of clinicians in family therapy. The skills are based on an integrated treatment model within a systems framework. Four major functions performed by a family therapist are separated and are further differentiated into general therapeutic competencies. Specific perceptual, conceptual, and executive skills are described in the form of instructional objectives and are listed under each competency. Occasional clarifying notes or examples are cited along with particular skills. Clinicians and trainees should find this outline a useful guide in skill development.     

A novel executive function battery for preschoolers: Sensitivity to age differences

The present study investigated sensitivity to age differences in a novel executive function (EF) battery for children aged 18 months to 5 years, and whether the pattern of associations among the measures was consistent with a hierarchical model of EF development. Participants (n = 261, aged 18–67 months) were administered a battery of novel tasks designed to assess 3 key EF components (working memory, inhibition, and shifting). The results indicate that the EF tasks were sensitive to age differences and provide partial support for the hierarchical model of EF development.     

Defining and measuring conceptual knowledge in mathematics

A long tradition of research on mathematical thinking has focused on procedural knowledge, or knowledge of how to solve problems and enact procedures. In recent years, however, there has been a shift toward focusing, not only on solving problems, but also on conceptual knowledge. In the current work, we reviewed (1) how conceptual knowledge is defined in the mathematical thinking literature, and (2) how conceptual knowledge is defined, operationalized, and measured in three mathematical domains: equivalence, cardinality, and inversion. We uncovered three general issues. First, few investigators provide explicit definitions of conceptual knowledge. Second, the definitions that are provided are often vague or poorly operationalized. Finally, the tasks used to measure conceptual knowledge do not always align with theoretical claims about mathematical understanding. Together, these three issues make it challenging to understand the development of conceptual knowledge, its relationship to procedural knowledge, and how it can best be taught to students. In light of these issues, we propose a general framework that divides conceptual knowledge into two facets: knowledge of general principles and knowledge of the principles underlying procedures.     

Prospective memory performance in preschoolers: Inhibitory control matters

The present study focuses on prospective memory in preschoolers. We specifically investigated the effects of age, retrospective memory, and task interruption on prospective memory performance. In the first experiment, testing 60 children aged 3, 4 and 5 years with a prospective memory task that required active ongoing task interruption we obtained an age effect indicating better prospective memory performance for the two older cohorts. Varying retrospective memory load did influence prospective memory response time but did not affect prospective memory accuracy. However, retrospective memory performance showed an age effect and individual differences in retrospective memory ability were related to individual differences in prospective memory performance, even after partialling age. In the second study, we applied a prospective memory task that did not require active ongoing task interruption. Here, testing 62 children aged 3, 4 and 5 years we still found an age effect in retrospective memory but neither an effect of age nor retrospective memory on prospective memory performance. It is concluded that preschoolers even at the age of 3 years can perform prospective memory tasks to a certain extent. Moreover, while retrospective memory still seems to be somewhat related to prospective memory in preschoolers, inhibitory control required for ongoing task interruption seems to be an especially important factor influencing task performance in preschoolers.     

PSN: A prolog declarative model of conceptual knowledge

This paper introduces a declarative model of semantic memory, called PSN, written in Prolog. It is shown to be a descendant of Quillian’s (1969) Teachable Language Comprehender (TLC) in its structuring of knowledge as a conceptual reticulum and in its use of spreading activation as a retrieval mechanism. PSN goes beyond TLC, however, in its ability to instantiate the essential benchmark properties of human semantic retrieval. As such, it can provide cognitive science with a normative model on which to assess further research and it demonstrates the value of the Prolog language for modeling psychological processes.