Executive Functions and Mental Attentional Capacity in Preschoolers

ABSTRACT

The structure of executive functions in preschoolers is controversial. Miyake and colleagues found that, in adults, inhibition, shifting, and updating are correlated but distinguishable processes; this finding was sometimes replicated with schoolchildren. Based on schoolchildren data, Im-Bolter, Johnson, and Pascual-Leone proposed a four-component model, with mental attentional capacity and inhibition as basic resources, and shifting and updating as executive processes that partly rely on those resources. Studies on preschoolers propose either a single factor or two factors. We tested 118 children (36 to 73 months old) using measures of mental attentional capacity (Mr. Cucumber, Direction Following Task, and Backward Word Span), inhibition (Bear/Dragon and Day-Night Stroop), shifting (Dimensional Change Card Sort) and updating (Magic House). Confirmatory factor analyzes showed that the best-fitting model comprises two highly correlated factors – one loading the mental attentional capacity measures, the other loading inhibition, shifting, and updating measures. Performance in inhibition, shifting, and updating tasks showed qualitative changes with increasing attentional capacity. In preschoolers, shifting and updating seem to emerge tied to inhibition – but only when sufficient capacity enables children to perform executive control tasks. This seems consistent with Im-Bolter’s et al.’s proposal of two basic resources.     

Imaging the future: Does a qualitative analysis add to the picture?

Various studies report that patients with dense amnesia experience difficulties in simulating future events. It is argued that this resembles an inability to remember past episodes in that both indicate a deficit in mental scene construction. Such findings, however, rely upon quantitative content-based analyses of participants' verbal reports. Here, samples of verbal reports produced by participants with hippocampal lesions are subjected to a qualitative, discourse analysis of how participants and researchers negotiated the status of these reports. This shows that failure in mental scene construction can be viewed as an interactional achievement rather than the mere reporting of mental events. A multidisciplinary perspective which combines qualitative analysis with other forms of analytic technique may explain subtle differences between participants with hippocampal lesions and control participants.     

Neural Processing to Visual Stimuli in a Three-Choice Reaction-Time Task

Some authors have suggested that certain components of the event-related potentials (ERPs) reflect underlying stages in the discrimination process. Previous studies have shown that in an auditive three-choice reaction-time task the discrimination is accomplished as a two-stage process, with the more frequently occurring stimulus discriminated at an earlier point than the rarer stimulus and the subjects could be classified as fast and slow responders in function of their response to the most frequent of the three tones. We continuously recorded the electrocerebral activity (EEG) from the scalp and the electromyographic activity (EMG) from the responding muscles in a visual three-choice reaction-time task in 10 strictly right-handed subjects. EEG and EMG responses were subsequently analyzed off-line by aligning them by the onset of either the stimulus (stimulus-synchronized) or the response (response-synchronized). The results suggest that processes of visual stimuli evaluation and response execution are continuously integrated. The discrimination and response systems to visual stimuli is accomplished as a three-stage process, one to frequent tone, another for rare 1, and the last for rare 2. The subjects were classified as fast and slow responders in function of their response to the most frequent of the three tones.     

Manipulating self-efficacy in the exercise environment in women: influences on affective responses.

Self-efficacy was experimentally manipulated in an exercise context, and its effect on affective responses was examined. College women (N = 46) were randomly assigned to a high- or low-efficacy condition, and efficacy expectations were manipulated by means of bogus feedback and graphs depicting contrived normative data. The manipulation successfully influenced affective responses, with participants in the high-efficacy group reporting more positive and less negative affect than did the low-efficacy group. Efficacy was significantly related to feeling-state responses during and after activity but only in the high-efficacy condition. The results suggest that self-efficacy can be manipulated and that these changes are related to the affective experience associated with exercise. Such findings may have important implications for the roles played by self-efficacy and affect in exercise adherence.