Speeded enumeration of visual stimuli typically produces a bilinear function, with a shallow subitizing rate (less than 100 ms/item) up to 3-4 items (subitizing span) and a steeper counting rate ([image omitted]300 ms/item) thereafter. FINST theory (L. M. Trick & Z. W. Pylyshyn, 1993, 1994) suggests that subitizing of targets is possible in…

In a variable foreperiod (FP) paradigm, reaction times (RTs) decrease as a function of FP on trial n (FP effect) but increase with FP on trial n = 1 (sequential effects). These phenomena have traditionally been ascribed to different strategic preparation processes. According to an alternative explanation, common conditioning laws underlie both…

This experiment used a modified go/no-go paradigm to investigate the processes by which response inhibition becomes more efficient during mid-childhood. The novel task, which measured trials on which a response was initiated but not completed, was sensitive to developmental changes in response inhibition. The effect of inducing time pressure by…

Purpose: The purpose of this study was to examine children's knowledge of semantic relations. Method: In Experiment 1, the 6-year-olds, 8-year-olds, and adults participated in an object decision task. Participants in the primed group made object decisions in response to primes that were related taxonomically, thematically, or perceptually to the…

Examined effects of a click signaling arrival of a visual stimulus to be timed on temporal discrimination in 3-, 5-, and 8-year-olds. Found that in all groups, the proportion of long responses increased with the stimulus duration, although the steepness of functions increased with age. Stimulus duration was judged longer with than without the…

In the research literature several positions concerning the role played by metacognition in adaptive strategy choice can be distinguished. While many authors adhere so-called metacognitive models of strategy choice and strategy change, others have questioned the extent to which metacognitive factors are associated with strategy choice and task…

Background: This study presents two experiments that investigated whether children with autism were susceptible to the Thatcher illusion. Perception of the Thatcher illusion requires being able to compute second-order configural relations for facial stimuli. Method: In both experiments children with autism were matched for non-verbal and verbal…

Background: Several theorists maintain that exact number abilities rely on language-relevant processes whereas approximate number calls on visuo-spatial skills. We chose two genetic disorders, Williams syndrome and Down's syndrome, which differ in their relative abilities in verbal versus spatial skills, to examine this hypothesis. Five…