Craig Leth-Steensen

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Response time (RT) distributions from three fixed foreperiod conditions (2, 4, and 8 s) in a warned four-choice RT task were obtained for a group of boys with attention-deficit/hyperactivity disorder, combined type (ADHD; n = 17) and for two groups of normal control boys (age-matched, n = 18, and younger-aged, n = 10). Quantitative measures of(More)
A cognitive process model is developed that predicts the 3 major symbolic comparison response time effects (distance, end, and semantic congruity) found in the results of the linear syllogistic reasoning task. The model includes a simple connectionist learning component and dual evidence accumulation decision-making components. It assumes that responses can(More)
With English-language readers in an experiment requiring pairwise comparative judgments of the sizes of animals, the nature of the association between the magnitudes of the animal pairs and the left or right sides of response (i.e., the SNARC effect) was reversed depending on whether the participants had to choose either the smaller or the larger member of(More)
Is the locus of the problem-size effect in mental arithmetic different across cultures? In a novel approach to this question, the ex-Gaussian distributional model was applied to response times for large (e.g., 8 x 9) and small (e.g., 2 x 3) problems obtained from Chinese and Canadian graduate students in a multiplication production task (LeFevre & Liu,(More)
On each trial of this study, participants either switched between or repeated two simple, two-choice tasks involving either letter or digit classifications. Speed-accuracy trade-off (SAT) curves were obtained using the response-signal method of eliciting speeded responses at various response time lags after the presentation of the stimulus for the second(More)
In this study, the effect of lengthening foreperiod duration (i.e. the time between the presentation of a warning signal and a subsequent target stimulus) on choice RTs is examined. The foreperiod durations used were either 2 or 8s and were fixed within pure blocks of trials. The task was to determine whether a single-digit target stimulus was either(More)
Since the inception of the empirical study of personality, and even before it, individual differences in anxiety and distress have been viewed as key predictors of behavioral performance. Yet such literatures have always entertained 2 perspectives, one contending that anxious individuals are "driven" and the other contending that anxious individuals are(More)
Legalized gambling in Canada is governed by Provincial legislation. In Ontario, the Ontario Lottery and Gaming Corporation is responsible for all aspects of gambling in the Province. There have been a number of recent lawsuits against this Crown agency of the Government of Ontario by gamblers, most of which have been settled or otherwise resolved. A recent(More)
Semantic congruity effects (SCEs) were obtained in each of two experiments, one with symbolic comparisons and the other with comparisons of visual extents. SCEs were reliably larger when the instructions indicating the direction of the comparison were represented by consonant-vowel-consonant (CVC) nonsense syllables, which had been associated with the(More)
In the present experiments, failures of selective visual attention were invoked using the B. A. Eriksen and C. W. Eriksen (1974) flanker task. On each trial, a three-letter stimulus array was flashed briefly, followed by a mask. The identity of the two flanking letters was response congruent, neutral, or incongruent with the identity of the middle target(More)