Differential effects of priming at the encoding and judgment stage

Two experiments investigated whether the direction of priming effects depends on the processing stage at which the individual links the prime to a trait that is applicable to the evaluation of an ambiguously described target person. In line with previous research, it is hypothesized that assimilation effects will emerge when primes are processed in terms of a trait concept that is applicable to the encoding task. However, when the primes are not processed in applicable trait terms, they may still affect subsequent Judgments if the individual recalls the prime when judging the target along a trait dimension. In this case, the primes may serve as an anchor, resulting in contrast effects. Two experiments, in which subjects were primed with names of prototypically nice or hostile famous individuals under instructions that did or did not prompt subjects to process the prime in applicable trait terms, supported these hypotheses. Implications for the emergence of priming effects in everyday social interaction are discussed.     

Size invariance in curve tracing

Subjects decided whether two dots were on the same curve or on different curves in patterns consisting of two curves and two dots in displays that had an exposure duration of 200 msec or that remained in view until the subjects' response. The overall size of the patterns was varied by a factor of two. Furthermore, across experiments, we manipulated the predictability of the size of the pattern on a particular trial. On half of the trials, the two dots were on the same curve; across these trials, the distance between the dots, along the curve, was manipulated systematically while the Euclidean distance between the dots was held constant. On the other half of the trials, the two dots were on different curves. The time to respond same increased monotonically as curve distance between the dots increased, suggesting that subjects mentally traced the curve in order to perform the task. The absolute size of the pattern had little or no effect on the response times, indicating that it was curve distance relative to the overall pattern size, rather than absolute distance, that controlled response times. Furthermore, expectancies about pattern size had essentially no effect on performance. Taken together, the results suggest that the rate of tracing is determined by various stimulus properties that covary with the overall size of the pattern on which tracing takes place, such as the distance between the traced curve and nearby distractor curves, or the curvature of the traced curve.     

TRAINING CONSERVATION OF QUANTITY (LIQUIDS) IN WEST AFRICAN (BAOULE) CHILDREN

A developmental ‘lag’ is found in the Conservation of Quantity (Liquids) in a sample of 73 rural, schooled Baoulé children (Ivory Coast, West Africa) aged 7 to 14 years. This study was designed to investigate if this ‘lag’ could be reduced or bridged through training and whether it could be attributed to differences in ‘performance’ or in ‘competence’. A sub-sample of 28 children aged 7 to 9 years was divided into two matched groups, one being trained for Conservation of Liquids and the other for Class Inclusion (Lavallée and Dasen in press). Statistically significant training effects were observed, which generalized to other concrete operational concepts and remained stable over at least one month. Since no ‘actualization’ or very fast learning occurred, the ‘lag’ was attributed to differences in competence; the training was sufficient to bridge the developmental lag.     

Discrimination of time intervals marked by brief acoustic pulses of various intensities and spectra

Experienced observers were asked to identify, in a four-level 2AFC situation, the longer of two unfilled time intervals, each of which was marked by a pair of 20-msec acoustic pulses. When all the markers were identical, high-level (186-dB SPL) bursts of coherently gated sinusoids or bursts of band-limited Gaussian noise, a change in the spectrum of the markers generally did not affect performance. On the other hand, for 1-kHz tone-burst markers, intensity decreases below 25 dB SL were accompanied by sizable deterioration of the discrimination performance, especially at short (25-msec) base intervals. Similarly large changes in performance were observed also when the two tonal markers of each interval were made very dissimilar from each other, either in frequency (frequency difference larger than 1 octave) or in intensity (level of the first marker at least 45 dB below the level of the second marker). Time-difference thresholds in these two latter cases were found to be nonmonotonically related to the base interval, the minima occurring between 40- and 80-msec onset separations.     

Preimaginal induction of adult behaviour in insects

This review illustrates the role of preimaginal experiences in four main aspects of insect life: feeding, habitat choice, host selection, and social relationships. After an illustration of the two former aspects with examples taken from various species, special attention is paid to the two latter aspects. First, an experiment is described, which demonstrates the existence of preimaginal induction involved in host selection by the solitary parasitoid wasp Dinarmus basalis (Hymenoptera: Pteromalidae). Then, a review of preimaginal induction in ants' behaviour is presented; orientation of social behaviour, particularly altruism, is mainly determined by preimaginal imprinting. All the examples developed in this review clearly show that insects can no longer be considered as strictly, rigidly “pre-programmed” beings. Their complex behavioural development and plasticity is clearly documented.     

Are thought experiments “disturbing”? The case of armchair physics

Philosophical Studies - Proponents of the “negative program” in experimental philosophy have argued that judgements in philosophical cases, also known as case judgements, are unreliable...     

Stroop interference is a composite phenomenon: Evidence from distinct developmental trajectories of its components

Only one previous developmental study of Stroop task performance (Schiller, 1966) has controlled for differences in processing speed that exist both within and between age groups. Therefore, the question of whether the early developmental change in the magnitude of Stroop interference actually persists after controlling for processing speed needs further investigation; work that is further motivated by the possibility that any remaining differences would be caused by process(es) other than processing speed. Analysis of data from two experiments revealed that, even after controlling for processing speed using z‐transformed reaction times, early developmental change persists such that the magnitude of overall Stroop interference is larger in 3rd‐ and 5th graders as compared to 1st graders. This pattern indicates that the magnitude of overall Stroop interference peaks after 2 or 3 years of reading practice (Schadler & Thissen, 1981). Furthermore, this peak is shown to be due to distinct components of Stroop interference (resulting from specific conflicts) progressively falling into place. Experiment 2 revealed that the change in the magnitude of Stroop interference specifically results from joint contributions of task, semantic and response conflicts in 3rd‐ and 5th graders as compared to a sole contribution of task conflict in 1st graders. The specific developmental trajectories of different conflicts presented in the present work provide unique evidence for multiple loci of Stroop interference in the processing stream (respectively task, semantic and response conflict) as opposed to a single (i.e. response) locus predicted by historically – favored response competition accounts.     

Developmental and content effects in reasoning with causal conditionals

Two predictions derived from Markovits and Barrouillet's (2001) developmental model of conditional reasoning were tested in a study in which 72 twelve-year-olds, 80 fifteen-year-olds, and 104 adults received a paper-and-pencil test of conditional reasoning with causal premises ("if cause P then effect Q"). First, we predicted that conditional premises would induce more correct uncertainty responses to the Affirmation of the consequent and Denial of the antecedent forms when the antecedent term is weakly associated to the consequent than when the two are strongly associated and that this effect would decrease with age. Second, uncertainty responding to the Denial of the antecedent form ("P is not true") should be easier when the formulation of the minor premise invites retrieval of alternate antecedents ("if something other than P is true"). The results were consistent with the hypotheses and indicate the importance of retrieval processes in understanding developmental patterns in conditional reasoning with familiar premises.