Influence of exploration time on haptic and visual matching of complex shape

The time adult Ss were allowed to explore stimuli was varied during intra- and cross-model equivalence matching involving vision and touch. Increasing time to explore either each standard, each comparison, or both standard and comparison from 4 to 16 sec significantly improved haptic intramodel matching. However, cross-modal matching, from either vision to touch or touch to vision, improved significantly only when time to explore each standard was increased. Videotape recordings of Ss’ hand movements revealed use of a greater variety of haptic scanning strategies by Ss in groups where increased exploration time enhanced accuracy. The difference in effects of exploration time on intra- compared to cross-model shape matching was discussed in terms of possible differences in requirements between the two tasks.     

Effects of a timing signal on simple reaction time with a rectangular distribution of foreperiods

It was hypothesized that the time course of preparation during a variable interstimulus interval (ISI) of a simple reaction time (RT) experiment was partly determined by the subjective distribution of conditional probabilities of the executive signal (ES). Sixty subjects performed a simple auditory RT task with various ranges of six ISI durations organized in rectangular frequency distributions. In order to give the subjects information about elapsed time during ISI, a recurring time-marking click, the periodicity of which was varied, was introduced during the ISI in one of the three series of trials each subject performed. A strong decreasing RT--ISI relationship was observed supporting the main hypothesis. However, a clear increase of mean RT over all ISIs combined, was also found. Because these two mixed effects were greatest when the click intervened at the possible times of ES occurrence only, three functions of time-information given by the click are discussed: (a) a reduction of the usual increase of time estimation error with increased ISI; (b) an increase of the subjects knowledge of the ISI range resulting from the discontinuity of the time-marking click which makes easier a discrete time-intervals numbering process; (c) a change of the simple-RT task into a discrimination task.     

Simultaneous linear prediction

Given a set of items (predictors) suppose one wishes to predict another set of items (predictands) in asimultaneous way. Such a situation may occur when the predictands are different measurable aspects of the same phenomenon. Alternatively one might wish to predict the success of an event (say a successfully performed task) which has many correlated or uncorrelated failure modes (say a set of possible mental or physical disabilities each of them by itself precluding the achievement of the said task.) In such a case a unidimensional prediction is of value only if prediction is simultaneous for all possible failure modes. A linear summarization of the predictors is suggested, which is unique and has maximum predictability value for all predictands simultaneously. Other summarizations or scores are found that give maximum explanation of residual measures on the predictands and that are uncorrelated. The set of those simultaneous linear predictions is compared to the set of the individual multiple regression predictions as used, for instance, in the same context by Horst [4] for each predictand given the original predictors. We suggest that this technique can be applied in particular to the summarization of a subset of items when the whole set of items constitutes the set of predictands.This work was initiated at Stanford University under contract 2-1-065 with U. S. Office of Education and was partly revised at the Université de Montréal.I wish to express my gratitude to Professor Herbert Solomon, Stanford University, for his unfailing assistance at all stages of my work.     

Flicker thresholds as determined by a modified conditioned suppression procedure,

Critical flicker fusion frequencies were determined as a function of stimulus intensity for three White Carneaux pigeons using a modified conditioned suppression paradigm as a threshold procedure. Critical frequencies ranged from 6 cps for the lowest intensity of 0.0014 ml to 77 cps for the maximum intensity of 41.86 ml.     

Sex differences in parental directives to young children

This study investigated how children learn sex-associated strategies for requesting action. We compared the directives which mothers and fathers address to their 2 1/2- to 5-year-old children. Ten children, 5 boys and 5 girls, engaged separately with each parent in a construction task. Fathers produced more directives than mothers and tended to phrase them as imperatives (e.g., Put the screw in) or as highly indirect “hints” (e.g., The wheel's going to fall off) more often than mothers, who relied more on relatively transparent indirect forms (e.g., Can you put the screw in?). There were no differences in the form of the directives addressed to girls and boys, nor were there any cross-sex effects. Parental modeling, rather than differential socialization of girls and boys, appears to be the mechanism by which children learn to request action in sex-associated ways.     

The effect of a commercial game on children's block design scores on the WISC-R IQ test

Two experiments investigated the extent to which 10-year old children's scores on the WISC-R Block Design subtest were affected by prior experience with a specific commercial game that involved blocks and matching patterns. Experiment 1 found that 12 10-year old children who happened to have experience with the particular commercial game scored approximately three scaled score points higher on the WISC-R Block Design subtest than 24 matched children without game experience. In Experiment 2, 24 children who did not have prior experience with this particular commercial game were randomly assigned either to a Game condition (involving two 15-minute sessions with the game) or to a No-Game condition (which involved no further game experience). Children in the Game condition subsequently increased their WISC-R Block Design scores more than children in the No-Game condition. Taken together, the experiments indicate that relatively brief interactions with a commercial game can cause a significant improvement in children's performance on an IQ subtest.     

Parents' reactions to finding out that their children have average or above average IQ scores

The parents of 41 children who had been given an individually-administered intelligence test were contacted approximately 19 months after testing. The sample included 20 parents who had learned their child had an Average IQ (children'smeanIQ = 100.8) and 21 parents who had learned their child had an Above Average IQ (children'smeanIQ = 130.0). Parents of Average IQ children were less accurate in their memory of test results, and they and their children experienced fewer positive consequences from IQ testing than Above Average children and their parents. Children with Above Average IQ experienced extremely low frequencies of sibling rivalry, conceit or pressure, and they and their parents experienced increased pride and/or self-confidence as a result of the IQ testing. The results as a whole suggest that parents of Average IQ children may need more psychological support during the parent informing process than parents of Above Average IQ children.