Color-object interference: Further tests of an executive control account

Young children are slower in naming the color of a meaningful picture than in naming the color of an abstract form (Stroop-like color-object interference). The current experiments tested an executive control account of this phenomenon. First, color-object interference was observed in 6- and 8-year-olds but not in 12- and 16-year-olds (Experiment 1). Second, meaningful pictures did not interfere in 5- to 7-year-olds’ manual sorting of objects on the basis of color (Experiment 2) or in their naming the number of colored objects in the display, that is, subitizing (Experiment 3). These findings provide support for the view that color-object interference results from the children’s immature inhibition of the prepotent but irrelevant task of object naming.     

Cohort differences in Big Five personality factors over a period of 25 years

The notion of personality traits implies a certain degree of stability in the life span of an individual. But what about generational effects? Are there generational changes in the distribution or structure of personality traits? This article examines cohort changes on the Big Five personality factors Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience, among first-year psychology students in The Netherlands, ages 18 to 25 years, between 1982 and 2007. Because measurement invariance of a personality test is essential for a sound interpretation of cohort differences in personality, we first assessed measurement invariance with respect to cohort for males and females separately on the Big Five personality factors, as measured by the Dutch instrument Five Personality Factors Test. Results identified 11 (females) and 2 (males) biased items with respect to cohort, out of a total of 70 items. Analyzing the unbiased items, results indicated small linear increases over time in Extraversion, Agreeableness, and Conscientiousness and small linear decreases over time in Neuroticism. No clear patterns were found on the Openness to Experience factor. Secondary analyses on students from 1971 to 2007 of females and males of different ages together revealed linear trends comparable to those in the main analyses among young adults between 1982 onward. The results imply that the broad sociocultural context may affect personality factors.     

A computer-based system providing pictorial instructions and prompts to promote task performance in persons with severe developmental disabilities

This study was aimed at assessing a new computer-based system to promote task performance in three adults with severe developmental disabilities. The new system, which was small and battery powered, could provide auditory and vibratory prompts in addition to pictorial instructions concerning the task steps. To control for the effects of the computer-based system, the subjects were also exposed to a card system. The results showed that the subjects had a significantly higher level of correct performance on the tasks presented with the computer-based system than on the tasks presented with the card system. Two of the subjects, moreover, seemed to prefer the computer-based system to the card system. © 1998 John Wiley & Sons, Ltd.     

Personality and team performance: a meta‐analysis

Using a meta‐analytical procedure, the relationship between team composition in terms of the Big‐Five personality traits (trait elevation and variability) and team performance were researched. The number of teams upon which analyses were performed ranged from 106 to 527. For the total sample, significant effects were found for elevation in agreeableness (ρ = 0.24) and conscientiousness (ρ = 0.20), and for variability in agreeableness (ρ = ?0.12) and conscientiousness (ρ = ?0.24). Moderation by type of team was tested for professional teams versus student teams. Moderation results for agreeableness and conscientiousness were in line with the total sample results. However, student and professional teams differed in effects for emotional stability and openness to experience. Based on these results, suggestions for future team composition research are presented. Copyright © 2006 John Wiley & Sons, Ltd.     

Concurrent schedules: Transient-state changeover behaviour

Ten pigeons responded in a two-alternative continuous-choice situation. Rein-forcers were programmed by a single variable-interval 30-sec schedule. The proportion of reinforcers assigned to one alternative was either 0.67 or 0.50 in different conditions. The changes in local changeover rates following changes of conditions were adequately described by an exponential function. This result can be explained by a model of changeover behaviour proposed by Myerson and Miezin (1980), if a simplifying assumption is made about reinforcement rates as controlling variables. A modification of the Myerson and Miezin model that accounts for the exponential function but does not make assumptions about reinforcement rates as controlling variables is presented.     

BRIEF REPORT: ENABLING BLIND PERSONS WITH SEVERE OR PROFOUND MENTAL RETARDATION TO OPERATE AN ACOUSTIC ORIENTATION SYSTEM INDEPENDENTLY

The aim of this study was to assess new technology for enabling two blind persons affected by severe or profound mental retardation to operate an acoustic orientation system independently. By operating this system, the subjects could move to different activity destinations within an occupational setting and carry out activities free from external assistance. The results showed that both subjects learned to operate the system on their own. The high level of independence they achieved is reviewed in relation to the new technology and the simplified responding it requires     

An analysis of emergent simple discrimination in children

In Experiment 1 eight five-year-old children received an arbitrary matching-to-sample task with sample stimuli A1 and A2 and comparison stimuli B1 and B2. This task was mixed with a simple, two-choice discrimination task with stimuli A1 and A2. In subsequent tests with B1 and B2 presented alone, the number of responses to B1 was greater when it had been paired with the correct stimulus of the simple discrimination task than when it had been paired with the incorrect stimulus. In Experiment 2 incorrect comparisons were omitted during the matching-to-sample task. Eight children were taught to point to either A1 or A2 first, and to either B1 or B2 second. Eight other children were taught to point to either B1 or B2 first, and to either A1 or A2 second. The effect of Experiment 1 was replicated with the first but not with the second group. The results of both experiments suggest that the functions of S+ and S- in a simple discrimination task can transfer to test stimuli if the training stimuli precede the test stimuli during paired presentations.     

Experimental treatment of early stuttering: a preliminary study

This pilot study compared two treatments for stuttering in preschool-age children. Thirty children were randomly assigned to either a Lidcombe Program (LP) treatment or a Demands and Capacities Model (DCM) treatment. Stuttering frequencies and severity ratings were obtained immediately before and after treatment (12 weeks). The stuttering frequencies and severity ratings significantly decreased for both treatment groups. No differences between groups were found. Parents of children in both groups were cooperative in many respects, and there were no differences between them on scales that measured their satisfaction with the two treatments. The findings suggest that randomized controlled trials of LP versus DCM treatments are feasible, and they underline the need for experimental analyses of the two treatments. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe the principles and methods of Lidcombe treatment for early stuttering; (2) delineate principles and methods of Demands and Capacities Model treatment; and (3) summarize results of an investigation that compared these programs' relative effects in a pilot study.     

Macro and Micro Goal Setting: In Search of Coherence

In this article we discuss macro and micro goal setting approaches, focusing on the relations between goals at different organisational levels. Translating strategic goals in a top-down manner throughout the organisation is a rather complex process. In organisations, at least one intermediate level between macro (i.e. strategic) and micro (i.e. operational) goals can be distinguished: the level of meso (i.e. tactical) goal setting. The process of a strategic dialogue is introduced to arrive at organisational goal coherence, which is defined as consensus on goal priorities within single constituencies and between multiple constituencies at different organisational levels. This process is illustrated in a case study, in which the CATPCA method has been applied to empirically operationalise degrees of consensus. Effects of the strategic dialogue on organisational goal coherence are demonstrated.     

Concurrent schedules: Maximization versus reinforcement of changeover behaviour

Pigeons responded on concurrent variable-interval 180-sec variable-interval 36-sec schedules during Conditions 1 and 3 of Experiment 1. Condition 2 arranged variable-interval 60-sec schedules for both response alternatives. The schedule assigned to the alternative that was associated with the variable-interval 36-sec schedule in Conditions 1 and 3 operated only when the subject responded on that alternative. The proportion of time spent responding on the alternative with the conventional variable-interval 60-sec schedule increased during Condition 2, but exclusive choice of that alternative did not develop. This result is inconsistent with maximization of the overall reinforcement rate and with maximization of the momentary probability of reinforcement (momentary maximizing). Increasing time proportions were also found in Experiment 2, which arranged similar conditions, except that reinforcement was provided on a variable-time basis. The time proportions were close to the momentary maximizing prediction in Experiment 2. The results of both experiments can be explained if it is assumed that time allocation is controlled by delayed reinforcement of changeovers between alternatives.