Effect of instructions on elementary cognitive tasks sensitive to individual differences

The effect of instructions on basic cognitive tasks was investigated. In the first study, 60 college students completed both a choice reaction time and a modified match-to-sample task. Students were given either written, non-verbal, or no instructions. Mean level of performance changed across type of instruction for each task. The correlations between the task parameters and a measure of general intelligence also appeared to change across instructional conditions. A second study was conducted with 464 Air Force and National Guard recruits who completed choice reaction time, match-to-sample, tachistoscopic threshold, and probed recall tasks. Approximately half of these subjects received standard written instructions while the others received no instructions. Mean group differences were substantial but decreased with practice. Patterns of individual differences between the instruction and no-instruction conditions varied more with increased task complexity, with greater change occurring in more complex tasks such as probed recall. In sum, instructions have a significant impact on mean performance on basic cognitive tasks and a lesser effect on individual differences.     

Individual differences on speeded cognitive tasks: Comment on Chen,Hale, and Myerson (2007)

Chen, Hale, and Myerson (2007) recently reported a test of the difference engine model (Myerson, Hale, Zheng, Jenkins, & Widaman, 2003). This test evaluated whether the standard deviation (SD) is proportional to the amount of processing—that is, mean reaction time (RT)—in a speeded cognitive task. We show that this evaluation is not a test of the model because its finding is a consequence of relationships in the data. We argue any model structure that produces increasing values of RT as a function of difficulty, with different slopes for different individuals, necessarily produces a correlation between SD and mean RT. We illustrate this with a different model structure—that is, the diffusion model proposed by Ratcliff (1978)—showing that it produces a fan out between fast- and slow-group means and produces the correlation between SD and mean RT that matches the empirical result.     

Individual differences in college students' performance on formal operations tasks

Piaget has suggested that the stage of formal operations may be present in all normal adults, albeit in different areas according to aptitudes and professional specialization. Three formal operations tasks (pendulum, political socialization concepts, and literary styles analysis) were chosen to represent the content of problems encountered in three fields of academic specialization (physics, political science, and English). Ten male junior and senior college students in each of the three academic majors were tested on the three tasks. A significant academic major by task interaction was obtained. Results supported the hypothesis that young adults evidence formal level reasoning in accordance with their college majors. Explanations of task-specific formal level performance were considered. Individual differences in formal operations attainment have implications for assessment of adult intelligence.     

Individual differences in reported visual imagery and cognitive performance

Selected on the basis of their scores on the Vividness of Visual Imagery Questionnaire, 16 High Visualizers and 14 Low Visualizers (equally divided by sex) completed various cognitive tasks thought to involve visual (Space Relations, Watch Rotation) and non-visual (Verbal Reasoning, Abstract Reasoning, Numerical Ability) processes. Although Low Visualizers (particularly males) were superior to High Visualizers in Numerical Ability, both groups performed equally well on the other tests. Since correlational analyses indicated that scores on the vividness questionnaire and the Gordon Controllability of Imagery Questionnaire were not independent, particularly for females, it was suggested that questionnaires ought to be developed better to differentiate the abilities to generate and control visual images.     

Black–White differences on IQ and grades: The mediating role of elementary cognitive tasks

The relationship between IQ scores and elementary cognitive task (ECT) performance is well established, with variance on each largely reflecting the general factor of intelligence, or g. Also ubiquitous are Black–White mean differences on IQ and measures of academic success, like grade point average (GPA). Given C. Spearman's (Spearman, C. (1927). The Abilities of Man. New York: Macmillan) hypothesis that group differences vary directly with a test's g loading, we explored whether ECT performance could mediate Black–White IQ and GPA differences. Undergraduates (139 White and 40 Black) completed the Wonderlic Personnel Test, followed by inspection time and choice reaction time ECTs. Despite restriction of range, ECT performance completely mediated Black–White differences on IQ (d = .45). Group differences on GPA (d = .73), however, were larger and ECT performance did not mediate them. We discuss findings in light of Spearman's hypothesis.     

Thinking aloud performance: Individual consistencies over tasks

Previous research (Gilhooly, 1987) indicated considerable individual consistency in quantity and quality of thinking aloud performance over three 8-puzzle tasks. The present study investigated the consistency of individual thinking aloud performance over two types of tasks. One type was largely spatial (the 8-puzzle) and the other largely verbal (the Poisoned Foods task). Considerable individual consistency in thinking aloud performance was found within each task type and, more importantly, between types of task. Thus, subjects who produced lengthy and complete protocols on the 8-puzzle problems also did so in the Poisoned Foods task. These results are discussed in the context of Ericsson and Simon’s (1984) model of thinking aloud.     

Individual differences in thinking-aloud performance

A key method in current research on thinking is to have subjects think aloud as they work on some task. Considerable individual differences usually emerge in the quantity and quality of thinking-aloud records. This article reports an experimental sudy of such individual differences. Subjects took Cattell’s 16-PF personality test, a self-relevation scale, and a test of verbal fluency. The 35 subjects then attempted three 8-puzzle tasks under thinking-aloud instructions. The resulting thinking-aloud records (protocols) were scored in terms of length, number of words per puzzle move, number of goal references, and number of goal references per move. The different protocol measures intercorrelated highly in each problem. Furthermore, each of the protocol measures correlated over different puzzles; that is, someone who produced a long protocol on one problem tended to produce a long protocol on other problems. However, none of the protocol measures correlated with any of the personality scores or with the verbal fluency measure. It is concluded that there is consistency within individuals in protocol quantity and completeness, and that this tendency merits further investigation.     

Two- vs. three-dimensional presentation of mental rotation tasks: Sex differences and effects of training on performance and brain activation

The well-documented sex difference in mental rotation favoring males has been shown to emerge only for 2-dimensional presentations of 3-dimensional objects, but not with actual 3-dimensional objects or with virtual reality presentations of 3-dimensional objects. Training studies using computer games with mental rotation-related content have demonstrated training effects on mental rotation performance. Here, we studied the combined effect of a two-week mental rotation (MR) training on 2-dimensional vs. 3-dimensional presentations of a classic Shepard–Metzler task (presented in a pretest–training–posttest design) and their accompanying cortical activation patterns assessed via EEG in a sample of 38 male and 39 female adolescents of about 15 years of age. Analysis of one performance parameter (reaction times) displayed only main effects of dimensionality (with shorter RTs on the 3D vs. 2D version of the MR task) and of training (significant shortening of RTs), but no significant sex difference. Analysis of the other performance parameter (scores) in the MR task revealed a sex difference favoring males that first, appeared only in the 2D version, but not in the 3D version of the MR task and, secondly, diminished after training. Neurophysiologically we observed a complex sex × dimensionality × training × hemisphere interaction showing that the hypothesized decrease of brain activation (increase in neural efficiency) with training emerged for males in both 2D and 3D conditions, whereas for females this decrease was found only in the 3D but not with the 2D version of the MR task.     

Individual differences in higher-level cognitive abilities do not predict overconfidence in complex task performance

Even when people perform tasks poorly, they often report unrealistically positive estimates of their own abilities in these situations. To better understand the origins of such overconfidence, we investigated whether it could be predicted by individual differences in working memory, attentional control, and self-reported trait impulsivity. Overconfidence was estimated by contrasting objective and subjective measures of situation awareness (the ability to perceive and understand task-relevant information in the environment), acquired during a challenging air traffic control simulation. We found no significant relationships between overconfidence and either working memory or attentional control. However, increased impulsivity significantly predicted greater overconfidence. In addition, overall levels of overconfidence were lower in our complex task than in previous studies that used less-complex lab-based tasks. Our results suggest that overconfidence may not be linked to high-level cognitive abilities, but that dynamic tasks with frequent opportunities for performance feedback may reduce misconceptions about personal performance.     

Individual differences in secondary task performance

The purpose of this research was to use secondary task performance as a predictor of performance on a difficult primary task. Reaction time (RT) to secondary probes that occurred during the rehearsal period of an easy memory task were used to measure spare capacity associated with the memory task. This measure was then correlated with performance on a harder version of the same memory task. Experiments 1-4 involved a paired associate memory task. Probe RT was sensitive to the difficulty of the paired associate task, and analysis of individual differences showed that probe RT during the easy version of the task was correlated with performance on a harder version of the task. Experiment 4 also utilized a spatial memory task. Probe RT was less sensitive to the demands of the spatial memory task, and in that case, the "easy-to-hard" prediction was not successful.     

Individual differences,aging, and IQ in two-choice tasks

The effects of aging and IQ on performance were examined in three two-choice tasks: numerosity discrimination, recognition memory, and lexical decision. The experimental data, accuracy, correct and error response times, and response time distributions, were well explained by Ratcliff’s (1978) diffusion model. The components of processing identified by the model were compared across levels of IQ (ranging from 83 to 146) and age (college students, 60–74, and 75–90 year olds). Declines in performance with age were not significantly different for low compared to high IQ subjects. IQ but not age had large effects on the quality of the evidence that was obtained from a stimulus or memory, that is, the evidence upon which decisions were based. Applying the model to individual subjects, the components of processing identified by the model for individuals correlated across tasks. In addition, the model’s predictions and the data were examined for the “worst performance rule”, the finding that age and IQ have larger effects on slower responses than faster responses.     

Individual differences in cognitive control on self-referenced and other-referenced memory

Self-referenced information is better recalled than other-referenced information – a mnemonic advantage known as the “self-reference effect” (SRE). By using a modified version of the “think/no-think” (TNT) paradigm (Anderson & Green, 2001), this study examined the effects of cognitive control on the SRE after the encoding stage. The results indicate that individual differences in personality traits and affective states strongly modulated the SRE after the TNT phase. For individuals high in negative cognitive style, an ironic enhancement of negative self-referenced memory produced a “maladaptive” SRE: better memory for negative self-referenced information than for negative other-referenced information, when trying to suppress that information. Before the TNT phase, instead, the SRE was characterized by the opposite bias. These results indicate that (1) the SRE is strongly affected by cognitive control after encoding, and (2) also in the non-clinical population, dysfunctional cognitive control can transform the SRE into a “maladaptive” memory bias.     

Individual differences in reported visual imagery and memory performance.

Seventy high school students completed the Vividness of Visual Imagery Questionnaire (VVIQ). Two months later, the 16 highest scores (low visualizers) and the 16 lowest scores (high visualizers) took part in a memory experiment involving abstract words, concrete words and pictures. Analyses of variance showed that high visualizers were superior to low visualizers on all three kinds of item in short-term recall, whereas they were only superior on the concrete words and pictures in long-term recall. Finally, both groups performed equally well on a subsequent recognition test. The results were interpreted as providing support for the validity of the VVIQ.     

Relating inter-individual differences in metacognitive performance on different perceptual tasks

Human behavior depends on the ability to effectively introspect about our performance. For simple perceptual decisions, this introspective or metacognitive ability varies substantially across individuals and is correlated with the structure of focal areas in prefrontal cortex. This raises the possibility that the ability to introspect about different perceptual decisions might be mediated by a common cognitive process. To test this hypothesis, we examined whether inter-individual differences in metacognitive ability were correlated across two different perceptual tasks where individuals made judgments about different and unrelated visual stimulus properties. We found that inter-individual differences were strongly correlated between the two tasks for metacognitive ability but not objective performance. Such stability of an individual’s metacognitive ability across different perceptual tasks indicates a general mechanism supporting metacognition independent of the specific task.     

Developmental and individual differences in performance on phonological synthesis tasks

This study was conducted in order to examine the role of individual differences in working memory and lexical access in accounting for age and reading skill related differences in performance on phonological synthesis tasks. The performance of 28 kindergarten, first-, and second-grade children with normal reading skills, as well as that of 28 reading-disabled second graders, was compared under four testing conditions. The testing conditions were formed by completely crossing rate of presentation of phoneme strings with type of stimulus to be blended (real or nonword). Both independent variables affected performance on the blending tasks, with better performance obtained at faster presentation rates and with real words. There was a developmental discontinuity in overall performance, with the kindergarten children obtaining substantially lower scores than the first or second graders. In the comparison of second-grade good and poor readers, there was a significant interaction between groups, presentation rates, and type of stimulus. The findings are discussed in terms of their implications for a general model of performance on the sound blending task, as well as their value for interpreting individual differences on the task.     

Sex differences in performance on three novel continuous response tasks

The Dynavision apparatus was used to assess psychomotor differences between men and women first-time users. Subjects, 50 men and 76 women, were tested on three 60-sec. Dynavision response tasks of graded difficulty. An analysis of variance with repeated measures indicated that men performed significantly better than women on all tasks. Performances on all tasks were also significantly different from each other within both sexes (p < or = .05). Furthermore, a significant interaction between sex and task was based on a greater drop in performance on the most complex task for women than for men.