Individual differences in information processing: An investigation of intellectual abilities and task performance during practice

A conceptual theory for predicting the relations between intellectual abilities and performance during task practice is proposed and evaluated. This macro-theory integrates modern hierarchical theories of intellectual abilities with information-processing theories of automatic and controlled processing (Schneider & Shiffrin, 1977) and performance-resource functions (Norman & Bobrow, 1975). An empirical evaluation of the theory is provided from an experiment with high school and college students. Subjects practiced for several hours on verbal and spatial memory tasks with consistent and varied information-processing manipulations. Derived correlations between ability factors and task performance measures indicate support for the theory and support for linkage of the concepts of intellectual abilities and attentional resources.     

The role of attentional networks in voluntary task switching

Coordination of task choice and performance in multitask environments likely involves attentional processes. Subjects completed the Attention Network Test (ANT) and a voluntary task-switching procedure. Task choice, but not task performance, was correlated with the executive score from the ANT, with higher switch probabilities for subjects with more efficient executive control networks. Task performance was correlated with the alerting score, with larger response time switch costs for subjects with larger alerting scores. The dissociation of task choice and task performance measures in terms of the pattern of correlations with attentional networks suggests that these two measures may reflect different cognitive processes engaged in voluntary task switching.     

Measurements of auditory-verbal STM span in aphasia: effects of item, task, and lexical impairment

In the first part of this study, we investigated effects of item and task type on span performance in a group of aphasic individuals with word processing and STM deficits. Group analyses revealed significant effects of item on span performance with span being greater for digits than for words. We also investigated associations between subjects' lexical-semantic and phonological processing abilities and performance on four measures of verbal span (digit and word span, each varied for type of response, verbal vs. pointing) as well as one measure of nonverbal span. We predicted and found that the patterns of association between verbal span tasks and lexical abilities reflected the integrity of language processes and representations deployed in each paradigm used to assess span. Performance on the pointing span task, which engages both lexical-semantic and phonological processes, correlated with measures of both lexical-semantic and phonological abilities. Performance on repetition span, which engages primarily input and output phonological processes, correlated with measures of phonological abilities but not measures of lexical-semantic abilities. However, when partial correlations were performed for two subject groups based on their relative preservation of lexical-semantic ability (less or more than phonological ability), repetition span correlated with lexical-semantic measures only in the subgroup with relatively impaired lexical-semantics. Additionally, performance on the nonverbal span task correlated with measures of phonological abilities, suggesting either a general cognitive deficit affecting verbal and nonverbal STM or possibly, the use of a verbal strategy to perform this task. Our discussion focuses on the interpretation of span measurements in clinical practice and research, as well as the implications of these data for theories of short-term memory and word processing.     

The role of pattern recognition in children's exact enumeration of small numbers

Enumeration can be accomplished by subitizing, counting, estimation, and combinations of these processes. We investigated whether the dissociation between subitizing and counting can be observed in 4‐ to 6‐year‐olds and studied whether the maximum number of elements that can be subitized changes with age. To detect a dissociation between subitizing and counting, it is tested whether task manipulations have different effects in the subitizing than in the counting range. Task manipulations concerned duration of presentation of elements (limited, unlimited) and configuration of elements (random, line, dice). In Study 1, forty‐nine 4‐ and 5‐year‐olds were tested with a computerized enumeration task. Study 2 concerned data from 4‐, 5‐, and 6‐year‐olds, collected with Math Garden, a computer‐adaptive application to practice math. Both task manipulations affected performance in the counting, but not the subitizing range, supporting the conclusion that children use two distinct enumeration processes in the two ranges. In all age groups, the maximum number of elements that could be subitized was three. The strong effect of configuration of elements suggests that subitizing might be based on a general ability of pattern recognition.     

Generic cognitive adaptations to task interference in task switching

The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing only the first trials of each run. Response times (RTs) and error rates were measured for task switching and task repetition conditions. Task interference was varied as a function of response-cue interval (RCI of 300 and 900 ms), that is, the interval between the task runs. Keeping the response-stimulus interval within the task runs constant at 300 ms allowed the disentangling of the direct effects of RCI manipulation on performance (first trials) from the general effects on performance (both trials in the run). The data showed similar performance improvement due to RCI increase on both trials in the task run. Furthermore, increasing RCI improved both switch and repetition performance to a similar extent. Together, our findings provide further evidence for accounts stressing generic effects of proactive task interference in task switching.     

On the relationship between task performance and associated verbalizable knowledge

Three experiments explore the relationship between performance on a cognitive task and the explicit or reportable knowledge associated with that performance (assessed here by written post-task questionnaire). They examine how this relationship is affected by task experience, verbal instruction and concurrent verbalization. It is shown that practice significantly improves ability to control semi-complex computer-implemented systems but has no effect on the ability to answer related questions. In contrast, verbal instruction significantly improves ability to answer questions but has no effect on control performance. Verbal instruction combined with concurrent verbalization does lead to a significant improvement in control scores. Verbalization alone, however, has no effect on task performance or question answering.     

The effects of age and task context on Stroop task performance

In this study, we investigated the impact of age and task context on Stroop task performance, using error scores, response latencies, and process dissociation estimates (e.g., Lindsay & Jacoby, 1994). Across three experiments, the findings showed that although older adults were able to evaluate Stroop task demands and modify their representations of task context in response to this knowledge, they were less able to maintain and update these representations on a trial-by-trial basis in tasks with high stimulus uncertainty or ambiguity. Moreover, although there was no age-related decline in the ability to modulate print color information, older adults were consistently less able to control the activation of conflicting word information. Together, these findings suggest that whereas age differences in the Stroop task may be magnified under conditions that promote transient failures to maintain task context, the primary source of these differences seems to be a more enduring decline in the efficiency of processes that are responsible for suppressing the activation of irrelevant lexical information.     

Personality predicts prospective memory task performance: an adult lifespan study

Do interindividual differences in prospective memory task performance reflect individual differences in personality and lifestyle? Do the cognitive abilities known to change with age retain their power to predict episodic prospective memory task performance after controlling for personality and lifestyle variables, and do personality and lifestyle variables offer predictive power apart from that provided by cognitive ability measures? To answer these questions, we conducted a study with community‐living healthy individuals (n= 141) between 18 and 81 years of age. They completed three different episodic prospective memory tasks – two laboratory tasks and one field task – as well as various measures of personality, lifestyle, and cognitive ability. The results indicated that personality and lifestyle reliably predicted who will succeed and who will fail on all three episodic prospective memory tasks. Conscientiousness predicted performance on two of the prospective memory tasks; socially prescribed perfectionism and neuroticism each predicted performance on one of the prospective memory tasks. Cognitive ability predicted performance on one of the laboratory prospective memory tasks but not on the other two prospective memory tasks. After we controlled for individual differences in personality and lifestyle variables, cognitive ability was no longer able to predict performance on the laboratory prospective memory task. By contrast, controlling for cognitive ability had no influence on the predictive power of the personality and lifestyle variables.     

The significance of task significance: Job performance effects, relational mechanisms, and boundary conditions

Does task significance increase job performance? Correlational designs and confounded manipulations have prevented researchers from assessing the causal impact of task significance on job performance. To address this gap, 3 field experiments examined the performance effects, relational mechanisms, and boundary conditions of task significance. In Experiment 1, fundraising callers who received a task significance intervention increased their levels of job performance relative to callers in 2 other conditions and to their own prior performance. In Experiment 2, task significance increased the job dedication and helping behavior of lifeguards, and these effects were mediated by increases in perceptions of social impact and social worth. In Experiment 3, conscientiousness and prosocial values moderated the effects of task significance on the performance of new fundraising callers. The results provide fresh insights into the effects, relational mechanisms, and boundary conditions of task significance, offering noteworthy implications for theory, research, and practice on job design, social information processing, and work motivation and performance.     

Signal-to-noise ratio sensitivity in ERPs to stimulus and task complexity: different effects for early and late components

Traditionally, early and late ERP components are evaluated by the latency and amplitude of their components. We investigated their signal-to-noise (S/N) ratio: how well individual ERP trials correlate with their overall averaged ERP. High correlations indicate minimal noise or individual trial variability while low correlations reflect greater trial variability. Continuous EEG activity was recorded from 57 university students during single- and dual-task conditions in a within-subjects paradigm (easy and difficult tone discrimination; with and without verbal working memory task). For early components, the addition of the second task increased the correlations between the individual trials and the averaged ERPs. For the late components, both the addition of the second task and an increase in stimulus difficulty decreased individual trial correlations. Results suggest that the S/N ratio analysis is a useful method for highlighting differences between early and late components associated with stimulus processing manipulations.     

Semantic processing in an incidental learning task

Recent research on implicit learning has suggested that perceptual learning could account for the observed dissociation between task performance and associated verbal knowledge. We report three experiments that investigate whether performance in an incidental learning task is based on knowledge held primarily at a perceptual or a semantic level. The results indicate that, under the task conditions described, processing of the semantic content of the stimuli is an automatic process. The implications of this result for implicit learning are discussed.     

Goal-performance relations: The effects of initial task complexity and task practice

The current study was conducted to examine the effects of task complexity and task practice (trials) on the goal-performance relationship. Specific, difficult goal assignments were predicted to enhance performance on a complex task only in later task practice. On a simpler task, specific, difficult goal assignments were predicted to enhance performance in early task practice and to disrupt performance in later task practice. The results indicated that goals exerted the predicted effects in the simple task version but had no effect in the complex task version. Possible relationships between amount of task practice and stages of skill acquisition are discussed for tasks differing in complexity. The results are also discussed in terms of cognitive resource demands and self-regulatory processes. Implications for the effectiveness of goals in relation to task complexity and task trials are also discussed.This article is based on the senior author's dissertation at the University of Minnesota. We thank Milt Hakel, Allan Jones, and Bart Osburn for their helpful comments on earlier drafts. The authors also wish to thank Phil Ackerman and John Campbell for their insightful comments throughout the research project and other members of the dissertation committee: Rich Arvey, Mark Davisson, and Marvin Dunnette.This research was partially supported by the Air Force Office of Scientific Research Project LAMP, under the auspices of the Air Force Human Resources Laboratory (contract AFOSR-87-0234) and by a Research Initiation Grant from the University of Houston.Portions of this data were presented at the American Psychological Association Meetings, Atlanta, 1988.     

Determinants of task performance and invested effort: a need for closure by relative cognitive capacity interaction analysis

This study examines the simultaneous effects of need for closure (NFC) and relative cognitive capacity on invested effort and task performance within the integrative analysis framework using behavioral data. Two main results were obtained. First, the authors revealed a significant interaction effect between relative cognitive capacity (manipulated through task difficulty) and NFC (manipulated through time pressure, noise, and fear of invalidity as well as assessed by an individual differences measure) on effort investment. Second, contrary to dispositional NFC, manipulations yielded a "dual effect" because they negatively affected task performance as well as invested effort. The latter result was interpreted as an indication that noise and time pressure manipulations also tax cognitive resources. The two main findings are discussed and the authors go further into the divergences between dispositional and manipulated NFC.     

Self-assessment and task performance

The present study tested the idea that the amount of effort expended in task performance is a function of the amount of uncertainty in one's ability level the resulting outcomes are expected to reduce. Two determinants of expected uncertainty reduction were manipulated: prior uncertainty about one's ability level and the diagnosticity of the task. Subjects first performed an initial task and then received fictitious feedback to manipulate their prior uncertainty. To induce low uncertainty, the feedback implied that the subjects are highly likely to have either low, intermediate, or a high level of ability. To induce high uncertainty, the feedback implied that the various ability levels were equally probable. Subjects then performed a task whose perceived diagnosticity regarding the ability under consideration was varied. As expected, subjects who were highly uncertain about their ability level performed better than subjects who were relatively certain they possessed either low, intermediate, or a high level of ability. Performance also improved with task diagnosticity, and the effect of task diagnosticity on performance was more pronounced when prior uncertainty was high than when it was low. Past research on the relationship between prior feedback and subsequent performance was discussed in light of the present results and a self-assessment model of achievement behavior.     

Dissociations between reaction times and temporal order judgments: a diffusion model approach

A diffusion model for simple reaction time (RT) and temporal order judgment (TOJ) tasks was developed to account for a commonly observed dissociation between these 2 tasks: Most stimulus manipulations (e.g., intensity) have larger effects in RT tasks than in TOJ tasks. The model assumes that a detection criterion determines the level of sensory evidence needed to conclude that a stimulus has been presented. Analysis of the performance that would be achieved with different possible criterion settings revealed that performance was optimal with a lower criterion setting for the TOJ task than for the RT task. In addition, the model predicts that effects of stimulus manipulations should increase with the size of the detection criterion. Thus, the model suggests that commonly observed dissociations between RT and TOJ tasks may simply be due to performance optimization in the face of conflicting task demands.     

An investigation of the relationship between trait emotional intelligence and emotional task performance

This study examined the relationships between trait emotional intelligence (EI) and tasks involving the recognition of facial expressions of emotion. Two facial expression recognition tasks using the inspection time (IT) paradigm assessed speed of emotional information processing. An unspeeded emotion recognition task was also included, and a symbol IT task was used to assess speed of processing of non-emotional information. It was found that scores on all three emotion-related tasks were strongly intercorrelated, as were scores on the three IT tasks. The two emotional IT scores remained significantly correlated when symbol IT performance was partialled out. This finding, together with the associations between the speeded (IT) and unspeeded face tasks suggests that the association between the emotional IT tasks is not entirely accounted for by general processing speed, and that a general emotion-processing ability also contributes to performance on these tasks. An EI subscale assessing Appraisal of Emotions was significantly correlated with performance on the emotional IT tasks, suggesting that self-reports of emotional perception ability do relate to performance measures.     

Performance on a coincidence timing task correlates with intelligence

Timed performance measures from a coincidence timing (CT) task taking about 10 minutes are shown to have significant correlations with psychometric general intelligence in a group of 56 children. This task required subjects to press a key when a moving target is coincident with a stationary line. The mean absolute error across three conditions (CTE) correlated - .294 with Raven's Standard Progressive Matrices (SPM) scores but was sex biased, with girls being less accurate than boys. The mean intrasubject standard deviation or consistency (CTC) correlated - .359 and showed no sex bias. The overall performance score (CTP, the sum of CTE and CTC) correlated - .357, and had a smaller but significant sex bias. The correlations partialing out sex were - .363, - .371, - .369 for CTE, CTC, and CTP, respectively. It is suggested that CT tasks are a useful addition to the already known timed performance measures that correlate with intelligence and can provide a tool to increase our understanding of psychometric intelligence.     

Mental planning and the Tower of London task

The Tower of London (TOL) task has been used extensively as a test of planning ability in neuropsychological patients and normal populations. Participants are asked to preplan mentally a sequence of moves to match a start set of discs to a goal, and then to execute the moves one by one. The mental preplanning stage has been identified as critical to efficient performance. The current experiments examined whether manipulations of mental preplanning influence performance on the TOL. In Experiment 1, the effect of different planning instructions was examined. Those told to make full mental plans spent considerably longer in planning than participants given no specific planning instructions, yet there was no effect of instruction condition on the efficiency of executing plans. Experiment 2 investigated whether people were able to plan mentally, by looking at their ability to identify intermediate states of an optimum mental plan. Results indicated that most individuals could make accurate preplans up to two subgoals ahead, but not three. However, making an efficient preplan did not result in better subsequent execution of moves to solve the TOL trial. It is concluded that people can make effective mental plans for a limited number of moves. However, on the TOL task, mental preplanning does not offer benefits in terms of quicker performance, or more accurate solution. The nature of planning in the TOL task is therefore questioned.     

Interference resolution in the elderly: evidence suggestive of differences in strategy on measures of prepotent inhibition and dual task processing

The ability to effectively resolve interference was investigated in young and elderly participants using a test of inhibition and a dual task measure. The tasks stressed the ability to suppress prepotent responding, and balance primary and secondary task demands, respectively. Successful performance on both measures hinged on the ability to minimize the distraction generated between competing aspects of each task. Increasing demands resulted in performance decrements despite titration for individual differences in span size and generalized slowing. These were more pronounced on the hardest condition of each task, especially in older participants. Furthermore, the nature of the decrements suggested the use of different strategies between groups. It is argued that a fundamental source of the age-associated variability in cognition is due to compromised ability to effectively resolve interference, and cannot be sufficiently explained by memory span differences or generalized slowing.     

Assessing Sequential Knowledge through Performance Measures: The Influence of Short-term Sequential Effects

Studies on implicit sequence learning have employed the methodology oftask dissociations to show that tasks of conscious memory fail to reveal knowledge expressed in performance measures of learning. One critical requirement of this methodology is that the conscious memory tests tap the same type of information that is expressed in performance measures. When a deterministic sequence is being repeated during practice, identification of the exact type of sequential information that is learned can be achieved by a trial-by-trial comparison between the practised sequence and a control sequence. In Experiment 1 we examine whether short-term sequential effects are present in choice response time tasks and may therefore contaminate this trial-by-trial comparison. In Experiment 2 we control for these effects and demonstrate how specification of the exact sub-parts of the sequence that are learned is necessary before testing for task dissociations. Our findings indicate a dissociation between a response time task and a free generation task. This dissociation, however, is obtained for selected sub-parts of the sequence and may be caused by the insensitivity of the free-generation task to low confidence knowledge.