Improved intertask coordination after extensive dual-task practice

This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual–manual task and an auditory–vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice group was transferred to the same dual-task situation as that for the hybrid practice group (Experiment 1), both groups were transferred to a dual-task situation with a new visual task (Experiment 2), and both groups were transferred to a dual-task situation with a new auditory task matched in task difficulty (Experiment 3). The results show a dual-task performance advantage in the hybrid practice group over the single-task practice group in the practised dual-task situation (Experiment 1), the manipulated visual-task situation (Experiment 2), and the manipulated auditory-task situation (Experiment 3). In all experiments, the dual-task performance advantage was consistently found for the auditory task only. These findings suggest that extended dual-task practice improves the skill to coordinate two tasks, which may be defined as an accelerated switching operation between both tasks. This skill is relatively robust against changes of the component visual and auditory tasks. We discuss how the finding of task coordination could be integrated in present models of dual-task research.     

Improved intertask coordination after extensive dual-task practice

This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual-manual task and an auditory-vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice group was transferred to the same dual-task situation as that for the hybrid practice group (Experiment 1), both groups were transferred to a dual-task situation with a new visual task (Experiment 2), and both groups were transferred to a dual-task situation with a new auditory task matched in task difficulty (Experiment 3). The results show a dual-task performance advantage in the hybrid practice group over the single-task practice group in the practised dual-task situation (Experiment 1), the manipulated visual-task situation (Experiment 2), and the manipulated auditory-task situation (Experiment 3). In all experiments, the dual-task performance advantage was consistently found for the auditory task only. These findings suggest that extended dual-task practice improves the skill to coordinate two tasks, which may be defined as an accelerated switching operation between both tasks. This skill is relatively robust against changes of the component visual and auditory tasks. We discuss how the finding of task coordination could be integrated in present models of dual-task research.     

The path to glory is paved with hierarchy: when hierarchical differentiation increases group effectiveness

Two experiments examined the psychological and biological antecedents of hierarchical differentiation and the resulting consequences for productivity and conflict within small groups. In Experiment 1, which used a priming manipulation, hierarchically differentiated groups (i.e., groups comprising 1 high-power-primed, 1 low-power-primed, and 1 baseline individual) performed better on a procedurally interdependent task than did groups comprising exclusively either all high-power-primed or all low-power-primed individuals. There were no effects of hierarchical differentiation on performance on a procedurally independent task. Experiment 2 used a biological marker of dominance motivation (prenatal testosterone exposure as measured by a digit-length ratio) to manipulate hierarchical differentiation. The pattern of results from Experiment 1 was replicated; mixed-testosterone groups achieved greater productivity than did groups comprising all high-testosterone or all low-testosterone individuals. Furthermore, intragroup conflict mediated the productivity decrements for the high-testosterone but not the low-testosterone groups. This research suggests possible directions for future research and the need to further delineate the conditions and types of hierarchy under which hierarchical differentiation enhances rather than undermines group effectiveness.     

Attentional focus on suprapostural tasks affects balance learning

We examined whether the attentional focus induced by a suprapostural task has an influence on the learning of a dynamic balance task. Participants balanced on a stabilometer and were required to hold a tube horizontal with both hands. In Experiment 1, the tube contained a table tennis ball, whereas it was empty in Experiment 2. Participants were instructed to focus on either their hands (internal focus) or the tube (external focus). We measured balance performance as a function of attentional focus on the suprapostural task. Participants practised for 2 days, and on Day 3 they performed a retention test (with tube) and a transfer test (without tube). In both experiments, the external focus groups demonstrated more effective retention and transfer than the internal focus groups (and than the control group in transfer in Experiment 2). In addition, in Experiment 1 the external group was superior in keeping the tube horizontal. This suggests that the performer's attentional focus regarding the suprapostural task affects performance and learning not only of the suprapostural task itself, but also of the postural task.     

Conflict's consequences: effects of social motives on postnegotiation creative and convergent group functioning and performance

Two studies tested the effects of social motives during negotiation on postnegotiation group performance. In both experiments, a prosocial or a proself motivation was induced, and participants negotiated in 3-person groups about a joint market. In Experiment 1, groups subsequently performed an advertisement task. Consistent with the authors' predictions, results showed that proself groups performed worse on the convergent aspects of this task but better on the divergent aspects than prosocial groups. In Experiment 2, the authors manipulated social motive and negotiation (negotiation vs. no negotiation), and groups performed a creativity task (requiring divergent performance) or a planning task (requiring convergent performance). Proself groups showed greater dedication, functioned more effectively, and performed better than prosocial groups on the creativity task, whereas prosocial groups showed greater dedication, functioned more effectively, and performed better than proself groups on the planning task, and these effects only occurred when the task was preceded by group negotiation.     

Irrelevant thoughts,emotional mood states,and cognitive task performance

In two experiments, we investigated the relationship shared by irrelevant thoughts, emotional mood states, and cognitive task performance. At an empirical level, irrelevant thoughts were defined as thoughts that did not facilitate successful task performance. We used the same general procedure for both experiments: three groups of college students received happy-, neutral-(control), or sad-mood inductions and performed a memory task. The procedure for obtaining thoughts varied between experiments. The subjects in Experiment 1 listed their thoughts after the memory recall task. In Experiment 2, the subjects were tape-recorded while performing a memory task and producing concurrent verbal protocols. The subjects in both experiments then judged their thoughts in terms of frequency, intensity, and irrelevance. We found a similar pattern of results in both experiments: (1) The proportions of irrelevant thoughts and recall performance were negatively related, and (2) happy and sad students produced reliably greater proportions of irrelevant thoughts than did neutral (control) students.     

Familiarity effects in visual comparison tasks and their implications for studying human intelligence.

Two experiments were carried out to study the effect of prior knowledge on cognitive processes related to human intelligence by examining its role in defining task novelty. In Experiment 1, Ss performed a letter-matching task involving same-different judgments based on 4 rules of sameness: physical identity, form, system, and name. When the stimuli were unfamiliar, performance on the name classification task was correlated with measures of fluid abilities, whereas when the stimuli were familiar, performance on this task was not correlated with measures of fluid abilities. In Experiment 2, Ss performed 3 different forms of a mental rotation task. When the stimuli were unfamiliar, the slope of the rotation function was correlated with a test of fluid ability, whereas when the stimuli were familiar, the slope of the rotation function was not correlated with a test of fluid ability. These results are discussed in terms of their implications for understanding the nature of task complexity and the way knowledge and processing interact in the development of skilled performance.     

The effect of motivation and positive affect on ego depletion: Replenishment versus release mechanism

In this study, 2 experiments were conducted to investigate whether motivation and positive affect can alleviate ego depletion and to elucidate their possible mechanisms. In Experiment 1, a crossing‐out‐letter task was adapted to reach an ego depletion state for Chinese participants. Participants were then randomly assigned to the extrinsic motivation group, the positive affect group or the depletion control group. After the experimental treatment, a dumbbell task was used to measure participants' remaining self‐regulatory resources. The results showed that participants in the motivation and positive affect groups performed better on the dumbbell task than participants in the depletion control group. Experiment 2 was similar to Experiment 1 except that participants were asked to perform an additional unexpected dumbbell task after a neutral video following the above procedure. The results of Experiment 1 were replicated; however, participants' performance on the additional dumbbell task differed. The positive affect group performed better than the depletion control group, indicating an increase in self‐regulatory resources and thus supporting the replenishment effect of positive affect. No significant difference was found between the motivation group and the depletion control group.     

Increased performance with increased personal control: A self-presentation interpretation

Past research has found that allowing people a choice of task materials sometimes increases performance on the task. A self-presentation interpretation for this effect was tested and supported in two experiments. In Experiment 1, subjects performed better on a paired-associate learning task when allowed to select some of the words for the test, but only when they believed the experimenter would know of their choice and their performance. In Experiment 2, subjects performed better on what they believed was a cognitive abilities test when allowed to select the test, but again only when they believed their performance would be known by those who were aware of the choice. It was concluded that providing increased control over a task often results in increased concern for self-presentation that may lead to a better performance on the task.     

Individual Versus Group Decision Making: Social Comparison in Goals for Individual Task Performance

This experiment compares the decisions of individuals and groups on goals for the performance expected from individuals on a problem-solving or an error-checking task. For both tasks, two versions were constructed to reflect low and high levels of task difficulty. Predictions from two different social comparison of abilities approaches were formulated, with the social comparison based on success approach predicting that group goals would be easier than individual goals, while social comparison based on performance predicted the opposite pattern. Consistent with the social comparison based on success predictions, group goals were observed to be significantly less difficult than individual goals for both tasks, both levels of task difficulty, and for both an initial and a second goal-setting occasion. Of particular interest was a finding that the easier group goals reflected group member preferences for easy goals in anticipation of group decision making. It is proposed that social factors such as evaluation apprehension and social comparison may be responsible for the differences observed in group and individual goal decisions, and that social factors may have an important role in a variety of goal-setting situations.     

The effects of member expertise on group decision-making and performance

This study assesses the effects of member expertise on group decision-making and group performance. Three-person cooperative groups and three independent individuals solved either an easy or moderately difficult version of the deductive logic game Mastermind. Experimental groups were given veridical performance information, i.e., the members' rankings on prior individual administrations of the task. Control groups were not provided with this information. Results supported the predictions of this study: (1) groups gave more weight to the input of their highest performing members with the group decision-making process being best approximated by post hoc “expert weighted” social decision schemes and (2) groups performed at the level of the best of an equivalent number of individuals.     

The relation between spatial and mathematical abilities: Potential factors underlying suppression

Two experiments examined possible factors underlying the finding that grades in mathematics act as a suppressor variable in the relation between spatial abilities and gender. Specifically, the role of reading abilities was investigated in Experiment 1 by using English grades as a measure of these abilities. Experiment 2 was based on the notion that time pressures are involved at some level in both spatial performance and mathematics grades. The influence of this factor was examined by administering a spatial task with or without time limit and examining the suppression effect in both conditions. In both experiments, participants completed the Mental Rotations Test (MRT) as a measure of spatial ability. In Experiment 1, all participants were tested with limited time to complete the MRT and they were required to report their high school course grades in mathematics and English. Results revealed that both grades in high school mathematics and English produced significant suppression. However, the amount of suppression produced by each measure was similar. Therefore, the prediction that suppression would be greater with English than with mathematics grades was not supported. Experiment 2 involved testing in groups or individually with or without time limits on the MRT, whereas the Water Level Test was administered untimed, and only grades in mathematics were obtained from participants. Results supported the prediction that the suppression effect is greater when time limits are applied than when they are not. Implications of the results for an explanation of the observed suppression are discussed. Emphasis is placed on the difficulties inherent to the identification of factors underlying suppression.     

Effects of monetary incentives on task switching

In two experiments, effects of incentives on task switching were investigated. Incentives were provided as a monetary bonus. In both experiments, the availability of a bonus varied on a trial-to-trial basis. The main difference between the experiments relates to the association of incentives to individual tasks. In Experiment 1, the association of incentives to individual tasks was fixed. Under these conditions, the effect of incentives was largely due to reward expectancy. Switch costs were reduced to statistical insignificance. This was true even with the task that was not associated with a bonus. In Experiment 2, there was a variable association of incentives to individual tasks. Under these conditions, the reward expectancy effect was bound to conditions with a well-established bonus-task association. In conditions in which the bonus-task association was not established in advance, enhanced performance of the bonus task was accompanied by performance decrements with the task that was not associated with a bonus. Reward expectancy affected mainly the general level of performance. The outcome of this study may also inform recently suggested neurobiological accounts about the temporal dynamics of reward processing.     

Breaking a habit: A further role of the phonological loop in action control

Recent research has suggested that keeping track of a task goal in rapid task switching may depend on the phonological loop component of working memory. In this study, we investigated whether the phonological loop plays a similar role when a single switch extending over several trials is required after many trials on which one has performed a competing task. Participants were shown pairs of digits varying in numerical and physical size, and they were required to decide which digit was numerically or physically larger. An experimental cycle consisted of four blocks of 24 trials. In Experiment 1, participants in the task change groups performed the numerical-size judgment task during the first three blocks, and then changed to the physical-size judgment task in the fourth. Participants in the continuation groups performed only the physical-size judgment task throughout all four blocks. We found negative effects of articulatory suppression on the fourth block, but only in the task change groups. Experiment 2 was a replication, with the modification that both groups received identical instructions and practice. Experiment 3 was a further replication using numerical-size judgment as the target task. The results showed a pattern similar to that from Experiment 1, with negative effects of articulatory suppression found only in the task change group. The congruity of numerical and physical size had a reliable effect on performance in all three experiments, but unlike the task change, it did not reliably interact with articulatory suppression. The results suggest that in addition to its well-established role in rapid task switching, the phonological loop also contributes to active goal maintenance in longer-term action control.     

The whole is indeed more than the sum of its parts: perceptual averaging in the absence of individual item representation

We tested Ariely's (2001) proposal that the visual system represents the overall statistical properties of sets of objects against alternative accounts of rapid averaging involving sub-sampling strategies. In four experiments, observers could rapidly extract the mean size of a set of circles presented in an RSVP sequence, but could not reliably identify individual members. Experiment 1 contrasted performance on a member identification task with performance on a mean judgment task, and showed that the tasks could be dissociated based on whether the test probe was presented before or after the sequence, suggesting that member identification and mean judgment are subserved by different mechanisms. In Experiment 2, we confirmed that when given a choice between a probe corresponding to the mean size of the set and a foil corresponding to the mean of the smallest and largest items only, the former is preferred to the latter, even when observers are explicitly instructed to average only the smallest and largest items. Experiment 3 showed that a test item corresponding to the mean size of the set could be reliably discriminated from a foil but the largest item in the set, differing by an equivalent amount, could not. In Experiment 4, observers rejected test items dissimilar to the mean size of the set in a member identification task, favoring test items that corresponded to the mean of the set over items that were actually shown. These findings suggest that mean representation is accomplished without explicitly encoding individual items.     

Being distinctive versus being conspicuous: The effects of numeric status and sex-stereotyped tasks on individual performance in groups

Being in the numeric minority (e.g., being a solo woman in a group of men) influences how well a person performs within a work group. But being the solo member is only one way in which people can be atypical in a group; a person can also represent a social or demographic category that has not typically been associated with the task that the group is working on. Using a design with four categories of group composition (minority, balanced, majority, homogeneous) and two categories of tasks (sex-typical, sex-atypical) we found that the sex composition of the group interacted with the sex typicality of the task to influence both positive deferrals by group members and individual performance in groups. But, rather than consistently reducing performance as prior research has suggested, being numerically atypical enhanced individual performance when the task was typical for that person’s sex. Further, positive deferrals mediated between the interaction of numeric composition and task typicality in influencing individual performance suggesting that both majority group members and the solo member affect one another’s performance in groups. We conclude by discussing why understanding the interplay between these two sources of stereotyping, numeric composition and task typicality, is important for understanding the social nature of individual performance in groups.     

Cognitive, perceptual-speed, and psychomotor determinants of individual differences during skill acquisition

The authors describe a series of experiments that explore 3 major ability determinants of individual differences in skill acquisition in the context of prior theory (e.g., P.L. Ackerman, 1988) and subsequent empirical and theoretical research. Experiment 1 assessed the predictability of individual differences in asymptotic skill levels on the Kanfer-Ackerman Air Traffic Controller (ATC) task. Experiment 2 provided an exploration of the construct space underlying perceptual-speed abilities. Experiment 3 concerned an evaluation of theoretical predictions for individual differences in performance over skill development in a complex air traffic control simulation task (TRACON) and the ATC task, with an extensive battery of general and perceptual-speed measures, along with a newly developed PC-based suite of psychomotor ability measures. Evidence addressing the predictability of individual differences in performance at early, intermediate, and asymptotic levels of practice is presented.     

Worse than feared? Failure induction modulates the electrophysiological signature of error monitoring during subsequent learning

This study examined how self-relevant failure influences error monitoring—as reflected in the error-related negativity (Ne/ERN) —and behavioral adaptation during subsequent feedback-based learning. We applied two phases (pre- and posttest) of a probabilistic learning task. Between pre- and posttest, participants were assigned to one of two groups receiving either failure feedback or no feedback during a visual search task described as diagnostic of intellectual abilities. To disentangle the effects of failure and motivational disengagement due to prolonged task performance, we linked the posttest to intelligence (Experiment 1) or described it in neutral terms (Experiment 2). Failure induction was associated with an increase in Ne/ERN amplitude at posttest in both experiments, although there were no differences in overall performance. In contrast, the Ne/ERN decreased from pre- to posttest in the no-failure-feedback group, particularly in Experiment 2. Furthermore, failure feedback affected error-related behavioral adjustments, suggesting a shift toward a reactive, error-driven mode of behavior control. These findings emphasize the importance of affective-motivational state in error processing and subsequent behavioral adaptation.     

The contributions of strategy use to working memory span: a comparison of strategy assessment methods

In two experiments, we tested whether individual differences in strategy production account for individual differences in performance on a working memory span task. We measured the strategies used during a standard experimenter-paced operation span (OSPAN) task by having participants make both set-by-set reports of strategy use for individual item sets and global reports of strategy use. In Experiment 1, although normatively effective strategies were self-reported on only a small proportion of OSPAN sets, individual differences in effective strategy use correlated with span performance. Experiment 2 replicated this outcome using a sample of 100 participants but, as important, it demonstrated that individual differences in effective strategy use did not mediate the relationship between OSPAN and measures of verbal ability. Discussion focuses on the interpretation of strategy-span relationships and the relative utility of general reports of strategy use versus the set-by-set reports introduced here for the OSPAN task.     

The Bright and Dark Sides of Performance-Dependent Monetary Rewards: Evidence From Visual Perception Tasks

Studies have shown that performance-dependent monetary rewards facilitate visual perception. However, no study has examined whether such a positive effect is limited to the rewarded task or may be generalized to other tasks. In the current study, two groups of people were asked to perform two visual perception tasks, one being a reward-relevant task and the other being a reward-irrelevant task. For the reward-relevant task, the experimental group received performance-dependent monetary rewards, whereas the control group did not. For the reward-irrelevant task, both groups were not rewarded. The two tasks were randomly intermixed trial by trial (Experiment 1) or presented block by block (Experiment 2) or session by session (Experiments 3a, 3b, and 3c). Results showed that performance-dependent monetary rewards improved participants' performance on the relevant task in all experiments and impaired their performance on the irrelevant task in Experiments 2, 3a, 3b, and 3c. These results suggested that monetary rewards might incur a cost on reward-irrelevant tasks. Finally, the benefit of monetary rewards disappeared when they were no longer provided during the final session. This is the first study that reveals both the bright and dark sides of the performance-dependent monetary rewards in visual perception.