The influence of motor expertise and motor experience on action and actor recognition

Two experiments examined whether different levels of motor and visual experience influence action perception and whether this effect depends on the type of perceptual task. Within an action recognition task (Experiment 1), professional basketball players and novice college students were asked to identify basketball dribbles from point-light displays. Results showed faster reaction times and greater accuracy in experts, but no advantage when observing either own or teammates’ actions compared with unknown expert players. Within an actor recognition task (Experiment 2), the same expert players were asked to identify the model actors. Results showed poor discrimination between teammates and players from another team, but a more accurate assignment of own actions to the own team. When asked to name the actor, experts recognised themselves slightly better than teammates. Results support the hypothesis that motor experience influences action recognition. They also show that the influence of motor experience on the perception of own actions depends on the type of perceptual task.     

He throws like a girl (but only when he's sad): emotion affects sex-decoding of biological motion displays

Gender stereotypes have been implicated in sex-typed perceptions of facial emotion. Such interpretations were recently called into question because facial cues of emotion are confounded with sexually dimorphic facial cues. Here we examine the role of visual cues and gender stereotypes in perceptions of biological motion displays, thus overcoming the morphological confounding inherent in facial displays. In four studies, participants’ judgments revealed gender stereotyping. Observers accurately perceived emotion from biological motion displays (Study 1), and this affected sex categorizations. Angry displays were overwhelmingly judged to be men; sad displays were judged to be women (Studies 2–4). Moreover, this pattern remained strong when stimuli were equated for velocity (Study 3). We argue that these results were obtained because perceivers applied gender stereotypes of emotion to infer sex category (Study 4). Implications for both vision sciences and social psychology are discussed.     

Peak velocity as a cue in audiovisual synchrony perception of rhythmic stimuli

This study investigated audiovisual synchrony perception in a rhythmic context, where the sound was not consequent upon the observed movement. Participants judged synchrony between a bouncing point-light figure and an auditory rhythm in two experiments. Two questions were of interest: (1) whether the reference in the visual movement, with which the auditory beat should coincide, relies on a position or a velocity cue; (2) whether the figure form and motion profile affect synchrony perception. Experiment 1 required synchrony judgment with regard to the same (lowest) position of the movement in four visual conditions: two figure forms (human or non-human) combined with two motion profiles (human or ball trajectory). Whereas figure form did not affect synchrony perception, the point of subjective simultaneity differed between the two motions, suggesting that participants adopted the peak velocity in each downward trajectory as their visual reference. Experiment 2 further demonstrated that, when judgment was required with regard to the highest position, the maximal synchrony response was considerably low for ball motion, which lacked a peak velocity in the upward trajectory. The finding of peak velocity as a cue parallels results of visuomotor synchronization tasks employing biological stimuli, suggesting that synchrony judgment with rhythmic motions relies on the perceived visual beat.     

Young children's change in strategies of size comparison: Effects of task repetition and strategy evaluation

This study examined how young children change their strategies for size comparison. Twenty-two 5 and 6-year-old children were asked to compare the sizes of geometric figures and their strategies were observed once a week over three weeks. Half of the children were also asked to evaluate presented strategies for comparing geometric figures. It was found that over three weeks not only children who evaluated the strategies but also children who did not increased correct responses, the strategy of placing one figure on another, and the strategy of adjusting two figures by two dimensions. Although more children became aware of the effectiveness of those strategies, there was no relationship between the evaluation and use of strategies.     

Adaptation to increased work autonomy: The role of task reflection

Psychological contracts are a powerful concept in research on organizational behaviour. Substantial negative reactions towards perceived breaches to the psychological contract have been reported in many studies. There are sound theoretical arguments for the existence of a point in the continuous perception of contract breach, where sudden changes in attitudes occur in the relationship between breach and outcomes (i.e., thresholds). Using questionnaire data from 592 employees working in more than 30 different organizations across Germany, segmented regression models were tested against curvilinear effects for the relationship between breach of the psychological contract and job satisfaction, affective organizational commitment, intention to quit, violation, and trust. This study provides empirical evidence for threshold models of psychological contract breach. The results imply that prior studies have underestimated the impact of psychological contract breach.     

Weighting of contingency information in causal judgement: Evidence of hypothesis dependence and use of a positive-test strategy

Contingency is an important cue to causation. Research shows that people unequally weight the cells of a 2 × 2 contingency table as follows: cause-present/effect-present (A) > cause-present/effect-absent (B) > cause-absent/effect-present (C) > cause-absent/effect-absent (D). Although some models of causal judgement can accommodate that fact, most of them assume that the weighting of information is invariant as a function of whether one is assessing a hypothesized generative versus preventive relationship. An experiment was conducted that tested the hypothesis-independence assumption against the predictions of a novel weighted-positive-test-strategy account, which predicts hypothesis dependence in cell weighting. Supporting that account, judgements of hypothesized generative causes showed the standard A > B > C > D inequality, but judgements of hypothesized preventive causes showed the predicted B > A > D > C inequality. The findings reveal that cell weighting in causal judgement is both unequal and hypothesis dependent.     

Attention during visual secondary tasks in driving: Adaptation to the demands of the driving task

Visual attention in driving with visual secondary task is compared for two visual secondary tasks. N = 40 subjects completed a 1 h test drive in a motion-base driving simulator. During the drive, participants either solved an externally paced, highly demanding visual task or a self paced menu system task. The secondary tasks were offered in defined critical and non-critical driving situations. Eye movement behavior was analyzed and compared for both tasks. Before starting the secondary tasks, eye movement behavior shows a smaller standard deviation of gaze as well as longer fixation durations for both tasks. The comparison between the two tasks indicates that drivers use the possibilities the self paced task offers: during the secondary task, they monitor the driving scene with longer fixations and show a greater standard deviation of gaze position. Furthermore, independently of the type of secondary task, drivers adapt their eye movement behavior to the demands of the situation. In critical driving situations they direct a larger proportion of glance time to the driving task. Last, the relation between glance behavior and collisions is analyzed. Results indicate that collisions go together with an inadequate distribution of attention during distraction. The results are interpreted regarding the attentional processes involved in driving with visual secondary tasks. Based on the similarities and differences between the two secondary tasks, a cognitive approach is developed which assumes that the control of attention during distraction is based on a mental situational model of the driving situation.     

Body language reading of emotion in schizophrenia: Associations with symptoms and functional outcome

Our aim was to explore how body language reading of emotion relates to neurocognition, symptoms and functional outcome in schizophrenia. Fifty‐four individuals with schizophrenia and eighty‐four healthy controls participated in the study. Emotion perception was assessed with a point‐light display (PLD) task, the Emotion in Biological Motion (EmoBio) test, neurocognition was measured with the MATRICS Consensus Cognitive Battery (MCCB), and functioning was indexed by one measure of functional capacity and by one self‐report questionnaire. Clinical symptoms were assessed with a five factor Positive and Negative Syndrome Scale (PANSS) symptoms model. Participants with schizophrenia had impaired body language reading of emotions compared to healthy controls (Cohen's d = 0.69). In participants with schizophrenia, emotion perception was associated with neurocognition (r = 0.42), functional capacity (r = 0.27) and disorganization symptoms (r = –0.27). Mediation analyses showed that disorganization symptoms mediated the effects of emotion perception and neurocognition, respectively, on social functional capacity. These results suggest that in individuals with schizophrenia, reduced emotion perception from body movements has negative consequences for functional outcome, but that the effect is mediated through disorganization symptoms.     

Personality and the use of intuition: individual differences in strategy and performance on an implicit learning task

There is a divergence of opinion regarding the existence of individual differences in the use of intuition, ranging from intuition being the preserve of a creative minority to intuition as a basic cognitive process that is equally accessible to all. The existence and nature of individual differences in the use of intuition were explored by studying relationships between the sensing–intuition scale of the Myers–Briggs Type Indicator and strategy and performance on an implicit learning task. Results indicated differences in strategy and performance in implicit learning between sensing and intuitive types. Intuitive types were more likely to report a strategy of using intuition; sensing types were more likely to use explicit knowledge. In addition, intuitive types were more accurate than sensing types in their intuition. Thus, the position that there are individual differences in the use of intuition has been supported. Copyright © 2000 John Wiley & Sons, Ltd.     

Heterogeneity of strategy use in the Iowa gambling task: A comparison of win-stay/lose-shift and reinforcement learning models

The Iowa gambling task (IGT) has been used in numerous studies, often to examine decision-making performance in different clinical populations. Reinforcement learning (RL) models such as the expectancy valence (EV) model have often been used to characterize choice behavior in this work, and accordingly, parameter differences from these models have been used to examine differences in decision-making processes between different populations. These RL models assume a strategy whereby participants incrementally update the expected rewards for each option and probabilistically select options with higher expected rewards. Here we show that a formal model that assumes a win-stay/lose-shift (WSLS) strategy—which is sensitive only to the outcome of the previous choice—provides the best fit to IGT data from about half of our sample of healthy young adults, and that a prospect valence learning (PVL) model that utilizes a decay reinforcement learning rule provides the best fit to the other half of the data. Further analyses suggested that the better fits of the WSLS model to many participants’ data were not due to an enhanced ability of the WSLS model to mimic the RL strategy assumed by the PVL and EV models. These results suggest that WSLS is a common strategy in the IGT and that both heuristic-based and RL-based models should be used to inform decision-making behavior in the IGT and similar choice tasks.     

Adult age differences in subjective and objective measures of strategy use on a sequentially cued prediction task

Differences in strategy use are thought to underlie age-related performance deficits on many learning and decision-making tasks. Recently, age-related differences in learning to make predictions were reported on the Triplets Prediction Task (TPT). Notably, deficits appeared early in training and continued with experience. To assess if age differences were due to early strategy use, neural networks were used to objectively assess the strategies implemented by participants during Session 1. Then, the relationship between these strategies and performance was examined. Results revealed that older adults were more likely to implement a disadvantageous strategy early in learning, and this led to poorer task performance. Importantly, the relationship between age and task performance was partially mediated by early strategy use, suggesting that early strategy selection played a role in the lower quality of predictions in older adults.     

Testing the co-existence of two timing strategies for motor control in a unique task: The synchronisation spatial-tapping task

The control of rhythmic action sequences may involve two distinct timing strategies, i.e., event-based and emergent timing, which are usually revealed through finger-tapping and circle-drawing tasks, respectively. There is a lively debate concerning the possibility of coexistence of the two modes of timing for the execution of a single task. If one considers emergent timing as simply an absence of explicit representation of a time interval, then by definition, the two modes of timing cannot coexist. However, if one considers that emergent timing engages control of another motor parameter, e.g., a control of movement through space rather than time, then the possibility of coexistence needs to be reassessed. In the present study, we designed a hybrid of finger-tapping and circle-drawing tasks for which the demands for space and time control were present at the same time in order to reassess the coexistence hypothesis. Seventy-eight participants performed a spatial-tapping task in which finger taps were to be produced in synchrony with a regular metronome to 6 visual targets presented around a virtual circle. The metronome set ten distinct tempi (1100–300 ms). Using autocorrelation analyses on timing variables, we show that motor timing was event-based at slow tempi and emergent at faster tempi. Through an analysis of the trajectory, we confirm that an increase in the spatial control of movement took place congruently with a switch from event-based to emergent timing modes. At these fast tempi, timing and spatial errors were correlated but only at the specific target location for which a dynamical anchor point was revealed. Hence, we conclude that the coding of emergent timing has a spatial nature from which emerge timing regularities. This spatio-temporal strategy insures the performance of sequential motor actions when cognitive effort is too high for the use of pure event-based timing strategies.     

The relative importance of spatial versus temporal structure in the perception of biological motion: an event-related potential study

We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and scrambled spatial and temporal structure. As in a previous study, we identified two negative components at both occipitotemporal regions: N210 reflected general motion processing while N280 reflected the processing of BM. We analyzed the averaged ERPs in the 200-300 ms response time window and found that spatial structure had a substantial effect on the magnitude of the averaged response amplitude in both hemispheres. This finding suggests that spatial structure of point-lights elicits a stronger response in the occipitotemporal region than temporal structure for the BM perception.     

Rethinking volitional control over task choice in multitask environments: Use of a stimulus set selection strategy in voluntary task switching

Under conditions of volitional control in multitask environments, subjects may engage in a variety of strategies to guide task selection. The current research examines whether subjects may sometimes use a top-down control strategy of selecting a task-irrelevant stimulus dimension, such as location, to guide task selection. We term this approach a stimulus set selection strategy. Using a voluntary task switching procedure, subjects voluntarily switched between categorizing letter and number stimuli that appeared in two, four, or eight possible target locations. Effects of stimulus availability, manipulated by varying the stimulus onset asynchrony between the two target stimuli, and location repetition were analysed to assess the use of a stimulus set selection strategy. Considered across position condition, Experiment 1 showed effects of both stimulus availability and location repetition on task choice suggesting that only in the 2-position condition, where selection based on location always results in a target at the selected location, subjects may have been using a stimulus set selection strategy on some trials. Experiment 2 replicated and extended these findings in a visually more cluttered environment. These results indicate that, contrary to current models of task selection in voluntary task switching, the top-down control of task selection may occur in the absence of the formation of an intention to perform a particular task.     

Outsourcing cognitive control to the environment: Adult age differences in the use of task cues

When an initial phase of cued task switching is followed by a phase of single-task trials, older adults show difficulties changing to the more efficient single-task mode of processing (Mayr & Liebscher, 2001). In Experiment 1, we show that these costs follow older adults’ continued tendency to inspect task cues even though these provide no new information. In Experiment 2, we included a condition in which task cues were eliminated from the display after the task-switching phase. In this condition, older adults behaved the same as younger adults, suggesting that the presence of the task cue is critical for observing age differences while switching from a “high-control” to a “low-control” mode of processing. We discuss our results in terms of a life-span shift with regard to the reliance on internal versus external sources of information under conditions of high-control demands.     

Priming infants to use pattern information in an object individuation task: the role of comparison

There is evidence that 4.5-month-olds do not always use surface pattern to individuate objects but that they can be primed to attend to pattern differences through select experiences. For example, if infants are first shown events in which the pattern of an object predicts its function (dotted containers pound and striped containers pour), they will attend to pattern differences in a subsequent individuation task. However, 4.5-month-olds must see multiple exemplars of the pound and pour events and view the dotted and striped containers together during the events. These results suggest that it is the formation of event categories, in which pattern is linked to object function, that supports pattern priming and that direct comparison of the exemplars facilitates the extraction of event categories. The present research investigated conditions that support the comparison process in 4.5-month-olds. The results revealed that the comparison process was initiated only when the dotted and striped containers were seen directly adjacent to each other; if the containers sat far apart, so that infants had to shift their gaze to compare them, event categories were not extracted. In addition, it was comparison of the two patterned containers, and not comparison of the two function events, that was critical to the formation of event categories. These results join a growing body of research indicating the importance of comparison to category formation in infants and reveal the impact of categorization and comparison processes on object individuation in infancy.     

The role of metacognition in prospective memory: Anticipated task demands influence attention allocation strategies

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention–allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands.     

Risk strategy under task complexity: a multivariate analysis of behaviour in a naturalistic setting

This study complements the existing literature on decision-making processes and outcomes in complex settings by exploring the impact of different types of complexity on risk strategies in a naturalistic setting. The study analyses a large sample of decisions made by individuals in UK offcourse betting markets, a fertile environment for observing both a variety of risk strategies and a range of task complexities. Specifically, the investigation focuses on the comparative impacts of complexity defined in terms, respectively, of alternatives and attributes. The results suggest that the risk strategy employed is affected by task complexity. Complexity does not affect the size of risk accepted but alternative- and attribute-based complexity together influence the propensity to accept greater degrees of risk. In addition, the effect of attribute-based complexity on risk taking appears to be modified by the use of risk-hedging strategies. The results are observed to corroborate some earlier work on decision process and outcome; where differences with earlier findings are identified, some possible explanations are offered. © 1998 John Wiley & Sons, Ltd.     

From anticipation to behavioral intention: Insights into human processing of multiple retrieval cues in road traffic

Anticipation in road traffic enables safer and more comfortable driving. Anticipatory driving is achieved through effective retrieval of prior driving-relevant knowledge using mental models and appropriate cues. Knowing when and which retrieval cues have a critical impact on the anticipation process and how information compatibility affects anticipation can be the basis for supporting people in anticipating and appropriate behavior in road traffic.For generating in-depth insights into the processing of retrieval cues, a video-based experimental study was conducted combining specific compatible and incompatible retrieval cues in urban driving scenarios. From a driver's perspective, participants were asked to anticipate in a two-step approach (measuring low and high certainty anticipation) whether a vehicle ahead would enter their lane or turn onto another street due to a lane blockage ahead. Further, they choose their preferred behavioral intention (accelerate, decelerate or maintain speed). In general, drivers strived for coherent situation representation, and in this process, multiple retrieval cues influenced anticipation in different ways. Participants were more likely to be consistent in their anticipation response. That is, they tend to follow their first intention (equivalent low and high certainty anticipation for either lane change or turn) even in the presence of incompatible stimuli. Inconsistent compared to consistent anticipation responses, however, led to reduced subjective confidence, and in part to increased criticality. Not only anticipation but also intended behavior was influenced by retrieval cues. In accordance, the anticipation of others' behaviors can be considered a predictor of specific intended behavior in road traffic.     

Effects of speed and accuracy strategy on choice step execution in response to the flanker interference task

The purpose of this study is to examine the effects of a speed or accuracy strategy on response interference control during choice step execution. Eighteen healthy young participants were instructed to execute forward stepping on the side indicated by a central arrow (←, left vs. →, right) under task instructions that either emphasized speed or accuracy of response in the neutral condition. In the flanker condition, they were additionally required to ignore the 2 flanking arrows on each side (→→→→→, congruent or →→←→→, incongruent). Errors in the direction of the initial weight transfer (APA errors) and the step execution times were measured from the vertical force data. APA error was increased in response to the flanker task and step execution time was shortened with a speed strategy compared to an accuracy strategy. Furthermore, in response to the visual interference of the flanker task, speed instructions in particular increased APA errors more than other instructions. It may be important to manipulate the level of the speed-accuracy trade-off to improve efficiency and safety. Further research is needed to explore the effects of advancing age and disability on choice step reaction in a speed or accuracy strategy.