Why do the effects of delaying reinforcement in animals and delaying feedback in humans differ? A working-memory analysis

Animal research has shown that reinforcement is substantially less effective when it is delayed, but in studies of human motor learning delays in providing feedback typically have much less effect. One possible explanation is that in human research participants know the response to be learned and can thus focus on it during the delay; that is not the case in experiments on animals. We tested this hypothesis using a task in which participants had minimal information on what movement was correct and found that, as in animal experiments, participants learned only when feedback was immediate. A second experiment confirmed that the effects of the delay depended on how many responses had to be held in working memory: the greater the memory load, the poorer the learning. The results point to the importance of activity during a delay on learning; implications for the teaching of motor skills are discussed.     

Why do the effects of delaying reinforcement in animals and delaying feedback in humans differ? A working-memory analysis

Animal research has shown that reinforcement is substantially less effective when it is delayed, but in studies of human motor learning delays in providing feedback typically have much less effect. One possible explanation is that in human research participants know the response to be learned and can thus focus on it during the delay; that is not the case in experiments on animals. We tested this hypothesis using a task in which participants had minimal information on what movement was correct and found that, as in animal experiments, participants learned only when feedback was immediate. A second experiment confirmed that the effects of the delay depended on how many responses had to be held in working memory: the greater the memory load, the poorer the learning. The results point to the importance of activity during a delay on learning; implications for the teaching of motor skills are discussed.     

The role of feedback in shaping responses to risky road scenarios: Evidence from electrodermal activity

When faced with hazardous driving situations, rapid and effective risk perception and decision-making processes are of crucial importance for avoiding crashes. In these cases, the processes are accompanied and influenced by underlying psychophysiological mechanisms such as electrodermal activity (EDA) modulations. The present work aims to assess the psychophysiological mechanisms underlying participants’ risk perception and decision-making when facing risky road scenarios, as correlated to the feedback role in modulating participants’ behavior. Study 1 (n = 32) explores the behavioral effects of administering a contingent feedback in a decision (decision-making) and an evaluation (risk perception) task in response to a set of risky and not risky images. The behavioral data reveal an effect on the participants’ probability of response, independently from the type of image presented, when the feedback was administered. In the decision task, the effect is accompanied by a change in the amplitude and percentage of the skin conductance responses (SCRs), which are moderated by block of trials. Study 2 (n = 44) better assesses the role of task and block on participants’ physiological activation, as measured by EDA signal. The results show an increase in psychophysiological activation when the feedback is delivered, in the first part of the tasks, both in terms of SCRs amplitude and percentage to the presented road scenarios, followed by a decrease in the second part of the tasks. Moreover, this effect is more evident in the decision task than the evaluation task. These findings suggest that the role exerted by feedback when facing risky traffic images may be described as based on an associative process that, once the correct response has been learned, tends to be reduced as it becomes automatic. Overall, the results of the two studies represent an important step toward the development of training programs aimed at promoting safer behaviors in risky driving contexts.     

Predicting risk decisions in a modified Balloon Analogue Risk Task: Conventional and single-trial ERP analyses

Event-related potential (ERP) has the potential to reveal the temporal neurophysiological dynamics of risk decision-making, but this potential has not been fully explored in previous studies. When predicting risk decision with ERPs, most studies focus on between-trial analysis that reflects feedback learning, while within-trial analysis that could directly link option assessment with behavioral output has been largely ignored. Suitable task design is crucial for applying within-trial prediction. In this study, we used a modified version of the classic Balloon Analogue Risk Task (BART). In each trial of the task, participants made multiple rounds of decisions between a risky option (pump up the balloon) and a safe option (cash out). Behavioral results show that as the level of economic risk increased, participants were less willing to make a risky decision and also needed a longer response time to do so. In general, the ERP results showed distinct characteristics compared with previous findings based on between-trial prediction, particularly about the role of the P1 component. Specifically, both the P1 (amplitude and latency) and P3 (amplitude) components evoked by current outcomes predicted subsequent decisions. We suggest that these findings indicate the importance of selective attention (indexed by the P1) and motivational functions (indexed by the P3), which may help clarify the cognitive mechanism of risk decision-making. The theoretical significance of these findings is discussed.     

Fine and gross motor skills: The effects on skill-focused dual-tasks

Dual-task methodology often directs participants’ attention towards a gross motor skill involved in the execution of a skill, but researchers have not investigated the comparative effects of attention on fine motor skill tasks. Furthermore, there is limited information about participants’ subjective perception of workload with respect to task performance. To examine this, the current study administered the NASA-Task Load Index following a simulated shooting dual-task. The task required participants to stand 15 feet from a projector screen which depicted virtual targets and fire a modified Glock 17 handgun equipped with an infrared laser. Participants performed the primary shooting task alone (control), or were also instructed to focus their attention on a gross motor skill relevant to task execution (gross skill-focused) and a fine motor skill relevant to task execution (fine skill-focused). Results revealed that workload was significantly greater during the fine skill-focused task for both skill levels, but performance was only affected for the lesser-skilled participants. Shooting performance for the lesser-skilled participants was greater during the gross skill-focused condition compared to the fine skill-focused condition. Correlational analyses also demonstrated a significant negative relationship between shooting performance and workload during the gross skill-focused task for the higher-skilled participants. A discussion of the relationship between skill type, workload, skill level, and performance in dual-task paradigms is presented.     

The BOLD response during Stroop task-like inhibition paradigms: Effects of task difficulty and task-relevant modality

Previous studies of the Stroop task propose two key mediators: the prefrontal and cingulate cortices but hints exist of functional specialization within these regions. This study aimed to examine the effect of task modality upon the prefrontal and cingulate response by examining the response to colour, number, and shape Stroop tasks whilst BOLD fMRI images were acquired on a Siemens 3T MRI scanner. Behavioural analyses indicated facilitation and interference effects and a noticeable effect of task difficulty. Some modular effects of modality were observed in the prefrontal cortex that survived exclusion of task difficulty related activations. No effect of task-relevant information was observed in the anterior cingulate. Future comparisons of the mediation of selective attention need to consider the effects of task context and task difficulty.     

Seeing minds in others: Mind perception modulates low-level social-cognitive performance and relates to ventromedial prefrontal structures

In social interactions, we rely on nonverbal cues like gaze direction to understand the behavior of others. How we react to these cues is affected by whether they are believed to originate from an entity with a mind, capable of having internal states (i.e., mind perception). While prior work has established a set of neural regions linked to social-cognitive processes like mind perception, the degree to which activation within this network relates to performance in subsequent social-cognitive tasks remains unclear. In the current study, participants performed a mind perception task (i.e., judging the likelihood that faces, varying in physical human-likeness, have internal states) while event-related fMRI was collected. Afterwards, participants performed a social attention task outside the scanner, during which they were cued by the gaze of the same faces that they previously judged within the mind perception task. Parametric analyses of the fMRI data revealed that activity within ventromedial prefrontal cortex (vmPFC) was related to both mind ratings inside the scanner and gaze-cueing performance outside the scanner. In addition, other social brain regions were related to gaze-cueing performance, including frontal areas like the left insula, dorsolateral prefrontal cortex, and inferior frontal gyrus, as well as temporal areas like the left temporo-parietal junction and bilateral temporal gyri. The findings suggest that functions subserved by the vmPFC are relevant to both mind perception and social attention, implicating a role of vmPFC in the top-down modulation of low-level social-cognitive processes.     

Speed/accuracy decisions in task performance: Built-in trade-off or separate strategic concerns?

In four studies we show that participants’ regulatory focus influences speed/accuracy decisions in different tasks. According to regulatory focus theory (Higgins, 1997), promotion focus concerns with accomplishments and aspirations produce strategic eagerness whereas prevention focus concerns with safety and responsibilities produce strategic vigilance. Studies 1–3 show faster performance and less accuracy in simple drawing tasks for participants with a chronic or situationally induced promotion focus compared to participants with a prevention focus. These studies also show that as participants move closer to the goal of completing the task, speed increases and accuracy decreases for participants with a promotion focus, whereas speed decreases and accuracy increases for participants with a prevention focus. Study 4 basically replicates these results for situationally induced regulatory focus with a more complex proofreading task. The study found that a promotion focus led to faster proofreading compared to a prevention focus, whereas a prevention focus led to higher accuracy in finding more difficult errors than a promotion focus. Through speed and searching for easy errors, promotion focus participants maximized their proofreading performance. In all four studies, the speed effects were independent of the accuracy effects and vice versa. These results show that speed/accuracy (or quantity/quality) decisions are influenced by the strategic inclinations of participants varying in regulatory focus rather than by a built-in trade-off.     

Sentence comprehension affects the dynamics of bimanual coordination: Implications for embodied cognition

Recent work in embodied cognition has demonstrated that language comprehension involves the motor system (e.g., Glenberg & Kaschak, 2002). Such findings are often attributed to mechanisms involving simulations of linguistically described events (Barsalou, 1999; Fischer & Zwaan, 2008). We propose that research paradigms in which simulation is the central focus need to be augmented with paradigms that probe the organization of the motor system during language comprehension. The use of well-studied motor tasks may be appropriate to this endeavour. To this end, we present a study in which participants perform a bimanual rhythmic task (Kugler & Turvey, 1987) while judging the plausibility of sentences. We show that the dynamics of the bimanual task differ when participants judge sentences describing performable actions as opposed to sentences describing events that are not performable. We discuss the general implications of our results for accounts of embodied cognition.     

Impact of situational threat on the behavioral activation system

Previous research has indicated that individuals respond differently to difficult tasks, depending on whether the situational factors surrounding the task make the individual perceive it as a challenge or a threat. Distinct response patterns between these two stress responses have been identified and vary based on an individual’s personality traits. In keeping with this research, the current study examined how performance pressure-induced threat impacts the relationship between trait approach motivation and prefrontal cortex activation utilizing a simple line bisection task. Participants completed line bisection tasks before and after performing a difficult motor skill task under pressure intended to provoke a threat-based response. As expected, individuals with high levels of trait approach motivation showed a rightward line bisection bias at pretest absent in participants with low levels of trait approach motivation. However, in contrast to previous studies utilizing more challenge-based tasks that report consistent rightward line bisection bias in high approach motivation populations, the current study identified a shift towards a leftward line bisection bias after the study task. The results suggest that the inability to succeed under pressure caused high trait approach participants to temporarily lose their approach orientation due to threat response.     

The self: Your own worst enemy? A test of the self-invoking trigger hypothesis

The self-invoking trigger hypothesis was proposed by Wulf and Lewthwaite [Wulf, G., & Lewthwaite, R. (2010). Effortless motor learning? An external focus of attention enhances movement effectiveness and efficiency. In B. Bruya (Ed.), Effortless attention: A new perspective in attention and action (pp. 75–101). Cambridge, MA: MIT Press] as a mechanism underlying the robust effect of attentional focus on motor learning and performance. One component of this hypothesis, relevant beyond the attentional focus effect, suggests that causing individuals to access their self-schema will negatively impact their learning and performance of a motor skill. The purpose of the present two studies was to provide an initial test of the performance and learning aspects of the self-invoking trigger hypothesis by asking participants in one group to think about themselves between trial blocks—presumably activating their self-schema—to compare their performance and learning to that of a control group. In Experiment 1, participants performed 2 blocks of 10 trials on a throwing task. In one condition, participants were asked between blocks to think about their past throwing experience. While a control group maintained their performance across blocks, the self group's performance was degraded on the second block. In Experiment 2, participants were asked to practice a wiffleball hitting task on two separate days. Participants returned on a third day to perform retention and transfer tests without the self-activating manipulation. Results indicated that the self group learned the hitting task less effectively than the control group. The findings reported here provide initial support for the self-invoking trigger hypothesis.     

损失-收益框架下责任感对建议采纳的影响

实验1和实验2分别探讨了在损失-收益框架下特质责任感和状态责任感对建议采纳的影响。结果发现：（1）无论是特质责任感还是状态责任感,高责任感的个体比低责任感个体更倾向于采纳他人建议。（2）收益框架下的个体比损失框架下的个体更愿意采纳他人建议。（3）无论是特质责任感还是状态责任感,高责任感的个体对他人建议的采纳程度不受框架的影响,而低责任感个体在收益框架下比在损失框架下的建议采纳程度高。     

Framing matters: contextual influences on interracial interaction outcomes

Previous studies indicate that interracial interactions frequently have negative outcomes but have typically focused on social contexts. The current studies examined the effect of manipulating interaction context. In Study 1, Black and White participants worked together with instructions that created either a social focus or a task focus. With a task focus, interracial pairs were more consistently synchronized, Black participants showed less executive function depletion, and White participants generally showed reduced implicit bias. Follow-up studies suggested that prejudice concerns help explain these findings: White participants reported fewer concerns about appearing prejudiced when they imagined an interracial interaction with a task focus rather than a social focus (Study 2a), and Black participants reported less vigilance against prejudice in an imagined interracial interaction with a task focus rather than a social focus (Study 2b). Taken together, these studies illustrate the importance of interaction context for the experiences of both Blacks and Whites.     

Are perceptuo-motor decisions really more optimal than cognitive decisions?

Human high-level cognitive decisions appear sub-optimal (Kahneman and Slovic, 1982, Kahneman and Tversky, 1979). Paradoxically, perceptuo-motor decisions appear optimal, or nearly optimal (Trommershäuser, Maloney, & Landy, 2008). Here, we highlight limitations to the comparison of performance between and within domains. These limitations are illustrated by means of two perceptuo-motor decision-making experiments. The results indicate that participants did not optimize fundamental performance-related factors (precision and time usage), even though standard analyses may have classed participants as ‘optimal’. Moreover, simulations and comparisons across our studies demonstrate that optimality depends on task difficulty. Thus, it seems that a standard model of perceptuo-motor decision-making fails to provide an absolute standard of performance. Importantly, this appears to be a limitation of optimal models of human behaviour in general. This, in conjunction with non-trivial evaluative- and methodological differences, suggests that verdicts favouring perceptuo-motor, or perceptual, systems over higher-level cognitive systems in terms of level of performance are premature.     

Studying the neural bases of prism adaptation using fMRI: A technical and design challenge

Prism adaptation induces rapid recalibration of visuomotor coordination. The neural mechanisms of prism adaptation have come under scrutiny since the observations that the technique can alleviate hemispatial neglect following stroke, and can alter spatial cognition in healthy controls. Relative to non-imaging behavioral studies, fMRI investigations of prism adaptation face several challenges arising from the confined physical environment of the scanner and the supine position of the participants. Any researcher who wishes to administer prism adaptation in an fMRI environment must adjust their procedures enough to enable the experiment to be performed, but not so much that the behavioral task departs too much from true prism adaptation. Furthermore, the specific temporal dynamics of behavioral components of prism adaptation present additional challenges for measuring their neural correlates. We developed a system for measuring the key features of prism adaptation behavior within an fMRI environment. To validate our configuration, we present behavioral (pointing) and head movement data from 11 right-hemisphere lesioned patients and 17 older controls who underwent sham and real prism adaptation in an MRI scanner. Most participants could adapt to prismatic displacement with minimal head movements, and the procedure was well tolerated. We propose recommendations for fMRI studies of prism adaptation based on the design-specific constraints and our results.     

Flanker effects on motor output and the late-level response activation hypothesis.

When participants must respond to a relevant central target and ignore irrelevant flanking stimuli, the flankers produce a flanker compatibility effect on behavioural measures. Current accounts of the flanker compatibility effect assume that both target and flanker stimuli affect response activation. This idea is supported by electrophysiological studies, which show that irrelevant flanker stimuli can affect the motor system. The present experiments examined the characteristics of flanker effects on the motor system by analysing the details of the motor output with response force measures. A total of 60 participants responded in the flanker task to arrows (Experiment 1) or letters (Experiment 2). Reaction time as well as response force increased on incompatible trials. Analyses of the distribution of incorrect activation revealed that both response times and correct motor output increased with the amount of incorrect activity. However, the flanker compatibility effect was only marginally modulated by incorrect activity. Results suggest that the largest part of the flanker compatibility effect cannot be attributed to response activation and competition at late levels of the response system.     

Regulating cognitive control through approach-avoidance motor actions

In two studies, the regulatory function of approach-avoidance cues in activating cognitive control processes was investigated. It was hypothesized that avoidance motor actions, relative to approach motor actions, increase the recruitment of cognitive resources, resulting in better performance on tasks that draw on these capacities. In Study 1, error rates on a verbal response mode version of the Stroop task were analyzed. On inconsistent Stroop trials, participants in the avoidance condition made significantly fewer errors than those in the approach condition. In Study 2, performance differences on a task switching paradigm were investigated. Crucially, approach and avoidance motor actions were manipulated within-subjects by alternating between approach and avoidance motor actions on 4 blocks of trials. Temporal switching costs were significantly lower while performing an avoidance, compared to an approach motor action. These results support our hypothesis that avoidance cues, relative to approach cues, lead to improved performance on cognitive control tasks.     

Reciprocal influences of attentional focus on postural and suprapostural task performance

The authors examined the influence that attentional focus on either a postural or a suprapostural task had on the performance of each task. Participants (N = 32) stood on an inflated rubber disk and held a pole horizontally. All participants performed under 4 attentional focus conditions: external (disk) or internal (feet) focus on the postural task, and external (pole) or internal (hands) focus on the suprapostural task. Compared with internal focuses, external focuses on either task resulted in similar and reduced postural sway. Response frequency on each task increased when participants focused on the respective task. Finally, an external focus on either task produced higher frequencies of responding on the suprapostural task. The authors conclude that suprapostural task goals have a stronger influence on postural control than vice versa, reflecting the propensity of the motor system to optimize control processes on the basis of the desired movement effect.     

Two Factors to be Considered in the Design of Experiments in Anxiety and Motor Behavior

The authors examined the influence that attentional focus on either a postural or a suprapostural task had on the performance of each task. Participants (N = 32) stood on an inflated rubber disk and held a pole horizontally. All participants performed under 4 attentional focus conditions: external (disk) or internal (feet) focus on the postural task, and external (pole) or internal (hands) focus on the suprapostural task. Compared with internal focuses, external focuses on either task resulted in similar and reduced postural sway. Response frequency on each task increased when participants focused on the respective task. Finally, an external focus on either task produced higher frequencies of responding on the suprapostural task. The authors conclude that suprapostural task goals have a stronger influence on postural control than vice versa, reflecting the propensity of the motor system to optimize control processes on the basis of the desired movement effect.     

Action observation produces motor resonance in Parkinson's disease

Observation of movement activates the observer's own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task‐irrelevant) action. The impact of movement disorders such as Parkinson's disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus‐response compatibility effects. We examined visuomotor priming in 23 participants with mild‐to‐moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus‐response compatibility. Participants made a key press after observing a task‐irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus‐response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.