Perceiving while acting: action affects perception

In two experiments we studied how motor responses affect stimulus encoding when stimuli and responses are functionally unrelated and merely overlap in time. Such R-S effects across S-R assignments have been reported by Schubö, Aschersleben, and Prinz (2001), who found that stimulus encoding was affected by concurrent response execution in the sense of a contrast (i.e., emphasizing differences). The present study aimed at elucidating the mechanisms underlying this effect. Experiment 1 studied the time course of the R-S effect. Contrast was only obtained for short intertrial intervals (ITIs). With long ITIs contrast turned into assimilation (i.e., emphasizing similarities). Experiment 2 excluded an interpretation of the assimilation effect in terms of motor repetition. Our findings support the notion of a shared representational domain for perception and action control, and suggest that contrast between stimulus and response codes emerges when two S-R assignments compete with each other in perception. When perceptual competition is over, assimilation emerges in memory.     

Representing others' actions: just like one's own?

Previous research has shown that observing others' actions can affect individual performance of the same actions. In the present study, we developed a new paradigm to investigate whether and how complementary actions at the disposal of another agent are represented and influence one's own actions. A spatial compatibility task was distributed among two people so that each participant took care of one of two responses. The identical task was performed alone and alongside another participant. There was a spatial compatibility effect in the group setting only. It was similar to the effect obtained when one person took care of both responses. This result suggests that one's own actions and others' actions are represented in a functionally equivalent way.     

Off-line authorship effects in action perception

Does the perception of our actions differ from the perception of other individuals' actions when we observe them, like other individual's actions, in an offline perspective? Previous studies, using recognition as well as prediction judgments, suggest that it does even if the stimulus information is reduced to a single moving point-light. Here, we assessed whether this difference also affects the timing of actions. This was tested in two experiments, using a specific synchronization task. After some practice, self-generated action events were anticipated faster than other action events, provided that the anticipation could not be accomplished sufficiently well on the basis of easily detectable cues. The results are discussed with regard to the previous findings of off-line authorship effects in action perception.     

The early origins of goal attribution in infancy

We contrast two positions concerning the initial domain of actions that infants interpret as goal-directed. The 'narrow scope' view holds that goal-attribution in 6- and 9-month-olds is restricted to highly familiar actions (such as grasping). The cue-based approach of the infant's 'teleological stance', however, predicts that if the cues of equifinal variation of action and a salient action effect are present, young infants can attribute goals to a 'wide scope' of entities including unfamiliar human actions and actions of novel objects lacking human features. It is argued that previous failures to show goal-attribution to unfamiliar actions were due to the absence of these cues. We report a modified replication of Woodward (1999) showing that when a salient action-effect is presented, even young infants can attribute a goal to an unfamiliar manual action. This study together with other recent experiments reviewed support the 'wide scope' approach indicating that if the cues of goal-directedness are present even 6-month-olds attribute goals to unfamiliar actions.     

Next Steps in Research on Children Exposed to Domestic Violence

The papers in this special issue of Clinical Child and Family Psychology Review provided an overview of what is known about children's exposure to domestic violence, and include indications of gaps in extant research. These gaps and research needs are summarized in this conclusion. Specifically, there is need for further research in several broad areas: definition and measurement of children's exposure to domestic violence; development of research methods and statistical designs that provide detailed information and provide for evidence of intervention effectiveness; impact of domestic violence on parenting and family functioning; the role of child factors and exposure to violence factors in predicting developmental risk and resilience; medical and health consequences of exposure to violence; and the nature of child-system interaction in response to domestic violence. Research needs in these areas are discussed in greater detail, and specific questions are raised for further development.     

Next Steps in Research on Children Exposed to Community Violence or War/Terrorism

The articles in this special issue of Clinical Child and Family Psychology Review provide an overview of what is known about children's exposure to community violence and war/ terrorism, and indicate significant gaps in extant research. These gaps and research needs are summarized in this conclusion.     

Introduction

This issue of Clinical Child and Family Psychology Review, Children Exposed to Domestic Violence: Current Status and Research Directions, addresses the current status of our knowledge as well as critical research needs in the area of children exposed to domestic violence. Although much has been learned in recent years about children exposed to violence, significant research gaps remain, the identification of which may help to build a more complete and rigorous science base in this area. This journal issue represents the distillation of a 3-day workshop on children exposed to violence, held in July of 2002, that identified what is known about children exposed to violence and what this information tells us about future research directions. Although many federal agencies have supported some research in this area, there is a need for more targeted attention on the topic, particularly with regard to measurement, sampling, and interventions/services. The papers in this issue were selected with these themes in mind. Although no single issue could cover the entire field, we intend to offer a representative sample of where we are and where we need to go with the hope of stimulating additional thought, collaboration, and research in this important area.     

Motor learning enhances perceptual judgment: a case for action-perception transfer

Transfer from perception to action is well documented, for instance in the form of observational learning. Transfer from action to perception, on the other hand, has not been researched. Such action-perception transfer (APT) is compatible with several learning theories and has been predicted within the framework of common coding of perceptual and motor events (Prinz, 1992, 1997). Our first experiment aimed at an empirical evaluation of APT and involved motor practice of timed two-cycle arm movements on verbal command without visual feedback. In a transfer test, visual judgments of similar patterns had to be made. In addition, transfer from the visual to the motor task was studied. In Experiment 2 we separated kinesthetic aspects of motor practice from preparatory and efferent contributions to APT. The experiments provide evidence that transfer between perception and action is bi-directional. Transfer from perception to action and, more importantly, from action to perception was found. Furthermore, APT was equally pronounced for participants who had actively practiced movements during training and for passive participants who had received merely kinesthetic feedback about the movement. This kinesthetic-visual transfer is likely to be achieved via visuomotor-kinesthetic matching or via timekeeping mechanisms that are involved in both motor and visual performance. Received: 2 June 1999 / Accepted: 20 June 2000     

Directing attention to movement effects enhances learning: a review

Studies investigating the influence of the learner’s focus of attention, induced by instructions or feedback, on motor skill learning are reviewed. In general, directing performers’ attention to the effects of their movements (external focus of attention) appears to be more beneficial than directing their attention to their own movements (internal focus of attention). Preliminary evidence is presented indicating that an internal attentional focus constrains the motor system by interfering with natural control processes, whereas an external focus seems to allow automatic control processes to regulate the movements. Support for the view that actions are controlled by their anticipated effects comes from research demonstrating functional variability in motor control, as well as the benefits of purposeful activity in occupational therapy. We explain these results in terms of the ideomotor principle of human actions (James, 1890) and its more modern derivatives (Hommel, 1996; Prinz, 1990, 1997).     

Minimal mimicry: Mere effector matching induces preference

Both mimicking and being mimicked induces preference for a target. The present experiments investigate the minimal sufficient conditions for this mimicry-preference link to occur. We argue that mere effector matching between one’s own and the other person’s movement is sufficient to induce preference, independent of which movement is actually performed. In Experiments 1 and 2, participants moved either their arms or legs, and watched avatars that moved either their arms or legs, respectively, without any instructions to mimic. The executed movements themselves and their pace were completely different between participants (fast circular movements) and targets (slow linear movements). Participants preferred avatars that moved the same body part as they did over avatars that moved a different body part. In Experiment 3, using human targets and differently paced movements, movement similarity was manipulated in addition to effector overlap (moving forward–backward or sideways with arms or legs, respectively). Only effector matching, but not movement matching, influenced preference ratings. These findings suggest that mere effector overlap is sufficient to trigger preference by mimicry.