Alignment and commitment in joint action

Important work on alignment systems has been applied to philosophical work on joint action by Tollefsen and Dale. This paper builds from and expands on their work. The first aim of the paper is to spell out how the empirical research on alignment may be integrated into philosophical theories of joint action. The second aim is then to develop a successful characterization of joint action, which spells out the difference between genuine joint action and simpler forms of coordination based on alignment. I begin by introducing the empirical research and two definitions of joint action. I then argue that instead of using this research in conjunction with Searle’s account of collective intentionality, as Tollefsen and Dale suggest, we would be better served by applying this research to Gilbert’s account of plural subjects. In the final sections I distinguish between alignment, coordination, and joint action, clarify the roles of joint commitment and sub-personal alignment in joint action, and argue that these concepts are both consistent and mutually supportive. Combining these two research programs gives us an account of joint action that does justice to both the empirical and philosophical research.     

Investigating the Constrained Action Hypothesis: A Movement Coordination and Coordination Variability Approach

The purpose of this study was to examine the effects of focus of attention cues on movement coordination and coordination variability in the lower extremity. Twenty participants performed the standing long jump under both internal and external focus of attention conditions. A modified vector coding technique was used to evaluate the influence of attentional focus cues on lower extremity coordination patterns and coordination variability during the jumps. Participants jumped significantly further under an external focus of attention condition compared with an internal focus of attention condition (p = .035, effect size = .29). Focus of attention also influenced coordination between the ankle and knee, F(6, 19) = 2.87, p = .012, effect size = .388, with participants primarily using their knees under the internal focus of attention, and using both their ankles and knees under the external focus of attention. Attentional focus cues did not influence ankle-knee, F(1, 19) = 0.02, p = .98, effect size = .02, or hip-knee, F(1, 19) = 5.00, p = .49, effect size = .16, coordination variability. Results suggest that while attentional focus may not directly influence movement coordination condition, there is still a change in movement strategy resulting in greater jump distances following an external focus of attention.     

Being a non-drinking student: An interpretative phenomenological analysis

Recent research suggests that safer student alcohol consumption might be assisted by understanding how social occasions are managed by non-drinkers. In-depth, semi-structured interviews with five 19 – 22 year old non-drinking English undergraduates were subjected to interpretative phenomenological analysis. We present five inter-linked themes: ‘living with challenges to non-drinking’; ‘seeing what goes on in drinking environments’; ‘dealing with conversations about non-drinking (making excuses vs. coming out)’; ‘knowing which friends care about you’; and ‘the importance of minimising “legroom” for peer pressure’. Participants felt under persistent peer scrutiny (as a form of peer pressure) and could feel alienated in drinking environments. Talking about non-drinking was characterised by whether to ‘come out’ (as a non-drinker) or ‘fake it’ (e.g. ‘I’m on antibiotics’). Loyal friendships were reported as particularly important in this context. The decision not to drink was experienced as providing a successful buffer to peer pressure for former drinkers. Our findings unsettle traditional health promotion campaigns which advocate moderate drinking among students without always suggesting how it might be most successfully accomplished and offer tentative guidance on how non-drinking during specific social occasions might be managed more successfully. Findings are discussed in relation to extant literature and future research directions are suggested.     

Bridging the intention–behaviour gap: Planning,self-efficacy,and action control in the adoption and maintenance of physical exercise

Although some people may develop an intention to change their health behaviour, they might not take any action. This discrepancy has been labelled the “intention–behaviour gap.” Detailed action planning, perceived self-efficacy, and self-regulatory strategies (action control) may mediate between intentions and behaviour. This was examined in a longitudinal sample of 307 cardiac rehabilitation patients who were encouraged to adopt or maintain regular exercise. At the first time point, the predictors of intention and intention itself were assessed. Two months and four months later, the mediators and outcomes were measured. Results confirmed that all the three factors (planning, maintenance self-efficacy, and action control) served to mediate between earlier exercise intentions and later physical activity, each of them making a unique contribution. The results have implications for research on the “intention–behaviour gap,” and indicate that planning, maintenance self-efficacy and action control may be important volitional variables.     

Transfer of calibration in dynamic touch: What do perceivers learn when they learn about length of a wielded object?

Successfully performing everyday behaviours requires that perceptions and actions are properly calibrated to environmental properties. In three experiments, the authors tested whether calibration was specific to perception of a particular property of a wielded object from a particular grasp position on that object. The experiments investigate whether transfer of recalibration occurs across changes in grasp position (Experiment 1), object property (Experiment 2), and grasp position and object property (Experiment 3). The results suggest that a complete transfer of recalibration occurred in each case. Such results are consistent with recent research on dynamic touch and suggest that rather than recalibrating participants to one particular property of the wielded objects, feedback about a particular property served to recalibrate participants to the properties of the rod set as a whole.     

Timing of in situ visual information pick-up that differentiates expert and near-expert anticipation in a complex motor skill

The timing of visual information pick-up for visual anticipation was examined by comparing the capability of multiple skill groups, expert and near-expert karate athletes and novices, to block attacks using an in situ temporal occlusion paradigm. Participants stood facing a karate opponent and then attempted to block attacks (kicks and punches), whilst their vision of attacks was occluded: (a) prior to onset of opponent motion (O1), (b) after preparatory head movement (O2), and (c) after initiation of the attacking motion (O3). A no occlusion control condition provided complete vision of attacks (O4). Results revealed that expert anticipation was not significantly different to that of near-experts at O1, but was significantly different to the other group across O2–O4. Expert anticipation, however, was significantly above chance across all occlusion conditions, but near-experts performed above chance at O3 and O4, whilst novices were better than chance at O4. Unexpectedly, unique evidence was found that expert anticipation could be differentiated from near-expert anticipation in the earliest occlusion condition, where it was found that only experts were capable of using visual information from a static opponent to anticipate and block attacks above chance. The findings further understanding of expert visual anticipation to guide motor skills beyond existing expert–novice comparisons.     

Interference Effects from Observed Movement in Parkinson's Disease

Previous research has demonstrated that Parkinson's disease patients have an increased susceptibility to response conflict. In the present study, the authors investigate whether Parkinson's patients have a similar sensitivity to interference from observed movements. In all, 10 patients and 10 controls performed horizontal and vertical arm movements while watching a video of either a person performing similar movements or a moving dot. Movements were performed in the same plane (congruent) and orthogonal to the observed movement (incongruent). The off-axis variance of movements was our index of interference. Although patients tended to exhibit more off-axis variability than did controls, both groups demonstrated similar congruence effects, with greater variance in incongruent conditions. These results indicated that increased susceptibility to interference in Parkinson's disease does not extend to interference from observed movements.     

Schema Theory: A Critical Appraisal and Reevaluation

The authors replicated and extended results from the gunfight paradigm (A. Welchman, J. Stanley, M. Schomers, R. Miall, & H. Bulthoff, 2010a) in which participants moved faster when reacting to the perceived initiation of an opponent compared to initiating an action themselves. In addition to replicating these movement time effects, the authors found that time to peak velocity, peak velocity, and movement-endpoint dispersions were similarly impacted. The findings are discussed in terms of a triggering mechanism involved in ballistic and internally generated movements.     

Distinct Visual Cues Mediate Aperture Shaping for Grasping and Pantomime-Grasping Tasks

The authors examined whether the top-down requirements of dissociating the spatial relations between stimulus and response in a goal-directed grasping task renders the mediation of aperture trajectories via relative visual information. To address that issue, participants grasped differently sized target objects (i.e., grasping condition) and also grasped to a location that was dissociated from the target object (i.e., pantomime-grasping condition). Just noticeable difference (JND) values associated with the early through late stages of aperture shaping were computed to examine the extent to which motor output adhered to, or violated, the psychophysical principles of Weber's law. As expected, JNDs during the late stages of the grasping condition violated Weber's law: a result evincing the use of absolute visual information. In contrast, JNDs for the pantomime-grasping condition produced a continuous adherence to Weber's law. Such a result indicates that dissociating a stimulus from a response is a perception-based task and results in aperture shaping via relative visual information.