Social Inhibition of return: Causes and properties

The present thesis was dedicated to examining individuals’ performance on a low-level reaching task conducted under social-interactive conditions. In this paradigm named Social Inhibition of Return (social IOR) two individuals, sitting opposite each other take turns to respond to targets appearing on either side of a visual display. Typical results reveal that reaction times are longer when responses are directed to where the co-actor just responded. Despite being fairly simple, this task is intriguing to examine as it potentially incorporates features of both an inhibition of return (IOR) effect and, a joint-action phenomenon, due to its interactive nature. Indeed, the results of the standard social IOR paradigm where participants sit opposite are consistent with both explanations as the potential involvement of attentional inhibition and/or action co-representation cannot be disentangled. The present work examined the causes and properties of this intriguing effect over the course of four empirical chapters. First, Chapter 2 revealed that social IOR possesses a number of properties, characteristic of traditional IOR. Second, Chapter 3 convincingly demonstrated that action co-representation does not seem to contribute to the phenomenon. Furthermore, Chapter 4 confirmed these findings by revealing that social IOR does not depend on the socialness of the co-actor. Finally, Chapter 5 showed that it could even bias a range of free choice decisions which revealed another novel property of the effect. Taken together these findings were interpreted as mostly consistent with a low-level inhibitory account as opposed to a theory, advocating an involvement of action imitation/co-representation in the effect. The present work had a number of theoretical and methodological implications for the better understanding of social IOR. In more general terms, it also contributed to the quickly developing, alternative literature to the action co-representation account, advocating a bottom-up basis of some joint-action effects

When Your Decisions Are Not (Quite) Your Own: Action Observation Influences Free Choices

A growing number of studies have begun to assess how the actions of one individual are represented in an observer. Using a variant of an action observation paradigm, four experiments examined whether one person's behaviour can influence the subjective decisions and judgements of another. In Experiment 1, two observers sat adjacent to each other and took turns to freely select and reach to one of two locations. Results showed that participants were less likely to make a response to the same location as their partner. In three further experiments observers were asked to decide which of two familiar products they preferred or which of two faces were most attractive. Results showed that participants were less likely to choose the product or face occupying the location of their partner's previous reaching response. These findings suggest that action observation can influence a range of free choice preferences and decisions. Possible mechanisms through which this influence occurs are discussed

The Role of Attention in a Joint-Action Effect

The most common explanation for joint-action effects has been the action co-representation account in which observation of another's action is represented within one's own action system. However, recent evidence has shown that the most prominent of these joint-action effects (i.e., the Social Simon effect), can occur when no co-actor is present. In the current work we examined whether another joint-action phenomenon (a movement congruency effect) can be induced when a participant performs their part of the task with a different effector to that of their co-actor and when a co-actor's action is replaced by an attention-capturing luminance signal. Contrary to what is predicted by the action co-representation account, results show that the basic movement congruency effect occurred in both situations. These findings challenge the action co-representation account of this particular effect and suggest instead that it is driven by bottom-up mechanisms

Deep Space Network-Wide Portal Development: Planning Service Pilot Project

The Deep Space Network (DSN) is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. DSN provides the vital two-way communications link that guides and controls planetary explorers, and brings back the images and new scientific information they collect. In an attempt to streamline operations and improve overall services provided by the Deep Space Network a DSN-wide portal is under development. The project is one step in a larger effort to centralize the data collected from current missions including user input parameters for spacecraft to be tracked. This information will be placed into a principal repository where all operations related to the DSN are stored. Furthermore, providing statistical characterization of data volumes will help identify technically feasible tracking opportunities and more precise mission planning by providing upfront scheduling proposals. Business intelligence tools are to be incorporated in the output to deliver data visualization

More conservative go/no-go response criterion under high working memory load

Previous work has shown that the efficiency of selective attention depends on the availability of cognitive control functions, including working memory. Here we examined the role of working memory in another task involving executive control, namely, a go/no-go task. Participants performed the Sustained Attention to Response Task, which requires withholding a prepotent response to an infrequent target, when at the same time placing a low or high load on an unrelated working memory task. Working memory load had the effect of reducing accuracy on the go trials, when at the same time increasing accuracy on the no-go trials. We interpret these findings to suggest that high working memory load led to a shift to a more conservative response criterion

Mean RTs to localise targets as a function of effector and movement congruency in Experiment 1.

<p>Error bars represent standard errors of the mean.</p

An illustration of the standard condition in the movement congruency paradigm used in Experiments 1 and 2.

<p>Each person takes turns to reach out and touch one of two targets presented on the left or right. In the figure shown, one person is reaching to their right where the target has illuminated.</p

Trial sequence in Experiment 2.

<p>Trial sequence in Experiment 2.</p

Mean RTs to localise targets as a function of partner and movement congruency in Experiment 2.

<p>Error bars represent standard errors of the mean.</p