The Impact of Asymmetric Partial Feedback on Response‐Bias

For many decisions we make, we are more likely to receive feedback about some outcomes than about others, and thus we must operate under conditions of asymmetric partial feedback. In this paper, we examine the effects of asymmetric partial feedback on decision making across three experiments. Experiment 1 examines the effects of four partial feedback schedules on decision making in a single‐attribute auditory detection task. Experiment 2 examines these same schedules in the context of a simulated experiment in which virtual participants perform a multi‐attribute choice task. Experiment 3 then examines effects of one partial feedback schedule representative of a real‐world decision‐making domain (personnel selection) using an ecologically informed multi‐attribute choice task. All three experiments reveal that asymmetric partial feedback primarily impacts on response‐bias, a parameter of signal detection theory. These findings can be explained in terms of decision makers' attempts to maximize accuracy and the fact that shifts in response‐bias will, under partial feedback, produce misleading impressions of greater accuracy. Copyright © 2013 John Wiley & Sons, Ltd.     

Human–Grey parrot (Psittacus erithacus) reciprocity: a follow-up study

In a previous study (Péron et al. in Anim Cogn, doi:10.1007/s10071-012.05640, 2012), Grey parrots, working in dyads, took turns choosing one of four differently coloured cups with differing outcomes: empty (null, non-rewarding), selfish (keeping reward for oneself), share (sharing a divisible reward), or giving (donating reward to other). When the dyads involved three humans with different specific intentions (selfish, giving, or copying the bird’s behaviour), birds’ responses only tended towards consistency with human behaviour. Our dominant bird was willing to share a reward with a human who was willing to give up her reward, was selfish with the selfish human, and tended towards sharing with the copycat human; our subordinate bird tended slightly towards increased sharing with the generous human and selfishness with the selfish human, but did not clearly mirror the behaviour of the copycat. We theorized that the birds’ inability to understand the copycat condition fully—that they could potentially maximize reward by choosing to share—was a consequence of their viewing the copycat’s behaviour as erratic compared with the consistently selfish or giving humans and thus not realizing that they were indeed being mirrored. We suggested that copycat trials subsequently be performed as a separate experiment, without being contrasted with trials in which humans acted consistently, in order to determine if results might have differed. We have now performed that experiment, and shown that at least one Grey parrot—our dominant—responded in a manner suggesting that he deduced the appropriate contingencies.     

Eye movement control during scene viewing: Immediate degradation and enhancement effects of spatial frequency filtering

What controls how long the eyes remain fixated during scene perception? We investigated whether fixation durations are under the immediate control of the quality of the current scene image. Subjects freely viewed photographs of scenes in preparation for a later memory test while their eye movements were recorded. Using the saccade-contingent display change method, scenes were degraded (Experiment 1) or enhanced (Experiment 2) via blurring (low-pass filtering) during predefined saccades. Results showed that fixation durations immediately after a display change were influenced by the degree of blur, with a monotonic relationship between degree of blur and fixation duration. The results also demonstrated that fixation durations can be both increased and decreased by changes in the degree of blur. The results suggest that fixation durations in scene viewing are influenced by the ease of processing of the image currently in view. The results are consistent with models of saccade generation in scenes in which moment-to-moment difficulty in visual and cognitive processing modulates fixation durations.     

The influence of emotion regulation on social interactive decision-making

Although adequate emotion regulation is considered to be essential in every day life, it is especially important in social interactions. However, the question as to what extent two different regulation strategies are effective in changing decision-making in a consequential socially interactive context remains unanswered. We investigated the effect of expressive suppression and emotional reappraisal on strategic decision-making in a social interactive task, that is, the Ultimatum Game. As hypothesized, participants in the emotional reappraisal condition accepted unfair offers more often than participants in the suppression and no-regulation condition. Additionally, the effect of emotional reappraisal influenced the amount of money participants proposed during a second interaction with partners that had treated them unfairly in a previous interaction. These results support and extend previous findings that emotional reappraisal as compared to expressive suppression, is a powerful regulation strategy that influences and changes how we interact with others even in the face of inequity.     

Causal foundationalism, physical causation, and difference-making

An influential tradition in the philosophy of causation has it that all token causal facts are, or are reducible to, facts about difference-making. Challenges to this tradition have typically focused on pre-emption cases, in which a cause apparently fails to make a difference to its effect. However, a novel challenge to the difference-making approach has recently been issued by Alyssa Ney. Ney defends causal foundationalism, which she characterizes as the thesis that facts about difference-making depend upon facts about physical causation. She takes this to imply that causation is not fundamentally a matter of difference-making. In this paper, I defend the difference-making approach against Ney’s argument. I also offer some positive reasons for thinking, pace Ney, that causation is fundamentally a matter of difference-making.     

Lower limb kinematic variability in dancers performing drop landings onto floor surfaces with varied mechanical properties

Elite dancers perform highly skilled and consistent movements. These movements require effective regulation of the intrinsic and extrinsic forces acting within and on the body. Customized, compliant floors typically used in dance are assumed to enhance dance performance and reduce injury risk by dampening ground reaction forces during tasks such as landings. As floor compliance can affect the extrinsic forces applied to the body, secondary effects of floor properties may be observed in the movement consistency or kinematic variability exhibited during dance performance. The aim of this study was to investigate the effects of floor mechanical properties on lower extremity kinematic variability in dancers performing landing tasks. A vector coding technique was used to analyze sagittal plane knee and ankle joint kinematic variability, in a cohort of 12 pre-professional dancers, through discrete phases of drop landings from a height of 0.2 m. No effect on kinematic variability was observed between floors, indicating that dancers could accommodate the changing extrinsic floor conditions. Future research may consider repeat analysis under more dynamic task constraints with a less experienced cohort. However, knee/ankle joint kinematic variability was observed to increase late in the landing phase which was predominantly comprised of knee flexion coupled with the terminal range of ankle dorsiflexion. These findings may be the result of greater neural input late in the landing phase as opposed to the suggested passive mechanical interaction of the foot and ankle complex at initial contact with a floor. Analysis of joint coordination in discrete movement phases may be of benefit in identifying intrinsic sources of variability in dynamic tasks that involve multiple movement phases.