Fixed-point drift and hysteresis in frequency-scaled unimanual coordination

ABSTRACT Research on human rhythmic coordination has shown that the in-phase and antiphase coordination modes are typically stable and that the coordination of asymmetric effectors frequently exhibits fixed-point drift. The author extended research on symmetry breaking in coordination dynamics by examining a frequency-scaled unimanual pronation-supination task. The results showed symmetry breaking and fixed-point drift, with the radioulnar joint increasingly more phase advanced than the shoulder with increments in movement frequency. Hysteresis was also observed, as the relative phase patterns produced at 3 of the 4 movement frequencies were lower in the upward frequency scaling direction than in the downward direction. These results showed that the dynamic properties of symmetry breaking and fixed-point drift in unimanual pronation-supination movements were consistent with prior research and modeling. The hysteresis effect was explained as potentially being due to the control structures that organize this redundant coordination task.     

Building a bridge of trust: collaborative assessment with a person with serious mental illness

Collaborative assessment utilizes psychological testing to help people make positive changes in their lives. Limited research has evaluated the utility of collaborative assessment for persons with serious mental illness. This case example uses the Personality Assessment Inventory to illustrate the usefulness of collaborative assessment with a person with serious mental illness. This approach informed not only diagnostic considerations but also revealed the client's current level of distress, contributed to enhanced therapeutic alliance, and directly pointed to psychiatric rehabilitation strategies.     

Resistance to change and relapse of observing

Four experiments examined relapse of extinguished observing behavior of pigeons using a two-component multiple schedule of observing-response procedures. In both components, unsignaled periods of variable-interval (VI) food reinforcement alternated with extinction and observing responses produced stimuli associated with the availability of the VI schedule (i.e., S+). The components differed in the rate of food arranged (Rich = VI 30 s; Lean = VI 120 s). In Experiment 1, following baseline training, extinction of observing involved removal of both food and S+ deliveries, and reinstatement was examined by presenting either response-independent food or S+ deliveries. In Experiment 2, extinction involved removal of only food deliveries while observing responses continued to produce S+. Reinstatement was examined by delivering food contingent upon the first two food-key responses occurring in the presence of the S+. Experiment 3 assessed ABA renewal of observing by extinguishing food-key and observing responses in the presence of one contextual stimulus (i.e., B) and then returning to the original training context (i.e., A) during continued extinction. Experiment 4 examined resurgence by introducing food reinforcement for an alternative response during extinction, and subsequently removing that alternative source of food. Across experiments, relative resistance to extinction and relapse of observing tended to be greater in the component previously associated with the higher rate of primary reinforcement. Relapse of observing or attending to stimuli associated with primary reinforcement appears to be impacted by frequency of primary reinforcement in a manner similar to responding maintained directly by primary reinforcement.     

Rapid acquisition of bias in signal detection: dynamics of effective reinforcement allocation

We investigated changes in bias (preference for one response alternative) in signal detection when relative reinforcer frequency for correct responses varied across sessions. In Experiment 1, 4 rats responded in a two-stimulus, two-response identification procedure employing temporal stimuli (short vs. long houselight presentations). Relative reinforcer frequency varied according to a 31-step pseudorandom binary sequence and stimulus duration difference varied over two values across conditions. In Experiment 2, 3 rats responded in a five-stimulus, two-response classification procedure employing temporal stimuli. Relative reinforcer frequency was varied according to a 36-step pseudorandom ternary sequence. Results of both experiments were analyzed according to a behavioral model of detection. The model was extended to incorporate the effects of current and previous session reinforcer frequency ratios on current-session performance. Similar to findings with concurrent schedules, effects on bias of relative reinforcer frequency were highest for the current session. However, carryover from reinforcer ratios of previous sessions was evident. Generally, the results indicate that bias can come under control of frequent changes in relative reinforcer frequency in both identification and classification procedures.     

Confucianism and Youth Suicide in Rural China

This study examined the relationship between core Confucian ethics and suicide. We used a proxy sample of youths randomly selected from rural areas of three provinces in China. The proxy sample consisted of 382 completed suicides and 414 community living controls, all aged 15–34 years. Logistic regression analyses showed that among the Chinese youths (1) the Confucian ethic of filial piety was negatively associated with suicide; (2) the Confucian ethic of harmony moderated the estimated net effect of negative life events on suicide; and (3) the Confucian ethic of female subordination was positively linked with suicide. We also discussed implications of our study for future research.     

The IAT is sensitive to the perceived accuracy of newly learned associations

Three experiments tested whether the Implicit Association Test (IAT) is sensitive to the perceived accuracy of newly learned associations. In experiment 1, participants learned to associate positive or negative attributes with two novel groups. Participants in one condition were told that the attributes accurately described the groups; in a second condition, prior to learning, they were made aware that the attributes were randomly assigned to the groups. Participants were given an IAT and an explicit measure testing attitudes towards the two groups. When the participants were told that the attributes were accurate, their IAT performance and explicit measure responses indicated a preference for the more positively described group but when the attributes were known to be arbitrary, preferences were reduced according to both measures. Experiment 2 replicated these results and demonstrated that the associations were learned even in the random condition. Experiment 3 included a condition that placed “not” before each attribute, which demonstrated that people can incorporate a negative modifier into a learned association. Explicit attitudes and the IAT showed reversed preferences in this negation condition. These experiments imply that the IAT is sensitive to the perceived accuracy of learned associations. Copyright © 2011 John Wiley & Sons, Ltd.     

Is pride a prosocial emotion? Interpersonal effects of authentic and hubristic pride

Pride is associated with both prosocial and antisocial behaviour. Do others also infer such behaviours when pride is expressed and does this affect their own prosocial behaviour? We expected that authentic pride (i.e., confidence, accomplishment) would signal and elicit more prosocial behaviour than hubristic pride (i.e., arrogance, conceit). In a first laboratory experiment, a target in a public-good dilemma was inferred to have acted less prosocially when displaying a nonverbal expression of pride versus no emotion. As predicted, inferences of hubristic pride-but not authentic pride-mediated this effect. Participants themselves also responded less prosocially. A second laboratory experiment where a target verbally expressed authentic pride, hubristic pride, or no emotion replicated the effects of hubristic pride and showed that authentically proud targets were assumed to have acted prosocially, but especially by perceivers with a dispositional tendency to take the perspective of others. We conclude that authentic pride is generally perceived as a more prosocial emotion than hubristic pride.     

Reciprocal relationships between resource loss and psychological distress following exposure to political violence: an empirical investigation of COR theory's loss spirals

Abstract We conducted a four-wave prospective study of Palestinian adults living in the West Bank, Gaza Strip, and East Jerusalem, interviewed between 2007 and 2009 at 6-month interval to explore transactional relationships between resource loss (i.e., intra and interpersonal resource loss) and psychological distress (i.e., posttraumatic stress disorder and depression symptoms). Initially, 1196 Palestinians completed the first wave interview and 752 of these participants completed all four interviews. A cross-lagged panel design was constructed to model the effects of trauma exposure on both resource loss and psychological distress and the subsequent reciprocal effects of resource loss and psychological distress across four time waves. Specifically, resource loss was modeled to predict distress, which in turn was expected to predict further resource loss. Structural equation modeling was used to test this design. We found that psychological distress significantly predicts resource loss across shorter, 6-month time waves, but that resource loss predicts distress across longer, 12-month intervals. These findings support the Conservation of Resources theory's corollary of loss spirals.