The effects of voluntary movements on auditory-haptic and haptic-haptic temporal order judgments

In two experiments we investigated the effects of voluntary movements on temporal haptic perception. Measures of sensitivity (JND) and temporal alignment (PSS) were obtained from temporal order judgments made on intermodal auditory-haptic (Experiment 1) or intramodal haptic (Experiment 2) stimulus pairs under three movement conditions. In the baseline, static condition, the arm of the participants remained stationary. In the passive condition, the arm was displaced by a servo-controlled motorized device. In the active condition, the participants moved voluntarily. The auditory stimulus was a short, 500Hz tone presented over headphones and the haptic stimulus was a brief suprathreshold force pulse applied to the tip of the index finger orthogonally to the finger movement. Active movement did not significantly affect discrimination sensitivity on the auditory-haptic stimulus pairs, whereas it significantly improved sensitivity in the case of the haptic stimulus pair, demonstrating a key role for motor command information in temporal sensitivity in the haptic system. Points of subjective simultaneity were by-and-large coincident with physical simultaneity, with one striking exception in the passive condition with the auditory-haptic stimulus pair. In the latter case, the haptic stimulus had to be presented 45ms before the auditory stimulus in order to obtain subjective simultaneity. A model is proposed to explain the discrimination performance.     

AN EVALUATION OF THE NUMBER OF PRESENTATIONS OF TARGET SOUNDS DURING STIMULUS—STIMULUS PAIRING TRIALS

We evaluated the differential effects of 2 variations of a stimulus–stimulus pairing procedure on the vocalizations of 2 children with autism. For both participants, presenting 1 sound per pairing trial resulted in a higher rate of vocalizations than 3 sounds per pairing trial.     

Conflict Transformation, Stigma, and HIV-Preventive Structural Change

Over the prior decade, structural change efforts have become an important component of community-based HIV prevention initiatives. However, these efforts may not succeed when structural change initiatives encounter political resistance or invoke conflicting values, which may be likely when changes are intended to benefit a stigmatized population. The current study sought to examine the impact of target population stigma on the ability of 13 community coalitions to achieve structural change objectives. Results indicated that coalitions working on behalf of highly stigmatized populations had to abandon objectives more often than did coalitions working for less stigmatized populations because of external opposition to coalition objectives and resultant internal conflict over goals. Those coalitions that were most successful in meeting external challenges used opposition and conflict as transformative occasions by targeting conflicts directly and attempting to neutralize oppositional groups or turn them into strategic allies; less successful coalitions working on behalf of stigmatized groups struggled to determine an appropriate response to opposition. The role of conflict transformation as a success strategy for working on behalf of stigmatized groups is discussed.     

The price of anarchy in social dilemmas: Traditional research paradigms and new network applications

Research on social dilemmas has largely been concerned with whether, and under what conditions, selfish decisions by autonomous individuals jointly result in socially inefficient outcomes. By contrast, considerably less emphasis has been placed on the extent of the inefficiency in those outcomes relative to the social optimum, and how the extent of inefficiency in theory compares with what is observed in experiments or practice. In this expository article, we introduce and subsequently extend the price of anarchy (PoA), an index that originated in studies on communication in computer science, and illustrate how it can be used to characterize the extent of inefficiency in social dilemmas. A second purpose of our article is to introduce a class of social dilemmas that occur when individuals selfishly choose routes in networks, and illustrate how the concept of PoA can be helpful in studying them.     

Personality and perfectionism in chronic fatigue syndrome: A closer look

Objective: To test the hypothesis that people with chronic fatigue syndrome (CFS) would differ significantly from a healthy control group on measures of general personality and perfectionism, specifically on measures of neuroticism and unhealthy perfectionism. Method: A total of 27 female CFS outpatients and 30 female healthy controls completed questionnaires, including the NEO Personality Inventory-Revised, the Multi-dimensional Perfectionism Scale and measures of anxiety and depression. Results: The CFS group was significantly more fatigued, anxious and depressed than healthy controls. They scored significantly higher on neuroticism and unhealthy perfectionism. Healthy and unhealthy perfectionism were positively correlated in the CFS group, but not in the control group. Conclusion: The present study confirms the link between neuroticism and fatigue and finds a link between unhealthy perfectionism and fatigue. A ‘healthy trait’, such as healthy perfectionism, when coupled with evaluative concerns is not necessarily healthy in a fatigued population. Researchers and clinicians should note the context in which apparently benign traits are expressed, and how they interact with other traits.     

Analysis of a displacive superlattice in nickel arsenide

Abstract

The structural analysis by convergent-beam electron diffraction is described for a weak orthorhombic superlattice observed in both mineral and synthetic samples of NiAs. The three equivalent directions for the commensurate wavevector, q = ?(a? + b?), defined a domain structure within the hexagonal subcell. Within a single domain, the symmetry around the c axis was reduced from 6mm to 2mm. The internal structure of higher-order Laue-zone reflections in diffraction patterns recorded at 100 K was used to associate a specific phonon eigenvector or condensed soft mode with the atomic displacement pattern.     

‘WITH PSYCHOSIS IN MIND’ – the reverberations of the psychotic encounter

Psychoanalytic theory offers a varied conceptual system for considering psychosis by providing a coherent representation of the anxieties and processes at work in adult patients. But at the practical clinical level, it is not enough simply to ‘think about psychosis’ and have a theoretical system in place. The therapist must also ‘have psychosis in mind’, that is, get to grips with its forms of logic, gain familiarity with its workings, and learn to understand and accept the effects it has on the therapeutic relationship and on their own expectations. Clinicians engaged in this type of work must be able to tolerate getting back in touch with processes deemed archaic at the core of their own psychological functioning, which will impact their ability to listen and think. These chaotic processes demand a change of approach since they cause a ‘desymbolisation’ that perturbs the internal mental structure of the therapist. This ‘desymbolisation’ is therefore the locus of the therapeutic work, which must attempt to render it comprehensible and represent it. A case study illustrates these processes.     

Social anxiety biases the evaluation of facial displays: Evidence from single face and multi-facial stimuli

This study examined the contribution of social anxiety to the evaluation of emotional facial stimuli, while controlling for the gender of participants and stimuli. Participants (n=63) completed two tasks: a single face evaluation task in which they had to evaluate angry versus neutral faces and, a facial crowd evaluation task in which they had to evaluate displays with a varying number of neutral and angry faces. In each task, participants had to evaluate the stimuli with respect to (a) the degree of disapproval expressed by the single face/crowd, and (b) the perceived difficulty of interacting with the face/crowd (emotional cost). Consistent with earlier studies, results showed that social anxiety modulated the evaluation of single faces for emotional cost, but not for disapproval ratings. In contrast, the evaluation of facial crowds was modulated by social anxiety on both ratings.     

The discrimination of angry and fearful facial expressions in 7-month-old infants: An event-related potential study

The important ability to discriminate facial expressions of emotion develops early in human ontogeny. In the present study, 7-month-old infants’ event-related potentials (ERPs) in response to angry and fearful emotional expressions were measured. The angry face evoked a larger negative component (Nc) at fronto-central leads between 300 and 600 ms after stimulus onset when compared to the amplitude of the Nc to the fearful face. Furthermore, over posterior channels, the angry expression elicited a N290 that was larger in amplitude and a P400 that was smaller in amplitude than for the fearful expression. This is the first study that shows that the ability of infants to discriminate angry and fearful facial expressions can be measured at the electrophysiological level. These data suggest that 7-month-olds allocated more attentional resources to the angry face as indexed by the Nc. Implications of this result may be that the social signal values were perceived differentially, not merely as “negative”. Furthermore, it is possible that the angry expression might have been more arousing and discomforting for the infant compared with the fearful expression.