Computer‐mediated communication: synchronicity and compensatory effort

Groups might perform compensatory communicative actions if media characteristics impede a particular communication process. The present study examined this hypothesis for the process of information integration, which is a sub‐task in collaborative problem‐solving. Synchronous media characteristics support the information integration process, while asynchronous media characteristics impede it. The synchronicity of the medium was varied by manipulating parallelism and the immediacy of feedback within real‐time, text‐based computer‐mediated communication. A Conversational Games Analysis (CGA) was performed in order to investigate the functional purposes of the task‐oriented contributions. All groups successfully solved the problem. However, groups interacting in the asynchronous communication mode produced significantly more functional contributions for the purpose of mutual task‐oriented understanding and clarification, compared to the synchronous groups. Moreover, members of asynchronous groups repeated unshared pieces of information more often. These differences are interpreted as communicative efforts that balance the hindering influence of asynchronous media characteristics on the process of information integration. Copyright © 2007 John Wiley & Sons, Ltd.     

The high-hurdle technique put to the test: Failure to find evidence that increasing loading times enhances data quality in Web-based studies

Two Web-based experiments examined the usefulness of artificially delaying the loading of the first page of the study. The idea pursued in this technique is to filter out less-motivated respondents through a higher respondent burden in the form of waiting time. Participants who remain in the study despite having had to wait for the first page of the study to appear on the screenare expected to be more highly motivated, and thus to produce data of higher quality. In both experiments, as expected, the longer the loading time, the lower the likelihood of people responding to the study. However, contrary to expectation, the dropout rate and quality of data were independent of the loading time. Therefore, artificially delaying the loading of the first page of the study is counterproductive.     

Multisensory identification of natural objects in a two-way crossmodal priming paradigm

The question of how vision and audition interact in natural object identification is currently a matter of debate. We developed a large set of auditory and visual stimuli representing natural objects in order to facilitate research in the field of multisensory processing. Normative data was obtained for 270 brief environmental sounds and 320 visual object stimuli. Each stimulus was named, categorized, and rated with regard to familiarity and emotional valence by N=56 participants (Study 1). This multimodal stimulus set was employed in two subsequent crossmodal priming experiments that used semantically congruent and incongruent stimulus pairs in a S1-S2 paradigm. Task-relevant targets were either auditory (Study 2) or visual stimuli (Study 3). The behavioral data of both experiments expressed a crossmodal priming effect with shorter reaction times for congruent as compared to incongruent stimulus pairs. The observed facilitation effect suggests that object identification in one modality is influenced by input from another modality. This result implicates that congruent visual and auditory stimulus pairs were perceived as the same object and demonstrates a first validation of the multimodal stimulus set.     

The Power of Expectation – Understanding the Placebo and Nocebo Phenomenon

Although placebo pills are supposed to have no pharmacological activity, people taking placebo pills describe a variety of positive (i.e., placebo phenomenon) and negative (i.e., nocebo phenomenon) reactions. This has major clinical implications. Placebo reactions account for a substantial part of improvement when treating patients with hypertension, mental disorders, and even after surgical procedures. The nocebo phenomenon on the other hand is responsible for non‐compliance and discontinuation of many pharmaceutical interventions. Mechanisms that underlie the placebo and nocebo effects may be related to expectation and/or classical conditioning, but some methodological issues should also be considered. Most experimental studies investigating the placebo effect have used paradigms to induce ‘placebo analgesia’, the reduction of pain perception after receiving an inert substance and an instruction that this medication would relieve pain. This paradigm allows investigators to examine the neurobiological circuitry of the placebo response using neuroimaging techniques.     

Continuity and Change in Emotional Reactivity in Rhesus Monkeys Throughout the Prepubertal Period

We examined continuity and change in emotional reactiviy as assessed by hypothalamic–pituitary–adrenal (HPA) activity in rhesus monkeys. Plasma samples were obtained from mother-peer–reared and surrogate-peer–reared monkeys and assayed for cortisol concentrations at 5 time points in infancy. Both plasma and saliva samples were collected for cortisol assay from the same monkeys as 1-, 2-, and 3-year-old juveniles, respectively. Plasma cortisol concentrations increased during the first 5 months of life and decreased from 1 to 3 years of age. Females consistently had higher plasma cortisol concentrations than males. Plasma cortisol concentrations were lower in surrogate-peer–reared than mother-peer–reared monkeys during the first month of life. Juvenile plasma cortisol concentrations were significantly correlated with infant cortisol levels at all but the earliest time point. Analysis of salivary cortisol from a subset of animals showed a similar age-related decline and the presence of a significant rearing effect, with lower concentrations in surrogate-peer–reared juveniles, but no sex difference. Salivary and plasma cortisol concentrations in these animals were significantly correlated.     

Event-related potentials reveal the development of stable face representations from natural variability

Natural variability between instances of unfamiliar faces can make it difficult to reconcile two images as the same person. Yet for familiar faces, effortless recognition occurs even with considerable variability between images. To explore how stable face representations develop, we employed incidental learning in the form of a face sorting task. In each trial, multiple images of two facial identities were sorted into two corresponding piles. Following the sort, participants showed evidence of having learnt the faces performing more accurately on a matching task with seen than with unseen identities. Furthermore, ventral temporal event-related potentials were more negative in the N250 time range for previously seen than for previously unseen identities. These effects appear to demonstrate some degree of abstraction, rather than simple picture learning, as the neurophysiological and behavioural effects were observed with novel images of the previously seen identities. The results provide evidence of the development of facial representations, allowing a window onto natural mechanisms of face learning.     

Reward modulation of contextual cueing: Repeated context overshadows repeated target location

Contextual cueing can be enhanced by reward. However, there is a debate if reward is associated with the repeated target–distractor configurations or with the repeated target locations that occur in both repeated and new displays. Based on neuroimaging evidence, we hypothesized that reward becomes associated with the target location only in new displays, but not in repeated displays, where the repeated target location is overshadowed by the more salient repeated target–distractor configuration. To test this hypothesis, we varied the reward value associated with the same target location in repeated and new displays. The results confirmed the overshadowing hypothesis in that search facilitation in repeated target–distractor configurations was modulated by the variable value associated with the target location. This effect was observed mainly in early learning.     

The influence of synesthesia on eye movements: no synesthetic pop-out in an oculomotor target selection task

Recent research on grapheme-colour synesthesia has focused on whether visual attention is necessary to induce a synesthetic percept. The current study investigated the influence of synesthesia on overt visual attention during an oculomotor target selection task. Chromatic and achromatic stimuli were presented with one target among distractors (e.g. a ‘2’ (target) among multiple ‘5’s (distractors)). Participants executed an eye movement to the target. Synesthetes and controls showed a comparable target selection performance across conditions and a ‘pop-out effect’ was only seen in the chromatic condition. As a pop-out effect was absent for the synesthetes in the achromatic condition, a synesthetic element appears not to elicit a synesthetic colour, even when it is the target. The synesthetic percepts are not pre-attentively available to distinguish the synesthetic target from synesthetic distractors when elements are presented in the periphery. Synesthesia appears to require full recognition to bind form and colour.