Virtual reality: A new track in psychological research

One major challenge of social interaction research is to achieve high experimental control over social interactions to allow for rigorous scientific reasoning. Virtual reality (VR) promises this level of control. Pan and Hamilton guide us with a detailed review on existing and future possibilities and challenges of using VR for social interaction research. Here, we extend the discussion to methodological and practical implications when using VR.     

Effects of procedure and outcome accountability on interview validity

This study tested effects of holding interviewers accountable for either the procedure they follow to make interview judgments (procedure accountability) or the accuracy of their judgments (outcome accountability) on interview validity. Undergraduates (N = 338) simulated employment interviewers in an experiment that crossed 2 levels of procedure accountability with 2 levels of outcome accountability. They watched videotapes of 60 managers answering an interview question and rated the managers on leadership potential. The dependent variable was the correlation between their interview judgments and supervisory ratings of the managers' actual leadership performance on the job. Results showed that procedure accountability increased interview validity and outcome accountability lowered it. Participants' apparent attentiveness fully mediated effects of procedure accountability on interview validity.     

Learning subjective health complaints

Symptom episodes often show a spatio-temporal structure, that is, they occur in a specific context for a certain duration. Repeated experiences may therefore be construed as associative learning trials, in which context elements are turned into predictive cues, triggering anticipatory processes conducive to subjective health complaints. A series of experiments, using inhalations of air enriched with CO2 and external (odors) or internal (mental images) stimuli as cues, is discussed to show that subjective health complaints may occur upon presenting the cue alone. Learned symptoms may be unrelated to bodily responses and easily generalize to new related cues. Better learning occurs to cues with a negative affective valence and in participants scoring high for negative affectivity. Our findings are relevant to the understanding of medically unexplained ("functional") syndromes and the poor relationship between objective and subjective health indicators in general.     

Simplified learning in complex situations: knowledge partitioning in function learning

The authors explored the phenomenon that knowledge is not always integrated and consistent but may be partitioned into independent parcels that may contain mutually contradictory information. In 4 experiments, using a function learning paradigm, a binary context variable was paired with the continuous stimulus variable of a to-be-learned function. In the first 2 experiments, when context predicted the slope of a quadratic function, generalization was context specific. Because context did not predict function values, it is suggested that people use context to gate separate learning of simpler partial functions. The 3rd experiment showed that partitioning also occurs with a decreasing linear function, whereas the 4th study showed that partitioning is absent for a linearly increasing function. The results support the notion that people simplify complex learning tasks by acquiring independent parcels of knowledge.     

Identification of the eye-brain-hand system with point processes: a new approach to simple reaction time

By presenting a Poisson process of flashes to observers who hit a button as quickly as possible after each, the authors identified the system involved in simple reaction time (RT). The nonlinear kernels up to 2nd order were measured from the stimulus and response point processes. The 1st-order kernel is analogous to a histogram of simple RTs. The 2nd-order kernel shows complex patterns of nonlinear suppression and facilitation between pairs of flashes. Simple RT measured as the lag of the 1st-order kernel's peak agrees with RT from conventional discrete trial experiments. RTs are shorter and less variable when the flashes are separated by uniform rather than exponential delays, which shows that observers use the stimulus hazard function to become prepared to detect and respond to the flash.     

Emergence and Its Place in Nature: A Case Study of Biochemical Networks

We will show that there is a strong form of emergence in cell biology. Beginning with C.D. Broads classic discussion of emergence, we distinguish two conditions sufficient for emergence. Emergence in biology must be compatible with the thought that all explanations of systemic properties are mechanistic explanations and with their sufficiency. Explanations of systemic properties are always in terms of the properties of the parts within the system. Nonetheless, systemic properties can still be emergent. If the properties of the components within the system cannot be predicted, even in principle, from the behavior of the systems parts within simpler wholes then there also will be systemic properties which cannot be predicted, even in principle, on basis of the behavior of these parts. We show in an explicit case study drawn from molecular cell physiology that biochemical networks display this kind of emergence, even though they deploy only mechanistic explanations. This illustrates emergence and its place in nature.     

Hierarchical organisation of neuro-anatomical constraints in interlimb coordination

Based on the observation that bimanual finger tapping movements tend toward mirror symmetry with respect to the body midline, despite the synchronous activation of non-homologous muscles, F. Mechsner, D. Kerzel, G. Knoblich, and W. Prinz (2001) [Perceptual basis of bimanual coordination. Nature, 414, 69-73] suggested that the basis of rhythmic coordination is purely spatial/perceptual in nature, and independent of the neuro-anatomical constraints of the motor system. To investigate this issue further, we employed a four finger tapping task similar to that used by F. Mechsner and G. Knoblich (2004) [Do muscle matter in bimanual coordination? Journal of Experimental Psychology: Human Perception and Performance, 30, 490-503] in which six male participants were required to alternately tap combinations of adjacent pairs of index (I), middle (M) and ring (R) fingers of each hand in time with an auditory metronome. The metronome pace increased continuously from 1 Hz to 3 Hz over the course of a 30-s trial. Each participant performed three blocks of trials in which finger combination for each hand (IM or MR) and mode of coordination (mirror or parallel) were presented in random order. Within each block, the right hand was placed in one of three orientations; prone, neutral and supine. The order of blocks was counterbalanced across the six participants. The left hand maintained a prone position throughout the experiment. On the basis of discrete relative phase analyses between synchronised taps, the time at which the initial mode of coordination was lost was determined for each trial. When the right hand was prone, transitions occurred only from parallel symmetry to mirror symmetry, regardless of finger combination. In contrast, when the right hand was supine, transitions occurred only from mirror symmetry to parallel but no transitions were observed in the opposite direction. In the right hand neutral condition, mirror and parallel symmetry are insufficient to describe the modes of coordination since the hands are oriented orthogonally. When defined anatomically, however, the results in each of the three right hand orientations are consistent. That is, synchronisation of finger tapping is determined by a hierarchy of control of individual fingers based on their intrinsic neuro-mechanical properties rather than on the basis of their spatial orientation.     

Configural processing and perceptions of head tilt

Configural processing is important for face recognition, but its role in other types of face processing is unclear. In the present study, participants made judgments of head tilt for faces in which the vertical position of the internal facial region was varied. We found a highly reliable relationship between inner-face position and perceived head tilt. We also found that changes in inner-face position affected the perceived dimensions of an individual unchanged facial feature: compared to control faces, nearly two-thirds of faces in which the features had been moved down were judged to have a longer nose. This finding suggests an early integration of configural and featural processing to create a stable holistic percept of the face. The demonstration of holistic processing at a basic perceptual level (as opposed to during face recognition) is important as it constrains possible models of the relationships between featural and configural processing.     

Serial recall and presentation schedule: a micro-analysis of local distinctiveness

According to temporal distinctiveness theories, items that are temporally isolated from their neighbours during presentation are more distinct and thus are recalled better. Event-based theories, which deny that elapsed time plays a role at encoding, explain isolation effects by assuming that temporal isolation provides extra time for rehearsal or consolidation of encoding. The two classes of theories can be differentiated by examining the symmetry of isolation effects: Event-based accounts predict that performance should be affected only by pauses following item presentation (because they allow time for rehearsal or consolidation), whereas distinctiveness predicts that items should also benefit from preceding pauses. The first experiment manipulated inter-item intervals and showed an effect of intervals following but not preceding presentation, in line with event-based accounts. The second experiment showed that the effect of following interval was abolished by articulatory suppression. The data are consistent with event-based theories but can be handled by time-based distinctiveness models if they allow for additional encoding during inter-item pauses.