Disinhibition of return: Unnecessary and unlikely

Recently, from data obtained with a temporal order judgment (TOJ) task, Gibson and Egeth (1994) concluded that inhibition of return (IOR; a response time effect that reveals slower responding to targets at previously cued versus uncued locations) reflects impaired perceptual processing. By replotting their data, we demonstrate that the perception of temporal order is influenced only by the facilitatory effect of a cue at short stimulus onset asynchronies (SOAs) and is unaffected by IOR at long SO As. The target paper proposed that, when extra stimuli are presented at task-relevant locations (i.e., in the TOJ task), IOR is prevented by a hypothetical process that is known as disinhibition of return (DOR). We argue that the assumptions that IOR affects perceptual processing and that DOR exists are unnecessary, as a more parsimonious response-based interpretation of IOR is consistent with their data. Further, we summarize recent results and present new data that demonstrate that DOR is unlikely.     

Role of the striatum and the cerebellum in motor skill acquisition

Motor skill acquisition was investigated in patients with Parkinson's disease (PD) or cerebellar dysfunction using two sensory-guided tracking tasks. The subjects had to learn to track a visual target (a square) on a computer screen by moving a joystick under two different conditions. In the unreversed task, the horizontal target movements were semi-predictable and could be anticipated. In the reversed task, the horizontal movements of a pointer which had to be kept within the target square were mirror-reversed to the joystick movements. PD patients showed intact learning of the semi-predictable task and reduced learning of the mirror-reversed task; patients with cerebellar dysfunction showed the opposite pattern. These findings are discussed in relation to the differential contribution of the cerebellum and the striatum to motor skill acquisition: the cerebellum appears to participate in the implementation of anticipatory movements, whereas the striatum may be critically involved in types of motor learning which require a high degree of internal elaboration.     

Arbitrariness in nature: synergetics and evolutionary laws of prohibition

The philosophical consequences of synergetics, the interdisciplinary theory of evolution and self-organization of complex systems, are being drawn in the paper. The idea of discreteness of evolutionary paths is in the focus of attention. Although the future is open, and there are many alternative evolutionary paths for complex systems, not any arbitrary (either conceivable or desirable) evolutionary path is feasible in a given system. There are discrete spectra of possible evolutionary paths which are determined exclusively by inner properties of the corresponding systems. Synergetics allows us to reveal general laws of self-organization and, therefore, certain limits of arbitrariness of nature in choosing possible paths of evolution as well as in constructing of a complex evolutionary whole. A comparative analysis between the modern synergetic notions and a few ideas of the Western philosophy (F. Nietzsche, N. Hartmann, M. Heidegger) and of the Eastern teachings (Taoism, Buddhism) is made. This revised version was published online in August 2006 with corrections to the Cover Date.     

A secondary task is not always costly: Context‐based guidance of visual search survives interference from a demanding working memory task

Repeatedly encountering a visual search display with the target located at a fixed position relative to the distractors facilitates target detection, relative to novel displays – which is attributed to search guidance by (acquired) long‐term memory (LTM) of the distractor ‘context’ of the target. Previous research has shown that this ‘contextual cueing’ effect is severely impeded during learning when participants have to perform a demanding spatial working memory (WM) task concurrently with the search task, though it does become manifest when the WM task is removed. This has led to the proposal that search guidance by LT context memories critically depends on spatial WM to become ‘expressed’ in behaviour. On this background, this study, of two experiments, asked: (1) Would contextual cueing eventually emerge under dual‐task learning conditions if the practice on the task(s) is extended beyond the short training implemented in previous studies? and given sufficient practice, (2) Would performing the search under dual‐task conditions actually lead to an increased cueing effect compared to performing the visual search task alone? The answer is affirmative to both questions. In particular, Experiment 1 showed that a robust contextual cueing effect emerges within 360–720 dual‐task trials as compared to some 240 single‐task trials. Further, Experiment 2 showed that when dual‐ and single‐task conditions are performed in alternating trials blocks, the cueing effect for the very same set of repeated displays is significantly larger in dual‐task blocks than in single‐task blocks. This pattern of effects suggests that dual‐task practice eventually leads to direct, or ‘automatic’, guidance of visual search by learnt spatial LTM representations, bypassing WM processes. These processes are normally engaged in single‐task performance might actually interfere with direct LTM‐based search guidance.     

How green defaults promote environmentally friendly decisions: Attitude‐conditional default acceptance but attitude‐unconditional effects on actual choices

Defaults (i.e., options that become effective without an active choice) have been found to be powerful tools to influence decision‐making in a range of behavioral domains. However, seemingly conflicting assumptions have been expressed regarding the interplay of defaults with individual attitudes. Whereas some expect attitude‐conditional effects (i.e., a statistical default‐by‐attitude interaction), others assume an attitude‐unconditional effectiveness of defaults (i.e., statistically additive effects). Integrating both assumptions, we argue that the interplay of defaults and attitudes depends on what is considered a default effect. Specifically, whereas default acceptance is likely to be attitude‐conditional, we predicted that defaults and attitudes would add up in explaining people's actual choices. We tested these hypotheses in an online shopping scenario presenting environmentally friendly or conventional default products to 231 participants. Participants’ environmental attitude was assessed with the General Ecological Behavior scale and actual product choices were identified if participants rejected a given default product. In line with our hypotheses, default acceptance was predicted by a default‐by‐attitude interaction. In contrast, actual environmentally friendly product choices were found to be an additive function of defaults and participants’ environmental attitude. From an applied perspective, our findings suggest that defaults can readily be applied even in attitude‐heterogeneous target populations. Concurrently, however, our findings also speak of the importance of people's attitudes for understanding individual decision‐making.     

Social support and verbal interaction are differentially associated with cognitive function in midlife and older age

Social engagement is associated with healthy aging and preserved cognition. Two dimensions of engagement, verbal interactions and perceived support, likely impact cognition via distinct mechanistic pathways. We explored the cognitive benefit of each construct among enrollees (N = 1,052, mean age = 60.2 years) in the Wisconsin Registry for Alzheimer’s Prevention study, who provide neuropsychological and sociobehavioral data at two-year intervals. Outcomes included six cognitive factor scores representing key domains of executive function and memory. Key predictors included self-reported perceived social support and weekly verbal interaction. Results indicated that after adjusting for lifestyle covariates, social support was positively associated with Speed and Flexibility and that verbal interactions were associated with Verbal Learning and Memory. These findings suggest that support, which may buffer stress, and verbal interaction, an accessible, aging-friendly form of environmental enrichment, are uniquely beneficial. Both are integral in the design of clinical and community interventions and programs that promote successful aging.     

Dimension intertrial and cueing effects in localization: support for pre-attentively weighted one-route models of saliency

There are several alternative accounts of dimensional intertrial and cueing effects in singleton feature search tasks. Some accounts assume that these effects arise at post-selective processing stages; dual-route accounts assume them to be perceptual in nature, but coming into play only in non-spatial tasks (e.g., detection but not localization). By contrast, the Dimension Weighting Account (DWA) assumes dimensional effects to arise at pre-attentive processing stages of spatial as well as non-spatial tasks. The data available are ambiguous, permitting no clear-cut choice among these accounts. Therefore, the present study examined for early effects of dimensional weighting in a spatial task, the presence of which is only predicted by the DWA and not by post-selective or dual-route accounts. Salience is known to saturate for high feature contrast and long presentation times. Consequently, with lower bottom-up salience that still permits efficient search, dimensional weights would produce a greater modulation--if present at all. Thus, we examined localization accuracy under brief-presentation conditions in Experiment 1, and localization speed under conditions of low versus high feature contrast in Experiment 2. Both experiments revealed significant dimension intertrial and cueing effects. This strongly argues against dual-route accounts and strengthens evidence for a pre-attentive origin of these effects.     

Disentangling the adult attention-deficit hyperactivity disorder endophenotype: parametric measurement of attention

Attention deficit hyperactivity disorder (ADHD) persists frequently into adulthood. The decomposition of endophenotypes by means of experimental neuro-cognitive assessment has the potential to improve diagnostic assessment, evaluation of treatment response, and disentanglement of genetic and environmental influences. We assessed four parameters of attentional capacity and selectivity derived from simple psychophysical tasks (verbal report of briefly presented letter displays) and based on a "theory of visual attention." These parameters are mathematically independent, quantitative measures, and previous studies have shown that they are highly sensitive for subtle attention deficits. Potential reductions of attentional capacity, that is, of perceptual processing speed and working memory storage capacity, were assessed with a whole report paradigm. Furthermore, possible pathologies of attentional selectivity, that is, selection of task-relevant information and bias in the spatial distribution of attention, were measured with a partial report paradigm. A group of 30 unmedicated adult ADHD patients and a group of 30 demographically matched healthy controls were tested. ADHD patients showed significant reductions of working memory storage capacity of a moderate to large effect size. Perceptual processing speed, task-based, and spatial selection were unaffected. The results imply a working memory deficit as an important source of behavioral impairments. The theory of visual attention parameter working memory storage capacity might constitute a quantifiable and testable endophenotype of ADHD.     

Evaluation of a DVD-based self-help program in highly socially anxious individuals--pilot study

High social anxiety is a risk factor for the incidence of social anxiety disorder (SAD). Early diagnosis and intervention may prevent more severe psychiatric courses. Self-help programs may be a convenient, accessible, and effective intervention. This study examined the efficacy of a newly developed self-help program for SAD in individuals with subthreshold social anxiety. A total of 24 highly socially anxious individuals were randomly assigned to a DVD-based self-help program or to a wait-list control group. The self-help program is based on the cognitive model according to Clark and Wells (1995; adapted to German by Stangier, Clark, & Ehlers, 2006) and comprises eight sessions. ANOVAs based on an intention-to-treat model were used for data analyses. The self-help program was well accepted; just one person withdrew during the intervention. There were significant Time × Group interactions on all primary outcome measures. For the intervention group moderate to high within-groups effect sizes up to Cohen's d = 1.05 were obtained. Between-groups effect sizes ranged from 0.24 to 0.65 in favor of the active intervention. The newly developed DVD-based self-help program seems to be a promising intervention for highly socially anxious individuals as it reduces social anxiety symptoms.