How do object reference frames and motion vector decomposition emerge in laminar cortical circuits?

How do spatially disjoint and ambiguous local motion signals in multiple directions generate coherent and unambiguous representations of object motion? Various motion percepts, starting with those of Duncker (Induced motion, 1929/1938) and Johansson (Configurations in event perception, 1950), obey a rule of vector decomposition, in which global motion appears to be subtracted from the true motion path of localized stimulus components, so that objects and their parts are seen as moving relative to a common reference frame. A neural model predicts how vector decomposition results from multiple-scale and multiple-depth interactions within and between the form- and motion-processing streams in V1–V2 and V1–MST, which include form grouping, form-to-motion capture, figure–ground separation, and object motion capture mechanisms. Particular advantages of the model are that these mechanisms solve the aperture problem, group spatially disjoint moving objects via illusory contours, capture object motion direction signals on real and illusory contours, and use interdepth directional inhibition to cause a vector decomposition, whereby the motion directions of a moving frame at a nearer depth suppress those directions at a farther depth, and thereby cause a peak shift in the perceived directions of object parts moving with respect to the frame.     

Predicting Evacuation in Two Major Disasters: Risk Perception,Social Influence,and Access to Resources1

The complex and somewhat bewildering phenomenon of why people sometimes decide not to evacuate from a dangerous situation is influenced by a combination of individual characteristics and 3 basic social psychological processes: (a) risk perception, (b) social influence, and (c) access to resources. This study used a combined sample of 777 adults interviewed after Hurricanes Hugo and Andrew. Although numerous variables significantly predicted evacuation, much variance in this behavior still remained unexplained. Different population subgroups gave different reasons for not evacuating (e.g., severeness of storm, territoriality). A multifaceted and tailored approach to both individuals and communities is needed; a simple warning is often not enough.     

Healthcare utilization following cognitive-behavioral treatment for panic disorder with agoraphobia

The aim of this study was to examine the overall changes in healthcare services utilization after providing an empirically supported cognitive-behavioral treatment for panic disorder with agoraphobia. Data on healthcare utilization were collected for a total of 84 adults meeting DSM-IV criteria. Participants were completers of a cognitive-behavioral treatment for panic disorder with agoraphobia. Data on utilization of healthcare services and medication were obtained from semi-structured interviews from baseline to 1-year after treatment. Results of the Friedman non-parametric analysis reveal a significant decrease in overall and mental health-related costs following treatment. This study shows a significant reduction in healthcare costs following cognitive behavior therapy for panic disorder with agoraphobia. More studies are needed to examine the potential long-term cost-offset effect of empirically supported treatments for panic disorder.     

Auditory ERP in extremely premature 5-year-old children

The aim of this research was to test the hypothesis of a functional impairment in the automatic detection of deviant tones in 141 children born after 25 to 28 weeks of gestational age, as compared to 45 age-matched full-term control children. All of them were assessed at age 5 years 9 months and instructed to listen passively to two different pure tones (1000 vs 1200 Hz; 20 vs 80%) counterbalanced between ears. Rarity was thus defined by specific ear by tone combinations. The temporal N100 showed a clear contralateral functional organization of the central auditory pathway, especially for the left ear, but without group difference. By contrast, in full-term controls but not in premature children, the central N200 was specifically increased over frontal leads to rare stimuli as compared to frequent. Premature children demonstrated a lack of brain response when more complex processing integrating different informations was required.     

Breaking Down the Bilingual Cost in Speech Production

Bilinguals have been shown to perform worse than monolinguals in a variety of verbal tasks. This study investigated this bilingual verbal cost in a large‐scale picture‐naming study conducted in Spanish. We explored how individual characteristics of the participants and the linguistic properties of the words being spoken influence this performance cost. In particular, we focused on the contributions of lexical frequency and phonological similarity across translations. The naming performance of Spanish‐Catalan bilinguals speaking in their dominant and non‐dominant language was compared to that of Spanish monolinguals. Single trial naming latencies were analyzed by means of linear mixed models accounting for individual effects at the participant and item level. While decreasing lexical frequency was shown to increase naming latencies in all groups, this variable by itself did not account for the bilingual cost. In turn, our results showed that the bilingual cost disappeared when naming words with high phonological similarity across translations. In short, our results show that frequency of use can play a role in the emergence of the bilingual cost, but that phonological similarity across translations should be regarded as one of the most important variables that determine the bilingual cost in speech production. Low phonological similarity across translations yields worse performance in bilinguals and promotes the bilingual cost in naming performance. The implications of our results for the effect of phonological similarity across translations within the bilingual speech production system are discussed.     

Psychopathy in Bulgaria: The cross-cultural generalizability of the Hare Psychopathy Checklist

The generalizability of the psychopathy construct to Eastern European cultures has not been well-studied, and no prior studies have evaluated psychopathy in non-offender samples from this population. The current validation study examines the factor structure, internal consistency, and external validity of the Bulgarian translation of the Hare Psychopathy Checklist: Screening Version. Two hundred sixty-two Bulgarian adults from the general community were assessed, of which 185 had a history of substance dependence. Confirmatory factor analysis indicated good fit for the two-, three-, and four-factor models of psychopathy. Zero-order and partial correlation analyses were conducted between the two factors of psychopathy and criterion measures of antisocial behavior, internalizing and externalizing psychopathology, personality traits, addictive disorders and demographic characteristics. Relationships to external variables provided evidence for the convergent and discriminant validity of the psychopathy construct in a Bulgarian community sample.     

Posttraumatic stress severity is associated with coping motives for alcohol use among in-patient and community recruited adolescents

Background and Objectives: A growing body of work suggests individuals with more severe post-traumatic stress symptoms (PTSS) are at higher risk for developing problematic alcohol use outcomes. Extending work from the adult literature, the present study was the first to examine the extent to which PTSS is related to drinking motives for alcohol use in both clinical and non-clinical samples of adolescents.

Design: Hierarchical regression analyses were used to predict coping motives for alcohol use from PTSS, above and beyond demographic variables, alcohol use frequency, and other alcohol use motives.

Methods: Trauma-exposed adolescents before entering treatment (Sample 1 n?=?41) and recruited from the local community (Sample 2 n?=?55) self-reported on PTSS and alcohol use motives.

Results: PTSS positively predicted coping motives for alcohol use after controlling for age, gender, and alcohol use frequency.

Conclusions: The current study highlights the need to consider both PTSS severity, as well as underlying cognitive mechanisms (e.g., motives), to better understand the etiology of problematic alcohol use among trauma-exposed youth. Future work focused on clarifying the trajectory of alcohol use motives and problems as a function of PTSS is needed.     

Event-related brain potentials and the efficiency of visual search for vertically and horizontally oriented stimuli

Reports that visual search is more efficient for vertically than for horizontally shaded objects suggested that search is influenced by a priori knowledge about the source of light. In this study, we examined search for targets defined by the orientation of luminance gradients and measured event-related brain potentials (ERPs). In Experiment 1, we examined search for stimuli that comprised gradual luminance differences. Response times showed the expected orientation anisotropy effect. ERP amplitudes in the P1 latency range were slightly more positive in response to horizontally oriented stimuli, whereas P3 amplitudes were more positive in response to nonsingleton vertically oriented stimuli. Experiment 2 compared search for stimuli that comprised gradual versus step differences in luminance. All the anisotropies that we observed in Experiment 1 could be replicated in Experiment 2. Moreover, these anisotropies were not dependent on the type of the luminance gradient. This finding is inconsistent with the view that search efficiency is influenced by a priori knowledge about the source of light. The behavioral and electrophysiological data are consistent with a context model of visual search. We propose that contextual modulation reduces redundancy and contributes to computing the saliency of visual information by implementing divisive normalization and multiplicative filtering.     

The Links Between Social Anxiety Disorder,Insomnia Symptoms,and Alcohol Use Disorders: Findings From a Large Sample of Adolescents in the United States

Social anxiety disorder (SAD) is associated with increased risk of developing an alcohol use disorder (AUD). Most of the current literature has focused on the role of acute stress responding in this relation; however, both SAD and AUDs also are linked to insomnia symptoms (i.e., difficulty falling or staying asleep). As adolescence is a sensitive period for the onset of these disorders, the present study examined if insomnia symptoms might partially account for the SAD-AUD link in a large sample of adolescents. Data from the National Comorbidity Survey–Adolescent Supplement were examined. Participants (N = 10,140) completed interviews to assess past 12-month SAD and AUD diagnostic status as well as insomnia symptoms. Analyses tested whether insomnia symptoms accounted for a significant proportion of the SAD-AUD relation. Results indicated that insomnia symptoms were positively related to both SAD and AUD status, and the relation between SAD and AUD status was significantly reduced when insomnia symptoms were included in the model. Findings remained significant after controlling for the effects of age, gender, posttraumatic stress disorder, major depressive disorder, and other drug dependence status. Experimental examination and intensive longitudinal assessment of these relationships are needed before strong conclusions can be inferred about causality and temporal relationships. The current findings do indicate insomnia may be an important indirect and stigma-free treatment target to address in prevention and treatment efforts for SAD, AUDs, and their co-occurrence.