The role of the orbitofrontal cortex in normally developing compulsive-like behaviors and obsessive-compulsive disorder

Mounting evidence concerning obsessive-compulsive disorders points to abnormal functioning of the orbitofrontal cortices. First, patients with obsessive-compulsive disorder (OCD) perform poorly on tasks that rely on response suppression/motor inhibition functions mediated by the orbitofrontal cortex relative to both normal and clinical controls. Second, patients with OCD exhibit functional hyperactivity in lateral orbitofrontal and related structures corresponding with symptom severity. In this article, we compare these neurocognitive correlates of OCD with the executive and neural underpinnings of "compulsive-like" behaviors that are common in normal childhood. We discuss the phenomenology and natural history of normative compulsive-like behaviors as well as the behavioral, emotional, and cognitive continuities between typical and pathological obsessive-compulsive behaviors. We then examine associations between children's executive performance deficits and their observed compulsive-like characteristics. We relate these patterns to executive deficits shown by adults with OCD. Finally, we speculate on the developmental neurobiology of children's compulsive-like behaviors, with particular attention to orbitofrontal functions including behavioral and emotional regulation, and we suggest similarities and differences with the neurobiology of OCD. In making these comparisons, we hope to open a dialogue between researchers who study underlying brain pathologies associated with OCD and those who explore the neurocognitive bases of normal development.     

Attentional effects of counterpredictive gaze and arrow cues

The authors used counterpredictive cues to examine reflexive and volitional orienting to eyes and arrows. Experiment 1 investigated the effects of eyes with a novel design that allowed for a comparison of gazed-at (cued) target locations and likely (predicted) target locations against baseline locations that were not cued and not predicted. Attention shifted reflexively to the cued location and volitionally to the predicted location, and these 2 forms of orienting overlapped in time. Experiment 2 discovered that another well-learned directional stimulus, an arrow, produced a different effect: Attention was shifted only volitionally to the predicted location. The authors suggest that because there is a neural architecture specialized for processing eyes, gaze-triggered attention is more strongly reflexive than orienting to arrows.     

Do behavioral disturbances in persons with Alzheimer's disease predict caregiver depression over time?

Random effects models were used to examine the association between behavioral disturbances in persons with Alzheimer's disease (N = 90) and caregiver depressive symptoms at 2-month intervals over an 18-month period. There was substantial variability in trajectories of change in caregiver depressive symptoms over time but no systematic increase in distress despite increased severity of dementia symptoms. Total behavioral disturbances were associated with higher levels of caregiver depressive symptoms: this effect was primarily attributable to aggressive behaviors. No consistent departure from linearity was evident in the relationship between behavior and depression over time.     

Mislocalizations of touch to a fake hand

Observers can mislocalize a tactile target delivered to an unseen hand if a visible rubber glove is positioned next to a pair of distractor lights that flash in correlation with the tactile target (Pavani, Spence, & Driver, 2000). In the present study, we explored visual, tactile, and postural factors that influence this fake hand effect. Comparison with baseline conditions revealed that the fake hand effect was larger than a general spatial congruity effect but weaker than the effect obtained when tactile and visual stimuli were actually in the same locations (Experiment 1). Surprisingly, the effect did not depend on direct vision of the fake hand (Experiments 1 and 2), nor was it enhanced by congruent tactile information (Experiment 3). However, the fake hand effect was sensitive to the postural compatibility of the real and the fake hands (Experiment 4). These findings indicate that the available sensory information is used flexibly to incorporate the rubber glove into the body schema.     

Stability and transitions in mother-infant face-to-face communication during the first 6 months: a microhistorical approach

In this study the authors attempted to unravel the relational, dynamical, and historical nature of mother-infant communication during the first 6 months. Thirteen mothers and their infants were videotaped weekly from 4 to 24 weeks during face-to-face interactions. Three distinct patterns of mother-infant communication were identified: symmetrical, asymmetrical, and unilateral. Guided by a dynamic systems perspective, the authors explored the stability of and transitions between these communication patterns. Findings from event history analysis showed that (a) there are regularly recurring dyadic communication patterns in early infancy, (b) these recurring patterns show differential stabilities and likelihoods of transitions, (c) dynamic stability in dyadic communication is shaped not only by individual characteristics (e.g., infant sex and maternal parity) but also by the dyad's communication history, and (d) depending on their recency, communication histories varying in temporal proximity exert differential effects on the self-organization processes of a dyadic system.     

Hemispheric specialization for spatial frequency processing in the analysis of natural scenes

Experimental data coming from visual cognitive sciences suggest that visual analysis starts with a parallel extraction of different visual attributes at different scales/frequencies. Neuropsychological and functional imagery data have suggested that each hemisphere (at the level of temporo-parietal junctions-TPJ) could play a key role in spatial frequency processing: The right TPJ should predominantly be involved in low spatial frequency (LFs) analysis and the left TPJ in high spatial frequency (HFs) analysis. Nevertheless, this functional hypothesis had been inferred from data obtained when using the hierarchical form paradigm, without any explicit spatial frequency manipulation per se. The aims of this research are (i) to investigate, in healthy subjects, the hemispheric asymmetry hypothesis with an explicit manipulation of spatial frequencies of natural scenes and (ii) to examine whether the 'precedence effect' (the relative rapidity of LFs and HFs processing) depends on the visual field of scene presentation or not. For this purpose, participants were to identify either non-filtered or LFs and HFs filtered target scene displayed either in the left, central, or right visual field. Results showed a hemispheric specialization for spatial frequency processing and different 'precedence effects' depending on the visual field of presentation.     

Georg von Békésy: visualization of hearing

Georg von Békésy received the Nobel Prize in 1961 for his research on the functioning of the auditory system. In psychoacoustics, Békésy both extended and perfected the lines of research begun by von Helmholtz in the 19th century. First in his native Hungary and later at Harvard, Békésy used novel and imaginative devices and methods to observe and model the functioning of the inner ear. He also explored the nature of sensory inhibition by which the nervous system sharpens sensory transitions.     

Deleterious effects of alcohol intoxication: diminished cognitive control and its behavioral consequences

The authors tested the hypothesis that impaired behavioral performance during intoxication results partly from alcohol's deleterious effects on cognitive control. The impact of alcohol on perseverative behavior was examined with an n-back working memory task that included manipulations of task complexity and prepotency of inclinations to respond or withhold responding. Thirty-two social drinkers (16 men) participated in either an alcohol (.075g/100ml) or a no-alcohol condition. Alcohol increased perseveration of prepotent, task-inappropriate response patterns only under cognitively demanding (heavy memory load) conditions. This effect was evident for both commission errors (response persistence despite contingencies altered to require restraint) and omission errors (failure to respond when contingencies were revised to encourage action). Findings suggested that alcohol-induced perseveration arises from impairments in cognitive control.