Inhibition of return in children with Tourette's syndrome and comorbid forms: a preliminary study.

BACKGROUND: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with "pure" Tourette's syndrome (TS), and those with comorbid forms of TS. METHOD: Children with TS-only and "TS + comorbid" (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. RESULTS: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. CONCLUSIONS: The findings suggest abnormalities in attentional "disengage" and "move" mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

A Life Domains Perspective on Acculturation and Psychological Adjustment: A Study of Refugees from the Former Soviet Union

The study articulates a contextual approach to research on acculturation of immigrants, suggesting that the relationship between acculturation and adjustment is dependent on the cultural demands of the life domains considered. Specifically, the study investigated the mediating effects of adjustment in occupational and social life domains on the relationship between acculturation and psychological adjustment for 391 refugees from the former Soviet Union. The study used bilinear measures of acculturation to the host (American) and heritage (Russian) cultures. Using Structural Equation Modeling, the study confirmed the hypothesized relationships, such that the positive effects of American acculturation on psychological adjustment were mediated by occupational adjustment, and the effects of Russian acculturation on psychological adjustment were mediated by satisfaction with co-ethnic social support. Psychological adjustment was measured in two ways, as psychological well-being, using a measure of life satisfaction, and as symptoms of depression and anxiety, using the Hopkins symptom checklist (HSCL). Life satisfaction served as a mediator between adjustment in occupational and social domains and HSCL, suggesting that it may be an intervening variable through which environmental stress associated with immigration contributes to the development of symptoms of mental disorder.     

“American” as a Proxy for “Whiteness”: Racial Color-Blindness in Everyday Life

This article discusses racial color-blindness as it relates to a modern strategy used by both Whites and People of Color (POC) to mask their discussions of race and privilege. People who endorse racial color-blindness tend to believe that race should not matter and currently does not matter in understanding individuals’ lived experiences. Therefore, racially color-blind individuals use strategies to justify their racial privilege and racist beliefs and attitudes. One such strategy is to use the term “American” as a proxy for “White” in describing instances of White privilege as norms and to hide discussions of race more generally. Study 1 findings show that there are many different socially constructed definitions for the term American. Study 2 findings reveal differences in definitions for American depending on an individual’s race and generational status.     

Corporeal awareness and proprioceptive sense of the phantom

Phantom limb perception almost invariably follows limb amputation, and can be characterized by various corporeal and proprioceptive qualities. We report a study of 283 amputees, which administered a structured questionnaire to systematically determine the relative frequency and nature of various bodily aspects of phantom limb perception. These include the size, shape, posture, and telescoping of the phantom; exteroceptive sensations of itch, touch, pressure, vibration, temperature, and ‘electric’ sensations; and prosthesis embodiment. Phantom limbs were generally found to be characterized by properties that parallel those of the intact body, although with anatomically impossible configurations sometimes being perceived. We suggest that both the internal limb image and limb schemata play a significant role in the continued perception of phantom limbs.     

The effect of attending to motor overflow on its voluntary inhibition in young and older adults

Motor overflow refers to involuntary movement or muscle activity coinciding with voluntary movement. We examined whether 16 young adults (18-30 years) and 16 older adults (50-80 years) could voluntarily inhibit overflow. Participants performed a finger pressing task, exerting 50% of their maximal force. Overflow was concurrently recorded in the non-task hand. In the first condition, participants were not made aware of their motor overflow. Then participants, though informed of it, were asked to ignore their overflow. Finally, participants were requested to inhibit overflow with, and then without visual feedback, or vice versa. Overflow was exacerbated when older adults were unaware of it, and was reduced once they were informed. For young adults there was no significant difference between these conditions. Both Age Groups could significantly reduce overflow when so requested, independent of visual feedback. Thus motor overflow can be modulated by higher order cognitive control with directed attention.     

The semantic Simon effect in Tourette's syndrome and obsessive-compulsive disorder

Core symptoms of Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) may be attributed to an impairment in inhibitory control. Neuropsychological studies have addressed inhibition in both disorders, but findings have been inconsistent. The aim of this study was to examine cognitive inhibition, using a semantic Simon effect paradigm, in patients with TS and OCD. Furthermore, to address comorbidity a group of TS+OCD patients was also examined. Results indicated that patients with TS and OCD were affected by the inhibitory components of the task. TS groups performed similarly to controls on simple and choice RT tasks, but were particularly compromised as increasingly complex inhibitory demands were imposed. OCD patients were slower and committed more errors than controls, especially in the more cognitively demanding conditions, and were particularly disadvantaged by incongruent stimulus-response compatibilities. Findings implicate possible fronto-striatal dysfunction, are consistent with previously reported inhibitory deficits in TS and OCD, and support the theory that comorbid TS+OCD is more closely linked to pure TS than OCD.     

Decreased functional brain activation in Friedreich ataxia using the Simon effect task

The present study applied the Simon effect task to examine the pattern of functional brain reorganization in individuals with Friedreich ataxia (FRDA), using functional magnetic resonance imaging (fMRI). Thirteen individuals with FRDA and 14 age and sex matched controls participated, and were required to respond to either congruent or incongruent arrow stimuli, presented either to the left or right of a screen, via laterally-located button press responses. Although the Simon effect (incongruent minus congruent stimuli) showed common regions of activation in both groups, including the superior and middle prefrontal cortices, insulae, superior and inferior parietal lobules (LPs, LPi), occipital cortex and cerebellum, there was reduced functional activation across a range of brain regions (cortical, subcortical and cerebellar) in individuals with FRDA. The greater Simon effect behaviourally in individuals with FRDA, compared with controls, together with concomitant reductions in functional brain activation and reduced functional connectivity between cortical and sub-cortical regions, implies a likely disruption of cortico-cerebellar loops and ineffective engagement of cognitive/attention regions required for response suppression.     

A measure of agreement: an exploration of the relationship of D. W. Winnicott and Phyllis Greenacre

The British psychoanalyst D. W. Winnicott and the American psychoanalyst Phyllis Greenacre were both deeply absorbed by the vicissitudes of the infant's and young child's psychic development. Their clinical observations and theoretical ideas display striking convergences and reciprocal influences. Winnicott was deeply influenced by Greenacre's account of maturational processes, an important stimulus to his thinking that originated outside of the British Psychoanalytical Society. Greenacre's writings on early ego development and creativity were influenced by Winnicott's concept of transitional phenomena. The fact that these relationships have remained unexplored until now indicates the need for less insular accounts of the development of psychoanalytic thought on the two sides of the Atlantic.     

The influence of task characteristics on younger and older adult motor overflow

This study investigated the influence of attentional and motor demands on motor overflow in 17 healthy young (18-35 years) and 17 older adults (60-80 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant or nondominant hand. Overflow was concurrently recorded in the passive hand. Attention was manipulated via a tactile stimulus presented to one or both hands for certain trials. Results showed that older adults exhibited greater overflow than young adults and that the effect of target force was exacerbated in older adults. Further, only older adult overflow was increased when tactile stimulation was directed to one or both hands. Increased overflow in older adults may result from bilateral cortical activation that is influenced by increased task demands. To perform comparatively to younger adults, older adults may compensate for age-related brain changes by recruiting an increased cortical network.