Left, right, left, right, eyes to the front! Müller-Lyer bias in grasping is not a function of hand used, hand preferred or visual hemifield, but foveation does matter

We investigated whether the control of movement of the left hand is more likely to involve the use of allocentric information than movements performed with the right hand. Previous studies (Gonzalez et al. in J Neurophys 95:3496–3501, 2006; De Grave et al. in Exp Br Res 193:421–427, 2009) have reported contradictory findings in this respect. In the present study, right-handed participants (N = 12) and left-handed participants (N = 12) made right- and left-handed grasps to foveated objects and peripheral, non-foveated objects that were located in the right or left visual hemifield and embedded within a Müller-Lyer illusion. They were also asked to judge the size of the object by matching their hand aperture to its length. Hand apertures did not show significant differences in illusory bias as a function of hand used, handedness or visual hemifield. However, the illusory effect was significantly larger for perception than for action, and for the non-foveated compared to foveated objects. No significant illusory biases were found for reach movement times. These findings are consistent with the two-visual system model that holds that the use of allocentric information is more prominent in perception than in movement control. We propose that the increased involvement of allocentric information in movements toward peripheral, non-foveated objects may be a consequence of more awkward, less automatized grasps of nonfoveated than foveated objects. The current study does not support the conjecture that the control of left-handed and right-handed grasps is predicated on different sources of information

Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces

Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface

Developmental abnormalities in brain white matter in prodromes with 22q11.2 Deletion Syndrome: A tract based spatial statistics study

Background Schizophrenia is believed to be a neurodevelopmental disorder, and might originate earlier than the first symptoms present clinically. Subjects with 22q11.2 Deletion Syndrome (22q11DS) represent a promising cohort to explore biomarkers of schizophrenia prior to symptoms onset, as there is a 30% incidence of schizophrenia in adult life. In this study, we explored whether changes in whole brain white matter are present in adolescents with 22q11.2DS and in prodromes (22q11DS subjects with a high score on Brief Psychiatric Rating Scale). Methods Diffusion Magnetic Resonance Images (dMRI) of the brain white matter were acquired from 47 controls and 50 subjects with 22q11DS, including 9 prodromes (mean age 18 ± 2 years). Whole brain white matter was analyzed using the Tract Based Spatial Statistics (TBSS) method. dMRI measures, such as Fractional Anisotropy (FA), Mean Diffusivity (MD), Axial Diffusivity (AD) and Radial Diffusivity (RD) were compared between the groups. Results When controls were compared to all the subjects with 22q11DS, statistically significant reductions in MD, AD and RD were found in the 22q11DS group. The changes were localized to the corpus callosum (CC) and the long association fiber tracts. When the 22q11DS group was split, the prodromes showed statistically significant reductions in MD, AD and RD in the CC and Superior Longitudinal Fasciculus (SLF). Discussion Changes in white matter were observed in individuals with 22q11.2DS, which could be interpreted as developmental and axonal abnormalities. The changes found in the prodromes point to even more severe developmental abnormalities. The changes in dMRI indices, reported here, differ from those observed in chronic schizophrenia. In chronic schizophrenia reduced FA and increased RD are being interpreted as abnormalities of the myelin. We hope that studying these prodromes will allow us to develop a more complete understanding of the changes in brain white matter that lead to schizophrenia.N

Facial emotion recognition and mood symptom course in young adults with childhood-onset bipolar disorder

Facial emotion recognition deficits are common in bipolar disorder (BD) and associated with impairment. However, the relationship between facial emotion recognition and mood course is not well understood. This study examined facial emotion recognition and subsequent mood symptoms in young adults with childhood-onset BD versus typically developing controls (TDCs). The sample included 116 young adults (ages 18-30, 58% male, 78% White) with prospectively verified childhood-onset BD (n = 52) and TDCs (n = 64). At baseline, participants completed a facial emotion recognition task (Diagnostic Analysis of Non-Verbal Accuracy-2) and clinical measures. Then, participants with BD completed mood symptom assessments every 6 months (M = 8.7 ± 5.2 months) over two years. Analyses included independent-samples t tests and mixed-effects regression models. Participants with BD made significantly more recognition errors for child expressions than TDCs. There were no significant between-group differences for recognition errors for adult expressions, or errors for specific child or adult emotional expressions. Participants had moderate baseline mood symptoms. Significant time-by-facial emotion recognition interactions revealed more recognition errors for child emotional expressions predicted lower baseline mania and stable/consistent trajectory; fewer recognition errors for child expressions predicted higher baseline mania and decreasing trajectory. In addition, more recognition errors for adult sad expressions predicted stable/consistent depression trajectory and decreasing mania; fewer recognition errors for adult sad expressions predicted decreasing depression trajectory and stable/consistent mania. Effects remained when controlling for baseline demographics and clinical variables. Facial emotion recognition may be an important brain/behavior mechanism, prognostic indicator, and intervention target for childhood-onset BD, which endures into young adulthood and is associated with mood trajectory

Relationship between cognitive flexibility and subsequent course of mood symptoms and suicidal ideation in young adults with childhood-onset bipolar disorder

Neurocognitive deficits, such as cognitive flexibility impairments, are common in bipolar disorder (BD) and predict poor academic, occupational, and functional outcomes. However, the association between neurocognition and illness trajectory is not well understood, especially across developmental transitions. This study examined cognitive flexibility and subsequent mood symptom and suicidal ideation (SI) course in young adults with childhood-onset BD-I (with distinct mood episodes) vs. BD-not otherwise specified (BD-NOS) vs. typically-developing controls (TDCs). Sample included 93 young adults (ages 18-30) with prospectively verified childhood-onset DSM-IV BD-I (n = 34) or BD-NOS (n = 15) and TDCs (n = 44). Participants completed cross-sectional neuropsychological tasks and clinical measures. Then participants with BD completed longitudinal assessments of mood symptoms and SI at 6-month intervals (M = 39.18 ± 16.57 months of follow-up data). Analyses included ANOVAs, independent-samples t tests, chi-square analyses, and multiple linear regressions. Participants with BD-I had significant deficits in cognitive flexibility and executive functioning vs. BD-NOS and TDCs, and impaired spatial working memory vs. TDCs only. Two significant BD subtype-by-cognitive flexibility interactions revealed that cognitive flexibility deficits were associated with subsequent percentage of time depressed and with SI in BD-I but not BD-NOS, regardless of other neurocognitive factors (full-scale IQ, executive functioning, spatial working memory) and clinical factors (current and prior mood and SI symptoms, age of BD onset, global functioning, psychiatric medications, comorbidity). Thus, cognitive flexibility may be an important etiological brain/behavior mechanism, prognostic indicator, and intervention target for childhood-onset BD-I, as this deficit appears to endure into young adulthood and is associated with worse prognosis for subsequent depression and SI