Footedness is a Better Predictor of Language Lateralisation than Handedness

A tremendous amount of experimental work has attempted to identify a reliable behavioural predictor of language lateralisation. Preferred handedness has probably received the most attention, but there are some recent reports that preferred footedness may serve as a more reliable predictor. The present study sought to test this claim by selectively recruiting 32 participants such that the factors of handedness, footedness, and gender were completely crossed. Language lateralisation was assessed with the Fused Dichotic Words Test (FDWT), and lateral preference for both handedness and footedness was assessed using selfreport questionnaires. Ear advantage on the dichotic task varied significantly with preferred foot (P <.001) but not with preferred hand (P = .196). This result is problematic for evolutionary theories of cerebral lateralisation that claim lefthemispheric language is related to fine manual motor skill and sequencing. Language lateralisation may be more closely related to asymmetrical control of whole-body finely sequenced movements.     

Dynamic brain connectivity is a better predictor of PTSD than static connectivity

Using resting‐state functional magnetic resonance imaging, we test the hypothesis that subjects with post‐traumatic stress disorder (PTSD) are characterized by reduced temporal variability of brain connectivity compared to matched healthy controls. Specifically, we test whether PTSD is characterized by elevated static connectivity, coupled with decreased temporal variability of those connections, with the latter providing greater sensitivity toward the pathology than the former. Static functional connectivity (FC; nondirectional zero‐lag correlation) and static effective connectivity (EC; directional time‐lagged relationships) were obtained over the entire brain using conventional models. Dynamic FC and dynamic EC were estimated by letting the conventional models to vary as a function of time. Statistical separation and discriminability of these metrics between the groups and their ability to accurately predict the diagnostic label of a novel subject were ascertained using separate support vector machine classifiers. Our findings support our hypothesis that PTSD subjects have stronger static connectivity, but reduced temporal variability of connectivity. Further, machine learning classification accuracy obtained with dynamic FC and dynamic EC was significantly higher than that obtained with static FC and static EC, respectively. Furthermore, results also indicate that the ease with which brain regions engage or disengage with other regions may be more sensitive to underlying pathology than the strength with which they are engaged. Future studies must examine whether this is true only in the case of PTSD or is a general organizing principle in the human brain. Hum Brain Mapp 38:4479–4496, 2017. © 2017 Wiley Periodicals, Inc.     

Crossed anarthria and a dissociated lateralisation of language

INTRODUCTION: Crossed anarthria cases are uncommon and rather old. OBSERVATION: We report the case of a right-handed 55-year-old man who presented crossed pure anarthria due to a hemorrhage in the premotor cortex (feet of F1 and F2) and in the high part of Pierre-Marie's quadrangle. CONCLUSION: The study of different tasks (articulation, verbal fluency, direct object word-generation from a verb) showed a dissociated lateralisation of his language. Lexico-semantic and grammatical tasks are processed in the left hemisphere. Articulation programming occurs in the right hemisphere.     

Self-compassion is a better predictor than mindfulness of symptom severity and quality of life in mixed anxiety and depression

Mindfulness has received considerable attention as a correlate of psychological well-being and potential mechanism for the success of mindfulness-based interventions (MBIs). Despite a common emphasis of mindfulness, at least in name, among MBIs, mindfulness proves difficult to assess, warranting consideration of other common components. Self-compassion, an important construct that relates to many of the theoretical and practical components of MBIs, may be an important predictor of psychological health. The present study compared ability of the Self-Compassion Scale (SCS) and the Mindful Attention Awareness Scale (MAAS) to predict anxiety, depression, worry, and quality of life in a large community sample seeking self-help for anxious distress (N = 504). Multivariate and univariate analyses showed that self-compassion is a robust predictor of symptom severity and quality of life, accounting for as much as ten times more unique variance in the dependent variables than mindfulness. Of particular predictive utility are the self-judgment and isolation subscales of the SCS. These findings suggest that self-compassion is a robust and important predictor of psychological health that may be an important component of MBIs for anxiety and depression.     

Low blood pressure is a better predictor of cognitive deficits than the apolipoprotein e4 allele in the oldest old

OBJECTIVE: To study the correlates of cognitive deficits in persons 80 years and older. MATERIALS AND METHODS: Data from 271 individuals between 80 and 102 years of age, drawn from a central registrar (response rate 50%) were analyzed regarding e apolipoprotein E (Apo-E) polymorphism, blood pressure (BP), homocysteine, sex, age and education as predictors for low score on Mini Mental Status Examination (MMSE). RESULTS: Low systolic and diastolic BP were highly associated with low score on the MMSE, followed by age and Apo-E e4. No relationship was found between Apo-E allele groups and BP. Homocysteine, sex, and education were only of marginal importance. CONCLUSIONS: Hypotension is an important factor for performance on the MMSE. To some extent, this was also true for having the Apo-E e4 allele. A combined effect on cognition for these two factors was not found.     

Tyramine sulfate excretion may be a better predictor of antidepressant response than monoamine oxidase activity

The tyramine sulfate excretion test was performed on 62 nonmelancholic depressed outpatients who then took part in a 6-week double-blind trial comparing imipramine, phenelzine, and placebo. In a double-blind design, nonresponders were switched to one of the active medications. Tyramine sulfate excretion failed to differentiate response from nonresponse to placebo. By contrast, phenelzine responders excreted significantly less tyramine sulfate than did phenelzine nonresponders, while there was a trend in the same direction for imipramine-treated patients. The presence of only eight phenelzine nonresponders dictates caution in interpreting these results. Baseline monoamine oxidase (MAO) activity did not distinguish responders from nonresponders or correlate with tyramine sulfate excretion. Although males had significantly lower MAO activity than females, controlling for sex did not alter these negative findings. These results fail to confirm a previous report of a significant correlation between MAO activity and treatment response in older, mainly melancholic patients.     

Investigation into inconsistent lateralisation of language functions as a potential risk factor for language impairment

Disruption to language lateralisation has been proposed as a cause of developmental language impairments. In this study, we tested the idea that consistency of lateralisation across different language functions is associated with language ability. A large sample of adults with variable language abilities (N = 67 with a developmental disorder affecting language and N = 37 controls) were recruited. Lateralisation was measured using functional transcranial Doppler sonography (fTCD) for three language tasks that engage different language subprocesses (phonological decision, semantic decision and sentence generation). The whole sample was divided into those with consistent versus inconsistent lateralisation across the three tasks. Language ability (using a battery of standardised tests) was compared between the consistent and inconsistent groups. The results did not show a significant effect of lateralisation consistency on language skills. However, of the 31 individuals showing inconsistent lateralisation, the vast majority (84%) were in the disorder group with only five controls showing such a pattern, a difference that was higher than would be expected by chance. The developmental disorder group also demonstrated weaker correlations between laterality indices across pairs of tasks. In summary, although the data did not support the hypothesis that inconsistent language lateralisation is a major cause of poor language skills, the results suggested that some subtypes of language disorder are associated with inefficient distribution of language functions between hemispheres. Inconsistent lateralisation could be a causal factor in the aetiology of language disorder or may arise in some cases as the consequence of developmental disorder, possibly reflective of compensatory reorganisation.     

Individual differences in reading skill and language lateralisation: a cluster analysis

Individual differences in reading and cerebral lateralisation were investigated in 200 college students who completed reading assessments and divided visual field word recognition tasks, and received a structural MRI scan. Prior studies on this data set indicated that little variance in brain-behaviour correlations could be attributed to the effects of sex and handedness variables (Chiarello, Welcome, Halderman, & Leonard, 2009; Chiarello, Welcome, Halderman, Towler, et al., 2009; Welcome et al., 2009). Here a more bottom-up approach to behavioural classification (cluster analysis) was used to explore individual differences that need not depend on a priori decisions about relevant subgroups. The cluster solution identified four subgroups of college age readers with differing reading skill and visual field lateralisation profiles. These findings generalised to measures that were not included in the cluster analysis. Poorer reading skill was associated with somewhat reduced VF asymmetry, while average readers demonstrated exaggerated RVF/left hemisphere advantages. Skilled readers had either reduced asymmetries, or asymmetries that varied by task. The clusters did not differ by sex or handedness, suggesting that there are identifiable sources of variance among individuals that are not captured by these standard participant variables. All clusters had typical leftward asymmetry of the planum temporale. However, the size of areas in the posterior corpus callosum distinguished the two subgroups with high reading skill. A total of 17 participants, identified as multivariate outliers, had unusual behavioural profiles and differed from the remainder of the sample in not having significant leftward asymmetry of the planum temporale. A less buffered type of neurodevelopment that is more open to the effects of random genetic and environmental influences may characterise such individuals.     

Musicians detect pitch violation in a foreign language better than nonmusicians: behavioral and electrophysiological evidence

The aim of this study was to determine whether musical expertise influences the detection of pitch variations in a foreign language that participants did not understand. To this end, French adults, musicians and nonmusicians, were presented with sentences spoken in Portuguese. The final words of the sentences were prosodically congruous (spoken at normal pitch height) or incongruous (pitch was increased by 35% or 120%). Results showed that when the pitch deviations were small and difficult to detect (35%: weak prosodic incongruities), the level of performance was higher for musicians than for nonmusicians. Moreover, analysis of the time course of pitch processing, as revealed by the event-related brain potentials to the prosodically congruous and incongruous sentence-final words, showed that musicians were, on average, 300 msec faster than nonmusicians to categorize prosodically congruous and incongruous endings. These results are in line with previous ones showing that musical expertise, by increasing discrimination of pitch--a basic acoustic parameter equally important for music and speech prosody--does facilitate the processing of pitch variations not only in music but also in language. Finally, comparison with previous results [Sch?n, D., Magne, C., & Besson, M. The music of speech: Music training facilitates pitch processing in both music and language. Psychophysiology, 41, 341-349, 2004] points to the influence of semantics on the perception of acoustic prosodic cues.