Is one hand always better than two? A replication study

Abstract

Recently, it has been shown that the active movement of the left hand in the left hemispace reduces left neglect in visual exploratory tasks. Despite the important theoretical and practlcal implications, there exists no direct confirmation of these findings in the literature. To verify the presence of the beneficial effect of left hand movement in left space, we replicated three of the nine experiments devised by Robertson and North (Neuropsychologia 1992; 30: 553-63, Neuropsychologia 1994; 32: 1-11). To this end, we tested 10 consecutive patients with right brain damage and left neglect. We found the expected pattern of performance in only one patient: on reading and cancellation the total number of omissions significantly decreased when irrelevant movements were performed with the left hand in the left space. This finding underlines the importance of replication studies in cognitive neuropsychology.     

Selective versus multi-transmitter antidepressants: are two mechanisms better than one?

The issue of selectivity versus efficacy has now reappeared as newer agents have emerged that are less selective than the selective serotonin reuptake inhibitors (SSRIs) but more selective than the tricyclic antidepressants (TCAs). This article provides a critical examination of the clinical literature concerning what evidence there is for differential efficacy. Two broad areas will be discussed: (1) comparisons of SSRIs to TCAs and (2) comparisons of the SSRIs to a somewhat more selective compound (by comparison to the TCAs), venlafaxine. This review should caution one in accepting claims of superiority of any agent based on purported mechanism of action.     

Do susceptibility loci contribute to the expression of more than one mental disorder? A view from the genetics of Alzheimer's disease

The susceptibility of developing most major psychiatric disorders is determined in part by contributions from risk alleles at multiple genetic loci. The central aim of this article is to highlight evidence from studies of neurodegenerative disorders suggesting that some of these alleles are shared by more than one psychiatric disorder, and to explore mechanisms that may underly these pleiotropic effects. The identification of constellations of susceptibility alleles associated with particular mental disorders will provide opportunities for new insights into the molecular and cellular pathophysiology of these disorders, and will have a major impact on psychiatric research and clinical care. This approach to reducing the variance in etiopathogenesis is also likely to be important for achieving the optimal use of available treatments (maximizing effectiveness and minimizing side effects), and for the discovery of novel medications or other interventions.     

What is novel in the novelty oddball paradigm? Functional significance of the novelty P3 event-related potential as revealed by independent component analysis

To better understand whether voluntary attention affects how the brain processes novel events, variants of the auditory novelty oddball paradigm were presented to two different groups of human volunteers. One group of subjects (n=16) silently counted rarely presented 'infrequent' tones (p=0.10), interspersed with 'novel' task-irrelevant unique environmental sounds (p=0.10) and frequently presented 'standard' tones (p=0.80). A second group of subjects (n=17) silently counted the 'novel' environmental sounds, the 'infrequent' tones now serving as the task-irrelevant deviant events. Analysis of event-related potentials (ERPs) recorded from 63 scalp channels suggested a spatiotemporal overlap of fronto-central novelty P3 and centro-parietal P3 (P3b) ERP features in both groups. Application of independent component analysis (ICA) to concatenated single trials revealed two independent component clusters that accounted for portions of the novelty P3 and P3b response features, respectively. The P3b-related ICA cluster contributed to the novelty P3 amplitude response to novel environmental sounds. In contrast to the scalp ERPs, the amplitude of the novelty P3 related cluster was not affected by voluntary attention, that is, by the target/nontarget distinction. This result demonstrates the usefulness of ICA for disentangling spatiotemporally overlapping ERP processes and provides evidence that task irrelevance is not a necessary feature of novelty processing.     

A critical period for the impact of amygdala damage on the emotional enhancement of memory?

The amygdala is crucial in modulating enhanced memory for emotionally arousing material. The authors provide evidence that unilateral lesions of the human amygdala arising early in development, but not in adulthood, are associated with a loss of the expected superior retrieval of emotionally arousing over neutral material. This adds to evidence for an early critical period in the development of amygdala function.     

Is sleep duration related to obesity? A critical review of the epidemiological evidence

1. Observational studies have implicated habitual sleep duration as a risk factor for mortality and morbidity. Part of this association might be mediated by obesity, which has also been associated with habitual sleep duration. These studies generate wide media attention because of the public's health concerns surrounding increasing obesity and the temporal association with the other modern "epidemic" of sleep loss. Some commentators have recommended public health interventions to control obesity via habitual sleep duration modification. We conducted a critical review of the available literature describing the relationship between habitual sleep duration and obesity in community-based studies in both adults and children, with particular emphasis on longitudinal studies and on studies with objective measures of habitual sleep duration. 2. Existing data have variable consistency. Only one study objectively measured sleep duration for more than one 24-h period. Cross-sectional and longitudinal studies in adults often demonstrated an association of short sleep duration with BMI. However, some of these studies also showed that long sleep duration was also associated with obesity. In contrast, other studies showed that neither long nor short sleep was associated with obesity. In paediatric populations there appeared to be a clear pattern where shorter sleep durations were associated with obesity. We did not locate any interventional studies where sleep duration had been manipulated in order to prevent or treat obesity. 3. We contend that the evidence base is not yet strong enough to give public health advice to the general population or specific groups about sleep duration being a modifiable risk factor for obesity. We need to experimentally clarify whether sleep duration variability is a risk factor for obesity, in what manner, and in which populations. If a reliable aetiological model could be found, we would ideally then need community-based randomised controlled trials that show that sleep duration can be changed and that sleep duration manipulation produces actual weight loss and/or prevents the development of obesity without undue side-effects.     

Is the increased reporting of symptomatic ill health in Gulf War veterans related to how one asks the question?

BACKGROUND: Following the 1991 Gulf War (GW) there was much controversy surrounding service-related health effects. Evidence from the Vietnam experience suggested that self-reported ill health following that conflict might be related to how service during the conflict is framed. The aim of this article is to determine if a GW health effect persisted when the same questions were asked in a "non-GW" context. METHOD: Prevalence of physical and psychological health problems were ascertained in a study assessing health screening from a random sample of UK Armed Forces. Record linkage between the screening survey and service history was conducted to obtain information on participation in the GW. RESULTS: Differences in health outcomes were found between the GW and the non-GW groups. This difference existed for symptomatic measures (OR=1.84, 95% CI, 1.17-2.91) rather than psychological or behavioral measures. No differences were found in psychological measures such as PTSD or behavioral measures such as alcohol consumption. Those deployed to the GW had a poorer self-perception of health (OR=1.47, 95% CI 1.02-2.11). CONCLUSIONS: Even in the absence of framing, a Gulf-related ill health effect was found.     

Is total duration of distal compound muscle action potential better than negative peak duration in the diagnosis of chronic inflammatory demyelinating polyneuropathy?

Introduction: The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) is difficult, and the role of electrophysiology is crucial. Distal compound muscle action potential (CMAP) duration is a useful tool that is assessed by measuring negative peak duration (NP). The value of total distal CMAP duration (T), which seems more precise from a physiological standpoint, has not been studied. Methods: We reviewed retrospectively the records of 50 patients with CIDP and 50 controls with chronic axonal neuropathy. We constructed ROC curves for NP and T. Results: Comparison of AUC for T vs. NP showed an advantage for the former (P = 0.026 for the fibular nerve). Our derived cut‐offs offered a sensitivity of 42.3% for T vs. 35.3% for NP. Conclusion: This study suggests a slight advantage for T over NP duration of the distal CMAP in the diagnosis of CIDP. However, the clinical relevance of this result must be weighed against the feasibility of this measurement. Muscle Nerve 49 : 895–899, 2014     

Does the concept of emotional intelligence contribute to our understanding of temporal lobe resections?

Research on temporal lobe (TL) resection has revealed impairments in cognition and emotion that differ as a function of laterality. Until recently, however, a construct called "emotional intelligence" had not been investigated in surgical recipients. We asked if Bar-On's Emotional Quotient Inventory (EQ-i) was sensitive to the side of the temporal lobe lesion, and if the EQ-i correlated with intellectual and psychosocial functioning. EQ-i scores, estimated Full Scale IQ, verbal memory, confrontation naming, and psychosocial adjustment data were analyzed for 38 patients who underwent TL resection. Results indicated that the EQ-i self-ratings were significantly lower than the average-range Full Scale IQ. Verbal memory and naming skills were significantly worse after left than right TL resection, but EQ-i scores did not reflect a laterality effect. The EQ-i correlated significantly with psychosocial adjustment, but not with estimated Full Scale IQ. We concluded that there was no compelling evidence for lateral specialization of EI, although it seems to be a theoretically relevant construct that may be useful in understanding individuals with epilepsy.     

Is psychoanalytic theory relevant to the psychology of women?

This article reviews the literature addressing the relevance of psychoanalytic theory to the psychology of women and offers a possible rapprochement between these divergent perspectives. This rapprochement is accomplished first by defining "psychoanalytic theory" and "the psychology of women" in line with current scholarship, then by comparing and contrasting these definitions in an item-by-item analysis. The basic tenets of modern psychoanalytic theory emerge as highly relevant to the understanding of the psychology of women, despite the fact that particular "brands" of psychoanalytic theory may not demonstrate this same compatibility.