Neuropsychology Review

Repetitive transcranial magnetic stimulation (rTMS) is increasingly used as a therapeutic intervention for neuropsychiatric illnesses and has demonstrated efficacy for treatment of major depression. However, an unresolved question is whether a course of rTMS treatment results in effects on cognitive functioning. In this systematic review and meta-analysis we aimed to quantitatively determine whether a course of rTMS has cognitive enhancing effects. We examined cognitive outcomes from randomised, sham-controlled studies conducted in patients with neuropsychiatric conditions where rTMS was administered to the dorsolateral prefrontal cortex (DLPFC) across repeated sessions, searched from PubMed/MEDLINE and other databases up until October 2015. Thirty studies met our inclusion criteria. Cognitive outcomes were pooled and examined across the following domains: Global cognitive function, executive function, attention, working memory, processing speed, visual memory, verbal memory and visuospatial ability. Active rTMS treatment was unassociated with generalised gains across the majority of domains of cognitive functioning examined. Secondary analyses revealed a moderate sized positive effect for improved working memory in a small number of studies in patients with schizophrenia (k = 3, g = 0.507, 95 % CI = [0.183–0.831], p < .01). Therapeutic rTMS when administered to the DLPFC in patients with neuropsychiatric conditions does not result in robust cognitive enhancing effects.

This article is a systematic review of the literature on divided attention assessment inclusive of a cognitive and motor task (balance or gait) for use in concussion management. The systematic review drew from published papers listed in PubMed, MEDLINE, EMBASE and CINAHL databases. The search identified 19 empirical research papers meeting the inclusion criteria. Study results were considered for the psychometric properties of the paradigms, the influence of divided attention on measures of cognition and postural control and the comparison of divided attention task outcomes between individuals with concussion and healthy controls (all samples were age 17 years or older). The review highlights that the reliability of the tasks under a divided attention paradigm presented ranges from low to high (ICC: 0.1–0.9); however, only 3/19 articles included psychometric information. Response times are greater, gait strategies are less efficient, and postural control deficits are greater in concussed participants compared with healthy controls both immediately and for some period following concussive injury, specifically under divided attention conditions. Dual task assessments in some cases were more reliable than single task assessments and may be better able to detect lingering effects following concussion. Few of the studies have been replicated and applied across various age groups. A key limitation of these studies is that many include laboratory and time-intensive measures. Future research is needed to refine a time and cost efficient divided attention assessment paradigm, and more work is needed in younger (pre-teens) populations where the application may be of greatest utility.

Social cognition remains one of the most difficult cognitive domains to assess in diverse populations due to a lack of culturally appropriate tools. This study systematically reviewed literature on neuropsychological tests for social cognition that have been translated, adapted, are cross-cultural, or are assembled for diverse, specifically “Global South,” populations. The aim was to identify assessments appropriate for diverse populations, outline and evaluate their methodological approaches, and provide procedural recommendations for future research. The PRISMA systematic review search strategy produced 10,957 articles, of which 287 were selected for full-text screening. The study had to include a neuropsychological assessment of social cognition. The full text of the resulting 287 articles was then screened; the study had to include a translated, adapted, cross-cultural test, or an assembled test for Global South populations. Eighty-four articles were included in this study: 24 for emotion recognition, 45 for theory of mind, 9 for moral reasoning, and six for social cognition in general. Overall, there were 31 translations, 27 adaptations, 14 cross-cultural tests, and 12 assembled tests for Global South populations. Regarding quality, 35 were of low quality, 27 were of moderate quality, and 22 were high quality. This study provides an overview of social cognition tests modified or assembled for diverse populations and gives examples of methodological procedures. It highlights the variability in procedure quality and provides possible reasons for this variability. Finally, it suggests a need to report rigorous modification and assembly procedure in order to have modified and assembled social cognition tests appropriate for diverse populations.

Multiple chemical sensitivity (MCS) is a term used to describe a disorder characterized by a vast array of somatic, cognitive, and affective symptoms, the cause of which is attributed to exposure to extremely low levels of a variety of chemicals. Upon examination of the patient with a diagnosis of MCS, objective physical findings and consistent laboratory abnormalities are typically nonexistent. The concept of MCS has ignited considerable controversy in the fields of toxicology, immunology, allergy, psychology, and neuropsychology. Central to the controversy is the disagreement over the extent to which the manifestation of MCS is mediated by psychological factors. Because of the large number of neuropsychological symptoms associated with a diagnosis of MCS, neuropsychologists are increasingly receiving referrals for the assessment of these patients. It is important, therefore, that neuropsychologists become aware of the variety of clinical issues that must be taken into account when assessing an individual with a diagnosis of MCS. The theoretical and research literature on individuals with a diagnosis of MCS is reviewed here.

Traumatic brain injury (TBI) can lead to impairments in emotion recognition that can present considerable challenges to social communication and the maintenance of interpersonal relationships. This review aimed to estimate the magnitude of emotion recognition impairments in TBI patients overall, and at the emotion category level, and to determine if the magnitude of observed impairments were moderated by modality (e.g., face, voice, multi-modal) of emotional expression, and severity of injury. Searches of PubMed, Scopus, PsycINFO, and Medline databases identified 17 studies which satisfied strict inclusion and exclusion criteria for the systematic review (comparing TBI patients to matched controls). Of these studies, 15 were included in the meta-analysis (NTBI = 474; NControl = 461). Moderate/large average deficits emerged for TBI patients relative to controls (Hedges’ g = 0.79, 95% CI: 0.61 – 0.96, p < .001; Q = 22.53, p = .068, τ2 = 0.04, I2 = 37.84; indicating low heterogeneity). TBI patients were impaired across all emotion categories, with moderate/large effect sizes observed for fear and anger, moderate effect sizes for disgust, neutral and sadness, while effect sizes for happiness and surprise were small. The magnitude of impairment for individuals with TBI severity classified as moderate/severe TBI was moderate, whereas severe TBI was large. Moderate/large effect sizes were observed across the different modalities of presentation. This meta-analysis provides evidence for marked global impairments in emotion recognition, with the magnitude of impairment greatest for negative emotions (i.e., anger and fear). This meta-analysis provided no evidence to suggest that the magnitude of impairment is influenced by injury severity or modality of stimulus presentation. Recommendations for future research are discussed.

Impulsivity is a multi-dimensional construct that is regarded as a symptom of many psychiatric disorders. Harm resulting from impulsive behaviour can be substantial for the individuals concerned, for their social network, and for wider society. Therefore, the importance of developing therapeutic interventions to target impulsivity is paramount. We conducted a systematic review and meta-analysis of the literature from AMED, Embase, Medline, and PsycINFO databases on the use of repetitive transcranial magnetic stimulation (rTMS) in healthy adults to modulate different subdomains (motor, temporal and reflection) of impulsivity. The results indicated that rTMS has distinct effects on different impulsivity subdomains. It has a significant, albeit small, effect on modulating motor impulsivity (g = 0.30, 95% CI, 0.17 to 0.43, p < .001) and a moderate effect on temporal impulsivity (g = 0.59, 95% CI, 0.32 to 0.86, p < .001). Subgroup analyses (e.g., excitatory vs. inhibitory rTMS, conventional rTMS vs. theta burst stimulation, analyses by stimulation sites, and type of outcome measure used) identified key parameters associated with the effects of rTMS on motor and temporal impulsivity. Age, sex, stimulation intensity and the number of pulses were not significant moderators for effects of rTMS on motor impulsivity. Due to lack of sufficient data to inform a meta-analysis, it has not been possible to assess the effects of rTMS on reflection impulsivity. The present findings provide preliminary evidence that rTMS can be used to modulate motor and temporal impulsivity in healthy individuals. Further studies are required to extend the use of rTMS to modulate impulsivity in those at most risk of engaging in harmful behaviour as a result of impulsivity, such as patients with offending histories and those with a history of self-harming behaviour.

Although Autism Spectrum Disorders (ASD) are generally assumed to be lifelong, we review evidence that between 3% and 25% of children reportedly lose their ASD diagnosis and enter the normal range of cognitive, adaptive and social skills. Predictors of recovery include relatively high intelligence, receptive language, verbal and motor imitation, and motor development, but not overall symptom severity. Earlier age of diagnosis and treatment, and a diagnosis of Pervasive Developmental Disorder-Not Otherwise Specified are also favorable signs. The presence of seizures, mental retardation and genetic syndromes are unfavorable signs, whereas head growth does not predict outcome. Controlled studies that report the most recovery came about after the use of behavioral techniques. Residual vulnerabilities affect higher-order communication and attention. Tics, depression and phobias are frequent residual co-morbidities after recovery. Possible mechanisms of recovery include: normalizing input by forcing attention outward or enriching the environment; promoting the reinforcement value of social stimuli; preventing interfering behaviors; mass practice of weak skills; reducing stress and stabilizing arousal. Improving nutrition and sleep quality is non-specifically beneficial.

There is increasing impetus to improve the quality of research and scientific writing. Systematic reviews provide Class 1 research evidence, are based upon an established rigor and communicate results in a comprehensive manner, and are therefore particularly relevant to clinicians and researchers. Clinician requirements for quality systematic reviews are twofold: to keep up to date with research and to make informed decisions including those required for diagnoses, disease or risk assessment, and treatment. Researchers rely upon quality systematic reviews to compete for diminishing research funds, prove efficacy for intervention trials, and to meet increasing demand for evidence based intervention. However, insufficient systematic reviews are undertaken, and the methodological rigor and quality are often variable. The aim of this article is to guide researchers through the iterative systematic review process in order to improve quality and thereby increase publication rates. The step by step guide provides a road map through the EQUATOR network and practical suggestions in order to meet the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) (Moher et al. 2009) as well as encouraging high standards through the use of quality rating scales. Lastly, information is provided to encourage quantitative analysis to improve the synthesis of results and qualitative interpretation, such as calculating effect sizes or conducting a meta-analyses as the ultimate goal of a systematic review.