Sex differences in the response to emotional distraction: an event-related fMRI investigation

Evidence has suggested that women have greater emotional reactivity than men. However, it is unclear whether these differences in basic emotional responses are also associated with differences in emotional distractibility, and what the neural mechanisms that implement differences in emotional distractibility between women and men are. Functional MRI recording was used in conjunction with a working memory (WM) task, with emotional distraction (angry faces) presented during the interval between the memoranda and the probes. First, we found an increased impact of emotional distraction among women in trials associated with high-confidence responses, in the context of overall similar WM performance in women and men. Second, women showed increased sensitivity to emotional distraction in brain areas associated with “hot” emotional processing, whereas men showed increased sensitivity in areas associated with “cold” executive processing, in the context of overall similar patterns of response to emotional distraction in women and men. Third, a sex-related dorsal–ventral hemispheric dissociation emerged in the lateral PFC related to coping with emotional distraction, with women showing a positive correlation with WM performance in left ventral PFC, and men showing similar effects in the right dorsal PFC. In addition to extending to men results that have previously been reported in women, by showing that both sexes engage mechanisms that are similar overall in response to emotional distraction, the present study identifies sex differences in both the response to and coping with emotional distraction. These results have implications for understanding sex differences in the susceptibility to affective disorders, in which basic emotional responses, emotional distractibility, and coping abilities are altered.     

Psychosocial issues following traumatic brain injury

The author contends that Dean, Colantonio, Ratcliff, and Chase in 2000 probably underestimated the importance of psychosocial factors in the very long-term adaptation to disability by 166 individuals with traumatic brain injury.     

Family response to traumatic brain injury

The stress experienced by families with a member who has experienced a traumatic brain injury (TBI) has recently been addressed in the counselling and rehabilitation literature. Given that rehabilitation centres have physical restoration of the patient as a primary mandate, the emotional and social adjustment needs of family members are often overlooked. Information on TBI and its effect on families will help counsellors and psychologists contribute to the family adjustment process.     

Decreased parahippocampal activity in associative priming: evidence from an event-related fMRI study

In recent years, there has been intense debate on the neural basis of associative priming, particularly on the role of the medial temporal lobe (MTL) in retrieving associative information without awareness. In this study, event-related fMRI was used while healthy subjects performed a perceptual identification task on briefly presented unrelated word pairs and an associative recognition memory task. Contamination of priming by explicit memory was successfully controlled, as associative priming and explicit memory were dissociated on the behavioral level. The fMRI results showed a functional dissociation within the MTL with respect to associative priming effects. The right parahippocampal cortex, but not the hippocampus, showed decreased activation for old vs. new pairs and old vs. recombined pairs (associative priming). The bilateral hippocampus and the right parahippocampal cortex were involved in explicit associative memory. These data provide evidence that subregions of the MTL participate in associative priming even when explicit involvement was controlled. Thus, different regions within the MTL play distinct roles in explicit and implicit associative memory.     

Response inhibition in children with and without ADHD after traumatic brain injury

Children with attention‐deficit hyperactivity disorder (ADHD) and traumatic brain injury (TBI) show deficient response inhibition. ADHD itself is a common consequence of TBI, known as secondary ADHD (S‐ADHD). Similarity in inhibitory control in children with TBI, S‐ADHD, and ADHD would implicate impaired frontal‐striatal systems; however, it is first necessary to delineate similarities and differences in inhibitory control in these conditions. We compared performance of children with ADHD and those with TBI without pre‐injury ADHD on a stop signal, response inhibition task. Participants were 274 children aged 6–14 years. There were 92 children with ADHD, 103 children with TBI, and 79 typically developing children who served as controls. Among the TBI participants, injury severity ranged from mild to severe. Children with ADHD and TBI showed deficient inhibition. The deficit in children with ADHD was as great as or greater than that in children with TBI, regardless of degree of TBI severity or the presence of S‐ADHD. The finding indicates that TBI results in deficient inhibition regardless of the development of S‐ADHD.     

Exploration of perceptual and motor inhibition in children with traumatic brain injury

Perceptual and motor inhibition were examined using conflict resolution tasks for 12 children with traumatic brain injury and 24 matched controls. Direct comparisons of inhibition performances between the two groups showed a specific and disproportionate impairment of motor inhibition (compared with perceptual inhibition) for the children with traumatic brain injury, which suggests that inhibition processes might be differentially impaired in children after traumatic brain injury.     

Impairments of attention following childhood traumatic brain injury.

Attentional deficits are commonly reported following traumatic brain injury (TBI) in adults, although the occurrence of such problems is less well documented in young children. This study aimed to investigate residual attentional abilities associated with TBI during childhood, by examining a number of aspects of attention including sustained, focussed, and divided attention, attentional shift, and response inhibition. Eighteen children with a history of TBI, aged between 8 and 14 years and 18 non-injured matched controls participated in the study. Results show that attentional skills may be differentially impaired after TBI, with children who have sustained moderate-to-severe TBI exhibiting significant deficits on the following attentional domains: sustain, focus, and response inhibition. These findings support the view that attentional impairments following pediatric TBI, while not global, may be more generalized than those reported for adult samples, perhaps reflecting the relative immaturity of attentional skills at the time of injury.     

Effects of additional tasks on language perception: an event-related brain potential investigation

The authors investigated effects of task and overlapping processing load on semantic processing. In 3 experiments the brain potential component N400 was elicited by synonymous and nonsynonymous spoken noun pairs that were to be classified according to semantic relatedness. The time course of the N400 component to the nouns was delayed, and its amplitude was reduced when additional tasks had to be performed. The delay increased with temporal overlap and was more pronounced for language-related than for spatial additional tasks. Delays of N400 were also caused by a compatibility manipulation in the additional tasks. Theoretical accounts of the observed interference of overlapping tasks with language perception in terms of attentional shifts were discarded. Explanations in terms of resource sharing and single channel processing are discussed.     

Symptom cluster associated with mild traumatic brain injury in university students.

There is growing recognition that even a minor blow to the head can have serious consequences on physical, cognitive, behavioral, and social well-being. Previous studies have indicated that such changes may in turn have a dramatic effect on the ability of university students to carry out their studies. This survey measured the prevalence of mild traumatic brain injury in a nonclinical population of 1,075 university students from all disciplines. In addition to surveying the nature, cause, and sex distribution, it further investigated the relationships between the physical, cognitive, behavioral, and social repercussions of the incidents. Results replicated earlier findings and indicated a prevalence rate of mild traumatic brain injury of 34.9% (n = 375). Moreover, significant correlations were found among the physical, cognitive, behavioral, and social changes reported by the students, suggesting a cluster of symptoms associated with such incidents. Altogether, these results suggest that even currently enrolled and active university students may face unique and subtle challenges related to a mild traumatic brain injury.     

Working memory outcomes following traumatic brain injury in children: A systematic review with meta-analysis

The aim of this review is to systematically examine the literature concerning multicomponent working memory (WM)—comprising a central executive (CE), two storage components (phonological loop, PL and visuo-spatial sketchpad, VSSP), and episodic buffer (EB)—in pediatric traumatic brain injury (TBI). Electronic searches were conducted of MEDLINE, PsychINFO and EMBASE up to October 2014 with the inclusion criteria of children and adolescents with TBI, and quantitative methods to assess at least one component of WM. Meta-analytic procedures calculated pooled effect sizes for WM outcomes. Of the studies examined, 27 met the inclusion criteria. Children with TBI exhibited deficits in the CE and PL, but not in the VSSP, and no study could be found which examined the EB. Qualitative analysis found that greater TBI severity was associated with poorer CE functioning in five out of nine studies. Differences in patterns of brain activation were evident in four out of five fMRI studies that examined WM in TBI children and controls. Deficits in CE were associated with poorer mathematical skills in the only study that examined relations between WM and academic deficits. Notwithstanding the heterogeneity of the studies reviewed, TBI places children at risk of WM deficits. Moreover, this meta-analysis suggests that various components of WM have differential vulnerability to pediatric TBI, with significant deficits found in the CE and PL, but not in the VSSP (although the VSSP has rarely been examined to date). Future studies should be theoretically driven, employ tasks assessing all components of the WM model and examine the functional ramifications (including academic outcomes) of WM deficits in this population.     

Regional cortical volume and cognitive functioning following traumatic brain injury

There has been limited examination of the effect of brain pathology on subsequent function. The current study examined the relationships between regional variation in grey matter volume, age and cognitive impairment using a semi-automated image analysis tool. This study included 69 individuals with mild-to-severe TBI, 41 of whom also completed neuropsychological tests of attention, working memory, processing speed, memory and executive functions. A widespread reduction in grey matter volume was associated with increasing age. Regional volumes that were affected also related to the severity of injury, whereby the most severe TBI participants displayed the most significant pathology. Poorer retention of newly learned material was associated with reduced cortical volume in frontal, parietal, and occipital brain regions. In addition, poorer working memory and executive control performance was found for individuals with lower cortical volume in temporal, parietal, and occipital regions. These findings are largely in line with previous literature, which suggests that frontal, temporal, and parietal regions are integral for the encoding of memories into long-term storage, memory retrieval, and working memory. The present study suggests that automated image analysis methods may be used to explore the relationships between regional variation in grey matter volume and cognitive function following TBI.     

Counter‐intuitive moral judgement following traumatic brain injury

Several neurological patient populations, including traumatic brain injury (TBI), appear to produce an abnormally ‘utilitarian’ pattern of judgements to moral dilemmas; they tend to make judgements that maximize the welfare of the majority, rather than deontological judgements based on the following of moral rules (e.g., do not harm others). However, this patient research has always used extreme dilemmas with highly valued moral rules (e.g., do not kill). Data from healthy participants, however, suggest that when a wider range of dilemmas are employed, involving less valued moral rules (e.g., do not lie), moral judgements demonstrate sensitivity to the psychological intuitiveness of the judgements, rather than their deontological or utilitarian content (Kahane et al., Social Cognitive and Affective Neuroscience, 7, 2011, 393). We sought the moral judgements of 30 TBI participants and 30 controls on moral dilemmas where content (utilitarian/deontological) and intuition (intuitive/counter‐intuitive) were measured concurrently. Overall TBI participants made utilitarian judgements in equal proportions to controls; disproportionately favouring utilitarian judgements only when they were counter‐intuitive, and deontological judgements only when they were counter‐intuitive. These results speak against the view that TBI causes a specific utilitarian bias, suggesting instead that moral intuition is broadly disrupted following TBI.     

Neuropsychological correlates of impaired emotion recognition following traumatic brain injury

Previous research has shown that individuals with traumatic brain injury (TBI) are significantly impaired on emotion recognition tasks. In this study, the relationship between neuropsychological functioning and emotion recognition was examined in 11 individuals with moderate to severe TBI and a control group of 13 individuals matched for age,sex, and education. Emotion recognition stimuli were from Ekman and Friesen's pictures of facial affect. The group with TBI showed neuropsychological deficits consistent with those commonly found following moderate to severe TBI. The group with TBI also identified significantly fewer emotion recognition stimuli than the control group.The number of correctly identified emotion recognition stimuli was significantly correlated with measures of verbal cognitive processing in the group with TBI. These findings suggest that the role of left hemisphere brain mechanisms in the recognition of facial (nonverbal)emotion may be more important than previously recognized.     

Disfluency clusters in speakers with and without neurogenic stuttering following traumatic brain injury

PurposeAnalyze the characteristics and rate of disfluency clusters in adults with and without neurogenic stuttering after traumatic brain injury (TBI).MethodTwenty adults with TBI participated in this study, including 10 with neurogenic stuttering (Group B) and 10 without -stuttering (Group A). Disfluency clusters in speech samples were classified into three types: Stuttering-like (SLD), other (OD), and mixed (MIX).ResultsSpeakers with and without neurogenic stuttering produced the same mean number of disfluency clusters. In addition, the mean length of clusters did not differ between these speaker groups although the longest clusters did. The most frequently occurring cluster type for people with neurogenic stuttering was MIX and OD for people without stuttering. Although the speakers in Group A produced stuttering-like disfluencies, these never occurred together to form a SLD type cluster. For Group B, the starter units of the clusters were usually stuttering-like disfluencies, while for Group A, the starter units were mostly interruptions.ConclusionsCompared to non-stuttering speakers, stuttering after TBI did not increase the number of clusters, but rather lengthened them. In speakers with neurogenic stuttering, the number and length of clusters were related to the manifestation of other communication deficits, not to the frequency of stuttering-like disfluencies. Still, SLD clusters occurred only in those people with neurogenic stuttering. These findings raise questions about the nature of both neurogenic stuttering and the dynamics of disfluency clustering.     

Auditory verb perception recruits motor systems in the developing brain: an fMRI investigation

This study investigated neural activation patterns during verb processing in children, using fMRI (functional Magnetic Resonance Imaging). Preschool children (aged 4–6) passively listened to lists of verbs and adjectives while neural activation was measured. Findings indicated that verbs were processed differently than adjectives, as the verbs recruited motor systems in the frontal cortex during auditory perception, but the adjectives did not. Further evidence suggested that different types of verbs activated different regions in the motor cortex. The results demonstrate that the motor system is recruited during verb perception in the developing brain, reflecting the embodied nature of language learning and processing.     

An investigation of neuronal integrity in severe paediatric traumatic brain injury.

Magnetic Resonance Spectroscopy (MRS) and its association with neuropsychological functioning was examined in the chronic injury phase of paediatric traumatic brain injury (TBI). Fifteen children, aged 10-16 years, with severe TBIs were compared with 15 controls, matched for age and gender. The TBI group was found to have significantly lower levels of -acetyl aspartate (NAA) and Choline (Cho) in the right frontal lobe and generally displayed reduced performances on neuropsychological tests. A correlation between metabolites and reaction times was also obtained. Findings indicate a role of proton MRS as a measure of neuronal integrity following severe paediatric TBI and suggest a potential association of MRS with specific neuropsychological impairments.     

Emotional and pain-related factors in neuropsychological assessment following mild traumatic brain injury

A critical issue in the field of clinical neuropsychology is the idea that emotional or pain-related factors may compromise the validity of neuropsychological assessment. In this study, 53 individuals suffering from mild traumatic brain injury related to motor vehicle accident injury completed commonly used measures of emotional and pain-related functioning. A battery of commonly used neuropsychological tests, assessing attention, learning and memory, language, visuospatial and visuomotor functions, speeded processing, fine-motor skill, and symptom validity, was administered concurrently. Findings revealed a significant and negative correlation between anxiety and impaired delayed verbal memory, suggesting that as anxiety increased, delayed verbal memory decreased. The results otherwise provided little support for the idea that emotional or pain-related factors are detrimental to neuropsychological test performance following mild traumatic brain injury.     

Attentional skills in the acute phase following pediatric traumatic brain injury.

Only a limited number of studies have investigated attention following pediatric head-injury. The present study examined sustained attention and processing speed in a group of children who had sustained a mild (n = 27), moderate (n = 33) or severe (n = 16) traumatic brain injury (TBI). No significant differences were evident between the TBI groups on reaction time measures. Results did show that the severe TBI group exhibited greater deficits in the area of sustained attention, in comparison to children with mild and moderate injuries, in the acute stage following traumatic brain injury. This difficulty may impact on the future development of skills dependent on intact attentional capacity.