The neural organization of cognitive processes, particularly hemispheric lateralization, changes throughout childhood and adolescence. Differences in the neural basis of relational memory between children and adults are not well characterized. In this study we used magnetoencephalography to observe the lateralization differences of hippocampal activation in children and adults during performance of a relational memory task, transverse patterning (TP). The TP task was paired with an elemental control task, which does not depend upon the hippocampus. We contrasted two hypotheses; the compensation hypothesis would suggest that more bilateral activation in children would lead to better TP performance, whereas the maturation hypothesis would predict that a more adult-like right-lateralized pattern of hippocampal activation would lead to better performance. Mean-centered partial least squares analysis was used to determine unique patterns of brain activation specific to each task per group, while diminishing activation that is consistent across tasks. Our findings support the maturation hypothesis that a more adult-like pattern of increased right hippocampal lateralization in children leads to superior performance on the TP task. We also found dynamic changes of lateralization throughout the time course for all three groups, suggesting that caution is needed when interpreting conclusions about brain lateralization. (JINS, 2013, 19, 1–11)

Although neurocognition is commonly described in terms of different functional domains, some factor analytic studies have suggested a simpler dimensional structure for neuropsychological (NP) tests in patients with schizophrenia. Standardized tasks of everyday functioning, or tests of “functional capacity” (FC), are viewed differently from traditional NP tests, and are hence used as a co-primary measure in treatment studies. However, FC and NP tests have been found to be highly correlated. In fact, a recent study of ours suggested that performances on these different types of tasks constituted a single latent trait in a cross-sectional analysis. The current study examined the longitudinal factor structure of a combined set of NP and FC tests. Patients with schizophrenia (n = 195) were examined at two assessment occasions separated by periods ranging from 6 weeks to 6 months. Participants were assessed with the MATRICS Consensus Cognitive Battery (MCCB) and two performance-based assessments of FC. A single latent trait was extracted using full information maximum likelihood procedures, and its temporal stability was examined in terms of: stability of the latent trait scores, the inter-correlations of the three indicators of the latent trait, and the stability of loadings for the FC and NP items underlying the latent trait at the two measurement occasions. All indices of temporal stability were confirmed, with stability not related to follow-up duration. Variation in clinical symptoms and treatments across the measurement occasions was negligible. These findings raise the question of whether cognitive abilities measured by NP tests and FC instruments are tapping a single ability construct, which might have shared causal influences as well. (JINS, 2013, 19, 1–8)

According to the procedural deficit hypothesis (PDH), abnormal development in the procedural memory system could account for the language deficits observed in specific language impairment (SLI). Recent studies have supported this hypothesis by using a serial reaction time (SRT) task, during which a slower learning rate is observed in children with SLI compared to controls. Recently, we obtained contrasting results, demonstrating that children with SLI were able to learn a sequence as quickly and as accurately as controls. These discrepancies could be related to differences in the statistical structure of the SRT sequence between these studies. The aim of this study was to further assess, in a group of 21 children with SLI, the PDH with second-order conditional sequences, which are more difficult to learn than those used in previous studies. Our results show that children with SLI had impaired procedural memory, as evidenced by both longer reaction times and no sign of sequence-specific learning in comparison with typically developing controls. These results are consistent with the PDH proposed by Ullman and Pierpont (2005) and suggest that procedural sequence-learning in SLI children depends on the complexity of the to-be-learned sequence. (JINS, 2013, 19, 1–8)

This study examined cognitive test performance of second- and third-generation Japanese American (JA) adults, a relatively homogeneous Asian American subgroup. Sixty-five JA and 65 non-Hispanic White (NHW) adults, ages between 45 and 91, were administered the Boston Naming Test-2 (BNT), Letter Fluency Test, Semantic Fluency Test, California Verbal Learning Test (CVLT), Brief Visuospatial Memory Test-Revised (BVMT-R), and Trail Making Test. Levels of acculturation, quality of educational attainment, and generation status in the United States, were also collected. There were no significant differences in the scores between the two groups on the tests administered. JA and NHW groups, however, differed in the patterns of the associations between some of the test performance and demographic variables. JA adults showed a stronger age-score relationship on BNT, CVLT, and the BVMT-R. Furthermore, second-generation JA adults performed lower than the third-generation adults even after controlling for basic demographic variables on CVLT and Trail Making Test. Acculturation on the other hand did not explain score differences once demographic variables were considered. Our results suggest the importance of considering unique history and characteristics of ethnic groups, and interactions of the aging process and culture on tasks with different cognitive demands. (JINS, 2013, 19, 1–9)

This study examined peer relationships in children with traumatic brain injury (TBI) relative to children with orthopedic injuries (OI), and explored whether differences in peer relationships correlated with white matter volumes. Classroom procedures were used to elicit peer perceptions of social behavior, acceptance, and friendships for eighty-seven 8- to 13-year-old children, 15 with severe TBI, 40 with complicated mild/moderate TBI, and 32 with OI. Magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to investigate volumetric correlates of peer relationship measures. Children with severe TBI were rated higher in rejection-victimization than children with OI, and were less likely than children with OI to have a mutual friendship in their classroom (47% vs. 88%). Children with TBI without a mutual friend were rated lower than those with a mutual friend on sociability-popularity and prosocial behavior and higher on rejection-victimization, and had lower peer acceptance ratings. Mutual friendship ratings were related to white matter volumes in several posterior brain regions, but not to overall brain atrophy. Severe TBI in children is associated with detrimental peer relationships that are related to focal volumetric reductions in white matter within regions of the brain involved in social information-processing. (JINS, 2013, 19, 1–10)

Amnestic mild cognitive impairment (aMCI) is the transitional, heterogeneous continuum from normal elderly to Alzheimer's disease (AD). Previous studies have shown that brain functional activity in the default mode network (DMN) is impaired in aMCI patients with saliently cognitive and memory decline. However, the effective connectivity among the spatially isolated, but functionally related areas within the DMN in aMCI patients remains largely unknown. The present study examined dysfunctional connectivity of the DMN by combining an independent component analysis (ICA) approach with multivariate Granger causality analysis (mGCA) in 18 aMCI patients and 18 age-matched cognitively normal elderly. Results from mGCA showed decreased effective connectivity occurred among the middle temporal gyrus (MTG), hippocampus (HC) and fusiform gyrus (FG), as well as between the precuneus/posterior cingulate cortex (PreCN/PCC) and HC in patients with aMCI. Such an impaired connectivity was also correlated with patients’ cognitive performance of the auditory verbal learning. Moreover, enhanced effective connectivity within frontal cortex emerged, which may maintain memory functions after attenuated connections within DMN activity. These findings may elucidate the dysfunctional processes in brain networks of aMCI patients, highlighting the importance of connectivity changes in the pathophysiology of aMCI. (JINS, 2013, 19, 1–10)

Facial emotion expresses feelings, but is also a vehicle for social communication. Using five basic emotions (happiness, sadness, fear, disgust, and anger) in a comprehension paradigm, we studied how facial expression reflects inner feelings (emotional expression) but may be socially modulated to communicate a different emotion from the inner feeling (emotive communication, a form of affective theory of mind). Participants were 8- to 12-year-old children with TBI (n = 78) and peers with orthopedic injuries (n = 56). Children with mild–moderate or severe TBI performed more poorly than the OI group, and chose less cognitively sophisticated strategies for emotive communication. Compared to the OI and mild–moderate TBI groups, children with severe TBI had more deficits in anger, fear, and sadness; neutralized emotions less often; produced socially inappropriate responses; and failed to differentiate the core emotional dimension of arousal. Children with TBI have difficulty understanding the dual role of facial emotions in expressing feelings and communicating socially relevant but deceptive emotions, and these difficulties likely contribute to their social problems. (JINS, 2013, 18, 1–10)

Processing speed is the most impaired neuropsychological domain in schizophrenia and a robust predictor of functional outcome. Determining the specific cognitive operations underlying processing speed dysfunction and identifying their neural correlates may assist in developing pro-cognitive interventions. Response selection, the process of mapping stimuli onto motor responses, correlates with neuropsychological tests of processing speed and may contribute to processing speed impairment in schizophrenia. This study investigated the relationship between behavioral and neural measures of response selection, and a neuropsychological index of processing speed in schizophrenia. Twenty-six patients with schizophrenia and 21 healthy subjects underwent functional magnetic resonance imaging scanning during performance of two- and four-choice reaction time (RT) tasks and completed the Wechsler Adult Intelligence Scale-III (WAIS) Processing Speed Index (PSI). Response selection, defined as RT slowing between two- and four-choice RT, was impaired in schizophrenia and correlated with psychometric processing speed. Greater activation of the dorsolateral prefrontal cortex (PFC) was observed in schizophrenia and correlated with poorer WAIS PSI scores. Deficient response selection and abnormal recruitment of the dorsolateral PFC during response selection contribute to processing speed impairment in schizophrenia. Interventions that improve response selection and normalize dorsolateral PFC function may improve processing speed in schizophrenia. (JINS, 2013, 19, 1–10)

Traumatic brain injuries (TBI) in children and adolescents can impair social cognition and communication skills but there are few assessment tools suitable for adolescents. The Awareness of Social Inference Test (TASIT) uses professionally enacted audiovisual vignettes of everyday conversational exchanges and is a valid measure of social perception disorders in adults. This study examined its utility for assessing impairments in social cognition in a group of 16 adolescents with TBI, compared to a group of 16 typically developing (TD) adolescents. Adolescents with TBI were, on average, no different to their TD peers on TASIT 1 (emotion recognition) and TASIT 3 (recognizing lies and sarcasm when provided with additional cues) but performed more poorly on TASIT 2 which required them to interpret sarcastic and sincere conversational exchanges with few cues other than the demeanor of the speakers. Within the TBI group, poor performance on TASIT correlated to both relative and self-reported communication difficulties at home. It also correlated with IQ, face recognition and severity of injury as indexed by duration of post-traumatic amnesia. Overall, this study suggests TASIT is a valid measure for adolescents although it raised questions as to how effective normative data is for comparing performance in social cognition during childhood and adolescence. (JINS, 2013, 19, 1–11)

Letter fluency deficits are commonly detected in non-demented Parkinson's disease (PD) patients but the underlying cause remains uncertain. We investigated the role of slowed processing speed and executive dysfunction. Eighteen non-demented PD participants and nineteen controls were compared on letter fluency using a fluency index (Fi); the average time to “think” of each word, a measure independent of motor speed. Video analyses produced thinking times to switch between word clusters and generate a word within a cluster. Correlational and regression analyses were undertaken with tests of processing speed and executive functioning. The PD group exhibited significantly longer fluency indices than controls across all components. Performance on tests of executive functioning explained a significant proportion of variance whereas performance in processing speed tests did not. Moreover, PD participants with an executive functioning impairment showed significantly worse switching fluency indices only compared with Controls and PD participants without executive dysfunction. PD participants with executive dysfunction exhibited a disproportionate impairment in the time taken to switch between clusters than to think of words within clusters. Executive functioning contributed to fluency performance more than processing speed. Cognitive heterogeneity and motor slowing, may mask the profile of cognitive dysfunction in neurodegenerative disease. (JINS, 2013, 19, 1–9)

Traumatic brain injury (TBI) is the most common cause of brain damage, resulting in long-term disability. The “reserve” construct has been proposed to account for the reported mismatch between brain damage and its clinical expression. Although numerous studies have used various measures thought to reflect this construct, few studies have examined its underlying structure in clinical populations, and no studies have systematically studied this construct in TBI. In the present study, structural equation modeling technique was used to evaluate several models hypothesized to represent cognitive reserve (CR) in TBI. A broad range of data typically reported in the literature as representing CR was collected from 89 individuals who sustained moderate-to-severe TBI. Analyses revealed a best fitting model that consisted of three separate factors representing premorbid intelligence, socioeconomic status and leisure activity, with distinct pattern of associations among the three factors. Findings provide empirical support for the notion of a multi-factorial CR and suggest a coherent framework for further investigation. (JINS, 2013, 19, 1–8)

Deficits in neurocognitive functioning are an important area of late effects in survivors of pediatric brain tumors; however, a quantitative analysis of the magnitude of these deficits in survivors of brain tumors of the posterior fossa has not been conducted. Despite tumor locations in the posterior regions of the brain, individual studies have documented deficits in a variety of domains, reflective of impairment in other brain regions. The current study provides a comprehensive meta-analysis of literature on neurocognitive late effects found in survivors of posterior fossa tumors. Results indicated significant deficits in both specific and broad indices of neurocognitive functioning, and the overall magnitude of effects across domains ranged from medium to large (g = −0.62 to −1.69) with a large mean overall effect size (g = −1.03). Moderator analyses indicated significantly greater effects for survivors diagnosed at a younger age and those who received radiation therapy. These findings underscore the importance of monitoring neurocognitive late effects in survivors of pediatric brain tumors of the posterior fossa, as well as the need for more consistent consideration of demographic, diagnostic, and treatment-related variables to allow for examination of factors that moderate these deficits. (JINS, 2012, 19, 1–10)

Using multi-process framework by McDaniel and Einstein (2000), the current study examined whether the length of prospective memory (PM) delay intervals as measured by the 2- and 15-min subscales of the Memory for Intentions Screening Test (MIST) have differential predictive value for antiretroviral (ARV) adherence. Participants included 74 HIV-infected individuals whose ARV adherence was tracked with an electronic monitoring system. Participants were classified as “adherent” (n = 49) or “non-adherent” (n = 25) based on recorded pill bottle openings of ≥90% of prescribed doses over 30 days. An adherence group by MIST delay interval interaction was observed, such that non-adherent participants had worse performance on the 15-min, but not 2-min delay PM MIST subscales. The observed MIST 15-min delay effects were significantly more pronounced on time- versus event-cued PM trials. Long-delay time-based PM was predictive of non-adherence independent of demographics, mood state, self-reported adherence, and general cognitive functioning. Findings from this clinical study indicate that ARV non-adherence may be particularly associated with deficits in strategic cue monitoring over longer PM delays, which may inform interventions to improve adherence among persons living with HIV infection. (JINS, 2012, 18, 1–7)

Research reveals mixed results regarding the utility of standardized cognitive and academic tests to predict educational outcomes in youth following a traumatic brain injury (TBI). Yet, deficits in everyday school-based outcomes are prevalent after pediatric TBI. The current study used path modeling to test the hypothesis that parent ratings of adolescents’ daily behaviors associated with executive functioning (EF) would predict long-term functional educational outcomes following pediatric TBI, even when injury severity and patient demographics were included in the model. Furthermore, we contrasted the predictive strength of the EF behavioral ratings with that of a common measure of verbal memory. A total of 132 adolescents who were hospitalized for moderate to severe TBI were recruited to participate in a randomized clinical intervention trial. EF ratings and verbal memory were measured within 6 months of the injury; functional educational outcomes were measured 12 months later. EF ratings and verbal memory added to injury severity in predicting educational competence post injury but did not predict post-injury initiation of special education. The results demonstrated that measurement of EF behaviors is an important research and clinical tool for prediction of functional outcomes in pediatric TBI. (JINS, 2013, 19, 1–9)

This study traces the development of spatial memory abilities in monkeys and reports the effects of selective neonatal hippocampal lesions on performance across development. Two different versions of the visual paired-comparison (VPC) task were used. The VPC-Spatial-Location task tested memory for object-locations that could be solved using an egocentric spatial frame of reference and the VPC-Object-In-Place task taxed memory for spatial relations using an allocentric reference frame. Eleven rhesus macaques (6 neonatal sham-operated controls and 5 with neonatal neurotoxic hippocampal lesions) were tested on both tasks as infants (8 months), juveniles (18 months), and adults (5–6 years). Memory for spatial locations was present by 18 months of age, whereas memory for object-place relations was present only in adulthood. Also, neonatal hippocampal lesions delayed the emergence of memory for spatial locations and abolished memory for object-place associations, particularly in animals that had sustained extensive and bilateral hippocampal lesions. The differential developmental time course of spatial memory functions and of the effects of neonatal hippocampal lesions on these functions are discussed in relation to morphological maturation of the medial temporal lobe structures in monkeys. Implications of the findings for the neural basis of spatial memory development in humans are also considered. (JINS, 2013, 19, 1–12)

Reduced left-hemispheric language lateralization has been proposed to be a trait marker for schizophrenia, but the empirical evidence is ambiguous. Recent studies suggest that auditory hallucinations are critical for whether a patient shows reduced language lateralization. Therefore, the aim of the study was to statistically integrate studies investigating language lateralization in schizophrenia patients using dichotic listening. To this end, two meta-analyses were conducted, one comparing schizophrenia patients with healthy controls (n = 1407), the other comparing schizophrenia patients experiencing auditory hallucinations with non-hallucinating controls (n = 407). Schizophrenia patients showed weaker language lateralization than healthy controls but the effect size was small (g = −0.26). When patients with auditory hallucinations were compared to non-hallucinating controls, the effect size was substantially larger (g = −0.45). These effect sizes suggest that reduced language lateralization is a weak trait marker for schizophrenia as such and a strong trait marker for the experience of auditory hallucinations within the schizophrenia population. (JINS, 2013, 19, 1–9.)

The current study explored the picture naming performance of patients with Alzheimer's disease (AD). First, we evaluated the utility of the Multilingual Naming Test (MINT; Gollan et al., 2011), which was designed to assess naming skills in speakers of multiple languages, for detecting naming impairments in monolingual AD and amnestic mild cognitive impairment (MCI). If the MINT were sensitive to linguistic impairment in AD, using it in clinical practice might have advantages over using tests exclusively designed for English monolinguals. We found that the MINT can be used with both monolinguals and bilinguals: A 32-item subset of the MINT is best for distinguishing monolingual patients from controls, while the full MINT is best for assessing degree of bilingualism and language dominance in bilinguals. We then investigated the cognitive mechanisms underlying naming impairment in AD. To this end, we explored which MINT item characteristics best predicted performance differences between monolingual patients and controls. We found that contextual diversity and imageability, but not word frequency (nor words’ number of senses), contributed unique variance to explaining naming impairments in AD. These findings suggest a semantic component to the naming impairment in AD (modulated by names’ semantic richness and network size). (JINS, 2013, 19, 1–12)

Using magnetic resonance imaging, this study compared hippocampal volume between 145 very preterm children and 34 children born full-term at 7 years of age. The relationship between hippocampal volume and memory and learning impairments at 7 years was also investigated. Manual hippocampal segmentation and subsequent three-dimensional volumetric analysis revealed reduced hippocampal volumes in very preterm children compared with term peers. However, this relationship did not remain after correcting for whole brain volume and neonatal brain abnormality. Contrary to expectations, hippocampal volume in the very preterm cohort was not related to memory and learning outcomes. Further research investigating the effects of very preterm birth on more extensive networks in the brain that support memory and learning in middle childhood is needed. (JINS, 2013, 19, 1–11)

The primary purpose of this study was to test the hypothesis that multiple sclerosis (MS) patients have impaired acquisition rather than a retrieval deficit. Verbal memory impairment in MS was examined in 53 relapsing-remitting MS patients and 31 healthy controls (HC), and in a meta-analysis of studies that examined memory functioning in MS with list-learning tasks. The MS group demonstrated significantly lower acquisition and delayed recall performance than the HC group, and the meta-analysis revealed that the largest effect sizes were obtained for acquisition measures relative to delayed recall and recognition. Our data argue against a retrieval deficit as the sole explanation for verbal memory impairment in MS, and make a consistent case for the position that deficient acquisition contributes to the memory dysfunction of MS patients. Deficient acquisition may result from demyelination in relevant white matter tracts that reduces encoding efficiency as a result of impaired speed of information processing. (JINS, 2013, 19, 995–1008)