We compared aspects of verbal memory and executive functioning in 51 community-dwelling persons with chronic kidney disease (CKD) and 55 healthy controls matched on age and education. Depressive symptoms were assessed with the Centre for Epidemiological Studies-Depression Scale (CES-D), and illness variables included glomerular filtration rate (GFR) and hemoglobin. Findings indicate that persons with CKD exhibited poorer performance on measures of memory (CVLT-II) and executive functioning (DKEFS Trailmaking Test B and Color-Word Interference Tests) in comparison with healthy controls. Furthermore, performance decrements were magnified in older CKD participants on measures of verbal memory and inhibition. Nearly half of CKD participants aged 61 and older exhibited significant impairments in verbal memory and inhibition in comparison to matched controls. Cognitive performance in CKD was not associated with measures of illness severity. The differences observed were not accounted for by depressive symptoms, which were only weakly associated with cognitive performance, and negatively associated with age. Findings highlight the need for further exploration of the etiologies and functional consequences of the neuropsychological presentation of CKD. (JINS, 2007, 13, 344–353.)

Objectives: The current study examined neuropsychological performance among children with spina bifida (SB) to determine biological and functional correlates of distinct “profiles” of cognitive functioning. Methods: A total of 95 children with SB myelomeningocele (ages, 8–15 years) completed a neuropsychological assessment battery. Hierarchical and non-hierarchical cluster analyses were used to identify and confirm a cluster solution. Hypothesized predictors of cluster membership included lesion level, number of shunt surgeries, history of seizures, age, ethnicity, socio-economic status, and family stress. Outcomes included independence, academic success, expectations for the future, and quality of life. Results: Ward’s cluster method indicated a three-cluster solution, and was replicated with two other cluster analytic methods. The following labels were applied to the clusters: “average to low average” (n=39), “extremely low to borderline” (n=27), and “broadly average with verbal strength” (n=29). Socio-econimc status, lesion level, and seizure history significantly predicted group membership. Cluster membership significantly predicted independence, academic success, parent expectations for the future, and child reported physical quality of life. Conclusions: Findings from this study suggest qualitatively different cognitive profiles exist among children with SB, and the relevance of neuropsychological functioning for day-to-day adaptive functioning and quality of life. Clinical implications and future research are discussed. (JINS, 2016, 22, 804–815)

Objectives: Pedophilia (P) is a psychiatric disease associated with sexual attraction toward children and often accompanied by child sexual offending (CSO). Consequently, it is important to address the understanding of executive dysfunctions that may increase the probability of CSO. Moreover, this research field has been lacking to disentangle executive deficits associated with pedophilia (as a deviant sexual preference) from those associated with CSO (as a deviant sexual behavior). Methods: The German multi-sided research network NeMUP offers the opportunity to overcome these limitations. By applying the Cambridge Automated Neuropsychological Test Battery in four carefully matched groups of men: (1) pedophiles with (N=45) and (2) without (N=45) a history of sexual offending against children; (3) child molesters without pedophilia (N=19), and (4) non-offending controls (N=49), we were able to analyze executive functioning in pedophilia and CSO independently. Results: Both CSO groups as compared to both non-CSO groups exhibited worsened response inhibition ability. However, only non-pedophilic offenders showed additionally disabled strategy use ability. Regarding set-shifting abilities, the P+CSO group showed the best performance. We also found that performances were affected by age: only in pedophiles, response inhibition worsened with age, while age-related deficits in set-shifting abilities were restricted to non-pedophilic participants. The latter also differentiated between both sexual preference groups. Conclusions: Our results are the first to demonstrate that executive dysfunctions are related to offense status rather than pedophilic preference. Furthermore, there was evidence for differentiating age and performance correlations between pedophiles and non-pedophiles, which warrants further investigation. (JINS, 2017, 23, 460–470)

Aged and young adults were tested by category cued recall after learning with category cues (CCR) or with item cues (ICR). CCR was about twice ICR for both aged and young adults. The aged recalled less than the young and did not benefit as much from greater encoding specificity and deeper processing in CCR. ICR and CCR were correlated, so that expected CCR can be predicted from ICR. The regression of CCR on ICR was linear for young adults, but was piecewise linear for the aged, showing that the relationship between ICR and CCR was not uniform for the aged adults. Lower than expected CCR by a subset of aged without clinical dementia may be a sign of preclinical dementia. (JINS, 1995, I, 483–493.)

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)

The effect of mild head injury on event-related potential (ERP) correlates of Stroop task performance was explored with the aim of further elucidating the basis of processing impairments after mild head injury. Computer- and card-based Stroop tasks were employed to assess attention function. A sequence of incongruent color words were presented followed by a sequence of congruent color words (printed in congruent colors). Control performance was equivalent on computer- and card-based versions of the incongruent task and faster on the congruent card task than the preceding congruent computer task. The mild head injury group were as fast as controls on the computer-based task but made more errors. However, they were relatively slower on both the congruent and incongruent parts of the card-based task and made more errors in the incongruent task. ERP correlates of computer-based Stroop task performance suggested a greater allocation of attention resources in the incongruent condition in both groups in the form of relatively greater negativity in the latency range 350 to 450 ms with a distribution consistent with the activation of the anterior cingulate gyrus. In addition the mild head injured group showed relatively greater enhancement than the control group in this latency range in both congruent and incongruent conditions. There was, however no evidence of reduced amplitude P1, N1, N2, or P3b deflections. Trails, digit symbol, digit span and auditory verbal learning tests (AVLT) were also administered. Mild head injured participants were impaired only on the AVLT. The finding of greater ERP negativity in the mild head injured group is consistent with greater allocation of attention resources to achieve equivalent performance in the computer-based Stroop task. (JINS, 2002, 8, 828–837.)

Impairments in executive functioning frequently occur after acquired brain damage, in psychiatric disorders, and in relation to aging. The Brixton Spatial Anticipation Test is a relatively new measure for assessing the ability to detect and follow a rule, an important aspect of executive functioning. To date, normative data on this task are limited, particularly concerning the elderly. This study presents age- and education-adjusted regression-based norms obtained in a group of healthy older participants (n = 283; mean age 67.4 ± 8.5 years). The applicability and validity of these norms were further examined in different groups of patients with stroke (n = 106), diabetes mellitus (n = 376), MCI/early dementia (n = 70), psychiatric disorders (n = 63), and Korsakoff’s syndrome (n = 41). The results showed that patients with Korsakoff’s syndrome, stroke, and psychiatric disorders performed significantly worse than healthy controls. Test-retest correlation (n = 83), learning effects, and correlations with other neuropsychological tests were also explored. Based on the present study, the Brixton test appears a useful addition to existing measures of executive functioning. Moreover, the test can be reliably applied in different groups of clinical patients. (JINS, 2009, 15, 695–703.)

This study investigated the basic mechanisms of the impairment of memory for actions to be performed in a group of 16 chronic survivors of severe closed-head injury (CHI). The experimental paradigm allowed discrimination between the deficit in spontaneously remembering the intention at the appropriate moment (prospective component of the task) and the deficit in remembering the specific actions to perform (retrospective component). The experimental procedure also contrasted a condition in which the time expiration was marked by the ringing of a timer (event-based condition) and one in which the time expiration was not marked by any event and the patient had to monitor the passing of time and completely self-activate the recall of the intention (time-based condition). Two other experimental manipulations were concerned with the duration of the delay interval from the examiner's instructions to the time expiration (10 vs. 45 min) and the fact that the three actions to be performed could be functionally related or not. With respect to a group of 16 normal controls, the patients with CHI were impaired in both the prospective and retrospective components of the memory for actions. Although an impairment of episodic memory is a plausible explanation for the poor retrieval of specific actions to perform, it is unlikely that this deficit played a major role in the CHI patients' reduced accuracy in spontaneously recalling the intention when the event occurred or the time expired. Instead, reduced frequency and less strategic utilization of time monitoring and/or self-reminding likely played a significant role in this sense. (JINS, 2004, 10, 679–688.)

Survivors of severe traumatic brain injury (TBI) often demonstrate impairments in the cognitive control functions of detecting response conflict and signaling for recruitment of cognitive resources to appropriately adjust performance. These cognitive control functions can be measured using conflict adaptation effects, wherein manifestations of conflict detection and processing are reduced following high- relative to low-conflict trials. Event-related potentials (ERPs) were collected while 18 survivors of severe traumatic brain injury (TBI) and 21 demographically matched control participants performed a modified Stroop task. The incongruent-minus-congruent trial Stroop effect for trials preceded by incongruent (high conflict) and congruent (low conflict) trials were compared for behavioral (response time [RT] and error rate) and ERP reflections of cognitive control. Behavioral data showed a reduction in the Stroop effect for both control and TBI participant RTs when preceded by incongruent trials. The magnitude of these effects did not differentiate control and TBI participants. ERP data revealed a centro-parietal conflict slow potential (conflict SP) that differentiated incongruent from congruent trials. Planned comparisons showed a decreased amplitude conflict SP when ERPs were preceded by incongruent trials in control, but not TBI participants. Results indicate subtle TBI-related impairments in conflict resolution mechanisms in the context of intact RT-related conflict adaptation. (JINS, 2009, 15, 927–937.)

Memory impairment is common following traumatic brain injury (TBI), but interventions to improve memory in persons with TBI have been ineffective. Retrieval practice is a robust memory strategy among healthy undergraduates, whereby practice retrieving information shortly after it is presented leads to better delayed recall than simple restudy. In a verbal paired associate paradigm, we investigated the effect of retrieval practice relative to massed and spaced restudy on delayed recall in 14 persons with chronic memory impairment following a TBI and 14 age-matched healthy controls. A significant learning condition (massed restudy, spaced restudy, retrieval practice) by group (TBI, healthy) interaction emerged, whereby only healthy controls benefited from spaced restudy (i.e., distributed learning) over massed restudy, but both groups greatly benefited from retrieval practice over massed and spaced restudy. That is, retrieval practice greatly improves memory in persons with TBI, even when other mnemonic strategies (e.g., distributed learning) are less effective. (JINS, 2010, 16, 1147–1150.)

Objectives: The goal of the present study was to elucidate the influence of demographic and neuropathological moderators on the longitudinal trajectory neuropsychological functions during the first year after moderate to severe traumatic brain injury (TBI). In addition to examining demographic moderators such as age and education, we included a measure of whole-brain diffuse axonal injury (DAI), and examined measures of processing speed (PS), executive function (EF), and verbal learning (VL) separately. Methods: Forty-six adults with moderate to severe TBI were examined at 3, 6, and 12 months post-injury. Participants underwent neuropsychological evaluation and neuroimaging including diffusion tensor imaging. Using linear mixed effects modeling, we examined longitudinal trajectories and moderating factors of cognitive outcomes separately for three domains: PS, VL, and EF. Results: VL and EF showed linear improvements, whereas PS exhibited a curvilinear trend characterized by initial improvements that plateaued or declined, depending on age. Age moderated the recovery trajectories of EF and PS. Education and DAI did not influence trajectory but were related to initial level of functioning for PS and EF in the case of DAI, and all three cognitive domains in the case of education. Conclusions: We found disparate recovery trajectories across cognitive domains. Younger age was associated with more favorable recovery of EF and PS. These findings have both clinical and theoretical implications. Future research with a larger sample followed over a longer time period is needed to further elucidate the factors that may influence cognitive change over the acute to chronic period after TBI. (JINS, 2018, 24, 237–246)

Parkinson's disease (PD) patients may experience fluctuations in executive performance after oral levodopa (LD). Their relationship with the pharmacokinetic profile of LD and with distinct cognitive processes associated with frontal-basal ganglia circuits is not well understood. In this randomized, double-blind, crossover study we plotted acute cognitive changes in 14 PD patients challenged with faster (immediate-release, IR) versus slower (controlled-release, CR) increases in LD plasma concentrations. We monitored motor status, LD plasma levels, and performance on four tasks of executive function (Wisconsin Card Sorting Test—WCST, Sternberg test, Stroop and Tower of Hanoi), 1 hr before and over +6 hr after IR and CR-LD dose. Analysis of variance demonstrated significant but divergent changes in the Sternberg (6-digit but not 2- and 4-digit) test: improvement after CR-LD and worsening after IR-LD. Marginal improvement (p = .085) was observed with CR-LD in the WCST, while no significant differences were seen for the Stroop or Tower of Hanoi tests. Executive-related performance after LD challenge may differ depending on the LD time-to-peak plasma concentration and specific task demands. A slower rise in LD levels appears to have a more favorable impact on more difficult working memory tests. These results require replication to determine their generalization. (JINS, 2008, 14, 832–841.)

This research compares the performance of a sample of non-litigating participants with severe brain injury on both the WMT and TOMM under conditions of (1) full effort, (2) distraction, or (3) simulated malingering. The study included 60 participants with a severe brain injury and used restricted randomization to assign participants to the groups. Following Craik (1982) an auditory distraction task was used during the learning phase of each test in the distraction group, while a scenario adapted from Tombaugh (1997) was used to encourage simulation of memory impairment in the simulated malingering group. The results of this study clearly showed that while both tests demonstrated excellent sensitivity, the false positive rates for the WMT were significantly greater than those for the TOMM. It was concluded that the so-called “effort” components of the WMT required more cognitive capacity than was previously believed. (JINS, 2008, 14, 1074–1080.)

Given the substantial overlap in cognitive dysfunction between bipolar disorder (BD) and schizophrenia (SZ), we examined the utility of the MATRICS Consensus Cognitive Battery (MCCB)—developed for use in SZ—for the measurement of cognition in patients with BD with psychosis (BDP) and its association with community functioning. The MCCB, Multnomah Community Ability Scale, and measures of clinical symptoms were administered to participants with BDP (n=56), SZ (n=37), and healthy controls (HC) (n=57). Groups were compared on clinical and cognitive measures; linear regressions examined associations between MCCB and community functioning. BDP and SZ groups performed significantly worse than HC on most neurocognitive domains; BDP and HC did not differ on Social Cognition. Patients with BDP performed better than patients with SZ on most cognitive measures, although groups only differed on social cognition, working memory, verbal memory, and the composite after controlling for clinical variables. MCCB was not associated with community functioning. The MCCB is an appropriate measure of neurocognition in BDP but does not appear to capture social cognitive deficits in this population. The addition of appropriate social cognitive measures is recommended. (JINS, 2015, 21, 468–472)

Objectives: One of the most prominent features of schizophrenia is relatively lower general cognitive ability (GCA). An emerging approach to understanding the roots of variation in GCA relies on network properties of the brain. In this multi-center study, we determined global characteristics of brain networks using graph theory and related these to GCA in healthy controls and individuals with schizophrenia. Methods: Participants (N=116 controls, 80 patients with schizophrenia) were recruited from four sites. GCA was represented by the first principal component of a large battery of neurocognitive tests. Graph metrics were derived from diffusion-weighted imaging. Results: The global metrics of longer characteristic path length and reduced overall connectivity predicted lower GCA across groups, and group differences were noted for both variables. Measures of clustering, efficiency, and modularity did not differ across groups or predict GCA. Follow-up analyses investigated three topological types of connectivity—connections among high degree “rich club” nodes, “feeder” connections to these rich club nodes, and “local” connections not involving the rich club. Rich club and local connectivity predicted performance across groups. In a subsample (N=101 controls, 56 patients), a genetic measure reflecting mutation load, based on rare copy number deletions, was associated with longer characteristic path length. Conclusions: Results highlight the importance of characteristic path lengths and rich club connectivity for GCA and provide no evidence for group differences in the relationships between graph metrics and GCA. (JINS, 2016, 22, 240–249)

Cognitive impairments are among the most frequently reported and least investigated components of the chronic fatigue syndrome (CFS). As part of a multifaceted study of the CFS, the present study investigated the cognitive functioning of chronic fatigue patients. The performance of 20 CFS patients was compared to that of controls (N = 20) on 4 tests of working memory (WM). Digit Span Forward was used to assess the storage capacity of WM. Multiple aspects of central executive functioning were assessed using several standard measures: Digit Span Backward, and Trails A and Trails B. More recently developed measures of WM were used to assess control of processing under temporal demands (working memory task) and resistance to interference (a sustained attention task). Deficits were restricted to more demanding tasks, requiring resistance to interference and efficient switching between processing routines. The overall results clearly implicate deficits in the control aspects of central executive function in CFS. (JINS, 2001, 7, 285–293.)

This study examined whether patients with mild cognitive impairment (MCI) who are at higher risk for later Alzheimer disease (AD) display deficits comparable to patients with diagnosed dementia. We assessed 27 patients with MCI, 36 patients with AD, and 20 healthy older adults with an emotional variant of the Deese–Roediger–McDermott-paradigm. Participants studied four lists that were semantically related to a nonpresented critical theme word. These theme words were either depression-related (i.e., loneliness) or delusion-related (betrayal) or had a positive (holidays) or neutral (window) valence. Despite a normal overall emotional memory and a normal corrected overall false recognition, patients with MCI, as predicted, produced as many false memories as patients with AD. On closer examination, both patient groups showed enhanced false memories to unrelated stimuli and a significant bias to falsely remember stimuli with a positive valence. We conclude that although patients with MCI are not distinguishable from healthy older adults in terms of their overall emotional recognition, positively valenced memories and more specifically false positive memories may represent the signature of a breakdown of emotional memory along the continuum between normal aging and AD. (JINS, 2009, 15, 268–276.)

Prospective memory (PM) is the ability to remember to perform a future action at a specified later time, which is investigated through the use of event-based and time-based tasks. Prior investigations have found that PM is impaired following traumatic brain injury (TBI). However, there is limited information regarding the cognitive functions that mediate TBI and PM performance. Thus, this study investigated time-based PM in TBI patients, and the relationship among time-based PM, time perception, and executive functions. To accomplish this objective, 18 severe TBI patients and 18 healthy matched controls performed a time-based PM task, a time reproduction task, and two executive functions (Stroop and n-back) tasks. While both groups increased their monitoring frequency close to the target time, TBI patients monitored more and were less accurate than healthy controls at the target time confirming the time-based PM dysfunction in these patients. Importantly, executive functions, particularly inhibition and updating abilities, were strongly related to time-based PM performance; both time perception and executive functions are involved in time-based prospective memory in controls, whereas, only executive functions appear to be involved in TBI time-based prospective memory performance. (JINS, 2012, 18, 1–9)

Background: The influence of psychotherapy on neurocognition in post-traumatic stress disorder (PTSD) has not been examined methodically. This is despite evidence that pre-treatment learning and memory has been associated with treatment success and that executive function theories emphasize weak executive functions (especially inhibition/switching) are associated with PTSD. Objectives: To determine (1) if higher pre-treatment learning/memory, inhibition/switching, or both predict treatment success; and (2) if treatment success is associated with specific improvement in inhibition/switching and not learning/memory or working memory, another aspect of executive function. Methods: Pre-treatment neurocognition and neurocognitive changes (inhibition/switching, learning/memory, working memory) were examined in female veterans with PTSD. They were evaluated before and after 16-weeks of group psychotherapy for PTSD that included three counterbalanced modules (cognitive restructuring therapy, exposure therapy, skills training) with fidelity checks for therapist adherence. Results: Only pre-treatment learning/memory predicted better treatment outcome. Treatment success was associated with improvement in inhibition/switching only, even after controlling for mild traumatic brain injury, and changes in depressive symptoms, working memory, and learning/memory. Conclusions: Our finding that learning/memory predicted treatment success is consistent with previous studies. We extended these studies by showing that the effect was restricted to learning/memory, which is contrary to the executive function theory of PTSD. In contrast, the fact that only inhibition/switching significantly improved with better treatment success is consistent with its potential importance in maintaining PTSD symptoms. Future research should determine whether inhibition/switching abilities are a risk for development and maintenance of PTSD or whether such abilities have a broader reciprocal relationship with PTSD symptom change. (JINS, 2016, 22, 643–651)

The degree of neuropsychological dysfunction across multiple domains was examined in individuals suffering from chronic fatigue syndrome (CFS). In this descriptive study, a similar series of neuropsychological tests was administered to a group of CFS patients and healthy participants. More specifically, CFS patients (n = 141) who met the 1994 Case Definition criteria were compared to 76 healthy control participants on tests of memory, attention (concentration), speed of information processing, motor speed, and executive functioning. On the 18 measures administered, CFS patients scored 1 standard deviation below the healthy mean on nine measures and scored 2 standard deviations below the healthy mean on four of the measures. Moreover, results indicated that CFS patients were more likely than healthy controls to fail (1.6 SD below the healthy mean) at least one test in each of the following domains: attention, speed of information processing, and motor speed, but not on measures of memory and executive functioning. Finally, CFS patients demonstrated a greater total number of tests failed across domains. (JINS, 2004, 10, 278–285.)