Previous fMRI research has found altered brain response after total sleep deprivation (TSD), with TSD effects moderated by task difficulty. Specific models of the impact of sleep deprivation and task difficulty on brain response have yet to be developed. Differences in networks of fMRI measured brain response during verbal encoding in sleep deprived and well-rested individuals were examined with structural equation modeling (SEM). During fMRI scanning, 23 healthy volunteers memorized words either easy or difficult to recall, 12 (well-rested) and 36 hours (sleep deprived) after awaking. A priori models that linked specified regions of interest were evaluated, with the focus on the extent to which two left parietal regions interacted with the left inferior frontal gyrus (Model 1) or with the right inferior frontal gyrus (Model 2). Task difficulty, not TSD, determined which model fit the brain response data; Model 2 fit best for hard words before and after TSD, whereas Model 1 fit best for easy words. TSD altered the patterns of interaction within each of the best fitting models: prefrontal interactions with the left inferior parietal lobe were diminished and intra-parietal interactions increased. Sleep deprivation and item difficulty produce different effects on brain networks involved in verbal learning. (JINS, 2006, 12, 591–597.)

Learning and performance on a ballistic task were investigated in children with spina bifida meningomyelocele (SBM), with either upper level spinal lesions (n = 21) or lower level spinal lesions (n = 81), and in typically developing controls (n = 35). Participants completed three phases (20 trials each) of an elbow goniometer task that required a ballistic arm movement to move a cursor to one of two target positions on a screen, including (1) an initial learning phase, (2) an adaptation phase with a gain change such that recalibration of the ballistic arm movement was required, and (3) a learning reactivation phase under the original gain condition. Initial error rate, asymptotic error rate, and learning rate did not differ significantly between the SBM and control groups. Relative to controls, the SBM group had reduced volumes in the cerebellar hemispheres and pericallosal gray matter (the region including the basal ganglia), although only the pericallosal gray matter was significantly correlated with motor adaptation. Congenital cerebellar dysmorphology is associated with preserved motor skill learning on voluntary, nonreflexive tasks in children with SBM, in whom the relative roles of the cerebellum and basal ganglia may differ from those in the adult brain. (JINS, 2006, 12, 598–608.)

This study examined the impact of childhood traumatic brain injury (TBI) on self-regulation and social and behavioral functioning, and the role of self-regulation as a predictor of children's social and behavioral functioning. Participants included 65 children with moderate to severe TBI and 65 children without TBI, all between 6 and 11 years of age. Self-regulation and social and behavioral functioning were assessed 2 to 5 years following injury. Children with TBI displayed deficits in self-regulation and social and behavioral functioning, after controlling for socioeconomic status (SES), although the magnitude of the deficits was not related to injury severity. Self-regulation accounted for significant variance in children's social and behavioral functioning, after controlling for SES and group membership. Self-regulation may be an important determinant of children's social and behavioral functioning following TBI. (JINS, 2006, 12, 609–621.)

The present study compared performance of children with Attention-Deficit/Hyperactivity Disorder (ADHD) and high functioning autism (HFA) with that of controls on 4 tasks assessing 2 components of motor control: motor response inhibition and motor persistence. A total of 136 children (52 ADHD, 24 HFA, 60 controls) ages 7 to 13 years completed 2 measures of motor inhibition (Conflicting Motor Response and Contralateral Motor Response Tasks) and 2 measures of motor persistence (Lateral Gaze Fixation and NEPSY Statue). After controlling for age, IQ, gender, and basic motor speed, children with ADHD performed significantly more poorly than controls on the Conflicting Motor Response and Contralateral Motor Response Tasks, as well as on Statue. In contrast, children with HFA achieved lower scores than controls only on measures of motor persistence, with no concomitant impairment on either motor inhibition task. These results are consistent with prior research that has demonstrated relatively spared motor inhibition in autism. The findings highlight the utility of brief assessments of motor control in delineating the unique neurobehavioral phenotypes of ADHD and HFA. (JINS, 2006, 12, 622–631.)

Recent cross-sectional studies have reported strong associations between visual and cognitive function, and longitudinal studies have shown relationships between visual and cognitive decline in late life. Improvement in cognitive performance after cataract surgery has been reported in patients with Mild Cognitive Impairment. We investigated whether improving visual function with cataract surgery would improve neuropsychological performance in healthy older adults. A randomized clinical trial of cataract surgery performed at acute hospitals was conducted on 56 patients (mean age 73) with bilateral cataract, after excluding a total of 54 patients at the screening stage, of whom 53 did not meet visual acuity criteria and one did not have cataract. In-home assessments included visual and neuropsychological function, computerized cognitive testing and health questionnaires. Results showed no cognitive benefits of cataract surgery in cognitively normal adults. We conclude that visual improvement following cataract surgery is not strongly associated with an improvement in neuropsychological test performance in otherwise healthy adults. Joint associations between visual and cognitive function in late life are likely to be due to central factors, and unlikely to be strongly related to eye disease. Short-term increased neural stimulation from improved visual function does not appear to affect cognitive performance. (JINS, 2006, 12, 632–639.)

Memory impairment is among the most common cognitive deficits in people with multiple sclerosis (MS). To remediate this problem, recent research has evaluated the benefits of self-generated encoding. These nascent investigations reveal that people with MS who have mild memory impairment demonstrate a significant memory benefit from self-generated encoding compared with didactic learning. To extend prior research, the present experiment included MS patients with moderate–severe, rather than just mild, memory impairment. Additionally, the experiment evaluated whether self-generated encoding improves memory for activities of daily living instead of abstract words. Specifically, the experiment determined whether self-generated encoding enhanced memory for names, appointments, and object locations. In agreement with and extending prior research, MS patients remembered more information if it was self-generated rather than didactically presented, and this finding occurred despite moderate–severe memory impairment. Furthermore, compared with didactic encoding, self-generation enhanced recall of activities of daily living. Implications of these findings for cognitive rehabilitation and the nature of memory impairment in MS are discussed (JINS, 2006, 12, 640–648.)

This study examined implicit semantic and rhyming cues on perception of auditory stimuli among nonaphasic participants who suffered a lesion of the right cerebral hemisphere and auditory neglect of sound perceived by the left ear. Because language represents an elaborate processing of auditory stimuli and the language centers were intact among these patients, it was hypothesized that interactive verbal stimuli presented in a dichotic manner would attenuate neglect. The selected participants were administered an experimental dichotic listening test composed of six types of word pairs: unrelated words, synonyms, antonyms, categorically related words, compound words, and rhyming words. Presentation of word pairs that were semantically related resulted in a dramatic reduction of auditory neglect. Dichotic presentations of rhyming words exacerbated auditory neglect. These findings suggest that the perception of auditory information is strongly affected by the specific content conveyed by the auditory system. Language centers will process a degraded stimulus that contains salient language content. A degraded auditory stimulus is neglected if it is devoid of content that activates the language centers or other cognitive systems. In general, these findings suggest that auditory neglect involves a complex interaction of intact and impaired cerebral processing centers with content that is selectively processed by these centers (JINS, 2006, 12, 649–656.)

Cognitive impairments in patients with basal ganglia dysfunction are primarily revealed where performance relies on internal, voluntary control processes. Evidence suggests that this also extends to impaired control of more automatic processes, including visuospatial attention. The present study used a non-predictive peripheral cueing paradigm to compare and contrast visuospatial deficits in patients with Parkinson's disease (PD) with those previously revealed in patients with Huntington's disease (HD) (Fielding et al., 2006a). Compared to age-matched controls, both PD and HD patients exhibited increased distractibility or poor fixation, however only PD patients responded erroneously to cue stimuli more frequently than control subjects. All subjects demonstrated initial facilitation for valid versus invalid cues following the shorter stimulus-onset asynchronies (SOAs) and a performance decrement at the longer SOAs (inhibition of return), although there was a clear differentiation between these groups for immediate SOAs. Unlike both control and PD subjects, where IOR manifested between 350 and 1000 msec, IOR was evident as early as 150 msec for HD patients. Further, for PD patients, spatially valid cues resulted in hyper-reflexivity following 150 msec SOAs, with saccadic latencies shorter than those generated in response to un-cued targets. Thus contrasting deficits were revealed in PD and HD, emphasizing the important contribution of the basal ganglia in the control of more automatic behaviors (JINS, 2006, 12, 657–667.)

Asperger's disorder (ASP), like other autism spectrum disorders, is associated with altered responsiveness to social stimuli. This study investigated learning and responsiveness to nonsocial, but motivational, stimuli in ASP. We examined choice behavior and galvanic skin conductance responses (SCRs) during the Iowa Gambling Task (IGT; Bechara et al., 1994) in 15 adolescents and young adults with ASP and 14 comparison subjects. We examined aspects of learning, attention to wins and losses, and response style with a formal cognitive model, the Expectancy–Valence Learning model (Busemeyer & Stout, 2002). The ASP group did not differ from the comparison group in proportions of selections from advantageous decks. However, ASP participants showed a distinct pattern of selection characterized by frequent shifts between the four IGT decks, whereas comparison participants developed clear deck preferences. SCR results showed some evidence of reduced responsiveness in the ASP group during the IGT. Results from the cognitive model indicated that, in contrast to the comparison group, the ASP group's selections were less consistent with the motivational significance they assigned to decks. Findings are discussed in the context of the neurobiological substrates associated with IGT performance (JINS, 2006, 12, 668–676.)

Working memory (WM) deficits are common in multiple sclerosis (MS). The Paced Auditory Serial Addition Test (PASAT) is used frequently to measure WM in clinical settings. The n-back paradigm is used often in experimental studies of WM. One unique component of the n-back task is that it provides a measure of reaction time (RT), an additional behavioral index of processing speed and task difficulty. Despite the use of both tasks to measure WM, their common variance has not been documented. We tested 32 MS patients and 20 controls; performance measures were obtained for both tasks. Compared with controls, MS patients generally had poorer performance on both the PASAT and n-back task. MS patients also had slower RTs on the n-back than controls and showed more slowing than controls as a function of WM load. Correlational analyses showed a high correspondence between performance measures on the PASAT and n-back. Principal components analysis pointed to a common feature of the PASAT, n-back, and specific other neuropsychological measures, that is, processing speed. Although the PASAT and n-back were shown to have a significant amount of shared variance, each test has specific advantages and disadvantages for use in clinical populations (JINS, 2006, 12, 677–687.)

The Forced Choice Recognition (FCR) and the Critical Item Analysis (CIA) indices of the California Verbal Learning Test-II (CVLT-II) have been identified by the CVLT-II test developers as potentially useful, brief screening indicators of effort in neuropsychological assessment. This retrospective study analyzes performance on these measures in three groups: (1) clinically referred individuals; (2) forensically referred individuals not suspected of inadequate effort; and (3) forensically referred individuals whose performance on freestanding tests of effort suggested inadequate effort. Performances on FCR were analyzed for their relation to actual memory impairment and with regard to concrete and abstract distractor endorsement. FCR and CIA performances were analyzed for agreement with formal tests of inadequate effort and their test characteristics. Incremental validity was assessed by hierarchical logistic regression with previously identified indices for detection of inadequate effort on the CVLT. Results indicate that (1) FCR and CIA performances are not related to decreased memory performance; (2) FCR and CIA indices exhibit higher specificity and lower sensitivity, with higher positive predictive value than negative predictive value; and (3) FCR and CIA indices exhibit modest incremental validity with previously identified indices. Implications for use of FCR and CIA indices in inadequate effort detection are discussed (JINS, 2006, 12, 688–696.)

Subarachnoid hemorrhage (SAH) survivors often report psychosocial and emotional changes, including a diminished capacity for decision making. However, systematic investigations into the nature of the changes have been limited to those patients surviving SAH secondary to aneurysms of the anterior communicating artery. This study aimed to explore the nature of decision making in survivors of SAH secondary to aneurysms of the middle cerebral or posterior communicating artery using a series of computerized tasks. Twenty SAH survivors and 20 matched controls completed a battery of computerized decision-making tasks. These included tasks examining an individual's ability to make probabilistic choices and risk-taking behavior, as well as tasks examining aspects of impulsivity. The results revealed two key patterns of abnormal decision-making behavior in the SAH survivors: altered sensitivity to both reward and punishment, and impulsive responding. These complex deficits may contribute to difficulties in daily living resulting from apathy, poor judgment, or inhibition in SAH survivors. (JINS, 2006, 12, 697–706.)

Alzheimer's disease (AD) is a common, devastating form of dementia. With the advent of promising symptomatic treatment, the importance of recognizing AD at its very earliest stages has increased. We review the extant neuropsychological and neuroimaging literature on preclinical AD, focusing on longitudinal studies of initially nondemented individuals and cross-sectional investigations comparing at-risk with normal individuals. We systematically reviewed 91 studies of neuropsychological functioning, structural neuroimaging, or functional neuroimaging in preclinical AD. The neuropsychological studies indicated that preclinical AD might be characterized by subtle deficits in a broad range of neuropsychological domains, particularly in attention, learning and memory, executive functioning, processing speed, and language. Recent findings from neuroimaging research suggest that volume loss and cerebral blood flow or metabolic changes, particularly in the temporal lobe, may be detected before the onset of dementia. There exist several markers of a preclinical period of AD, in which specific cognitive and biochemical changes precede the clinical manifestations. The preclinical indicators of AD reflect early compromise of generalized brain integrity and temporal lobe functioning in particular. (JINS, 2006, 12, 707–735.)

The relation of body side of motor symptom onset in Parkinson's disease (PD) to memory measures associated with hemispheric dominance was examined. Fourteen patients with right body side motor symptom onset (RPD, inferred left hemisphere dysfunction) and 16 patients with left side onset (LPD, right hemisphere dysfunction) were administered measures of verbal (Hopkins Verbal Learning Test-Revised) and visual memory (Brief Visual Memory Test-Revised), that require similar task demands and are associated with left or right hemisphere dominance, respectively. The LPD group demonstrated poorer visual than verbal memory, both within group and in comparison to the RPD group. By contrast, the RPD group showed poorer verbal than visual memory within group. These findings suggest that side of motor symptom onset is associated with asymmetrical memory dysfunction (JINS, 2006, 12, 736–740.)

Persistent chaotic feeding behavior (i.e., bingeing and purging), despite consequent adverse health and psychosocial consequences, is central to the definition and diagnosis of bulimia nervosa (BN). Repeatedly choosing immediate short-term gratification when long-term consequences are deleterious may reflect deficits in decision-making ability. However, to date, there has been no systematic examination of decision-making ability in individuals diagnosed with BN. In the present study, 20 undergraduate women with minimal bulimic symptoms (Control Group) and 20 with a diagnosis of BN (BN Group) were administered the Iowa Gambling Task (GT). Results indicated that the BN Group performed significantly worse on the GT in comparison to the Control Group and GT performance was negatively correlated with bulimic symptomatology. The presence of BN symptoms also predicted GT performance above and beyond demographic variables and depressive symptoms. These findings provide evidence for the presence of decision-making deficits in individuals with BN (JINS, 2006, 12, 741–745.)

Memory performance in obsessive–compulsive disorder (OCD) is discussed as a pathogenetic risk factor for the emergence of OCD, particularly checking compulsions. At present, however, findings are mixed and little is known about memory performance in tasks relevant to everyday functioning in patients with OCD. For the present study, memory performance was assessed in 31 patients diagnosed with OCD and 33 healthy controls with the Rivermead Behavioural Memory Test (RBMT), which covers a wide range of verbal and nonverbal memory components as well as prospective memory. OCD patients performed comparably to healthy controls on the memory task for verbal, nonverbal, and prospective memory (p > .1). According to norm values, memory performance was unimpaired in most OCD patients. The present findings further challenge a broad account of the “memory deficit” hypothesis of OCD and compulsive checking, respectively (JINS, 2006, 12, 746–749.)

Verbal learning and the organization of memory in patients with schizophrenia or schizotypal disorder were compared with normal subjects. Three indices of memory organization (semantic clustering, serial clustering, and subjective clustering) were calculated from participants' responses on the Japanese Verbal Learning Test. Schizophrenic and schizotypal patients showed similar decrements in semantic organization compared with normal subjects. Neither patient group showed any effect of learning on their use of semantic organization, although both groups recalled more items as the number of trials increased. These results suggest that impairment of memory organization is a common characteristic of schizophrenia spectrum disorders (JINS, 2006, 12, 750–754.)

Giovannetti and co-authors (Giovannetti et al., 2006) highlight the importance of measuring activities of daily living (ADL) and Instrumental activities of daily living (IADL) for the diagnosis of dementia. The method used, Naturalistic Action Test (NAT), is performance based. Study rationale was that “the relevance of diagnosis to everyday functioning has gone largely unexplored.” However, this statement seems to be invalid: cognitive impairment interfering with daily/social functioning is one of the DSM-IV dementia criteria. Secondly, many different ADL/IADL scales exist and are used in dementia research, including those that are performance based (Burns et al., 2004). Authors should have reviewed these scales more thoroughly and present a rationale for introducing a new one. NAT items model household chores and preparing a simple meal only. These activities are quite different from and perhaps easier to perform than using the telephone, handling finances, and similar instrumental activities. Simple activities or ADL may not be useful in differentiating dementia from normality, especially in the early stages of dementia.

The Cognitive Neuropsychology Laboratory at Temple University applies neuropsychological models of action processes to the study of everyday action (EA) in dementia. Our ultimate goals are to develop models of EA impairment and inform interventions that promote EA in the home. Our recent paper (Giovannetti et al., 2006b) was an initial step in this overarching plan. We examined differences in EA between participants with Alzheimer's disease (AD) versus Vascular dementia (VaD), two distinct neurocognitive syndromes (see Libon et al., 2004). The groups obtained comparable overall accomplishment scores, but VaD participants made more commissions and accomplished fewer steps when distractor objects were in the workspace. Thus, VaD participants demonstrated a different pattern of EA impairment than AD participants.

Fatigue as a Window to the Brain, John DeLuca (Ed.). 2005. Cambridge, MA: The MIT Press, 336 pp., $55.00 (HB).

Fatigue is ubiquitous and falls within the purview of several specialties, including neurology, psychiatry, neuropsychology, endocrinology, rheumatology, and immunology. As Simon Wessely points out in the Foreword of Fatigue as a Window to the Brain, fatigue has been virtually overlooked as an area of scientific study, because it is difficult to measure and, as a symptom, rarely aids in differential diagnosis. John DeLuca's edited book is part of the Issues in Clinical and Cognitive Neuropsychology series edited by Jordan Grafman. This is an ambitious book that examines the multidimensional and multifactorial nature of the neurobiology of central fatigue. This book advances the reader's understanding of the neural mechanisms of fatigue through review and integration of empirical data on fatigue and its cognitive correlates in neurological, medical, and psychiatric disorders.