Patterns Of Cognitive Performance Research Articles

Cognitive Profiles and Functional Connectivity in First-Episode Schizophrenia Spectrum Disorders - Linking Behavioral and Neuronal Data.

The character of cognitive deficit in schizophrenia is not clear due to the heterogeneity in research results. In heterogeneous conditions, the cluster solution allows the classification of individuals based on profiles. Our aim was to examine the cognitive profiles of first-episode schizophrenia spectrum disorder (FES) subjects based on cluster analysis, and to correlate these profiles with clinical variables and resting state brain connectivity, as measured with magnetic resonance imaging. A total of 67 FES subjects were assessed with a neuropsychological test battery and on clinical variables. The results of the cognitive domains were cluster analyzed. In addition, functional connectivity was calculated using ROI-to-ROI analysis with four groups: Three groups were defined based on the cluster analysis of cognitive performance and a control group with a normal cognitive performance. The connectivity was compared between the patient clusters and controls. We found different cognitive profiles based on three clusters: Cluster 1: decline in the attention, working memory/flexibility, and verbal memory domains. Cluster 2: decline in the verbal memory domain and above average performance in the attention domain. Cluster 3: generalized and severe deficit in all of the cognitive domains. FES diagnoses were distributed among all of the clusters. Cluster comparisons in neural connectivity also showed differences between the groups. Cluster 1 showed both hyperconnectivity between the cerebellum and precentral gyrus, the salience network (SN) (insula cortex), and fronto-parietal network (FPN) as well as between the PreCG and SN (insula cortex) and hypoconnectivity between the default mode network (DMN) and seeds of SN [insula and supramarginal gyrus (SMG)]; Cluster 2 showed hyperconnectivity between the DMN and cerebellum, SN (insula) and precentral gyrus, and FPN and IFG; Cluster 3 showed hypoconnectivity between the DMN and SN (insula) and SN (SMG) and pallidum. The cluster solution confirms the prevalence of a cognitive decline with different patterns of cognitive performance, and different levels of severity in FES. Moreover, separate behavioral cognitive subsets can be linked to patterns of brain functional connectivity.

(117) Characterizing Fibrofog in Daily Life: Ambulatory Cognitive Functioning in Adults with Fibromyalgia and Matched Controls

Most people with fibromyalgia (FM) report “fibrofog”, or cognitive dysfunction. To better characterize fibrofog in daily life, we conducted an ambulatory study of subjective and objective cognitive function in real-world settings in persons with FM and sex-, age-, and education-matched healthy controls (HC) to test whether: 1) people with FM demonstrate poorer cognitive function on ambulatory measures; 2) people with FM demonstrate a different diurnal pattern of cognitive function; and 3) subjective cognitive function corresponds more highly with objective cognitive measures in HC compared to FM. Participants (N=102; nFM=50; nHC=52) completed ecological momentary assessments of perceived cognitive function (perceived clarity and speed) on a numerical rating scale of 0-100 and cognitive tests of processing speed (Symbol Search) and working memory (Dot Matrix) via a smartphone app at 5 quasi-random times/day for 8 days. The FM group scored significantly lower than HC on measures of self-reported cognitive functioning, as well as on objective measures of processing speed and working memory. Results from multilevel models showed that both groups demonstrated similar diurnal patterns for objective measures of working memory, which was stable across the day, and objective processing speed, which was slowest at wake- and bed-times and fastest midday. For both groups, perceived cognitive dysfunction was highest upon waking and improved across the day; however, the HC group showed a significantly steeper rate of improvement. Perceived cognitive dysfunction corresponded only with processing speed, not working memory, and there were no group differences in these associations. Findings for ambulatory subjective and objective cognitive function in FM are generally consistent with findings from lab-based studies; the FM group demonstrated relatively worse cognitive functioning, but diurnal patterns and associations between objective/subjective functioning were similar to HC.

Cognitive Functioning in Late-life Depression: A Critical Review of Sociodemographic, Neurobiological, and Treatment Correlates

Both clinical and subthreshold depression in older adults are associated with cognitive dysfunction. This review summarizes the latest literature on patterns of cognitive functioning in late-life depression (LLD), including moderators of the relationship between depression and cognitive functioning and underlying neurobiological mechanisms. LLD is associated with cognitive dysfunction across multiple domains, particularly processing speed and executive functions. This relationship is moderated by demographic and clinical variables such as sex, race, age of onset, and severity of different symptom dimensions of depression. The impact of depression treatment on cognitive deficits in LLD differs across treatment approaches, but overall LLD is associated with persistent cognitive deficits after depression remission. Clarifying treatments with dual mood and cognitive benefits is an important area for future research. Our understanding of and treatment for cognitive deficits in LLD will also benefit from additional work that examines clinical and demographic contributions.

Patterns of cognitive function in middle-aged and elderly Chinese adults\u2014findings from the EMCOA study

BackgroundThe principal aim of this study was to demonstrate the gender-specific cognitive patterns among middle-aged and elderly Chinese adults, investigate the risk factors on global and domain-specific cognitive performance in men and women, respectively, and report demographically adjusted norms for cognitive tests.MethodsThe Effects and Mechanism of Cholesterol and Oxysterol on Alzheimer’s disease (EMCOA) study enrolled 4573 participants aged 50–70 years in three Chinese cities. All participants underwent an extensive neuropsychological test battery. Composite scores for specific domains were derived from principal component analysis (PCA). Multivariate linear regression models were used to determine gender-specific risk factors and demographically adjusted normative data.ResultsThree cognitive domains of verbal memory, attention/processing speed/executive function, and cognitive flexibility were extracted. A female advantage in verbal memory was observed regardless of age, whereas men tended to outperform women in global cognition and attention/processing speed/executive function. The effects of education on women were more substantial than men for general cognition and attention/processing speed/executive function. For all the cognitive tests, regression-based and demographically adjusted normative data were calculated.ConclusionsThere is a need for gender-specific intervention strategies for operationalizing cognitive impairment.Trial registrationEMCOA, ChiCTR-OOC-17011882. Retrospectively registered on 5 July 2017.

Neuropsychological phenotypes among men with and without HIV disease in the multicenter AIDS cohort study.

Mild forms of HIV-associated neurocognitive disorder (HAND) remain prevalent in the combination antiretroviral therapy (cART) era. This study's objective was to identify neuropsychological subgroups within the Multicenter AIDS Cohort Study (MACS) based on the participant-based latent structure of cognitive function and to identify factors associated with subgroups. The MACS is a four-site longitudinal study of the natural and treated history of HIV disease among gay and bisexual men. Using neuropsychological domain scores, we used a cluster variable selection algorithm to identify the optimal subset of domains with cluster information. Latent profile analysis was applied using scores from identified domains. Exploratory and posthoc analyses were conducted to identify factors associated with cluster membership and the drivers of the observed associations. Cluster variable selection identified all domains as containing cluster information except for Working Memory. A three-profile solution produced the best fit for the data. Profile 1 performed below average on all domains, Profile 2 performed average on executive functioning, motor, and speed and below average on learning and memory, Profile 3 performed at or above average across all domains. Several demographic, cognitive, and social factors were associated with profile membership; these associations were driven by differences between Profile 1 and the other profiles. There is an identifiable pattern of neuropsychological performance among MACS members determined by all domains except Working Memory. Neither HIV nor HIV-related biomarkers were related with cluster membership, consistent with other findings that cognitive performance patterns do not map directly onto HIV serostatus.

Reproducibility of Cognitive Profiles in Psychosis Using Cluster Analysis.

Cognitive dysfunction is a core symptom dimension that cuts across the psychoses. Recent findings support classification of patients along the cognitive dimension using cluster analysis; however, data-derived groupings may be highly determined by sampling characteristics and the measures used to derive the clusters, and so their interpretability must be established. We examined cognitive clusters in a cross-diagnostic sample of patients with psychosis and associations with clinical and functional outcomes. We then compared our findings to a previous report of cognitive clusters in a separate sample using a different cognitive battery. Participants with affective or non-affective psychosis (n=120) and healthy controls (n=31) were administered the MATRICS Consensus Cognitive Battery, and clinical and community functioning assessments. Cluster analyses were performed on cognitive variables, and clusters were compared on demographic, cognitive, and clinical measures. Results were compared to findings from our previous report. A four-cluster solution provided a good fit to the data; profiles included a neuropsychologically normal cluster, a globally impaired cluster, and two clusters of mixed profiles. Cognitive burden was associated with symptom severity and poorer community functioning. The patterns of cognitive performance by cluster were highly consistent with our previous findings. We found evidence of four cognitive subgroups of patients with psychosis, with cognitive profiles that map closely to those produced in our previous work. Clusters were associated with clinical and community variables and a measure of premorbid functioning, suggesting that they reflect meaningful groupings: replicable, and related to clinical presentation and functional outcomes. (JINS, 2018, 24, 382-390).

Cognitive Performance Patterns in Healthy Individuals with Substantia Nigra Hyperechogenicity and Early Parkinson's Disease.

Introduction: Hyperechogenicity of the substantia nigra (SN+) is a risk marker for Parkinson’s disease (PD) which can be detected before the diagnosis. In healthy individuals, SN+ has been associated with slight deficits in specific cognitive functions, suggesting cognitive impairment as a possible pre-diagnostic marker for PD. However, the pattern of cognitive deficits associated with SN+ has not yet been compared with those present in PD.Methods: Data of 262 healthy individuals with normal echogenicity (SN-) and 48 healthy individuals with SN+ were compared with 82 early stage PD patients using the “Consortium to Establish a Registry for Alzheimer’s disease” test battery. First, the test clusters (factors) were identified using a principal component analysis (PCA). Mean group performance of cognitive tests belonging to distinct factors, according to the PCA, and single subtest performances were compared using analyses of variance. Second, the number of individuals with abnormal cognitive performances (z-score < -1.0) were compared between groups.Results: Verbal memory, semantic and executive function, and praxis were identified as components of cognitive performances. The SN+ group performed significantly worse than the SN- group in tests assessing semantic and executive function, with a non-significant decrease in verbal memory. On the subtest level, individuals of the SN+ group scored significantly lower than the SN- group on the Boston Naming Test (BNT; p = 0.008). In all subtests, the percentages of PD patients with values below the cut-off for abnormal performance were higher than in the SN- group. Moreover, more individuals from the SN+ group scored below the cut-off in the BNT (SN- = 8.4%, SN+ = 20.8%, p = 0.01) and TMT-B (SN- = 6.9%, SN+ = 16.7%, p = 0.02), compared to the SN- group.Conclusion: This study confirms poorer performance of healthy individuals with SN+ compared to SN- in specific cognitive domains. However, against the SN- group, the cognitive profile of the SN+ group was not fully consistent with the profile of early PD patients. Our data argues that cognitive impairment associated with SN+ might differ slightly from that seen in early PD. Compensational mechanisms in the early phases of neurodegeneration, and the fact that only a subgroup of SN+ will develop PD, may partly explain these differences.

Computer-based tools for assessing micro-longitudinal patterns of cognitive function in older adults

Patterns of cognitive change over micro-longitudinal timescales (i.e., ranging from hours to days) are associated with a wide range of age-related health and functional outcomes. However, practical issues of conducting high-frequency assessments make investigations of micro-longitudinal cognition costly and burdensome to run. One way of addressing this is to develop cognitive assessments that can be performed by older adults, in their own homes, without a researcher being present. Here, we address the question of whether reliable and valid cognitive data can be collected over micro-longitudinal timescales using unsupervised cognitive tests.In study 1, 48 older adults completed two touchscreen cognitive tests, on three occasions, in controlled conditions, alongside a battery of standard tests of cognitive functions. In study 2, 40 older adults completed the same two computerized tasks on multiple occasions, over three separate week-long periods, in their own homes, without a researcher present. Here, the tasks were incorporated into a wider touchscreen system (Novel Assessment of Nutrition and Ageing (NANA)) developed to assess multiple domains of health and behavior. Standard tests of cognitive function were also administered prior to participants using the NANA system.Performance on the two “NANA” cognitive tasks showed convergent validity with, and similar levels of reliability to, the standard cognitive battery in both studies. Completion and accuracy rates were also very high. These results show that reliable and valid cognitive data can be collected from older adults using unsupervised computerized tests, thus affording new opportunities for the investigation of cognitive.

Magnetoencephalography Slow-Wave Detection in Patients with Mild Traumatic Brain Injury and Ongoing Symptoms Correlated with Long-Term Neuropsychological Outcome.

Mild traumatic brain injury (mTBI) is common in the United States, accounting for as many as 75-80% of all TBIs. It is recognized as a significant public health concern, but there are ongoing controversies regarding the etiology of persistent symptoms post-mTBI. This constellation of nonspecific symptoms is referred to as postconcussive syndrome (PCS). The present study combined results from magnetoencephalography (MEG) and cognitive assessment to examine group differences and relationships between brain activity and cognitive performance in 31 military and civilian individuals with a history of mTBI+PCS and 33 matched healthy control subjects. An operator-free analysis was used for MEG data to increase reliability of the technique. Subjects completed a comprehensive neuropsychological assessment, and measures of abnormal slow-wave activity from MEG were collected. Results demonstrated significant group differences on measures of executive functioning and processing speed. In addition, significant correlations between slow-wave activity on MEG and patterns of cognitive functioning were found in cortical areas, consistent with cognitive impairments on exams. Results provide more objective evidence that there may be subtle changes to the neurobiological integrity of the brain that can be detected by MEG. Further, these findings suggest that these abnormalities are associated with cognitive outcomes and may account, at least in part, for long-term PCS in those who have sustained an mTBI.

NEUROPSYCHOLOGICAL DIFFERENCES ACCORDING TO THE PRESENCE OF HIPPOCAMPAL LESIONS ON THE BRAIN: MRI IN TRANSIENT GLOBAL AMNESIA

Transient global amnesia (TGA) is an amnestic syndrome characterized by abrupt onset of recent memory impairment with preserved alertness, personal identity. Focal signal changes in the hippocampus on Diffusion weighted magnetic image (DWI) have been described in TGA. But the singal changes are not always shown on DWI and the pathophysiology of these lesions is still unclear. We aimed to investigate the neuropsychological differences in patients with TGA, and compare the cognitive feature according to the existence of the hippocampal lesion on the DWI. We reviewed the charts and neuropsychological tests of patients with TGA retrospectively from May 2012 to November 2013. We included 7 patients with Diffusion weighted magnetic image (DWI) and formal neuropsychological test in South Korea, MMSE and Seoul Neurolpsychological Screening Battery (SNSB). Diagnosis of TGA was made by the criteria of Caplan and Hodges. We divided the patients into two groups according to presence or absence of the hippocampal lesions on DWI, which was underwent with 48 to 72hours. (positive group vs. negative group) and compared cognitive pattern of patients between the two groups. Six out of 7 patients were women. The mean age was 55 years old and one patient experienced repeated attacks. All patients performed neuropsychological tests after clinical recovery from the attack within 7days. 4 patients (the positive group) showed high signal intensity lesion on the hippocampus (57%) : 2 on the right, 2 on the left. Mean scores of the MMSE in the total patients were 25.5 ±4.7. In the positive group, all 4 patients showed low performance in at least one cognitive domain, especially in the first delayed recall in the MMSE, and the score of Rey Complex Figure test (RCFT). In the negative group, 2 patients showed no cognitive decline in the neuropsychological test and the other one showed mildly low performance in attention respectively. We investigated the different pattern of cognitive performance according to the presence of hippocampal lesion on DWI. Although Clinical features last for one day, neurophsychological dysfunction persists longer in the positive group than negative group, that is to say, the patients with hippocampal lesions on the DWI have a tendency to show lower cognitive functions. Therefore the hippocampal lesion on the DWI could be a predictive value of lower cognitive function.

Patterns of Cognitive Performance in Subcortical Ischemic Vascular Disease (SIVD)

Subcortical ischemic vascular disease (SIVD) is characterized by extensive white-matter lesions and lacunar infarcts in deep gray matter. The aim of this study was to investigate patterns of cognitive impairment in patients with SIVD. In a retrospective analysis, the authors compared the cognitive performance of 58 patients meeting MRI-defined criteria for SIVD (26 women; 47.3%) with age- and gender-matched control subjects. SIVD patients showed impairments in measures of verbal fluency, verbal memory, speed of cognitive processing, and divided attention. There were no significant differences in constructional praxis, figurative memory, verbal recognition memory, or semantic processing.

Vicious minds

While there is now considerable anxiety about whether the psychological theory presupposed by virtue ethics is empirically sustainable, analogous issues have received little attention in the virtue epistemology literature. This paper argues that virtue epistemology encounters challenges reminiscent of those recently encountered by virtue ethics: just as seemingly trivial variation in context provokes unsettling variation in patterns of moral behavior, trivial variation in context elicits unsettling variation in patterns of cognitive functioning. Insofar as reliability is a condition on epistemic virtue, we have reason to doubt that human beings possess the cognitive materials required for epistemic virtue, and thereby reason to think that virtue epistemology is threatened by skepticism. We conclude that while virtue epistemology has resources for addressing this challenge, exploiting these resources forces tradeoffs between empirical and normative adequacy

Frontal and posterior subtypes of neuropsychological deficit in Parkinson's disease.

Mild cognitive impairment in Parkinson's disease (PD) is heterogeneous in regard to affected domains. Although patterns of cognitive performance that may predict later dementia are as yet undetermined, posterior- versus frontal-type assessments show promise for differential predictive value. The present study included 70 individuals: 42 with idiopathic PD without dementia and 28 age- and education-matched healthy control adults (HC). Participants completed assessments of cognition with emphasis on tests that are sensitive to frontal and posterior deficits. PD patients were classified into cognitive subgroups and the subgroups were compared on demographic and disease variables. Individual performance across neuropsychological tests was evaluated for the PD group. Patients with PD performed more poorly than HC on several measures of cognition, and they were classified into frontal (12), posterior (3), both (10) and neither subgroups (17), the latter two in reference to frontal- and posterior-type deficits. The neither subgroup was distinguished by less motor impairment than the both subgroup, but the four subgroups did not otherwise differ on demographic or disease variables. Across patients, the tests most sensitive to cognitive impairment included measures of attention and executive functioning (frontal-type tests). Examination of individual test performance for PD revealed substantial heterogeneity across tests with respect to number and severity of deficits. The current study provides insight into which commonly used neuropsychological tests are most sensitive to cognitive deficits (strictly defined) in a nondemented, well characterized PD sample, and into the relation of cognitive subgroups to demographic and disease-specific variables.

Cognition in nephropathic cystinosis: pattern of expression in heterozygous carriers.

Individuals with cystinosis exhibit specific cognitive deficits in visual spatial function. The purpose of the current study was to examine if obligate heterozygotes of the CTNS mutation have the same pattern of cognitive functioning seen in homozygotes, namely aberrant visual-spatial functioning against a background of relatively intact visual-perceptual functioning and overall cognitive ability. Study participants were 254 adults (100 heterozygotes and 154 controls), ages 17 years 10 months through 74 years 9 months. Tests of intelligence, visual perceptual, and visual spatial functioning were administered. Our results showed that cystinosis heterozygotes demonstrated intelligence within the normal range, and performed similarly to controls on tests of visual-perceptual ability. In contrast, the heterozygotes performed significantly more poorly on each of the visual-spatial tests when compared to controls. Obligate heterozygotes for the CTNS mutation display a similar pattern of visual processing decrements as do individuals with cystinosis. Namely, carriers demonstrate relative weaknesses in visual-spatial processing, while maintaining normal visual perceptual ability and intelligence in the normal range. The visual spatial decrements in heterozygotes were not as marked as those found in individuals with cystinosis, suggesting a gene dosing effect. This study provides an impetus for other studies of gene-behavior relationships in recessive disorders, and may stimulate further interest in the role of aberrant genes on "individual differences" in behavior.

P01-412 - Different patterns of cognitive functioning and their connection with clinical symptom severity in patients with bipolar disorder and schizophrenia

IntroductionCognitive deficits are core features of schizophrenia and they are also observed in bipolar disorder with psychotic episodes. Clinical symptom severity and cognitive performance might be related and they both affect everyday functioning.ObjectivesTo examine the patterns of cognition and clinical symptoms in patients with psychosis spectrum disorders.AimsTo learn how clinical symptom severity affect the cognitive performance in the two patient groups.MethodsTwenty-five bipolar and 40 schizophrenic patients were enrolled in the study. The following measures were used to assess the cognitive performance: Digit Span Task, Corsi Blocks Task, Tower of Hanoi Task, Visual Patterns Test, Letter and Category Fluency Tasks, Wisconsin Card Sorting Test. The Positive and Negative Syndrome Scale (PANSS) was also administered. The two groups were compared with Mann-Whitney test; the connections between clinical scales and cognitive measures were investigated through partial correlation.ResultsThe bipolar patients showed better performance on the majority of the cognitive tasks. The schizophrenic group had higher scores on all subscales of the PANSS (p &lt; 0.016). In the bipolar group only the Negative scale of the PANSS was correlated with the backwards task of the Corsi Blocks (p = 0.022 r = −0.584). The cognitive performance of the schizophrenic patients was more related to the clinical symptoms.ConclusionsOur results are in accordance with the notion that clinical symptoms are correlated to cognitive performance. Improving working memory processes might ease the coping with everyday difficulties caused by the symptoms, so this should be considered during the treatment of these patients.

Mapping facets of alexithymia to executive dysfunction in daily life

Alexithymia refers to a cluster of emotion processing weaknesses. Etiological theories suggest frontal lobe impairment, which implicates corresponding executive dysfunction. Although some studies have identified cognitive deficits in alexithymia, no study has systematically investigated executive functioning in this population while simultaneously deconstructing alexithymia and related constructs into empirically-derived dimensions. In this study, 104 adults completed self-report measures of alexithymia, emotional intelligence, and mood awareness as well as an ecologically-sensitive measure of discrete executive functions in daily life. Principal components analysis revealed two latent alexithymia factors: emotional clarity (EC) and emotional monitoring (EM). Analyses revealed that low-EC participants performed worse than high-EC participants across multiple executive function domains, including behavioral initiation/inhibition, set-shifting, self-monitoring, working memory, error recognition, and ability to plan and organize. No relationship was found between EM and patterns of cognitive performance. These data highlight the need to decompose alexithymia into discrete facets and suggest that executive dysfunction is related to lack of emotional clarity specifically rather than alexithymia broadly.

Attentional networks in euthymic patients with unipolar depression

The capacity to focus and concentrate or to direct attention supports many aspects of cognitive functioning including short-term memory and higher-level cognitive functions. The purpose was to assess attentional networks in euthymic patients with unipolar depression using the Attentional Network Test (ANT). We investigated performance of attention by virtue of ANT during remission from unipolar depressive disorder and tested a hypothesis that there are no differences between outpatient group (euthymic patients, N=32) and matched controls in attentional variables, the relationship of attentional networks and everyday cognitive failures. No differences between the groups in attentional networks were found and no relationship between attentional networks and cognitive failures was found. One assessment during remission could be insufficient to recognize long-term pattern of cognitive functions. These data show non-impaired attentional networks possibly explained by sufficient level of remission and ameliorated influence of high education on cognition.

Is ApoE ε4 Associated with Cognitive Functioning in African Americans Diagnosed with Alzheimer Disease? An Exploratory Study

The effect of the apolipoprotein epsilon4 allele (ApoE epsilon4) on cognitive performance in patients with probable Alzheimer disease (AD) has been studied in primarily Caucasian samples. The aim of this exploratory study was to examine whether the presence of ApoE epsilon4 is associated with cognitive performance in African American AD patients. A cross-sectional, retrospective design was used to address the study objective. Data were extracted from the records of 65 African American patients who participated in the National Institutes of Health-National Institute on Aging (NIH-NIA) Emory University Alzheimer Disease Center Registry. Inclusion criteria were a clinical diagnosis of probable AD, cognitive testing using the Mattis Dementia Rating Scale and the Consortium to Establish a Registry for Alzheimer Disease (CERAD) neuropsychological battery, and ApoE genotyping. Seventy percent of the patients were ApoE epsilon4 positive. Multiple regression analyses indicated that ApoE epsilon4 was significantly associated with poorer design copying (CERAD Constructional Praxis subtest), but other significant relationships were not observed between positive epsilon4 status and cognitive performance. These preliminary findings suggest that the ApoE epsilon4 allele is not strongly associated with a particular pattern of cognitive functioning in African Americans once they are diagnosed with AD. However, these findings require replication in a large prospectively recruited and population-based sample of African American AD patients before firm conclusions can be reached.

Cognitive dysfunction in primary progressive multiple sclerosis: a neuropsychological and MRI study

Although cognitive dysfunction is known to occur in multiple sclerosis (MS), only few studies have reported cognitive performance in patients with primary progressive MS (PPMS). To find out the pattern of cognitive performance in PPMS, 28 PPMS patients underwent an extensive battery of neuropsychological tests. The results were compared to those of healthy controls (n = 20) and patients with secondary progressive MS (SPMS, n = 28). Furthermore, the results of neuropsychological tests in PPMS were correlated to magnetic resonance imaging findings. Our study showed that the PPMS patients have deficits in several cognitive domains when compared to age-matched and education-matched controls, but the cognitive impairment in the PPMS and SPMS patients appeared to be similar. Cognitive deficits in PPMS patients correlated with diffuse brain lesion, T1- and T2-lesion load, but no correlations were found with atrophy.

Early Birds and Night Owls

In humans, peaks and troughs in alertness and cognitive performance partly depend on the timing of daily activities. Using brain imaging from the extreme ends of the spectrum of individuals whose performance is better in the mornings to those who do best in the evenings, Schmidt et al. (p. [516][1]) found that after more than 10 hours of wakefulness, morning types had less activity in brain areas linked to attention compared with evening types. Moreover, morning types felt sleepier and tended to perform slower on psychomotor vigilance tasks. It seems getting the balance of sleep at the right time is important for regulating the daily pattern of cognitive performance. [1]: /lookup/doi/10.1126/science.1167337