Cognitive and Behavioral Neurology最新文献

Background: Whether the effect of switch probability on switch and mixing costs is explained by an activation or preparation account is unclear.

Objective: To investigate the account of the effect of switch probability on switch and mixing costs.

Method: We used a cued task-switching paradigm with three switch probabilities (high, 75%; medium, 50%; and low, 25%) with 19 healthy young adults and recorded the cue- and target-locked event-related potentials (ERPs) and behavioral performance. The task included switch and stay trials under high, medium, and low switch conditions, as well as pure trials.

Results: There was no significant difference in reaction time (RT) in switch and mixing costs between the high and medium switch conditions. The RT in switch and mixing costs in the high and medium switch conditions was significantly less and more than in the low switch condition, respectively. The cue-locked ERPs revealed significant effects on mixing costs (stay - pure) that were cue early frontal positivity (260-300 ms) in the high and medium switch conditions, and on switch costs (switch - stay) that were cue early central positivity (240-260 ms) in the low switch condition. Moreover, the target-locked ERPs of the mixing costs revealed significant effects on mixing costs that were target P3b (440-540 ms) in all three switch conditions, and on switch costs that were target P3b in the medium and low switch conditions.

Conclusion: The effect of switch probability on switch and mixing costs is explained by the activation account.

Background: Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic small-vessel disease that is characterized by a wide range of neurologic and neuropsychological impairments. Constructional impairments have been reported in some cases but have never been assessed systematically.

Objective: To evaluate constructional abilities and their cognitive and neural correlates in nondemented individuals with CADASIL.

Method: Thirty individuals with CADASIL who were not affected by clinically relevant cognitive deterioration and 30 healthy controls (HC) underwent an extensive cognitive assessment and paper-and-pencil visuoconstructional tasks in order to detect constructional impairments. Performance on the visuoconstructional tasks was correlated with the cognitive assessment scores and with quantitative indices of regional gray matter atrophy (obtained via FreeSurfer image analysis) and white matter involvement.

Results: The individuals with CADASIL achieved significantly lower scores on the cognitive assessment compared with the HC. Poor visuoconstructional abilities were observed in seven (23.3%) of the individuals with CADASIL when performing the copy drawing task and in nine (30%) when performing the Rey Complex Figure Test. Logistic regression revealed that visuoconstructional impairments were significantly associated with scores on the Frontal Assessment Battery and the Attentional Matrices Test. Morphometric results revealed that scores on the visuoconstructional tasks were related to gray matter atrophy of the left frontal lobe and right parietal lobe.

Conclusion: Impairments on visuoconstructional tasks are quite common in individuals with CADASIL, even in the lack of clinically relevant cognitive deterioration, and are critically related to frontal and parietal atrophy.

Background: The Miro Health Mobile Assessment Platform consists of self-administered neurobehavioral and cognitive assessments that measure behaviors typically measured by specialized clinicians.

Objective: To evaluate the Miro Health Mobile Assessment Platform's concurrent validity, test-retest reliability, and mild cognitive impairment (MCI) classification performance.

Method: Sixty study participants were evaluated with Miro Health version V.2. Healthy controls (HC), amnestic MCI (aMCI), and nonamnestic MCI (naMCI) ages 64-85 were evaluated with version V.3. Additional participants were recruited at Johns Hopkins Hospital to represent clinic patients, with wider ranges of age and diagnosis. In all, 90 HC, 21 aMCI, 17 naMCI, and 15 other cases were evaluated with V.3. Concurrent validity of the Miro Health variables and legacy neuropsychological test scores was assessed with Spearman correlations. Reliability was quantified with the scores' intraclass correlations. A machine-learning algorithm combined Miro Health variable scores into a Risk score to differentiate HC from MCI or MCI subtypes.

Results: In HC, correlations of Miro Health variables with legacy test scores ranged 0.27-0.68. Test-retest reliabilities ranged 0.25-0.79, with minimal learning effects. The Risk score differentiated individuals with aMCI from HC with an area under the receiver operator curve (AUROC) of 0.97; naMCI from HC with an AUROC of 0.80; combined MCI from HC with an AUROC of 0.89; and aMCI from naMCI with an AUROC of 0.83.

Conclusion: The Miro Health Mobile Assessment Platform provides valid and reliable assessment of neurobehavioral and cognitive status, effectively distinguishes between HC and MCI, and differentiates aMCI from naMCI.

Background: Semantic category fluency is a widely used task involving language, memory, and executive function. Previous studies of bilingual semantic fluency have shown only small differences between languages. Graph theory analyzes complex relationships in networks, including node and edge number, clustering coefficient, average path length, average number of direct neighbors, and scale-free and small-world properties.

Objective: To shed light on whether the underlying neural processes involved in semantic category fluency testing yield substantially different networks in different languages.

Method: We compared languages and methods using both network analysis and conventional analysis of word production. We administered the animal naming task to 51 Russian-English bilinguals in each language. We constructed network graphs using three methods: (a) simple association of unique co-occurring neighbors, (b) corrected associations between consecutive words occurring beyond chance, and (c) a network community approach using planar maximally filtered graphs. We compared the resultant network analytics as well as their scale-free and small-world properties.

Results: Participants produced more words in Russian than in English. Small-worldness metrics were variable between Russian and English but were consistent across the three graph theory analytical methods.

Conclusion: The networks had similar graph theory properties in both languages. The optimal methodology for creating networks from semantic category fluency remains to be determined.

Microarray-based techniques are an important testing method in etiological studies of intellectual disability and autism spectrum disorder. Interstitial deletion in the p11-p12 region of chromosome 10 is rare, having been reported in just 12 cases to date. Intellectual disability associated with the WAC gene in this region is referred to as DeSanto-Shinawi syndrome . Although all individuals with p11-p12 region of chromosome 10 deletion share a common phenotype involving intellectual disability and dysmorphic features, individuals with DeSanto-Shinawi syndrome usually do not experience the cardiac and neurologic abnormalities or cryptorchidism associated with a 10p11-p12 deletion. With this case report, we aim to expand the phenotypic spectrum of 10p11-p12 deletion. Our patient was a 9-year-old boy with intellectual disability, autism symptoms, dysmorphic features, and behavioral abnormalities. He had no cardiac problems or neurologic symptoms such as hypotonia, feeding difficulties, or seizures. However, he presented cryptorchidism in addition to symptoms that are consistent with DeSanto-Shinawi syndrome. Array comparative genomic hybridization of genomic DNA isolated from a peripheral blood sample revealed a heterozygous deletion in 10p11.23-p12.1, which contains the WAC gene. We discuss our case in the context of a literature review of candidate genes. It is still difficult to establish genotype-phenotype correlations for neurologic, cardiac, and visual symptoms, and cryptorchidism, in individuals with a 10p11-p12 deletion. As more individuals are diagnosed with deletion in this chromosomal region, the associated phenotypes will become clearer.

Background: Individuals with probable Alzheimer disease (AD) may perform below cutoffs on traditional, memory-based performance validity tests. Previous studies have found success using event-related potentials (ERPs) to detect feigned neurocognitive impairment in younger populations.

Objective: To evaluate the utility of an auditory oddball task in conjunction with the P3b peak amplitude to distinguish probable AD from simulated dementia.

Method: Twenty individuals with probable AD and 20 older healthy controls (HC) underwent an ERP auditory oddball protocol and the Test of Memory Malingering (TOMM). The HC were asked to perform honestly for one condition and to simulate dementia for the other. The individuals with probable AD were asked to perform honestly. The P3b peak amplitude and button press accuracy were collected from each participant and were analyzed to determine their effectiveness in detecting performance validity.

Results: The P3b peak amplitude remained stable regardless of behavioral condition in the HC group. When combined with the TOMM Trial 2 score, the P3b peak amplitude further improved the ability to correctly differentiate individuals with probable AD from HC simulating dementia with 100% sensitivity and 90% specificity.

Conclusion: The P3b peak amplitude was found to be an effective physiologic measure of cognitive impairment in individuals with probable AD compared with HC simulating dementia. When combined with the TOMM Trial 2 score, the P3b peak amplitude served as a promising performance validity measure for differentiating individuals with probable AD from HC simulating dementia.

Background: In contrast to myotonic dystrophy type 1, the cognitive and radiologic profile of myotonic dystrophy type 2 (DM2) is relatively poorly characterized.

Objective: To conduct a pilot study to systematically evaluate cognitive and radiologic features in a cohort of Greek individuals with DM2.

Method: Eleven genetically confirmed individuals with DM2 and 26 age- and education-matched healthy controls were administered the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (ECAS) to screen for impairment in multiple cognitive domains. MRI data were evaluated by morphometric analyses to identify disease-specific gray and white matter alterations. The following statistical thresholds were used for cognitive comparisons: PFDR < 0.05 and Bayes factor (BF 10 ) >10.

Results: The DM2 group exhibited cognitive impairment (ECAS Total score; PFDR = 0.001; BF 10 = 108.887), which was dominated by executive impairment ( PFDR = 0.003; BF 10 = 25.330). A trend toward verbal fluency impairment was also identified. No significant impairments in memory, language, or visuospatial function were captured. The analysis of subscores revealed severe impairments in social cognition and alternation. Voxel-based morphometry identified widespread frontal, occipital, and subcortical gray matter atrophy, including the left superior medial frontal gyrus, right medial orbitofrontal gyrus, right operculum, right precuneus, bilateral fusiform gyri, and bilateral thalami.

Conclusion: DM2 may be associated with multifocal cortical and thalamic atrophy, which is likely to underpin the range of cognitive manifestations mostly characterized by executive impairment and specifically by impaired social cognition.