Computerized Simple Reaction Time and Balance in Nondemented Parkinson's Patients.

BACKGROUND: Parkinson's disease (PD) patients are known to suffer from subtle cognitive and balance deficits from the early stages although they usually manifest in advanced stages. Postural instability (PI) has been correlated with slower information processing speed. Simple reaction time (SRT) tasks can be used to measure the speed of information processing. The main objective of this study was to examine the usefulness of SRT as a valid predictor of balance in PD, thus providing a simple and complementary assessment method. METHODS: This cross-sectional study included 52 PD patients without dementia who were evaluated for balance using the pull test (PT) maneuver and Biodex® limits of stability (LOS). In addition, a reaction time task was used to measure processing speed. Correlation and linear regression analyses were performed. RESULTS: The performance of SRT tasks was correlated with the evaluation of LOS% and PT, suggesting that the SRT may be a predictor of balance performance. Longer reaction time and poorer postural stability were also associated with disease duration but not with age. CONCLUSIONS: Poor performance in a simple reaction task can predict altered PI and can complement staging and evaluation in PD patients.

Melodic intonation therapy in post-stroke nonfluent aphasia: a randomized pilot trial.

OBJECTIVE:: To collect data to estimate the sample size of a definitive randomized controlled trial to evaluate the effects of Melodic Intonation Therapy in post-stroke nonfluent aphasia. DESIGN:: A randomized, crossover, interventional pilot trial. SETTING:: Departments of Neurology and Rehabilitation from a university general hospital. PARTICIPANTS:: Stroke survivors with post-stroke nonfluent aphasia. INTERVENTIONS:: Patients randomized to group 1 had treatment with Melodic Intonation Therapy first (12 sessions over six weeks) followed by no treatment; the patients in group 2 started active treatment between three and six months after their inclusion in the study, serving as waiting list controls for the first phase. MAIN MEASURES:: The Communicative Activity Log (CAL) questionnaire and the Boston Diagnostic Aphasia Examination (BDAE) were evaluated at baseline, and at six and 12 weeks. RESULTS:: Twenty patients were included. Four of the patients allocated to group 2 crossed over to group 1, receiving the treatment at first. Intention-to-treat analysis: after adjustment for baseline scores, the mean difference in the CAL evaluation from baseline in the treated group was 8.5 points (95% confidence interval (CI), 0.11-17.0; P = .043), with no significant change in any of the BDAE sections. Per-protocol analysis showed similar results with a clear treatment effect ( P = .043) on the CAL. CONCLUSION:: Melodic Intonation Therapy might have a positive effect on the communication skills of stroke survivors with nonfluent aphasia as measured by the CAL questionnaire. A full-scale trial with at least 27 patients per group is necessary to confirm these results.

Efficacy of cognitive rehabilitation of attention, executive functions, and working memory in psychotic disorders: A systematic review.

dies have postulated that it is the basis of the disease as evidenced by its independent and persistent quality and its relation to prognosis. Research on cognitive deficits in psychotic disorders has led to the development of intervention strategies for the cognitive rehabilitation of these patients. Attention, working memory, and executive functions are among the most widely affected functions and are closely related to the functionality of these patients. This work aims to study the effectiveness of cognitive rehabilitation targeting attention, executive functions, and working memory in people diagnosed with a psychotic disorder (mostly schizophrenia). An exhaustive search in PubMed and PsycINFO was conducted up to January 2016. All research papers that were included studied a therapeutic technique to improve one or more of the aforementioned functions in patients over age 16 years diagnosed with psychotic disorder. Studies with methodological diversity were included, which were afterwards organized by levels of evidence. Thirty-four papers were studied, from which we can conclude that cognitive rehabilitation of the aforementioned cognitive functions brings about improvements in cognition. As a result of the influence of cognitive rehabilitation on other variables such as social functioning and symptoms of the disease, the results are promising.

The contribution of depressive symptoms to slowness of information processing in relapsing remitting multiple sclerosis.

BACKGROUND: Slowness of information processing has been suggested as a fundamental factor modulating cognitive impairment in multiple sclerosis (MS). However, the contribution of depressive symptoms (DS) to slowness remains unclear. One of the most accepted hypotheses on the impact of depression on the general population suggests that depression interferes only with tasks requiring high cognitive demands. However, no studies have investigated if the same pattern occurs in MS. OBJECTIVE: The aim of this study was to determine the profile of the contribution of DS to slowness. METHODS: Four Reaction Time (RT) tasks requiring an increasing level of cognitive demands were administered to 35 relapsing remitting MS patients with DS, 33 MS patients without DS, 17 depressed non-MS patients and 27 controls. RESULTS: MS patients without DS obtained longer RTs than controls in all the tasks. On the contrary, depressed non-MS patients were slower than controls only in the most demanding task. Finally, MS patients with DS were slower than MS patients without DS not only in the most demanding task but also in the task requiring a lower level of cognitive demands. CONCLUSION: The contribution of DS to slowness depends on the level of cognitive demands. However, its impact on MS is more deleterious than on the general population.

New functional dissociations between prefrontal and parietal cortex during task switching: A combined fMRI and TMS study.

Preparatory control in task-switching has been suggested to rely upon a set of distributed regions within a frontoparietal network, with frontal and parietal cortical areas cooperating to implement switch-specific preparation processes. Although recent causal evidence using transcranial magnetic stimulation (TMS) have generally supported this model, alternative results from both functional neuroimaging and neurophysiological studies have questioned the switch-specific role of both frontal and parietal cortices. The aim of the present study was to clarify the involvement of prefrontal and parietal areas in preparatory cognitive control. With this purpose, an fMRI study was conducted to identify the brain areas activated during cue events in a task-switching paradigm, indicating whether to switch or to repeat among numerical tasks. Then, TMS was applied over the specific coordinates previously identified through fMRI, that is, the right inferior frontal gyrus (IFG) and right intraparietal sulcus (IPS). Results revealed that TMS over the right IFG disrupted performance in both switch and repeat trails in terms of delayed responses as compared to Sham condition. In contrast, TMS over the right IPS selectively interfered performance in switch trials. These findings support a multi-component model of executive control with the IFG being involved in more general switch-unspecific process such as the episodic retrieval of goals, and the IPS being related to the implementation of switch-specific preparation mechanisms for activating stimulus-response mappings. The results are discussed within the framework of contemporary hierarchical models of prefrontal cortex organization, suggesting that distinct prefrontal areas may carry out coordinated functions in preparatory control.

Verbal Fluency Tasks: Influence of Age, Gender, and Education and Normative Data for the Spanish Native Adult Population.

OBJECTIVE: Phonological and semantic verbal fluency (VF) tasks are frequently used to assess language and executive functions in both clinical and research settings. F, A, and S are the most commonly used letters in phonological tasks across languages and cultures. Unfortunately, the lack of norms for the native Spanish population for these letters, and for certain semantic categories such as "proper names," may lead to misinterpretation of scores due to demographic differences. The aim of the present study was to provide normative data for F, A, and S and for "proper names," "animals," and "fruits and vegetables" for the native Spanish population. METHOD: 257 healthy subjects took part in the study (ages: 17-100 years, 3-20 years of education). Correlation, multiple regression, and t-tests were used to select the most appropriate variables for stratification. RESULTS: Education was the best predictor of performance in all tasks, followed by age. Given that t-test results showed no differences related to gender, with the only exception of the semantic category "animals," this variable was not considered for stratification. Consequently, the data were stratified in two education levels (<13, ≥13 years of education) and in two age levels (<60, ≥60) within the low-educational level group. Mean, standard deviation, and percentile scores for each group are provided. CONCLUSIONS: The present norms provide a reference for clinicians assessing VF. This data may also facilitate comparisons with other normative studies in cross-cultural and cross-linguistic research.

Construct Validity of the Stroop Color-Word Test: Influence of Speed of Visual Search, Verbal Fluency, Working Memory, Cognitive Flexibility, and Conflict Monitoring.

OBJECTIVE: 85 years after the description of the Stroop interference effect, there is still a lack of consensus regarding the cognitive constructs underlying scores from standardized versions of the test. The present work aimed to clarify the cognitive mechanisms underlying direct (word-reading, color-naming, and color-word) and derived scores (interference, difference, ratio, and relative scores) from Golden's standardized version of the test. METHOD: After a comprehensive review of the literature, five cognitive processes were selected for analysis: speed of visual search, phonemic verbal fluency, working memory, cognitive flexibility, and conflict monitoring. These constructs were operationalized by scoring five cognitive tasks (WAIS-IV Digit Symbol, phonemic verbal fluency [letter A], WAIS-IV Digit Span, TMT B-A, and reaction times to the incongruent condition of a computerized Stroop task, respectively). About 83 healthy individuals (mean age = 25.2 years) participated in the study. Correlation and regression analyses were used to clarify the contribution of the five cognitive processes on the prediction of Stroop scores. RESULTS: Data analyses revealed that Stroop word-reading reflected speed of visual search. Stroop color-naming reflected working memory and speed of visual search. Stroop color-word reflected working memory, conflict monitoring, and speed of visual search. Whereas the interference score was predicted by both conflict monitoring and working memory, the ratio score (color-word divided by color-naming) was predicted by conflict monitoring alone. CONCLUSION: The present results will help neuropsychologists to interpret altered patient scores in terms of a failure of the cognitive mechanisms detailed here, benefitting from the solid background of preceding experimental work.

Components determining the slowness of information processing in parkinson's disease.

INTRODUCTION: Bradyphrenia is a key cognitive feature in Parkinson's disease (PD). There is no consensus on whether information processing speed is impaired or not beyond motor performance. OBJECTIVE: This study aims to explore which perceptual, motor, or cognitive components of information processing are involved in the slowdown affecting cognitive performance. METHODS: The study included 48 patients with PD (age: 63, 3 ± 8, 18; HY I-III; UPDRS 15,46 ± 7,76) and 53 healthy controls (age: 60,09 ± 12,83). Five reaction time (RT) tasks were administered to all participants. The average RT in each of the tasks and the percentage of correct answers were measured. Patients with PD were in "ON state" at the time of the evaluation. Perceptual, motor, and cognitive components were isolated by means of a series of ANCOVAs. RESULTS: As expected, the motor component was slowed down in patients with PD. Moreover, while patients with PD showed slower RT than controls in all tasks, differences between groups did not exponentially increase with the increasing task complexity. ANCOVA analyses also revealed that the perceptual and sustained alert component resulted to be slowed down, with no differences being found in any of the remaining isolated cognitive components (i.e., response strategy-inhibition, decisional, visual search, or interference control). CONCLUSIONS: The results revealed that slowness of information processing in PD was mainly associated with an impaired processing speed of the motor and perceptual-alertness components analyzed. The results may help designing new neurorehabilitation strategies, focusing on the improvement of perceptual and alertness mechanisms.

Cognitive deficits and clinical symptoms in patients with treatment-refractory obsessive-compulsive disorder: The role of slowness in information processing.

Patients with Obsessive-Compulsive Disorder (OCD) present neuropsychological deficits across different cognitive domains, especially in executive functioning and information processing speed. Some studies have even suggested that speed deficits may underlie poor neuropsychological performance. However, this hypothesis remains unanswered in both OCD general population and OCD refractory subgroup. In addition, it is not clear whether such deficits are secondary to the clinical symptoms or may constitute a primary deficit. The aim of this study was to explore the speed of processing hypothesis in treatment-refractory OCD patients, and to clarify to what extent slowness is related to psychopathological symptoms. Both clinical and neuropsychological examination was conducted to assess 39 OCD refractory patients candidates for neurosurgery and 39 healthy matched individuals. Principal component analysis revealed a three-component structure in the neuropsychological battery being used, including a speed of processing, working memory, and conflict monitoring components. Group comparisons revealed that OCD patients performed significantly worse than healthy individuals in speed measures, but no differences were found in executive tests not influenced by time. Correlation analyses revealed a lack of association between neuropsychological and clinical measures. The results suggest that treatment-refractory OCD patients exhibit a primary deficit in information processing speed independent of clinical symptoms.

Identifying Perceptual, Motor, and Cognitive Components Contributing to Slowness of Information Processing in Multiple Sclerosis with and without Depressive Symptoms.

Increasing findings suggest that different components of the stimulus-response pathway (perceptual, motor or cognitive) may account for slowed performance in Multiple Sclerosis (MS). It has also been reported that depressive symptoms (DS) exacerbate slowness in MS. However, no prior studies have explored the independent and joint impact of MS and DS on each of these components in a comprehensive manner. The objective of this work was to identify perceptual, motor, and cognitive components contributing to slowness in MS patients with and without DS. The study includes 33 Relapsing-Remitting MS patients with DS, 33 without DS, and 26 healthy controls. Five information processing components were isolated by means of ANCOVA analyses applied to five Reaction Time tasks. Perceptual, motor, and visual search components were slowed down in MS, as revealed by ANCOVA comparisons between patients without DS, and controls. Moreover, the compounding effect of MS and DS exacerbated deficits in the motor component, and slowed down the decisional component, as revealed by ANCOVA comparisons between patients with and without DS. DS seem to exacerbate slowness caused by MS in specific processing components. Identifying the effects of having MS and of having both MS and DS may have relevant implications when targeting cognitive and mood interventions.

Clinical Spanish norms of the Stroop test for traumatic brain injury and schizophrenia.

The Stroop Color-Word Test is a useful tool to evaluate executive attention and speed of processing. Recent studies have provided norms for different populations of healthy individuals to avoid misinterpretation of scores due to demographic and cultural differences. In addition, clinical norms may improve the assessment of cognitive dysfunction severity and its clinical course. Spanish normative data are provided for 158 closed traumatic brain injury (TBI) and 149 first-episode schizophrenia spectrum disorder (SCH) patients. A group of 285 Spanish healthy individuals (HC) was also considered for comparison purposes. Differences between groups were found in all Stroop scores with HC outperforming both clinical groups (p .3 in all cases). TBI patients scored lower than SCH patients in word-reading (p < .001 and d = .6), and color-naming conditions (p < .001 and d = .4), but not in the color-word condition (p = .34 and d = .03). However, SCH patients exhibited a higher interference effect as compared to TBI (p < .002 and d = .5). Three sets of norms stratified by age and education (HC), and by education (TBI and SCH) are presented for clinical use.