Search results for "Memory"
showing 10 items of 2004 documents
Frontoparietal cortex and cerebellum contribution to the update of actual and mental motor performance during the day
2016
AbstractActual and imagined movement speed increases from early morning until mid-afternoon. Here, we investigated the neural correlates of these daily changes. Fifteen subjects performed actual and imagined right finger opposition movement sequences at 8 am and 2 pm. Both actual and imagined movements were significantly faster at 2 pm than 8 am. In the morning, actual movements significantly activated the left primary somatosensory and motor areas, and bilaterally the cerebellum; in the afternoon activations were similar but reduced. Contrast analysis revealed greater activity in the cerebellum, the left primary sensorimotor cortex and parietal lobe in the morning than in the afternoon. Im…
Domain-specific trends in cognitive impairment after acute ischaemic stroke.
2012
Little is known about the pattern of subacute cognitive domain impairments after ischaemic stroke, nor the temporal evolution of such impairments. Our objective was to investigate the pattern of cognitive impairment in different neuropsychological domains up to a year after ischaemic stroke. We included prospectively collected data from an observational database of stroke patients at the National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. Patients were categorised into temporal groups according to the time between the index stroke and neuropsychological profiling. The prevalence of impairment in different cognitive domains was then compared between these categories. …
Cerebral Microbleeds and Long-Term Cognitive Outcome: Longitudinal Cohort Study of Stroke Clinic Patients
2012
<i>Background:</i> Vascular cognitive impairment causes significant disability in the elderly and is common following ischaemic stroke. Although the underlying mechanisms and prognostic factors remain unclear, small vessel diseases are known to contribute. Cerebral microbleeds (CMBs) are a magnetic resonance imaging (MRI) manifestation of small vessel diseases and may contribute to vascular cognitive impairment, particularly frontal-executive functions. We hypothesized that baseline CMBs would predict long-term cognitive outcome, specifically frontal-executive function. <i>Methods:</i> A cohort of consecutive patients found to have CMBs when first referred to a strok…
Different interference effects in musicians and a control group.
2006
In the present study musicians and normal control subjects performed an S1-S2 pitch comparison task, which included the presentation of intervening tones during the retention interval. The time for encoding and storing the pitch of S1 was varied between 200 and 1,500 ms by changing the pause between the S1 offset and the onset of the intervening tones. Although musicians outperformed the control group with longer pauses after the S1 offset, this advantage was relatively small with shorter pauses. These results suggest that the advantage of musicians in storing auditory information is not solely due to their superior encoding of information but also to improved working memory operations.
Exploring recollection and familiarity impairments in Parkinson’s disease
2014
There is conflicting evidence on whether patients diagnosed with Parkinson's disease (PD) have cognitive deficits associated with episodic memory and particularly with recognition memory. The aim of the present study was to explore whether PD patients exhibit deficits in recollection and familiarity, the two processes involved in recognition. A sample of young healthy participants (22) was tested to verify that the experimental tasks were useful estimators of recognition processes. Two further samples ¿ one of elderly controls (16) and one of PD patients (20) ¿ were the main focus of this research. All participants were exposed to an associative recognition task aimed at estimating recollec…
Changing associations between cognitive impairment and imaging in multiple sclerosis as the disease progresses.
2013
The authors explored cross-sectional associations between MRI parameters (lesion metrics, brain volumes, magnetization transfer ratio histograms, and metabolite concentrations) and cognition in 61 patients who experienced clinically-isolated syndromes (CIS) 7 years earlier. IQ decline and poorer overall cognition were associated with T2 white-matter lesions, and slow information-processing with both T2 lesions and gray-matter atrophy. In a previous study of the same cohort, gray-matter atrophy measured shortly after CIS failed to predict development of cognitive impairment years later. Our findings suggest that gray-matter pathology, reflected by atrophy measurements, becomes increasingly i…
Monitoring cognitive changes: Psychometric properties of six cognitive tests
2004
Objectives. Repeated neuropsychological assessments are often used to monitor change in cognitive functioning over time. Thus, knowledge about the reliability and stability of neuropsychological tests and the effects of age and IQ is of paramount importance. In this study we document, for six cognitive tests: test-retest reliabilities, practice effects, reliable change (RC) indices corrected for practice, and the impact of premorbid IQ and age. Design. A sample of 188 normal adults (aged 40-70 years) were administered, on two occasions, one or more of the following tests: the Graded Naming Test (GNT), the Silhouettes Test, two tests of verbal fluency, the Modified Wisconsin Card Sorting Tes…
Neurocognitive Impairment in Bipolar Patients With and Without History of Psychosis
2008
Objective: Little is known regarding the impact of psychotic symptoms on the cognitive functioning of bipolar patients. Findings from previous reports are controversial and mainly focused on current psychotic symptoms. The main aim of this study was to ascertain whether the history of psychotic symptoms was associated with greater cognitive impairment in euthymic bipolar patients. Method: Sixty-five euthymic bipolar disorder patients (DSM-IV criteria; 35 with a history of psychotic symptoms and 30 without such a history) were assessed through a neuropsychological battery targeting attention, psychomotor speed, verbal memory, and executive functions. Thirty-five healthy controls were also in…
Brief cognitive assessment instruments in schizophrenia and bipolar patients, and healthy control subjects: A comparison study between the Brief Cogn…
2011
Cognitive impairment in schizophrenia and psychosis is ubiquitous and acknowledged as a core feature of clinical expression, pathophysiology, and prediction of functioning. However, assessment of cognitive functioning is excessively time-consuming in routine practice, and brief cognitive instruments specific to psychosis would be of value. Two screening tools have recently been created to address this issue, i.e., the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) and the Screen for Cognitive Impairment in Psychiatry (SCIP). The aim of this research was to examine the comparative validity of these two brief instruments in relation to a global cognitive score. 161 patients with p…
Bipolar I patients with and without a history of psychotic symptoms: do they differ in their cognitive functioning?
2007
Abstract Recently, many reports have consistently demonstrated cognitive deficits in patients with bipolar disorder (BD), but their relationship with symptomatology, specifically psychotic symptoms, remains unclear. Our main hypothesis was that a history of hallucinations and/or delusions in the course of BD-I is associated with severe cognitive deficits. We investigated several cognitive functions (memory, attention, verbal fluency and executive functions) in 18 BD-I patients with a history of psychotic symptoms (HPS+), 17 BD-I patients without a history of psychotic symptoms (HPS−), 33 schizophrenic patients and 26 healthy control subjects. Both groups of BD-I patients were more impaired …