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Biomedical subjects

R Portin

Publications and source records attributed to R Portin.

At least 19 recordsLinked to original sources
PubMed1999

Sematic memory deficit in multiple sclerosis; impaired understanding of conceptual meanings.

The aim of the present study was to determine whether a cognitive decline, related to multiple sclerosis (MS), also involves deficits in semantic memory. Semantic memory function was evaluated by studying the conscious understanding of conceptual meanings. A group of MS patients with cognitive decline was presented with four tasks concerning concepts, their attributes and relationships to other concepts. The tasks were designed to measure spontaneous, cued and recognition performance separately. The patients had difficulties in understanding conceptual meanings. Easing the retrieval demands of the tasks did not help them to improve their performance which was poorer than the control group's on every task used. The results indicate a retrieval deficit combined with an underlying storage deficit in the semantic memory of MS patients with cognitive decline.

Concept Formation↗
PubMed1998

Automatic influences of memory in Alzheimer's disease.

Automatic and controlled influences of memory were examined in 12 patients with early Alzheimer's disease (AD) and 12 control subjects. The subjects studied a list of words and then received three-letter word stems in three different retrieval tasks. In an indirect memory task (word-stem completion priming), they were asked to produce the first word that came to mind in response to each stem. In an inclusion task, they were required to produce a studied word in response to each stem, and in an exclusion task they were asked to produce a new, unstudied word for each stem. The performance of the subjects with AD was equal in the inclusion and exclusion conditions, showing no evidence of controlled recollection for the studied words, while their automatic memory as well as priming were preserved. The results provide neuropsychological support for the distinction between controlled and automatic memory processes.

Aged↗
PubMed1998

The effect of short-term estrogen replacement therapy on cognition: a randomized, double-blind, cross-over trial in postmenopausal women.

OBJECTIVE: To evaluate the effect of estrogen replacement therapy on cognitive functioning. METHODS: The study consisted of two 3-month treatment periods, one with estrogen and one with the placebo, in random order, separated by a 1-month wash-out period. The study group comprised 70 healthy postmenopausal women, aged 47-65 years, with previous hysterectomy. Sixty-two women completed the study. Cognitive speed and accuracy, attention, and memory were evaluated. Serum estradiol (E2) and FSH levels were controlled at the end of the estrogen, placebo, and wash-out periods. RESULTS: Most of the cognitive tests correlated with age: older women were slower and made more errors than younger women. Estrogen replacement therapy was not superior to the placebo in any test of cognitive performance. In two out of ten visual detection tasks, recognition thresholds were longer with estrogen than with the placebo (P < .001 and P = .004). On the most demanding test of working memory, the reaction times (P = .045) and error rates (P = .043) differed between treatments, yet this finding proved to be an effect of learning rather than treatment. There was no correlation between cognitive performance and serum E2 levels. CONCLUSION: Cognitive performance decreased with age. Short-term estrogen replacement therapy did not provide any advantage over the placebo in terms of improving the performance.

Aged↗
PubMed1998

Semantic processing of spoken words in Alzheimer's disease: an electrophysiological study.

Patients suffering from Alzheimer's disease (AD) have severe difficulties in tasks requiring the use of semantic knowledge. The semantic deficits associated with AD have been extensively studied by using behavioral methods. Many of these studies indicate that AD patients have a general deficit in voluntary access to semantic representations but that the structure of the representations themselves might be preserved. However, several studies also provide evidence that to some extent semantic representations in AD may in fact be degraded. Recently, a few studies have utilized event-related brain potentials (ERPs) that are sensitive to semantic factors in order to investigate the electrophysiological correlates of the semantic impairment in AD. Interest has focused on the N400 component, which is known to reflect the on-line semantic processing of linguistic and pictorial stimuli. The results from studies of N400 changes in AD remain somewhat controversial: Some studies report normal or enlarged N400 components in AD, whereas others report diminished ones. One issue not reported in previous studies is whether word-elicited ERPs other than N400 remain normal in AD. In the present study our aim was to find out whether the ERP waveforms N1, P2, N400, and Late Positive Component (LPC) to semantically congruous and incongruous spoken words are abnormal in AD and whether such abnormalities specifically reflect deficiencies in semantic activation in AD. Auditory ERPs from 20 scalp sites to semantically congruous and incongruous final words in spoken sentences were recorded from 17 healthy elderly adults and 9 AD patients. The early ERP waveforms N1 and P2 were relatively normal for the AD patients, but the N400 and LPC effects (amplitude difference between congruous and incongruous conditions) were significantly reduced. We interpret the present results as showing that semantic-conceptual activation and other high-level integration processes are defective in AD. However, a word congruity effect earlier than N400 (phonological mismatch negativity), reflecting lexical selection processes, is at least to some extent preserved in AD.

Aged↗
PubMed1997

Knowledge of concept meanings in Alzheimer's disease.

The present study focuses on semantic deficits in Alzheimer's disease (AD). We distinguish three different levels of semantic knowledge: (1) lexical, (2) semantic-conceptual, (3) conscious understanding. We devised methods that tap levels (2) and (3). Our aim was to determine how much guidance AD patients need to consciously access a given semantic-conceptual field and how well they can understand the meanings of concepts and semantic relations. Four different tasks were used to tap different kinds of concepts, the relationships between concepts and their attributes, and the hierarchical structure among different concepts. The retrieval demands of the tasks were eased by presenting guiding questions. The results revealed that AD patients have deficient voluntary access to semantic-conceptual representations. The deficits persist even in passive recognition and forced-choice tasks. We conclude that AD patients have a generalized access deficit, although some aspects of the results are suggestive of storage deficit.

Aged↗
PubMed1997

Tone duration discrimination in Parkinson's disease.

Patients with Parkinson's disease (PD) and healthy controls took a computerized test of tone duration discrimination (TDD) using pairs of tones of 0.4-1.6 sec duration, presented at intervals of 0.5-4 sec. In PD patients as well as controls, TDD was impaired by even slight degrees of cognitive deterioration. PD yielded impaired TDD in females, but not in males. This suggests that the dopamine-powered biological clock, which is vulnerable to PD, is more important for the processing of durations in the 1-sec range in women than in men.

Adult↗
PubMed1997

Climacteric symptoms do not impair cognitive performances in postmenopause.

OBJECTIVE: To investigate whether information processing and attention performances are affected by climacteric vasomotor symptoms. METHODS: The study group comprised 66 healthy hysterectomized postmenopausal women. The subjects were divided into two subgroups (high symptomatic and low symptomatic) according to the quantity of climacteric vasomotor symptoms. Information processing was examined using CogniSpeed, a reaction time software that separates, for example, pure controlled processing and working memory from perceptual and motor components. Attention was examined by using visual and auditory tasks. The role of climacteric depression as a determinant of cognitive performance was evaluated by the Beck Depression Inventory and dividing subjects according to self-reported climacteric mood symptoms. The effects of serum oestrogen level and ageing on cognitive performances were also studied. RESULTS: Cognitive performances were similar in high symptomatic and low symptomatic women. On the Verification test younger women had shorter reaction times (P = 0.002) and on the Subtraction test they had fewer errors (P = 0.015) than older women. These tests required working memory and decision making. Accuracy in the tests of sustained and auditory attention worsened slightly with age. Cognitive performances neither correlated with scores on the Beck Depression scale nor with serum oestrogen level. Climacteric mood symptoms did not impair cognitive performance. CONCLUSIONS: Despite subjective complaints of memory impairment in association with climacteric vasomotor symptoms, our results did not support a direct cause-and-effect relationship. Thus, the minor deficits found in cognitive processing efficiency seem to be related rather to age than climacteric symptoms.

Aging↗
PubMed1997

The progress of cognitive decline in multiple sclerosis. A controlled 3-year follow-up.

The purpose of this study was to illustrate how cognitive functioning evolves over time in patients with multiple sclerosis. We followed the evolution of cognitive performances in two clinically and demographically similar multiple sclerosis groups, the 'cognitively preserved' (n = 20) and the 'cognitively mildly deteriorated' (n = 22), and in healthy controls (n = 34). We conducted the follow-up examination using the Mild Deterioration Battery, the Mini-Mental State Examination, and a set of additional neuropsychological measures after an interval of 3 years. The drop-out rate in our study was only 5%. The 'cognitively preserved' multiple sclerosis group showed substantial neuropsychological stability by performing as well as the controls both at baseline and at follow-up. By contrast, the initially 'cognitively mildly deteriorated' group demonstrated progressive cognitive decline on many neuropsychological tests. The intermediate-length screening battery, the Mild Deterioration Battery, was sensitive to this decline, whereas the briefer Mini-Mental State Examination was not. The progressive cognitive decline could not be predicted from other disease variables. The study demonstrated that intact cognitive functioning in multiple sclerosis may remain stable, whereas incipient cognitive decline seems to be widespread and progressive in nature. Thus, progressive cognitive deterioration should be considered as one of the characteristics of multiple sclerosis.

Adult↗
PubMed1996

Language functions in incipient cognitive decline in multiple sclerosis.

Although the mechanisms of cognitive impairment in multiple sclerosis (MS) have been extensively studied, evaluation of language functions has been given little attention. In the present study, we evaluated whether impairment of language functions is associated with cognitive decline in MS. We studied naming, reading, and writing performance of two carefully matched patient groups differing only with respect to cognitive status. In language tasks, the patients with incipient cognitive decline not only demonstrated performance slowness but also made more errors than the patients with preserved cognitive capacity and the healthy controls. The comprehensive naming error analysis revealed that the cognitively deteriorated patients produced error types not present in the other two study groups. Contrary to previous suggestions, the present study indicates that impaired language performances in MS are attributable to mild cognitive deterioration rather than to sensory or motor factors. Thus, assessment of language functions should be included in neuropsychological evaluations of MS patients.

Adult↗
PubMed1996

Perceptual priming in Alzheimer's and Parkinson's diseases.

The present study focused on perceptual identification priming (implicit memory) in early stages of dementia by studying demographically and cognitively matched patients with Alzheimer's disease (AD) and Parkinson's disease (PD). The AD and PD groups performed normally on perceptual identification priming, whereas their explicit recognition memory was equally impaired compared to normal controls. These results imply that priming in perceptual identification relies on the perceptual memory system which can resist not only impairments of explicit memory but also widespread cognitive deterioration induced by the neurodegenerative processes in AD or PD.

Adolescent↗
PubMed1996

Memory deficits and early cognitive deterioration in MS.

INTRODUCTION: In the present study, the pattern of memory and learning deficits in two cognitively different, but clinically and demographically similar, multiple sclerosis (MS) groups was compared. MATERIAL & METHODS: 23 patients represented the cognitively preserved MS group and 22 patients the MS group with early cognitive decline. A control group of 35 healthy controls was also included. The cognitive status of the subjects was defined using the Mild Deterioration Battery (MDB). Furthermore, all subjects were given a set of memory and learning tests and were instructed to evaluate the frequency of their memory and learning difficulties. The Mini-Mental State Examination (MMSE) was also administered to all subjects. RESULTS: The cognitively deteriorated patients, even those with normal MMSE performance, showed widespread memory and learning deficits, but adequate self-evaluation of their everyday memory and learning difficulties. The preserved group, in turn, performed similarly to the controls. CONCLUSION: Widespread memory and learning deficits are associated with relatively mild cognitive decline in MS. These deficits were observable in the intermediate-length screening battery, the MDB, but not in the MMSE. The present study suggests that the accuracy of patients' own evaluations of their memory and other cognitive problems is superior to the results of very brief screening batteries, like the MMSE. Therefore, brief screening in neuropsychological assessment of MS patients is not recommendable.

Adult↗
PubMed1995

Education, gender and cognitive performance in a 62-year-old normal population: results from the Turva Project.

Four WAIS (Wechsler Adult Intelligence Scale) subtests, and tasks of memory and cognitive control were administered to a population sample of 143 men and 179 women. Subjects with a minor advantage in years of education out-performed those with only primary schooling. Gender-related effects were also remarkable. Whereas the general abilities were equal in the genders, women out-performed men on recall of word pairs and objects, on verbal cognitive control and on Digit Symbol. In contrast, men excelled on Trail Making A, and on Block Design. The findings emphasize the need for age norms by gender and education for cognitive tests.

Aging↗
PubMed1995

Attention related performance in two cognitively different subgroups of patients with multiple sclerosis.

To evaluate the underlying mechanisms of cognitive decline in multiple sclerosis, two clinically and demographically matched multiple sclerosis groups differing in cognitive status were assessed with attention related tasks. In addition to the attention tests recommended by the Cognitive Function Study Group of the American National Multiple Sclerosis Society, a test of sustained attention was used to evaluate the role of possible fatigue on cognitive performance. The cognitively mildly deteriorated group was slower than the cognitively preserved group and the controls on all tests of attention. The mildly deteriorated group did not, however, consistently differ from the other groups in the error scores of the attention tests. The preserved group exhibited slowness at the end of the visual vigilance test, but no deficits were found on the other attention related tests in this group. It is suggested that dissociable kinds of processing slowness are the origin of the deficits found on the attention tests in the two multiple sclerosis groups. Our preserved group exhibited signs of motor and fatigue related slowness, whereas the mildly deteriorated group also had extensive cognitive slowness. As sensitive indicators of cognitive slowness, attentional tests should be included in evaluation of the cognitive status of patients with multiple sclerosis.

Adult↗
PubMed1994

Automatic and controlled information processing in multiple sclerosis.

The purpose of this study was to evaluate the kind of slowing of information processing associated with multiple sclerosis and how this possible slowness is related to cognitive deterioration. We selected 45 patients with definitive multiple sclerosis diagnosis and 35 control subjects. Twenty-two patients had mild cognitive deterioration and 23 patients had preserved cognitive capacities, otherwise the groups were matched. Using computerized tests, we investigated three separate stages of information processing: automatic and controlled processing, and motor programming. The results indicate that patients with mild cognitive deterioration are slower than patients with preserved capacities or controls in every stage of processing measured in this study. Additionally, the preserved patients showed signs of mild slowing in automatic visual processing. These results show that, in multiple sclerosis patients, widespread information processing slowness is associated with multiple sclerosis-related cognitive deterioration. This study emphasizes the importance of studying subgroups rather than cognitively heterogeneous patient samples and, furthermore, the need to divide information processing into different stages is indicated.

Adult↗
PubMed1993

Slowing of information processing in Parkinson's disease.

In this study, we criticize the notion of bradyphrenia and argue that "slowness of thought" in Parkinson's disease (PD) must be analyzed as slowness of different information-processing stages and that unselected patients should not be used in experimental studies. We selected 32 patients with a long history of PD and 50 control subjects. Sixteen patients had mild cognitive deterioration (not dementia) and 16 patients had preserved cognitive capacities; otherwise the groups were matched. By using computerized tests, we investigated three separate stages: automatic and controlled processing and motor programming. The results indicate that patients with mild cognitive deterioration are slower than patients with preserved cognitive capacities or controls in automatic visual and in controlled processing but not in motor programming. We conclude that the slowing of controlled processing reflects the disruption of central neural networks, that a long history of PD does not necessitate cognitive slowing, and that PD is not a neuropsychologically serviceable category.

Aged↗
PubMed1992

Quality of life and cognitive performance after carotid endarterectomy during long-term follow-up.

The quality of life and the cognitive performance of patients with extracranial carotid stenosis were investigated 8-11 years after treatment in 18 non-operatively treated patients and 44 patients treated with carotid endarterectomy. The cognitive performance was compared with data on a normal control group. Cognitive performance was assessed with neuropsychological tests and the quality of life by personal interview based on a questionnaire. Most of the carotid stenosis patients recovered well both subjectively and cognitively regardless of the type of treatment. Only the subgroup operated twice was subjectively worse compared to the other groups. Even 10 years later the cognitive performance of carotid stenosis patients was remarkably close to normal.

Aged↗
PubMed1987

Senile dementia of the Alzheimer type treated with aniracetam: a new nootropic agent.

Forty-four patients with senile dementia of the Alzheimer type were randomly allocated into double-blind treatment with either aniracetam (RO 13-5057) 1 g or placebo daily for 3 months. Neurological examinations were made before and after treatment and psychometric tests were performed before and after 1 month's and after 3 month's treatment. Treatment was interrupted due to occurrence of confusion in four cases in the aniracetam group and in one case in the placebo group. During treatment, an improvement was seen in several cognitive tests, especially those associated with memory, but this improvement occurred in the placebo as well as in the aniracetam-treated group. In clinical evaluation no difference was seen in efficacy between the two treatment groups.

Aged↗