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At least 703 records · Page 39Linked to original sources

PubMed2005

Effects of ketamine on prefrontal and striatal regions in an overt verbal fluency task: a functional magnetic resonance imaging study.

RATIONALE: Glutamatergic dysfunction at N-methyl-D: -aspartate (NMDA) receptors has been proposed as a neurochemical model for schizophrenia. A key feature of this disorder is impairments in cognitive function. OBJECTIVE: The present study sought to investigate the effects of ketamine, an NMDA antagonist, on the performance and neural correlates of verbal fluency, a task that engages executive function. METHODS: Ten healthy dextral male volunteers received intravenous placebo normal saline or ketamine (bolus of 0.23 mg/kg and infusion of 0.65 mg/kg), administered in a double-blind, randomized order, during two functional magnetic resonance imaging sessions. During scanning, subjects performed a verbal fluency task. Two levels of cognitive load were examined in the task, and overt responses were acquired in order to measure subject performance on-line. RESULTS: Ketamine induced symptoms in the healthy individuals comparable to an acute psychotic state. Although ketamine did not significantly impair task performance relative to placebo, an interaction of task demand with ketamine was observed in the anterior cingulate, prefrontal, and striatal regions. CONCLUSIONS: The behavioural and functional effects of ketamine during verbal fluency in healthy individuals were comparable to those evident in patients with schizophrenia. The findings support a role for glutamatergic dysfunction in the pathophysiology of schizophrenia.

Corpus Striatum↗

PubMedDate not supplied

Stair climbing elicits a lower cardiovascular demand than walking in claudication patients.

PURPOSE: Peripheral arterial disease patients limited by claudication pain frequently have concomitant-cardiovascular problems during exercise, such as hypertension and myocardial ischemia. Thus, for testing and rehabilitation purposes, exercise which elicits lower heart rate and blood pressure at a given metabolic intensity would be preferred over a more demanding task. The purpose of this study was to compare the cardiovascular responses of claudication patients during walking and stair climbing at a similar level of oxygen uptake. METHODS: Ten patients limited by claudication pain performed treadmill walking and stair climbing tests. RESULTS: Oxygen uptake was similar (P > .05) during walking and stair climbing (13.7 vs. 13.5 mL/kg/min, respectively). The times to onset and to maximal claudication pain, as well as the peripheral hemodynamic measurements of ankle systolic pressure, ankle-to-brachial systolic pressure index, and foot transcutaneous oxygen tension were also similar between the two tests (P > .05). However, heart rate, systolic pressure, diastolic pressure, mean arterial pressure, and rate-pressure product values were lower during and following stair climbing than compared to walking (P < .05). CONCLUSION: Stair climbing may offer an advantage over treadmill walking for claudication patients because similar metabolic, claudication, and peripheral hemodynamic measurements are obtained with concomitantly less demand placed on the cardiovascular system. The stair climbing test was well tolerated and safely performed by each patient.

Aged↗

PubMedDate not supplied

Learning helpers: how they facilitated improvement and improved facilitation--lessons from a hospital-wide quality improvement initiative.

Quality improvement is a leading approach to the difficult yet inevitable task of managing organizational change. The literature suggests that facilitators can help organizations apply improvement principles and tools but it is unclear how facilitators actually do this and how they develop their own skills. Using a case study design we therefore examined how facilitators worked with 93 improvement projects in over 1000 sessions at one Swedish university hospital where systematic process improvement was successfully established over a 5-year period. They facilitated improvement by providing a framework and methods' support for improvement efforts--relying on experiential learning rather than didactic teaching--while letting clinical teams and managers maintain control over the content of improvement projects. They developed extensive experience that they documented and could transfer between teams, so that each team could benefit from lessons learned elsewhere. They improved facilitation through participant feedback and systematic review and reflection regarding their own practice. We suggest that facilitators can help organizations manage change by assuming responsibility for demanding tasks related to improvement work, developing specialized skill and extensive experience regarding improvement, and transferring insights across the organization, while using a learning approach throughout including to their own work.

Hospitals, University↗

PubMed1996

The role of sensory information in the production of periodic finger-tapping sequences.

A subject lacking proprioceptive and tactile sensibility below the neck and a group of control subjects performed sequences of periodic finger taps involving a pattern of accentuation. The required intertap interval was 700 ms. In some situations, the taps were synchronized with the clicks of a metronome. Feedback conditions were manipulated by either allowing or not allowing the subjects to hear the taps and see their finger movements. We recorded the trajectory of the subjects' finger displacement in the vertical plane, and the force and moment of contact of the finger with the response key. The control subjects achieved precise timing of the finger taps by trading off downstroke onset for movement duration, e.g., they initiated shorter-duration tapping movements with a delay. This strategy did not vary depending on task demands (e.g., synchronization) or feedback conditions. The deafferented patient produced intertap intervals on average close to the required value. However, his tap timing was characterized by increased variability and severe distortion (lengthening) after the accentuated tap, regardless of feedback conditions. He did not manifest the compensatory strategy whereby, in control subjects, movement onset was adjusted to movement duration. Thus, such a strategy in controls seems to depend on intact proprioceptive and/or tactile information from the moving limb. Upon withdrawal of visual and acoustic feedback, the deafferented subject increased the force of the taps and the amplitude of tapping movements; his mean synchronization error with the metronome also increased. However, he did not lose correct phasing between the taps and the clicks of the metronome. These findings suggest that, under normal circumstances, sequential movements are timed by an internal timekeeper which paces sensory consequences relating to the occurrence of behaviorally important events (e.g., finger taps), and not the onset of the movements eliciting those events. In the synchronization task, the timekeeper may be phase locked to the periodic acoustic stimuli by direct entrainment. Feedback information may be needed, however, for keeping any synchronization error as small as possible.

Acoustic Stimulation↗

PubMed1998

Assessment of stereopsis in college baseball pitchers and batters.

BACKGROUND/PURPOSE: In baseball pitching is a much less visually demanding task than hitting is. We sought to find a stronger relationship between visual function (as measured by stereopsis) and hitting a baseball than between stereopsis and pitching skill. METHODS: Multiple parameters including near and distance stereopsis (as a measure of visual function) were measured in 23 returning college baseball players (with a prior year's record). Their level of stereopsis (measured at distance with use of the B-VAT II BVS Binocular Vision Testing System) was compared with their batting statistics (in the case of the 14 position players) or their pitching statistics (for the 9 pitchers). Batting average and slugging percentage were used as measures of hitting skill, and earned run average, "out percentage" (1.000--Opposing players' batting average) and "strike-out percentage" (frequency of batters struck out) were used as pitching parameters. RESULTS: As a group, visual parameters were excellent in these college athletes. Although the newer test of distance stereopsis correlated with the standard near stereo test (Spearman coefficients), there was no correlation between distance stereopsis and any of the pitching or hitting performance parameters. CONCLUSIONS: The nature of the visual demands required of successful baseball hitters may have yet to be determined or are difficult to identify among a population homogeneous for excellent visual function, true for most groups of competitive athletes. In addition, simpler parameters such as plain visual acuity may be the most important factor(s).

Baseball↗

PubMed2001

Episodic-like memory in animals: psychological criteria, neural mechanisms and the value of episodic-like tasks to investigate animal models of neurodegenerative disease.

The question of whether any non-human species displays episodic memory is controversial. Associative accounts of animal learning recognize that behaviour can change in response to single events but this does not imply that animals need or are later able to recall representations of unique events at a different time and place. The lack of language is also relevant, being the usual medium for communicating about the world, but whether it is critical for the capacity to represent and recall events is a separate matter. One reason for suspecting that certain animals possess an episodic-like memory system is that a variety of learning and memory tasks have been developed that, even though they do not meet the strict criteria required for episodic memory, have an 'episodic-like' character. These include certain one-trial learning tasks, scene-specific discrimination learning, multiple reversal learning, delayed matching and non-matching tasks and, most recently, tasks demanding recollection of 'what, where and when' an event happened. Another reason is that the neuronal architecture of brain areas thought to be involved in episodic memory (including the hippocampal formation) are substantially similar in mammals and, arguably, all vertebrates. Third, our developing understanding of activity-dependent synaptic plasticity (which is a candidate neuronal mechanism for encoding memory traces) suggests that its expression reflects certain physiological characteristics that are ideal components of a neuronal episodic memory system. These include the apparently digital character of synaptic change at individual terminals and the variable persistence of potentiation accounted for by the synaptic tag hypothesis. A further value of studying episodic-like memory in animals is the opportunity it affords to model certain kinds of neurodegenerative disease that, in humans, affect episodic memory. An example is recent work on a transgenic mouse that over-expresses a mutation of human amyloid precursor protein (APP) that occurs in familial Alzheimer's disease, under the control of platelet derived (PD) growth factor promoter (the PDAPP mouse). A striking age- and amyloid plaque-related deficit is seen using a task in which the mice have to keep changing their memory representation of the world rather than learn a single fact.

Alzheimer Disease↗

PubMed2004

What drives children's limb selection for reaching in hemispace?

Arguably, the act of reaching constitutes one of the most devoted lines of contemporary developmental research. In addition to the underlying dynamical characteristics of motor coordination, a key element in programming is limb selection, a phenomenon (handedness) that has so far resisted any reasonable unified explanation. From a more contemporary view, two factors appear to have the most influence on hand selection for a given task: motor dominance and attentional information related to task demands. This study was designed to determine what factor(s) influence choice of limb for reaching in hemispace in reference to motor dominance, object proximity, and a hemispheric bias favoring use of the hand on the same side as the stimulus. Strong right-handed children were asked to reach and retrieve a small object across right and left hemispace locations beginning with the arms uncrossed and arms-crossed. With the arms-crossed condition, an imagined and actual movement execution was administered. Results from the uncrossed condition supported previous reported findings for adults and children. That is, participants responded ipsilaterally using the hand on the same side as the stimulus, thus supporting the case for object proximity and hemispheric bias. However, in the arms-crossed condition the vast majority of participants preferred keeping the limbs crossed in response to right and left hemispace stimuli, which leads to the suggestion that object proximity rather than hemispheric bias was the driving factor in this context. The behavioral pattern for imagined and actual movement was not significantly different. Overall, the findings add to the growing acceptance that limb selection is task and context dependent, rather than a biologically based invariant feature of motor behavior.

Arm↗

PubMed2005

Cognitive and psychomotor performance, mood, and pressor effects of caffeine after 4, 6 and 8 h caffeine abstinence.

RATIONALE: Many studies have found that caffeine consumed after overnight caffeine abstinence improves cognitive performance and mood. Much less is known, however, about the effects of caffeine after shorter periods of caffeine abstinence. OBJECTIVES: The aim of this study was to measure the effects on psychomotor and cognitive performance, mood, hand steadiness, blood pressure and heart rate of caffeine administration after periods of 4, 6, and 8 h of caffeine abstinence. METHODS: Participants (n = 49, 27 female) were moderate to moderate-high caffeine consumers (mean daily intake 370 mg/day). Following overnight caffeine abstinence, a 'pre-dose' of caffeine (1.2 mg/kg) was administered at 9 A.M, 11 A.M or 1 P.M. The participants started a baseline battery of measurements at 4 P.M.: before receiving caffeine (1.2 mg/kg) or placebo at 5 P.M.: They then performed the battery of tests again, starting at 5:30 P.M. This was a double-blind, placebo-controlled, randomised study. RESULTS: Performance and mood measurements confirmed a psychostimulant action of caffeine (versus placebo), but only after 8 h of caffeine abstinence. Caffeine also increased blood pressure after 8-h abstinence, whereas hand steadiness was decreased and perception of task demand was increased by caffeine after 4 h, but not after 6- and 8-h abstinence. CONCLUSIONS: A second cup-of-coffee equivalent dose of caffeine only reliably affected cognitive performance and mood after an 8-h interval between doses, but not after shorter intervals (when caffeine had some adverse effects). These results show that, apart from caffeine consumption soon after waking, the daily pattern of caffeine intake of many typical caffeine consumers is not well explained by the short-term psychostimulant effects of caffeine.

Administration, Oral↗

PubMedDate not supplied

The effects of fixed-time and contingent schedules of negative reinforcement on compliance and aberrant behavior.

Prior research has suggested that fixed-time (FT) schedules of reinforcement do not necessarily preclude the acquisition of appropriate behavior (e.g., mands) when combined with differential reinforcement (DRA). These studies also note that dense FT schedules are more likely to interfere with DRA packages than lean FT schedules. In the current investigation, we examined whether similar findings would occur with FT schedules of negative reinforcement. Schedule analyses were conducted with two participants following functional analyses that identified escape from task demands as the maintaining variable for problem behavior. Differential negative reinforcement of alternative behavior (DNRA) was implemented first to establish behavioral control (decreased problem behavior and increased compliance). Breaks (negative reinforcement) were then concurrently delivered on a FT basis under either dense (at a greater rate than that obtained during DNRA alone) or lean (at a lower rate than that obtained during DNRA) reinforcement schedules. In general, results showed that FT escape did not preclude compliance when the FT schedule was lean, but treatment gains were significantly disrupted when dense FT schedules were superimposed.

Attention Deficit and Disruptive Behavior Disorder↗

PubMed2000

EEG correlates of wrist kinematics as revealed by averaging techniques and Morlet wavelet transforms.

The question regarding the invariant movement properties the central nervous system may organize to accomplish different motor task demands as reflected in EEG remains unsolved. Surprisingly, no systematic electrocortical research in humans has related movement preparation with different movement distance, although this area has been widely investigated in the field of motor control. This study examined whether the amplitude of discrete wrist movements influences the various EEG components both in time and frequency domains. Time-domain averaging techniques and Morlet wavelet transforms of EEG single trials were applied in order to extract three components [BP(0), N1, and LPS] of movement related potentials (MRP) and to quantify changes in oscillatory activity of the movement-induced EEG waveforms accompanying 20, 40, and 60 unilateral wrist flexion movements. The experimental manipulations induced systematic changes in BP(0) and N1 amplitude along the midline (Fz, Cz, and Pz) with 20 movement showing the most negativity and 60 the least. The dominant energy within a 30-50 frequency cluster from bilateral precentral (C3, Cz, C4), frontal (F3, Fz, F4), and parietal (P3, Pz, P4) areas with maximum at vertex (Cz) also appeared to be sensitive to movement amplitude with the least power observed during 60 wrist flexion. This suggests that movement amplitude may be a controllable variable that is highly related with task-specific cortical activation primarily at frontocentral areas as reflected in EEG.

Adult↗

PubMed1997

Functional MR imaging of the prefrontal cortex: specific activation in a working memory task.

Functional magnetic resonance imaging was used to identify cortical regions activated by a working memory task involving letter detection. Twenty four normal subjects were scanned with a conventional 1.5-T magnet while performing one of two tasks: In the activation task, subjects responded by pressing a button whenever any presented letter was the same as the second last in the sequence. In the control condition, subjects had to respond to a single predefined letter without memory update requirements. The activation task and the control condition were identical with regard to perceptual input and motor output. They were different only regarding the task demand. Movement artifacts were minimized in a two way strategy and eight subjects were excluded from further analysis. Functional MR data from the remaining 16 subjects were analyzed on the basis of anatomical regions-of-interest which were manually defined in each subject. The engagement of working memory produced significant activation in the dorsolateral prefrontal cortex (Brodmann's areas 9, 10, 46, and 47) in both hemispheres. Results demonstrate the applicability of the paradigm within a clinical MRI setup and corroborate previous findings of non-lateralized dorsolateral prefrontal activation during continuous context updating and active maintenance.

Adult↗

PubMed1996

[Differentiation of pain-related and morphine related impairment of cognitive performance and mood in bone marrow transplantation patients].

AIMS: Severe pain of mucositis induced by cytostatic conditioning therapy in bone marrow transplantation (BMT) patients generally requires continuous parenteral opioid treatment. Cognitive and psychological disturbances are frequent complications subsequent to BMT and may result from cerebral opioid side effects. The aim of the study was to evaluate the efficiency of continuous morphine in mucositis pain and the side-effects in BMT patients. Particular emphasis was placed on the question of whether reaction times, which are usually measured to estimate opioid effects upon vigilance, are influenced by pain-induced cognitive impairments in pain patients. METHODS: While in hospital, 10 BMT patients were examined daily with the aid of a mucositis scale, subjective visual analog scales (VAS) for pain and mood parameters, a German version of the McGill pain questionnaire (MPQ), and a mental performance task battery, and the morphine given was documented. Mental performance tests were simple auditory reaction time and choice reaction time. Seven patients also performed a Sternberg memory search test in which they had to use 'yes' and 'no' response keys to match visually presented test letters to a previously memorized set of letters. Practice and baseline data were collected within the first week before BMT. RESULTS: The intensity and duration of mucositis differed from patient to patient, resulting in different pain intensities and MPQ scores. Prolongation of the choice reaction time averaged over the period of mucositis treatment correlated significantly with residual pain intensity (Spearman r(s) = 0.88, p < 0.01) but not with morphine dose (r(s) = 0.35, p = 0.33). For the Sternberg memory search test greater correlation coefficients resulted between reaction time and morphine dose (r(s) = 0.86, p = 0.014) than between reaction time and residual pain intensity (r(s) = 0.61, p = 0.15). In turn, pain intensity, unlike morphine dose, was significantly correlated with high scores in the mood parameters for depression, passivity, and tiredness. CONCLUSIONS: It is concluded that both pain and morphine can impair cognitive performance, but that these mental stressors seem to differ according to qualitative criteria. Whereas pain might slow reaction time by distracting a patient's attention, particularly in low mental demand tasks, morphine could interfere with more specific cognitive processes, such as short-term memory operations, that are required in more complex tasks.

English Abstract↗

PubMed2005

Further validation of the Daily Living Tasks Dependent on Vision: identification of domains.

AIM: To examine the Daily Living Tasks Dependent on Vision (DLTV), a visual function questionnaire for domain structure, and redundancy. METHOD: 235 subjects underwent full ophthalmic assessment and completed the DLTV questionnaire by interview. Principal component analysis with varimax rotation and item response theory (IRT) were used to assign the items to domains. The internal consistency of each domain was examined using Cronbach's alpha. Redundancy was assessed by regressing each item in a domain against the remainder of items in that domain. RESULTS: Four domains were identified. Domain 1 was formed by nine items, which after applying IRT were seen to be among the most difficult questions in the instrument. Domain 2 contained eight items, all of which fell in the easier half of the instrument on applying IRT. Domain 3 contained only three items, all of which were among the easier questions and appear to deal with peripheral vision function. Domain 4 consisted of two items dealing with adaptation to light and dark conditions. Cronbach's alpha for each domain was 0.96, 0.93, 0.73, 0.66. Redundancy was found to be present in domain 1, which was therefore reduced by two items, with little effect on internal consistency. CONCLUSIONS: The authors believe using the domains identified in this report will optimise the information provided by patients on their ability to function on visually demanding tasks.

Activities of Daily Living↗

PubMed2006

A dual-process account of digit invariance learning.

Performance in the McGeorge and Burton (1990) digit invariance task was originally thought to be mediated by unconscious abstraction of a "rule" that identified the invariant feature across all study items. Subsequent explanations have suggested explicit strategy use or similarity-to-exemplar matching rather than abstraction. This paper presents data that suggest that both similarity and abstraction can be used under different task demands. Delay between study and test afforded abstraction of the invariant knowledge whereas reducing the pool of study exemplars enhanced responding based on specific similarity. These results parallel effects found in the categorization literature. Rule abstraction in this sense may be due to statistical learning of feature frequency rather than abstraction of a central tendency or a complex/conceptual rule. Categorizing responses into subjective memory states (remember/know/guess) demonstrates that neither the similarity matching nor the abstraction mechanism uses information from episodic memory. Confidence measures show that participants are more confident of responses when the prototypical representation is used but not specific similarity. Taken together, these data suggest that abstracted knowledge is not held consciously but that participants have meta-awareness of when they are using the abstracted representation.

Analysis of Variance↗

PubMed1995

Information coding in the rodent prefrontal cortex. II. Ensemble activity in orbitofrontal cortex.

1. Neural activity was recorded from the orbitofrontal cortex (OF) of rats performing an eight-odor discrimination task that included predictable associations between particular odor pairs. A modified linear discriminant analysis was employed to characterize the population response in each trial of the task as a point in an N-dimensional activity space with the firing rate of each cell in the population represented on one of the N dimensions. The ability of the ensemble to discriminate among conditions of a variable was reflected in the tendency of population responses to cluster together in this activity space for repetitions of a given condition. We assessed coding of several variables describing the period of odor sampling, focusing on aspects of current, past, and future events reflected in single-neuron firing patterns, in ensembles composed of 22-138 cells active during the period when the rats sampled the discriminative stimulus in each trial. 2. OF ensembles performed well at discriminating variables with relevance to task demands represented in single-neuron firing patterns, specifically the physical attributes and assigned reward contingency of the current odor as well as the expectation of reward in the following trial that could be inferred from the predictable associations between particular pairs of odors. OF ensembles were able to correctly identify the identity and assigned reward contingency of the current odor in up to 52% (chance = 12.5%) and 99% (chance = 50%) of all trials, respectively, such that the observed behavioral performance required a population of 5,364 odor-responsive cells in the case of odor identity and only 40 cells in the case of valence. Expectations regarding upcoming rewards based on both assigned response contingency and associations between particular pairs of odors were correctly classified in up to 67% (chance = 20%) of all trials such that the observed level of behavioral performance required a population of 3,169 cells. 3. Other information represented in the single-neuron firing patterns, such as the identity and reward contingency of the preceding odor and specific odor-odor associations, was poorly encoded by OF ensembles. Thus neural ensembles in OF may represent only some of the information reflected in single-neuron activity. Stable coding of only the most useful and relevant information by the ensemble might emerge from the tuning properties of single neurons under the influence of the task at hand, producing in the well-trained animal the observed pattern of broad and diverse coding by single neurons and selective, task-relevant coding by neural ensembles in OF.

Animals↗

PubMed1998

Effects of different stress settings on cardiovascular parameters and their relationship to daily life blood pressure in normotensives, borderline hypertensives and hypertensives.

The aim of this study was to compare a traditional stress setting, consisting of two mental arithmetic tasks and two Stroop test modifications, and a stress setting of varying task demand and decision latitude according to Karasek's job strain model, with respect to their feasibility to elicit differences in cardiovascular reactivity and recovery in 20 normotensives, 20 borderline hypertensives, and 20 non-medicated hypertensives, carefully selected by means of World Health Organization criteria. In addition, the relationship between laboratory and everyday blood pressure was investigated. All subjects were tested under both stress settings in counterbalanced order. Blood pressure was recorded both intermittently from the brachial artery (Riva-Rocci) and continuously from the finger (Finapres). Heart rate and electrodermal activity were continuously measured as well. Furthermore, daily life blood pressure recorded by means of 24 h ambulatory monitoring during a normal working day served as criterion for the re-classification of the blood pressure groups by means of discriminant analysis using physiological recordings from baseline, test phases and rest phases. The groups did not show significant differences in their reactivity to the various mental stressors including the Karasek-model oriented ones but marked differences in their behaviour occurred during the 10 min of recovery following each stress setting. Both systolic and diastolic blood pressure in hypertensives failed to recover during this period. The results also showed the superiority of the Finapres method with respect to reflecting the dynamics of physiological recovery processes. None of the stress settings showed an advantage in predicting blood pressure in daily life. In general, the results question the validity of mental laboratory stressors for the prediction of cardiovascular changes in daily life but point to a possible role of recovery processes after stress in the development of essential hypertension.

Adult↗

PubMed1991

Regional cerebral blood flow correlates of language processes in reading disability.

This series of studies tests the hypothesis of abnormal left hemisphere activation in reading-disabled subjects during language task performance. First, a left superotemporal focus of activation, as measured by regional cerebral blood flow, was found to be positively correlated with task accuracy in a group of 69 normal adults. Next, that left superotemporal activation was replicated in a second group of 83 adults whose childhood reading ability was known from standardized tests given in childhood. Finally, in that latter group, childhood reading ability was also found to be inversely correlated with focal activation in a more posterior, temporoparietal area of cortex. Adult reading outcome was statistically unrelated to this finding. The results are interpreted as suggesting a trait anomaly of left hemisphere cerebral activation in adults who were dyslexic as children and as providing an existence proof of individual differences in focal cortical activation sites during constant task demands.

Adolescent↗

PubMed2000

Impairment of semantic knowledge in Parkinson disease.

BACKGROUND: Parkinson disease (PD) is commonly characterized by cognitive deterioration, but it is still unclear whether PD is associated with semantic impairments. OBJECTIVE: To evaluate semantic knowledge of concepts in patients with idiopathic PD, addressing concrete and abstract concepts, conceptual attributes, and conceptual relations. METHODS: Twelve patients with preserved cognitive status, 12 patients with mildly deteriorated cognitive status, and 12 control subjects were studied. The cognitive status of patients and controls was determined using detailed cognitive testing. Patients were participants in a university-based movement disorder program, and their PD diagnoses were clinically confirmed during long-term follow-up. The 2 patient groups were similar in age, level of education, disease duration, and parkinsonian disability. Patients were required to produce verbal descriptions of concrete and abstract concepts, to give ratings of the importance of concept attributes, and to assess and construct conceptual hierarchies. The description tasks included guiding questions, which were used if the spontaneous productions of the patients lacked any essentials expected in the answers. RESULTS: Patients with mild cognitive deterioration performed less well than the other groups in defining concrete and abstract concepts (P<.001 for both). External guidance did not help them markedly improve their performance. They also had difficulties in tasks calling for knowledge of the importance of given attributes to the concepts and in tasks demanding evaluation of hierarchical semantic relations between concepts (P<.001 for both). CONCLUSION: Semantic disruption is implied in idiopathic PD in association with incipient cognitive impairment.

Aged↗