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PubMed1999

Contingent negative variation and attention in schizophrenic and depressed patients.

Contingent negative variation (CNV) is supposed to be a psychophysiological indicator of attention and arousal. Both have been reported to be deteriorated in schizophrenic and depressed patients. Thirty-four patients with major depression, 43 patients with schizophrenia and 49 healthy subjects were investigated during acute illness with a complex three-stimulus go/no-go task which requires different states of attention: trials consisted of three complex figures that were tachistoscopically presented. Three identical figures had to be confirmed by pressing a button (target condition). CNV was measured: (1) after the first figure waiting for the second (baseline condition), (2) after two identical figures waiting for the third (response-relevant condition), (3) after two different figures waiting for the third (response-irrelevant condition). The response-relevant condition compared to baseline significantly intensified CNV in healthy controls and to a minor extent in depressed patients but not in schizophrenics. In the response-relevant conditions in healthy controls, CNV was significantly reduced compared to the response-relevant condition. This clear discrimination between response-relevant and response-irrelevant conditions was not observed in either group of patients. Thus, the applied CNV paradigm was able to discriminate schizophrenic and depressed patients from healthy controls. Furthermore, subtle differences between schizophrenic and depressed patients were detected, reflected by the different CNV development across experimental conditions.

Adult↗
PubMed2000

Impaired modulation of the saccadic contingent negative variation preceding antisaccades in schizophrenia.

BACKGROUND: The contingent negative variation (CNV) is considered to reflect prefrontal functioning and can be observed before manual and ocular motor responses. Schizophrenic patients exhibit reduced CNV amplitudes in tasks requiring manual motor responses. A number of studies has also found normal prosaccades, but delayed antisaccades and an augmented rate of erroneous prosaccades during the antisaccade task in schizophrenia. In this study we examined the CNV during pro- and antisaccade tasks in schizophrenic patients and healthy control subjects. METHODS: Data of 17 medicated schizophrenics (ICD-10, F20) and 18 control subjects, matched with patients for age, gender, and education were analyzed. Horizontal pro- and antisaccades were elicited in four blocks, each consisting of 80 trials. Electroencephalogram was recorded from 32 channels with a DC amplifier. RESULTS: Patients exhibited delayed correct responses and more erroneous prosaccades during the antisaccade task than control subjects, but normal prosaccadic reaction times. In control subjects, the vertex-predominant saccadic CNV was generally larger than in patients, and larger during the anti- than during the prosaccade task. This task-related amplitude augmentation was absent in patients. Analyses of additional components suggested specificity of impaired event-related potential modulation to the saccadic CNV. CONCLUSIONS: In accordance with the presumed prefrontal dysfunction, our results suggest deficient preparation and execution of antisaccades in schizophrenia.

Adult↗
PubMed1980

Improved contingent negative variation audiometry.

In earlier reports we described contingent negative variation audiometry (CNV-A) and explored the accuracy of the method used in clinical conditions. Amplitude was found to be the factor which determines the accuracy of CNV-A. With this study we aimed to increase the amplitude of the CNV so as to improve the accuracy of CNV-A. The amplitude of the CNV is dependent on the content of the information of the S2 stimulus in the CNV paradigm. For this purpose we used a light stimulus (red or green) for the S2. The patient had to recognize the stimulus and act accordingly. The tests were performed on 12 volunteers in whom we simultaneously registered the CNV and the slow vertex response. The amplitude of the CNV was on average higher than with the previous CNV-A methods. The mean value of the absolute difference of the results between CNV-A and subjective tonal audiometry (ADG) was 6.9 +/- 5.5 dB. The mean difference between the results of both methods, however, was only 4.3 +/- 7.8 dB. The new CNV-A method is more accurate than the previous one. Nevertheless, we believe that not all possibilities for the improvement of the method have been explored. By taking into account the psychological factors which influence the amplitude of the CNV, and with a better computer analysis of the recordings, it will probably be possible to obtain even more accurate objective data on the threshold of perception of auditory stimuli with the aid of CNV-A.

Adult↗
PubMed1999

Contingent negative variation in migraine: effect of beta blocker therapy.

The contingent negative variation (CNV) has been useful in differentiating common migraine from muscle tension headaches as well as classic migraine. This study evaluated CNV in a group of patients with muscle tension headache, common migraine, and classic migraine. Furthermore, we evaluated the effect of beta blocker therapy on the CNV. The patients with common migraine responded to beta blocker therapy. CNV amplitude decreased during beta blocker treatment and with resolution of headache episodes. Further studies are indicated as CNV may be useful to evaluate the effect of drug treatment in common migraine.

Adrenergic beta-Antagonists↗
PubMed1995

Physiological study of cervical dystonia. Task-specific abnormality in contingent negative variation.

To investigate the pathophysiology of dystonia, we recorded contingent negative variation (CNV) in 12 patients with cervical dystonia and in 12 age-matched normal subjects. In a simple reaction time paradigm, the subjects were given a pair of a warning stimulus and a subsequent stimulus that triggered head rotation to either side or extension of the fingers. In normal subjects, CNVs for head rotation were not affected by neck muscle pre-activation simulating torticollis, and were always symmetrical with equally high amplitudes over the frontal and central leads. By contrast, CNVs for finger movement had the maximum over the central lead and showed a characteristic distribution; those for the right finger movement had the left hemisphere dominance, whereas those for the left finger movement had similar amplitudes over both hemispheres. In patients with rotatory torticollis (rotatocollis), the components of CNVs for head rotation were markedly attenuated in all the leads, except for the initial negative deflection (orienting response). As a whole, cervical dystonia patients had significantly lower amplitudes of late CNVs for head rotation than normal subjects (P < 0.001), whereas late CNV amplitudes in finger extension did not differ in the two groups. Their reaction times for head rotation were similar, but durations of EMG activities were prolonged in the patients because of co-contractions of the antagonists. The task-specific CNV amplitude loss is therefore not explained by reaction times or by the abnormal neck muscle activities prior to the movement, but it reflects a failure of neural activities preparing for a phasic neck movement, resulting in co-contraction of the agonists and the antagonist. Dystonia may be associated with defective retrieval or retaining of specific motor programmes or subroutines in response to sensory stimuli.

Adult↗
PubMed1998

Correlation between contingent negative variation and regional cerebral blood flow.

The relationship between contingent negative variation (CNV) and regional cerebral blood flow was investigated, using the stable xenon computed tomography method. Seventeen cases of chronic multiple cerebral infarction in the perforating artery areas (vascular dementia, mean age 67.0), 6 cases of Alzheimer's disease (mean age 69.5) and 8 healthy controls (mean age 62.5) were studied. Regional cerebral blood flows in the frontal, temporal, parietal and occipital cortex, frontal, temporal and occipital white matter, caudate nucleus, putamen and thalamus were measured. The amplitude of early CNV was significantly smaller in the vascular dementia group than in the healthy control group. The blood flows in the parietal cortex and thalamus were significantly lower in the vascular dementia group than in the healthy control group. There was a significant positive correlation between the amplitude of early CNV and frontal cortex blood flow. No significant correlations were present between the CNV and the other regional cerebral blood flows nor in healthy controls. The amplitude of CNV has been reported to be decreased in dementia. From the present study, the amplitude of early CNV was considered to be influenced by the blood flow in the frontal cortex.

Aged↗
PubMed1994

The contingent negative variation in positive and negative types of schizophrenia.

The authors analyzed the contingent negative variations of 20 medicated patients with schizophrenia diagnosed according to DSM-III-R and 20 age- and sex-matched normal comparison subjects. For the patients with schizophrenia, there were significant correlations between contingent negative variation amplitude and two items on the Scale for the Assessment of Negative Symptoms (affective flattening and avolition-apathy) and the total score on this scale. These findings have implications regarding the underlying pathology of negative and positive symptoms of schizophrenia.

Adult↗
PubMed1983

Contingent negative variation and phobic disorders.

The authors studied the modifications in contingent negative variation (CNV) in a group of rupophobic subjects. A slide-projected phobogenic or a neutral stimulus was administered 5 s prior to the warning stimulus (S1). A marked reduction in CNV amplitude and the appearance of post-imperative negative variation were observed when the phobogenic stimulus was applied. No significant variations were noted after administration of a neutral stimulus. The results are discussed on the basis of psychological and neurophysiological findings concerning the relationship between attention, arousal and CNV.

Adult↗
PubMed1997

The cortical generators of the contingent negative variation in humans: a study with subdural electrodes.

Contingent negative variations (CNVs) and Bereitschaftspotentials (BPs) were recorded from subdural electrodes implanted in 14 patients with intractable epilepsy. For recording CNVs, a Go/NoGo S2 choice reaction-time paradigm was employed. Two seconds after presentation of a low tone burst (S1), either a medium (S2m) or a high tone burst (S2h) was delivered at random. Patients were instructed to make middle finger extensions after S2m but not after S2h. For recording BPs, patients repeated self-paced middle finger extensions. BPs were recorded from the primary motor area (MI), the primary sensory area (SI) and the supplementary sensorimotor area (SSMA). CNVs showed a patchy distribution in the prefrontal area and SSMA for the early component and in the prefrontal area, MI, SI, temporal area, occipital area and SSMA for the late component. These results suggest that the CNV recorded from the scalp is the summation of multiple cortical potentials which have different origins and different functions. The cortical distribution of the late CNVs was different from that of BPs. Late CNVs are not equivalent to BPs and are not related to motor preparation alone. After S2, 3 kinds of potentials, probably related to decision making, somatosensory feedback and motor execution under specific conditions, respectively, were observed.

Adolescent↗
PubMed1995

Contingent negative variation and movement-related cortical potentials in parkinsonism.

The contingent negative variation (CNV) and movement-related cortical potentials (MRCPs) were recorded in 10 cases of Parkinson's disease, 10 cases of vascular parkinsonism and 10 age-matched healthy controls. The amplitude of the early CNV was smaller in the Parkinson's disease group and the vascular parkinsonism group than in the healthy control group. The latencies of Bereitschaftspotential (BP) and negative slope (NS') were longer and the amplitude of BP was smaller in the Parkinson's disease group and the vascular parkinsonism group than in the healthy control group. These abnormalities in CNV and MRCPs were improved by intravenous injection of L-DOPA.

Aged↗
PubMed1976

The effect of motor-response-deprivation on contingent negative variation (CNV). III: relation with Maudsley Personality Inventory (MPI).

The contingent negative variation (CNV) was correlated with Maudsley Personality Inventory (MPI) in 43 healthy adults as follows: (1) The conventional CNV with motor-response showed a negative correlation with the scores of extroversion in the MPI (E-scores). The recovery of the conventional CNV after verbal extinction showed both a negative correlation with the E-scores and a politive correlation with the scores of neuroticism (N-scores). (2) The motor-response-deprived CNV in the stimuli and nonresponse sessions (Sa and Na) showed no correlation with the MPI, because they fluctuated according to the subject's attentiveness. On the other hand, the CNV in the discrimination session (Da) with constant attentiveness to stimuli showed a positive correlation with the N-scores. (3) The response times in the control and response sessions showed a positive correlation with the N-scores in males and a negative correlation in females. The correlation with the E-scores was nearly opposite.

Adult↗
PubMed1994

Dissociation between contingent negative variation and Bereitschaftspotential in a patient with cerebellar efferent lesion.

Contingent negative variation (CNV) and Bereitschaftspotential (BP) were from the scalp in a patient with a discrete infarct in the mesial tegmentum of the midbrain involving the decussation of the superior cerebellar peduncle. Bereitschaftspotential in association with hand movements was completely absent while CNV was normally present at the frontocentral midline. This indicates that CNV is, as opposed to BP, generated without cerebro-cerebellar interactivation, suggesting different generating mechanisms.

Cerebellar Diseases↗
PubMed1984

Effects of distraction on the contingent negative variation in presenile dementia and normal subjects.

The authors recorded contingent negative variation (CNV) in a group of subjects affected by presenile dementia, at the onset of the symptoms, with a slight degree of intellectual deterioration. Recordings were carried out in rest basal conditions and upon administration of an insignificant distracting stimulus. Results were compared with data obtained in a group of normal subjects of the same age under the same experimental conditions. In the patients a marked decrease of the wave was observed upon the administration of a distracting stimulus.

Attention↗
PubMed1994

Interaction between extraversion and drug-induced conditions as indicated by the contingent negative variation.

The effects of chlordiazepoxide, caffeine and placebo on the contingent negative variation (CNV) in relation to extraversion were investigated in a double-blind study. Forty-four healthy naive volunteers, varying in extraversion scores, took part in the study. The baseline values of the O wave, E wave and average CNV amplitudes decreased significantly in successive experiments for individual subjects. Administration of the drugs caused a change in the amplitude of the O wave from baseline, whereas placebo effects were negligible. For chlordiazepoxide the change was positive at the lower end of the extraversion score and negative at the upper end, while for caffeine the opposite was found. For the individual drugs the correlations with the change in O wave and extraversion score were not significant (P < 0.20 in the case of both drugs). Analysis of the difference in the effect on O wave between the drug and the placebo yielded a significant negative correlation for chlordiazepoxide (P < 0.05) whereas the positive correlation for caffeine was not significant (P < 0.40). The individual differences between the effects of chlordiazepoxide and caffeine on O wave correlated significantly with the extraversion score (P < 0.02). This difference was positive at the lower end of the extraversion score and negative at the upper end. The same trend was found in the case of E wave and average amplitude but not significantly so. This finding supports the hypothesis that CNV is an indicator of the interaction between extraversion and condition.

Adult↗
PubMed1989

The contingent negative variation in psychopaths.

There have been persistent claims that the contingent negative variation (CNV) is absent or greatly attenuated in psychopaths. However, these claims are based on a few studies with serious methodological and diagnostic problems. The present study attempted to avoid these problems. The subjects were male prison inmates divided into psychopaths and nonpsychopaths on the basis of scores on the Psychopathy Checklist. CNV was recorded while the subject performed a forewarned reaction time task with a relatively long interval (6 s) between the warning stimulus and the imperative stimulus. Motivation to perform well was ensured by having reaction times to the imperative stimulus determine how much money would be won or lost on a given trial. The early CNV of psychopaths was significantly larger than was that of the nonpsychopaths. There were no group differences in the late CNV or in reaction time. To the extent that the early CNV reflects processing of the warning stimulus and attention to task demands, the results are consistent with the hypothesis that psychopaths are proficient at focusing attention on events that interest them.

Adult↗
PubMed1980

Synthesis of the contingent negative variation brain potential from noncontingent stimulus and motor elements.

Slow shifts in brain potential (commonly called the contingent negative variation), obtained during a warned reaction-time task with a foreperiod of 1 second, were compared with waveforms synthesized by the addition of separately obtained potentials associated with individual (nonpaired) sensory stimuli and self-initiated motor movements. The synthesized waveforms match closely the actual contingent negative variation, suggesting that it is constituted largely of separate, noncontingent elements related to sensory and motor processes.

Auditory Perception↗
PubMed1975

REM sleep and contingent negative variation development.

Three subjects demonstrated the ability to respond in a contingent negative variation (CNV) paradigm during rapid eye movement (REM) sleep. However, the CNV did not appear as it does in the waking state. This failure of the CNV to develop during REM sleep might be attributed to electrophysiological changes accompanying REM sleep.

Adult↗