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PubMed1986

[Contingent negative variation and late components of evoked potentials during sleep in man].

The aim of this research was to study brain information processing during waking, deep slow sleep (stage IV) and paradoxical sleep (stage V) in humans, by using as a clue endogenous components of the sensory evoked potential, the emitted potential and the contingent negative variation (CNV). Eight subjects underwent three kinds of mixed auditory stimulus couples: (a) SI-SII: 2 identical clicks (50 msec, 5000 Hz); (b) SI-SIII: SIII (50 msec, 500 Hz) different from SI, was during waking, the target stimulus; (c) SI followed by an omitted click. During sleeping, the situation was used without motor response. The contingent negative variation was clearly observed during waking and paradoxical sleep as the evoked potential whose morphology during deep slow sleep was similar to K complexes. The emitted potential was obtained in four subjects out of seven during paradoxical sleep. These results suggest that during wakefulness, the discrimination of an unconditional stimulus involves a conditioning establishment revealed by the CNV and the emitted potential. The fact that the emitted potential and CNV were unavailable during stage IV is an argument in favor of the hypothesis that the conditioning effects disappear during deep slow sleep. The occurrence of CNV and emitted potential during the paradoxical stage of sleep, suggests that a conditioning established during waking can appear during this stage of sleep.

Contingent Negative Variation↗
PubMedDate not supplied

[Contingent negative variation in normal and dyslexic children].

The most prominent ERP to occur during intervals of preparation and anticipation is the contingent negative variation (CNV) or expectancy wave. The purpose of the study was to distinguish the characteristics of the CNV in a group of children with reading disabilities or dyslexia, and to compare it with a group of normal readers. Nine right handed boys aged between 9 and 13 years with reading disabilities were studied. The children were matched with a group of nine normal readers. Four derivations were used: F3, Cz, P3, and O1, with reference to linked ears. Data were analyzed using multivariate procedures. Significant differences between groups in the CNV amplitude at the left parietal site were observed. We discuss the participation of this zone and we consider processes like expectancy and attention in the differences observed.

Adolescent↗
PubMed1980

Separate and combined effects of alcohol and tobacco on the amplitude of the contingent negative variation.

To examine the separate and combined effects of alcohol and tobacco smoking on cortical functioning, the amplitude of the contingent negative variation (CNV) was studied during a simple reaction time task in non-smokers, tobacco-deprived smokers and non-deprived smokers in sessions involving administration of four cigarettes and/or 0.65 g/kg ethyl alcohol. Computer analysis indicated that alcohol and combined alcohol + tobacco significantly reduced the CNV amplitude in non-deprived smokers. Two sub-groups of non-smokers were identified, one showing large pre-drug CNV amplitudes and significant alcohol-induced reductions and the other showing small pre-drug amplitudes and no change in CNV amplitude after alcohol. No significant results were observed with alcohol, tobacco or alcohol + tobacco combined in tobacco-deprived smokers. The results are discussed in relation to previously reported studies which have indicated both synergistic and antagonistic interactions between alcohol and tobacco, and suggestions are forwarded regarding the experimental and clinical significance of tobacco-induced enhancement of CNV amplitude reduction by alcohol.

Adult↗
PubMed1992

Contingent negative variation as an indicator of sexual object preference: revisited.

This study attempted to replicate the finding of Costell et al. (1972) that contingent negative variation (CNV) in anticipation of opposite sex nudes is of greater amplitude than CNV in anticipation of same sex nudes. In order to control for variation in level of attention, which may have accounted for the result of Costell et al., a 'match/mismatch' CNV paradigm was used in which S2 was either identical to S1 or differed from it. Subjects (n = 6 males) were required to indicate a same/different judgement by button pressing at S2 offset. CNV in anticipation of opposite sex nudes was of significantly greater amplitude than CNV in anticipation of same sex nudes, confirming the finding of Costell et al. This offers encouragement for the application of CNV to the assessment of sexual object preference in sex offenders.

Adult↗
PubMed1987

Relation between warning stimuli and contingent negative variation in man.

Seven right handed male students were submitted to standard and target paired auditory stimuli to determine the relationship between contingent negative variation (CNV) and the slow negative waves following non paired stimuli. The warning stimuli informed subjects whether or not the impending unconditional stimulus implied a motor response. Subjects were instructed to execute the motor task at less than one second after unconditional stimulus. They were informed that the standard warning stimulus would be followed by an additional stimulus which confirmed its detection. Recordings of standard warning stimulus condition showed a subsequent increase in CNV amplitude. This significant increase appeared to be related to an enhancement in the subject's expectation towards the additional stimulus. The lowered CNV voltage in target condition seemed to be linked to the instructions, which involved a motor preparation after the imperative stimuli occurrence. It is suggested that the CNV may represent not only a general anticipatory but also an orienting process related to the signal value of the warning stimulus.

Acoustic Stimulation↗
PubMed1993

Is increased amplitude of contingent negative variation in migraine due to cortical hyperactivity or to reduced habituation?

The aim of this study was to compare the habituation kinetics of contingent negative variation (CNV) between 12 migraineurs without aura and matched healthy controls. CNV was studied with a 3 sec interval between the warning stimulus (WS) and the imperative stimulus (IS). The data from (a) the total interval (WS-IS), (b) early component, and (c) late component were analyzed. During successive trials the habituation kinetics were determined using regression analysis. On CNV averaged over 32 trials, migraine patients had a significantly higher negativity in the total interval compared to controls. When sequential blocks of four trials were analyzed, the most significant finding in migraineurs was lack of habituation of the early CNV component. The present study indicates that a delayed habituation, rather than a general increased cortical activity, is responsible for the CNV abnormalities in migraine without aura. We suggest that migraineurs between attacks not only have a cortical hyperexcitability, but also a lack of cortical inhibition causing delayed habituation.

Acoustic Stimulation↗
PubMed1976

Study of contingent negative variation and the post-imperative wave in the presence of interference.

The aim of this investigation was to study ways of inducing prolonged contingent negative variations (CNV) in human subjects. Fourteen subjects underwent the following experimental procedure: 1st day: 2 CNVs in control conditions were recorded (16 successive trials, each with standard S1--S2 paradigm). 2nd day: 5 successive CNVs were recorded:(1) control; (2) labyrinthine stimulation before 1st, 5th, 9th and 13th trials with simple mental calculation performed between S1 and S2, i.e. during CNV; (3) mental calculation only; (4) labyrinthine stimulation only; (5) control. None of the three interference situations caused any significant changes in the mean and maximal CNV amplitudes measured between S1 and S2. On the other hand, the post-imperative part of the CNV was significantly (P less than 0.025) prolonged but only in the situation where 2 types of interference were applied at the same time. This increase disappeared with removal of the double interference. This change, which matches that observed spontaneously and reversibly in certain mental patients in the acute phase of their illness, seems to reflect a transient alteration of the psychophysiological state of the subject. The possibility of inducing these changes in a normal subject could serve as a means of determining the individual threshold of stress.

Adult↗
PubMed1993

Olfactory evoked potentials and contingent negative variation simultaneously recorded for diagnosis of smell disorders.

Objective diagnosis of olfaction can be performed by registration of cortical olfactory evoked potentials (OEP) and of contingent negative variation (CNV). The CNV is a negative voltage developing at the vertex after discrimination of one of two smells while the patient is expecting a second stimulus. By an adequate procedure, including a long time window for averaging (2.56 seconds) with appropriate filters, the two tests can be performed simultaneously in a single session of less than 10 minutes. Anosmia is determinable by both OEP and CNV, although CNV shows less variability. On the other hand, CNV requires attention and some cooperation of the patient. Parosmia is accessible by CNV only; two odor qualities presented in random order have to be distinguished. Hyposmia can also be detected; just above the discrimination threshold, CNV amplitudes tend to be large--even enhanced--whereas OEP amplitudes may still be undetectable.

Contingent Negative Variation↗
PubMed1988

Psychophysiological effects of self-regulation method: EEG frequency analysis and contingent negative variations.

Experiments were conducted to investigate the psychophysiological effects of self-regulation method (SRM), a newly developed method of self-control, using EEG frequency analysis and contingent negative variations (CNV). The results of the EEG frequency analysis showed that there is a significant increase in the percentage (power) of the theta-band and a significant decrease in the percentage (power) of the beta-band during SRM. Moreover, the results of an identical experiment conducted on subjects in a drowsy state showed that the changes in EEG frequencies during SRM can be differentiated from those of a drowsy state. Furthermore, experiments using CNV showed that there is a significant reduction of CNV amplitude during SRM. Despite the reduced amplitude during SRM, the number of errors in a task to evoke the CNV was reduced significantly without significant delay of reaction time. When an identical experiment was conducted in a drowsy state, CNV amplitude was reduced significantly, but reaction time and errors increased. From these experiments, the state of vigilance during SRM was discussed as a state of 'relaxed alertness'.

Adult↗
PubMed1984

[Objective gustometry with adequate stimulation by registration of contingent negative variation].

Cortical evoked potentials require a steep and temporally reproduceable onset of sensory stimulation. As both items are difficult with gustatory stimuli, we tried to record the slow expectancy potential or "contingent negative variation" (CNV), which has turned out to be useful in objective olfactometry and speech audiometry. Sour, sweet, bitter or salty fluids were embedded in a water stream, which was sucked through a device well fitting to the tongue with holes at adequate locations. The negative vertex potential developped reproduceably between the recognition of taste and the acoustic signal, which could be expected only after one of the two alternatively offered gustatory stimuli. Clinical use of the method is demonstrated in a case of asymmetric loss of smell due to interruption of the chorda tympani during cholesteatoma operation. The CNV appeared only when stimulating the side of the tongue opposite to the ear operated on. In addition to the total or unilateral loss of taste, the ability to differentiate between two gustatory qualities can be diagnosed with an objective method, provided the patient cooperates by calm and attentive behaviour.

Contingent Negative Variation↗
PubMed1990

[Contingent negative variation prior to phonation in cleft palate-operated patients].

In an attempt to objectively measure psychological tension suffered by cleft palate-operated patients (CPs) with speech difficulty, the contingent negative variation (CNV) was recorded in CPs and normal subjects. The CNV is an expectancy-related brain potential recorded from the surface of the head. It begins to develop after the warning signal and reaches its maximum before the imperative signal, immediately after which a specific voluntary movement is promptly executed. The maximum amplitude of CNVs and the area encircled by each CNV and its base line were measured in the vertex and the left front-parietal region (FP) during tasks of sound production (voice CNV) or finger flexion (finger CNV). Significant differences between CPs and normals were found in the following CNV parameters: 1) The FP/vertex ratio of the amplitude of finger CNVs was smaller in CPs. 2) The amplitude of voice CNVs in the FP was lower in CPs when normals uttered a Japanese vowel "a" at a relatively low intensity (60 dB) while CPs uttered "a" or the sounds most difficult for them. 3) The ratio of the amplitude of voice CNVs led from the FP to that led simultaneously from the vertex was smaller in CPs during the tasks described in 2. 4) The ratio of the area of voice CNVs in the FP to the amplitude of each CNV was greater in CPs in two cases; firstly in the task where normals uttered "a" and CPs produced the sounds most difficult for them, and secondly in the task where the subjects were asked to make the articulation at a high sound level (80 dB).(ABSTRACT TRUNCATED AT 250 WORDS)

Cleft Palate↗
PubMed1984

[Contingent negative variation and endogenous components of the evoked potential].

After having evoked the problems raised by the definition of the different endogenous components of evoked potentials, the author reviews the experimental data related to contingent negative variation (CNV), the processing negativity, the N200, P300 and the slow waves (SW1 and SW2). Their characteristics of amplitude, latency, duration, topography and their functional significance are examined. Then, the particular point of these waves' variability is pointed out, in relation to maturation, level of arousal and personality. Finally, the different theories which preside over their interpretation are reviewed.

Adult↗
PubMed1978

Dissociation between motor potential and contingent negative variation after lesions of some basal ganglia in man: electrophysiological study of torticollis.

Studied slow cortical potentials associated with voluntary movements ("readiness potential", RP and "motor potential", MP) and discrimination tasks (contingent negative variation", CNV, "expectancy wave", EW) in 11 normal subjects and 11 patients with torticollis (every person going through 2 experimental sessions). The following was found: 1. In torticollis-patients, the RP appeared as a complex, irregular wave with low--voltage, ataxic course. 2. The mean amplitude of the RP was significantly lower in the torticollis-group than in the control group. 3. The mean amplitude of the late positive component P2 of the MP was also significantly lower in torticollis-patients than in controls. 4. The CNV showed a high-voltage course in patients with torticollis. 5. The mean amplitude of the CNV was significantly higher in torticollis--patients than in controls. 6. The mean amplitude of the late positive component P2 after the resolution of the discrimination task was also higher in the torticollis--group than in the control group, but the difference did not reach the level of significance.--This marked dissociation between the adynamic RP-MP field generators and the very responsive CNV field generators is being interpreted partly as an electrophysiological symptom of impairment in programming and performance of sequential motor acts (in the case of the RP-MP), partly as a disruption of the control of emotional and affective processes, as well as non-specific (extralemniscal) afferences (in the case of the CNV) resulting from a basal ganglia lesion in torticollis.

Adolescent↗
PubMed1978

Characteristics of the contingent negative variation in patients suffering from specific phobias.

The essential clinical feature of phobic neurosis is the anticipatory fear of certain objects and situations. Since an important factor in the generation of the contingent negative variation (CNV) is the anticipation of the imperative stimulus, records of CNVs were used as an indicator of electrocortical activity in a group of 14 patients suffering from specific phobias. After clinical evaluation, a CNV to a picture of a nondisturbing object was obtained. The amplitude of the CNV and duration of the PINV (postimperative negative variation) were taken as reference values against which response to the phobic objects were evaluated. Reaction time was automatically measured between the period of S2 and the button press. Significant differences, viz., larger CNV amplitude, longer PINV duration, and shorter reaction time, were found with phobogenic than with nondisturbing stimuli. After behavioral recovery with behavior therapy, no differences were noted in the CNVs obtained with the presentation of non-disturbing and the ones that were phobogenic stimuli. The significance of the results for an understanding of phobic neurosis and behavior therapy are discussed.

Adult↗
PubMedDate not supplied

Comparison of contingent negative variation between migraine interval and migraine attack before and after treatment with sumatriptan.

We compared in a placebo controlled, double blind, crossover within-subject design, the amplitude and area integral of contingent negative variation (CNV) using a 2 second interstimulus interval in migraine patients between attack and interval before and after treatment. The study was conducted on 14 female subjects suffering from migraine without aura. The measurements were performed in a balanced sequence at four different times on each patient, twice during the migraine interval and once in each of two migraine attacks. The CNV in the patients was measured first (baseline), then medication was administered on a double-blind basis with an autoinjector, using either 6 mg sumatriptan or a placebo solution. Thirty minutes after administration the CNV parameters were measured again and the changes between pre- and post-treatment were taken as dependent variables. CNV amplitude baseline readings did not differ significantly between the four conditions. Neither administration of placebo nor sumatriptan led to a significant change in CNV parameters independent of whether significant clinical improvement of migraine headache occurred or not. According to our findings CNV-mechanisms between attack and interval are not subject to short-term changes, even though a small, not significant tendency towards a decrease in CNV amplitude during migraine attacks appears to exist. Therefore, it can be assumed that changes in the systems which are depicted by CNV readings are not involved in initiating and terminating acute migraine attacks.

Adult↗
PubMed1989

The contingent negative variation in a Go/No Go avoidance task: relationships with personality and subjective state.

Howard et al. (1982) reported an association in mentally abnormal offenders between psychometric impulsiveness and the degree of differentiation in the contingent negative variation (CNV) recorded at the vertex between Go and No Go conditions in a Go/No Go signalled avoidance task. The present study aimed to investigate whether this finding extended to two samples of young, healthy volunteers using a variety of impulsiveness-related measures. As well as examining the Go/No Go CNV recorded from the vertex, the present study investigated the Go/No Go CNV recorded bilaterally at central (C3 and C4: Experiment 1) and temporal (T3 and T4: Experiment 2) electrode derivations. The study also investigated relationships between the Go/No Go CNV and subjective state. including stress and arousal as measured by a mood-adjective checklist, as well as several task-related state measures. The Go CNV recorded at the vertex was found to relate to a variety of impulsiveness-related measures, in particular to Eysenck's Impulsivity, Venturesomeness and Psychoticism. The Go/No Go CNV recorded at temporal sites was more closely related to measures of Emotionality. While the Go CNV appears to be an electrocortical index of a neuropsychological system mediating subjective stress, the No Go CNV appears to index subjective arousal. Results are interpreted in terms of orthogonal 'primary' and 'secondary' appraisal processes (Folkman et al., 1979), and their implications for Gray's (1982) neuropsychological theory of anxiety and Tucker and Williamson's (1984) neural control systems model of human self-regulation are outlined.

Adolescent↗
PubMed1988

Inhibitory influence of oxytocin infusion on contingent negative variation and some memory tasks in normal men.

A double-blind study combining electrophysiological and psychometrical approaches was carried out to investigate the central effects of an intravenous oxytocin (OT) infusion in normal men. Contingent negative variation (CNV) was selected as the measure of central cognitive evoked potential, and the psychometric tests measured mood, vigilance and memory. OT infusion induced a significant decrease of CNV amplitude and an increase of post-imperative positive potentials in vertex derivations. A similar effect was still evidenced one week after treatment in frontal derivations, suggesting a long time effect of OT on human brain. No significant influence of OT on mood or vigilance tests was apparent; only one item of a memory test revealed a significant impairment of some mnesic performances. These observations provide new electrophysiological arguments supporting a central action of peripheral OT administration in man.

Adult↗