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PubMed1998

Contingent negative variation in patients with chronic daily headache.

The aim of this study was the investigation of amplitude and habituation of contingent negative variation (CNV) in migraine and chronic daily headache (CDH) patients in order to describe possible neurophysiological features responsible for the clinical transformation and worsening of the headache. Fifteen females suffering from migraine without aura and 15 females diagnosed with CDH evolved from migraine without aura with interparoxysmal chronic tension-type headache (transformed migraine), underwent CNV recording. Fifteen healthy females matched for age served as controls. CNV was obtained from C3 and C4 using the standard reaction time paradigm and 3 sec ISI. The amplitudes and habituation of total CNV, early and late components, and of post-imperative negative variation (PINV) were calculated. The migraine patients were characterized by significantly more pronounced negativity of the early component and total CNV, compared to CDH sufferers and controls. CDH patients demonstrated significantly reduced negativity of the late component and pronounced PINV compared to the other groups. The early component of CNV did not habituate in migraine or CDH patients. However, the impaired habituation in CDH was related to significantly lower amplitudes. These results support the diagnostic and scientific value of habituation in migraine research and therapy. Late components of CNV and PINV can be considered as predictive variables for transformation of migraine. The results are discussed in terms of the relationship between late CNV, PINV, environment control abilities and susceptibility for development of depression.

Adaptation, Psychological↗
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↗
PubMed1997

Dissociation between contingent negative variation (CNV) and Bereitschaftspotential (BP) in patients with parkinsonism.

In order to clarify the generator mechanism of the late component of contingent negative variation (CNV), we compared the late CNV with Bereitschaftspotential (BP) in patients with parkinsonism (Parkinson's disease and progressive supranuclear palsy). In patients with mild symptoms (Hoehn Yahr grade I and II) both the late CNV and BP were clearly seen. In patients with severe symptoms (Hoehn Yahr grade III, IV and V) the BP was normally seen, but the late CNV was significantly smaller or absent (P < 0.001 at Cz) and it was also significantly smaller than that obtained from age-matched normals. In one patient (H-Y grade II) who had normal BP, the late CNV was diminished selectively at the midline area. Since it was reported that the late CNV arises from at least the supplementary motor area (SMA), selective diminution of the late CNV at the midline could be explained by the decreased activity of the SMA in parkinsonism. It was also previously reported that the BP was absent but the late CNV was normally present in a patient with cerebellar efferent lesion (Ikeda et al., 1994). Taken together with the experimental results indicating that movement-related neurons in the putamen behave contingent on external stimuli, it is suggested that subcortical generating mechanism is different for the late CNV and BP although both commonly share at least some cortical generators, and that the basal ganglia are most likely responsible for the generation of the late CNV and the cerebellar efferent system for the generation of the BP.

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↗
PubMed1996

Contingent negative variation response in chronic pain patients.

The present study assesses central processing of subjective appraisal, expectancy, orientation and reaction time as indexed by Contingent Negative variation (CNV) response in chronic pain patients. Waves N1, P3 and CNV were recorded during a CNV paradigm in a simple reaction time task with a constant interstimulus interval (ISI) of 1 sec. CNV was measured from CZ x FZ in controls and chronic pain patients suffering from cervical spondylosis and low backache due to sciatica. Duration of pain was 5 to 10 years and intensity varied from moderate to severe as adjudged by Visual Analogue Scale. CNV experiment consisted of 32 trials of S1 and S2 motor response sequence. Each trial consisted of warning sound click stimulus (S1) followed by the imperative stimulus in the form of flashes (S2). S2 could be terminated by the subject quickly by pressing a response button with the dominant hand. Cursors were hand set to score the latencies for N1 and P3 potentials to S1, maximal CNV amplitude was scored as the largest negative ongoing potential immediately prior to S2 onset. Similarly Reaction Time (RT), Orientation (O) and Expectancy (E) wave amplitudes and latencies were recorded. There was a significant increase in P3 latency, RT in chronic pain patients, indicating that there is a blunting of cognitive functions and increase in reaction time in patients suffering from chronic pain. These patients also take more time to orient to CNV paradigm.

Adult↗
PubMed1997

Event-related potentials associated with judgment: comparison of S1- and S2-choice conditions in a contingent negative variation (CNV) paradigm.

To elucidate the functional role of association cortex in judgment and decision-making about external stimuli, the scalp topography of contingent negative variation (CNV) recorded in 9 normal volunteers was compared in two settings; dichotomous S1- and S2-choice paradigms using right wrist extension or flexion movement upon S2 as the choice reaction task with an S1-S2 interstimulus interval of 2 s. Two main findings were obtained. First, early CNV in the S1-choice paradigm consisted of a frontal to frontopolar midline negative potential, most likely representing judgment more than orienting response, and a left-sided parietal positive potential, at least partially representing P3b, whereas in the S2-choice paradigm it consisted only of a smaller frontal negative potential shift, most likely representing merely an orienting response. This suggests that the prefrontal and left parietal association cortexes might be active in the judgment and decision-making process. Second, after S2, two positive peaks (334 and 545 ms after S2) were observed at the midline central to left parietal areas only in the S2-choice paradigm. In the S1-choice paradigm, one large negative peak (275 ms after S2) was observed. We postulate that the first peak of the S2-choice paradigm is related to decision making or judgment and that the second peak is related to the following cognitive process. We conclude that at least the prefrontal and parietal association cortexes generate transient potentials accompanying judgment, and possibly decision making.

Adult↗
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↗
PubMed1997

Effects of changes in arousal level by continuous light stimulus on contingent negative variation (CNV).

The purpose of the present study was to investigate an inverted-U relationship between contingent negative variation (CNV) and arousal level which was influenced by extraneous environment. As an extraneous stimulant, stimulation by light was adopted, and five levels of luminance conditions, 10 cd/m2, 100 cd/m2, 320 cd/ m2, 1,000 cd/m2, and 1,800 cd/m2 were provided randomly. Under five luminance conditions, seven subjects who had been accustomed a measurement of CNV executed simple reaction time tasks to evoke CNV. Outside CNV, spontaneous EEG prior to S1 was measured as an indicator for arousal level. As a result, a negative correlation existed between the logarithm of luminance and the relative power value of alpha waves at Fz. Otherwise, an increase in luminance caused an increase in CNV amplitude until the luminance level reached 320 cd/m2, beyond which however CNV amplitude was found to decrease. These tendencies were most remarkable in the phase of early CNV at Fz. The low amplitude of early CNV seen in the high luminance conditions was inferred to have been induced by excessive arousal state because of the low relative power value of alpha waves, while the low amplitude in the low luminance conditions was inferred to have been induced by low arousal state because of the high relative power value of alpha waves. However, changes in arousal level by light stimulus caused no effect on reaction time. From these findings, it was suggested that a definite "inverted-U" relationship existed between the change in arousal level by light stimulation and resultant CNV, and that it could be discriminated as to whether reduction in CNV is caused by excessive arousal effect of environment by analyzing spontaneous EEG preceding S1.

Adult↗
PubMed1999

Two different components of contingent negative variation (CNV) and their relation to changes in reaction time under hypobaric hypoxic conditions.

BACKGROUND: Acute hypoxic conditions cause deterioration of the higher cerebral functions. The contingent negative variation (CNV), which represents both psychological and motor functions, is useful in evaluating cerebral functions. However, few attempts have been made to understand CNV change, especially for components under acute hypoxic conditions. HYPOTHESIS: If recognition of stimulus is affected by acute hypoxic conditions, the CNV response may be decreased and reaction times (RTs) may be prolonged. In addition, the differing effects of hypoxia on the early and late CNV would be demonstrated. METHODS: Hypobaric hypoxic conditions at altitudes of 0-6000 m were simulated in an experimental decompression chamber, at a decompression speed of 110 m x min(-1). Peak amplitudes of the entire, early and late CNV were measured at each altitude together with RT measurements. RESULTS: At 6000 m, the complete CNV decreased significantly compared with that at 0 m (p<0.01). Early CNV also showed a significant decrease (p<0.05), but there was no significant change in late CNV. The RTs were prolonged significantly at 5000 and 6000 m (p<0.05, p<0.01). At the altitudes of 3000 and 0 m, a negative correlation between the peak amplitude late CNV and the RT was recognized statistically (p< 0.01), while at 4000 m and above, it was rather the early CNV and the RT that were negatively correlated (p<0.01). CONCLUSIONS: With interstimulus intervals of 2 s, acute hypoxia served to reveal the functional properties of the early and late components of CNV. CNVs may be regarded as good indexes of higher cerebral function under hypoxic conditions.

Acute Disease↗
PubMed1998

[Contingent negative variation (CNV) in the detection of deception task using a serial presentation of pictures].

The purpose of the experiment was to investigate the feasibility of using contingent negative variation (CNV) as an index of detection of deception. Twelve subjects were required to complete both an innocent and guilty condition in that order. In the innocent condition, a series of six pictures, two of which depicted different landscapes and four others which depicted different female faces, was presented repeatedly on a computer display. Subjects responded by pressing a button following the landscape picture (target stimulus) that was presented last in the sequence. In the guilty condition, the procedures were the same except that subjects were also required not to detect one of the female pictures in mind (critical item), which they had chosen after the completion of the innocent condition. As compared with the innocent condition, the CNV amplitudes decreased significantly immediately before the target stimulus in the guilty condition where subjects had to conceal the critical item. The implication of these data both for the psychological completion of the concealed task and the practice in the field were discussed.

Adult↗
PubMed1999

Shortening of the cortical silent period following transcranial magnetic brain stimulation during an experimental paradigm for generating contingent negative variation (CNV).

OBJECTIVES: We investigated changes in the cortical silent period (CSP) following transcranial magnetic cortical stimulation (TCMS) during a standard paradigm which was designed to evoke contingent negative variation (CNV) in ten normal subjects. METHODS: We recorded the motor evoked potentials (MEP) and CSP during the inter-stimulus interval (ISI) of a CNV paradigm in ten normal subjects. The CNV paradigm consisted of a visual warning stimulus (S1) followed by a visual response stimulus (S2). The CSP following TCMS on the hand motor area was recorded from mildly contracted first dorsal interosseous muscles. RESULTS: The CSP was significantly shortened during the ISI (P < 0.01, t test) with a highly significant correlation with the TCMS timing during the ISI (P < 0.02, Spearman's correlation coefficient), while the MEP amplitude and latency were unchanged. CONCLUSIONS: The results suggested that shortening of the CSP was associated with neural processes related to preparation for voluntary movement during the paradigm.

Adult↗
PubMed1997

Cortical mechanism underlying externally cued gait initiation studied by contingent negative variation.

In order to clarify the cortical mechanism underlying gait initiation, we examined the scalp distribution of the contingent negative variation (CNV) preceding externally cued gait initiation in a simple reaction-time paradigm in 10 healthy right-handed men, and compared the results with the CNV preceding simple foot dorsiflexion. A pair of auditory stimuli was given with an interstimulus (S1-S2) interval of 2 s and gait consisting of at least 3 steps was initiated with the right footstep as fast as possible in response to S2. Brisk dorsiflexion of the right foot was employed as a control task. It was found that the late CNV in the gait initiation task started about 1 s before S2, and was largest at Cz (-9.3 +/- 3.1 microV) without clear asymmetry over the scalp. However, it was ill defined in the parietal area. In the foot dorsiflexion task, the late CNV was maximal at Cz (-7.1 +/- 2.9 microV), and clearly seen also over the parietal area. The late CNV at Cz was significantly (P < 0.01) larger in the gait initiation than in the simple foot dorsiflexion. The amplitude of the late CNV preceding the foot dorsiflexion task was not significantly different between the sitting and the standing posture. In view of the results of previous invasive studies in both humans and animals which showed some frontal areas, including the supplementary motor area (SMA) and the primary motor cortex, as the generators of the late CNV, it is suggested that the cerebral cortex is active in initiation of externally triggered gait in a different way from the simple foot movement, and that bilateral SMAs may play a more important role in gait initiation than in simple foot movement.

Adolescent↗
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↗