Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Contingent Negative Variation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
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↗
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↗
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↗
PubMed1996

[Contingent negative variations associated with vocalization in humans].

We investigated the late negative components of the contingent negative variations (CNVs) in the verbalization task. Six subjects were instructed to perform three different motor tasks, jaw opening, vocalization of a meaningless sound and that of a word, in response to a sound stimulus following a visual warning stimulus with interstimulus interval of 4.0 sec. The electroencephalograms (EEGs) were recorded from the midline-central (Cz), left and right temporal areas (T3 and T4) and frontal areas (F7 and F8). EEGs were averaged 16 times using the visual stimulus pulse as a trigger to obtain the CNVs in each motor task. There was no significant difference between the tasks of the jaw opening and vocalization of the sound in the CNV amplitudes at bilateral electrodes. However, the amplitudes of the CNVs at the left frontal and temporal areas were significantly larger in the case of vocalization of the word than in that of jaw opening (p < 0.05). On the other hand, there was no significant difference between these two tasks in the CNV amplitudes at the right frontal and temporal areas. Our results suggested that the CNVs generated over the left hemisphere might reflect the brain activities involved in language production.

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↗
PubMed1996

The psychological factors of a premature response based on contingent negative variation.

The psychological factors of a premature response on simple reaction-time tasks were examined by comparing the difference between control responses (33 samples) and premature responses (33 samples) using the index of Contingent Negative Variation (CNV). The first (warning) stimulus was a click, the second (imperative) stimulus was a colored circular figure presented on a CRT, and the interstimulus interval was set at 3 sec. 72 trials were administered to the 24 subjects, then 33 artifact-free CNV data in a premature response were shown. Analyses indicated that CNV amplitudes in the premature response were lower than those in the control response at frontal position. Especially in the premature response, CNV waveforms stayed around baseline toward S2 at F3 and F4. In the analyses of variance, every CNV component (early, late, and whole components) at F4 or FZ was significantly lower for the premature response. These results suggested that the optimal prediction, arousal, and attention do not seem to be maintained in a premature response.

Acoustic Stimulation↗
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↗
PubMed1995

Intracerebral recordings of slow potentials in a contingent negative variation paradigm: an exploration in epileptic patients.

While exploring epileptic patients with intracerebral multilead electrodes, we applied a forewarned reaction time task with two successive sound stimuli, a paradigm that is known to elicit a contingent negative variation (CNV). The second, imperative sound stimulus was followed by a hand or a foot movement. Eleven patients suffering drug-resistant partial epilepsies were tested. The slow potentials developing during the time between the two stimuli were usually not typical CNVs (sometimes comprising multiple successive components with distinct polarities). Such "CNV-like" potentials were obtained from two main cortical zones: a central one including premotor, motor, supplementary motor, postcentral and cingulate areas; and a temporal zone, mainly including the auditory cortex and its vicinity, and in some cases the amygdala. This restricted localization contrasted with the broader extent of the CNVs on the scalp. Intracerebral CNV-like events were obtained from both hemispheres, independent of the side of the performed movement. In some patients, readiness potentials (RPs) were also recorded for comparison and displayed a more restricted extent, being present only on the contralateral motor cortex and bilaterally in the supplementary motor areas. Our data suggest that the last part of the CNV cannot just be identified with the RP.

Adolescent↗
PubMed1978

Contingent negative variation and alpha attenuation responses in children with different abilities to concentrate.

In three paralleled groups, each of seven children (age, 11 years) with reliable high, average and low ability to concentrate, measured by psychological tests, the contingent negative variation (CNV) and the concomitant alpha attenuation responses were studied in warned reaction time experiments. Stimuli were tone (S1) and patterned light (S2). In half of the trials, S2 was a square, in the other half a triagle, stimuli being projected in random order onto the fixation point. In two experiments the children had to react (a) to each type of S2, and (b) selectively to one type of S2. Significant group differences were found. In comparison to the children with low ability to concentrate, the children with average and especially those with high ability to concentrate showed: (1) stronger central occipital alpha attenuation responses to the warning stimulus, but no differences in the early CNVs; (2) more occipital alpha reduction and enhanced development of central negativity before the imperative stimulus; (3) task-specific modulation of these responses, i.e. larger pre-S2 rise in negativity in the simple reaction task, and stronger pre-S2 reduction of alpha amplitudes in the discriminative reaction task.

Alpha Rhythm↗