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PubMed1981

The contingent negative variation as an indicator of speech discrimination difficulty.

Recent studies have illustrated the usefulness of the contingent negative variation (CNV) in exploring language processing capabilities. The purpose of this study was to investigate how CNV magnitude is influenced by speech discrimination tasks of graded difficulty. Nine young adult subjects performed easy and difficult speech discrimination tasks while cortical activity was recorded from the vertex. Stimuli consisted of consonant-vowel pairs that were presented in a background of noise. Consistently larger CNV responses were obtained for the difficult versus the easy discrimination task in the nonimperative condition. No consistent trend was found for the imperative condition. There electrophysiological results correspond well with both correct and incorrect discrimination behavior. The clinical implications of these findings are discussed.

Adult↗
PubMed1995

The contingent negative variation in an odor labeling paradigm.

Fifteen subjects participated in an experiment designed to assess the contingent negative variation (CNV) during the labeling of odors and shapes. Odors or shapes were presented (S1) and followed 3 s later by a lexical label (A, B, or C) (S2). In 75% of the trials, the S2 was the correct label for the odor or shape. In the remaining trials, the S2 was an incorrect label. Subjects' olfactory performance was correlated with both the CNV during in the S1/S2 interval and also the P300 following the S2 stimulus. The CNV over the left frontal area was significantly larger in the olfactory phase of the experiment. CNV activity also correlated with olfactory performance such that subjects with the largest odor-related CNVs had the best olfactory performance. Although P300 differed as a function of label matches versus mismatches, no odor-specific effects or correlations were found.

Adolescent↗
PubMed1999

Contingent negative variation in children with anorexia nervosa.

BACKGROUND: Central catecholamines, particularly dopaminergic and noradrenergic systems, have affected the appetitive behavior in patients with anorexia nervosa (AN). The purpose of this study is to distinguish the characteristics of contingent negative variation (CNV) and postimperative negative variation (PINV), which may reflect the level of catecholamine in children with AN. METHODS: Eight children with AN aged 10 to 15 years and 23 age-matched healthy children were recruited. Contingent negative variation was recorded from the frontal midline (Fz), central midline (Cz) and parietal midline (Pz) referenced to linked earlobes during 30 trials consisting of a warning stimulus and an imperative stimulus with an interstimulus interval of 2 s and an intertrial interval of 10 s. The imperative stimulus of each trial required a button press. RESULTS: Children with AN had a diminished amplitude of the CNV. They had a significantly more attenuated early CNV and late CNV amplitude at Cz than normal children. No significant differences were observed between AN children and normal children in the amplitude of PINV at all three electrode sites. No difference could be found between the two groups in the frequencies of normal and abnormal duration of PINV. CONCLUSION: These findings suggest that early CNV may be diminished by norepinephrine deficiency and late CNV may be attenuated by dopaminergic deficiency in children with AN. Reduced CNV may represent impaired cognitive processes which reflect impaired appetitive behavior in AN children.

Adolescent↗
PubMedDate not supplied

Personality and the effects of acute alcohol intake. A contingent negative variation study in healthy subjects.

This study investigates the relationship between blood alcohol concentrations (BACs) and contingent negative variation (CNV). Fourteen healthy subjects were divided on the basis of their personality profiles--the Minnesota Multiphasic Personality Inventory (Hs+Hy+D/3)--into a high score (HS) and low score (LS) subgroup. The CNV was recorded using a choice-reaction time (RT) task. CNV recording was performed in two conditions: inter-stimulus intervals (ISIs) of 1500 ms and 2500 ms at three different BACs (0.3, 0.5 and 0.8 g/L) after acute alcohol administration. At the high BAC (0.8 g/L), both subgroups showed a reduced CNV amplitude area and a longer RT (p<.05) in both ISI conditions. No effects either on the CNV or on the RT were observed at the low BAC (0.3 g/L). At the intermediate BAC (0.5 g/L), the HS subgroup displayed an increased CNV amplitude (p<.05), not accompanied by a significantly longer RT (short ISI condition), and a reduced late CNV (p<.05) with a longer RT (p<.05) (long ISI condition). In the LS group, only a longer RT was observed in the long ISI condition. CNV modifications point to an individual, apparently personality-related, threshold of sensitivity to different alcohol levels.

Adult↗
PubMed2002

Lack of age-dependent development of the contingent negative variation (CNV) in migraine children?

Increased negativity of contingent negative variation (CNV) in adult migraineurs is thought to reflect cortical hyperexcitability. CNV amplitude changes with age in healthy adults. Recently, evidence emerged that this might not be the case for migraineurs. Our study investigates age-dependency of CNV during childhood age. Seventy-six healthy controls and 61 children with migraine without aura (IHS code 1.1) between 6 and 18 years were examined using an acoustic S1-S2-CNV-paradigm with a 3-s inter-stimulus interval. The amplitude of the late component of CNV, as well as total CNV at the vertex (Cz according to the international 10-20 system), were significantly higher in migraineurs without aura than in controls. Healthy controls showed increasing amplitudes of CNV with age, whereas in migraine children without aura amplitudes did not change. Thus group differences were reduced during adolescence. Increased CNV negativity might reflect a biological vulnerability to migraine, rather than being a result of chronification. Migraineurs seem to lack age-dependent development of CNV also during early age, which supports the hypothesis of migraine as a maturation disorder.

Adolescent↗
PubMed1979

Contingent negative variation and accuracy of time estimation: a study on cats.

Slow cortical potential shifts, similar to the contingent negative variation (CNV) discovered in man, were analysed in cats submitted to a schedule of temporal conditioning. Two situations were compared, according to information delivered during a 7 sec delay: in the first (A), a fixed visual signal appeared on an oscilloscope screen; in the second (B), the signal moved across with time. In both cases, the cat had to press a lever 5-7 sec after signal onset. The CNV recorded during the delay had different amplitudes according to the cortical site involved. It could be dissociated into two components, which showed similar evolutions as a function of experimental conditions. The characteristics of the CNV as a whole varied with temporal parameters. CNV amplitude and time course were related to the accuracy of the cat's responses; prolonged training in unchanged experimental conditions led to a decline in negativity, which seemed to reflect automation of time estimation processes. These data suggest that CNV may be an index of a phase of information processing aimed at constituting internal time bases congruent with a particular situation.

Animals↗
PubMed1979

Relationships between the late component of the contingent negative variation and the bereitschaftspotential.

The purpose of this study was to determine whether the late component of the contingent negative variation (CNV) in a S1-S2-respond paradigm shares critical features with the Bereitschaftspotential (BP) prior to self-paced voluntary movements. In a group of 8 subjects, the late CNV and the BP exhibited: (a) similar effects of response speed variation, (b) corresponding influences of subjective factors, and (c) a similar scalp distribution with the exception that the BP was much more lateralized. In contrast, no such relationships were found between early CNV and BP.

Brain↗
PubMed1995

Contingent negative variation during migraine attack and interval: evidence for normalization of slow cortical potentials during the attack.

The contingent negative variation (CNV) amplitudes of 16 subjects with migraine without aura were studied during pain-free intervals and during attacks and the results were compared with those of 22 healthy subjects. In 32 trials the CNV amplitudes were calculated for (a) "total interval", (b) "early CNV component", (c) "late CNV component", and (d) habituation. There was a significantly higher total CNV amplitude in migraine subjects during pain-free intervals compared to that of the healthy subjects and migraine patients during an attack. Healthy subjects as well as subjects studied during the attack showed a significant habituation whereas migraine subjects studied during pain-free intervals did not. This suggests that the higher CNV amplitude in migraine patients studied between pain-free attacks may be due in part to impaired habituation.

Adult↗
PubMed1977

The effect of diazepam, chlorpromazine and amobarbital on the contingent negative variation.

The effects of diazepam (5 mg), chlorpromazine (CPZ, 12.5 mg) and amobarbital (100 mg) on the contingent negative variation (CNV) at Cz and Oz were studied in groups of 10 subjects each. Amobarbital and placebo were given by the double-blind crossover method. Two kinds of experimental paradigms were used: Click (warning stimulus, S1)--flashes (imperative stimulus, S2)--and click--electrical stimulation--motor response. The results obtained were as follows; 1) CNV amplitudes were decreased significantly by administration of diazepam only at Cz when S2 was flashes and at both Cz and Oz when S2 was electrical stimulation. 2) CPZ-induced effects were of either augmentation or decrement in CNV amplitudes depending on the subject and on the modality of S2. Involvement of dose-dependent factor was suggested. 3) Amobarbital and placebo did not give any significant changes to the CNV. 4) Significant correlations between CNV amplitudes at Cz and Oz were found before drug administration and even after taking drugs exclusive of diazepam. Its decremental ratio from Cz to Oz was approximately 0.6 to 0.8. The correlation coefficient became to be insignificant after taking diazepam only when S2 was flashes.

Adult↗
PubMed1995

Event-related changes of background electroencephalogram during contingent negative variation paradigm.

The autoregressive model was applied to the background electroencephalogram during the tone(S1)-tone(S2)-respond contingent negative variation paradigm under eyes-open condition. The EEG data were obtained at the scalp sites of Fz, Cz, and Pz in seven normal males. During the first half of the interstimulus interval (ISI) of 2.5 s, Fz-dominant excitatory process was suggested in concordance with an orienting response to stimulus 1. In the second half of the ISI, Pz-dominant inhibitory process was considered. The stimulus 2 presentation and the required motor response promoted the Pz-dominant process.

Adult↗
PubMed1986

Contingent negative variation and efficacy of beta-blocking agents in migraine.

Thirty-three patients with common migraine underwent contingent negative variation (CNV) recordings before receiving prophylactic beta-blocker treatment with either metoprolol (27 patients) or propranolol (6 patients) at mean daily dosages of 110 mg and 122 mg, respectively. After 3 months the therapeutic efficacy of the beta-blocker was assessed in each patient by means of a global severity score and compared with the initial CNV recordings. The mean clinical improvement was 62%. A significant positive correlation was found between CNV amplitude before prophylaxis and the clinical response to beta-blockers: patients with higher CNV tended to respond better to therapy. Eight of 10 patients with a CNV amplitude higher than -25 microV had a more than 50% reduction of the severity score--that is, a good or excellent response to the beta-blocking agent--whereas only 2 of 9 patients with an amplitude lower than -20 microV had a good response.

Adrenergic beta-Antagonists↗
PubMed1988

Contingent negative variation (CNV) differences between cerebrovascular patients with and without dementia.

This study investigated the clinical usefulness of the contingent negative variation (CNV) as a neurophysiological index of cognitive dysfunction associated with cerebrovascular disease. A total of 31 patients ranging in age from 45 to 88 years with the diagnosis of a stroke were included. Nineteen patients were classified as demented according to clinical assessment and the Mental Deterioration Index (MDI) based on the WAIS, the other 12 patients as non-demented. In a discriminative CNV-paradigm two different tones served as warning stimuli for a flash of light presented 1.5 s later that could be turned off by a press on a button only after the relevant tone. According to our hypothesis, CNV amplitudes of demented patients were significantly smaller than those of the non-demented group. Moreover, a significant relationship was observed between severity of dementia (MDI) and degree of amplitude reduction. Thus, it was concluded that the CNV method could make an important clinical contribution to the assessment and course of dementia.

Aged↗
PubMed1978

The effect of warning stimulus novelty on the P300 and components of the contingent negative variation.

This experiment evaluated the effects of stimulus and response probability on the P300 and components of the contingent negative variation (CNV) in three different reaction tasks. In the first task the warning stimulus (S1) indicated that the imperative stimulus (S2) would require either a left or a right button press response; in the two other tasks the S1 indicated that S2 would either require a button press response or not. The a priori probability of S1 and the response to S2 were independently varied. The results show that a novel S1 significantly increased the amplitude and latency of the P300 and early CNV component: the late CNV component, however, increased significantly when a motor response to S2 was required. Early and late CNV components also differed in midline distribution. It is concluded that the early CNV can be viewed as the slow wave part of the event-related potential to S1, while the late CNV is an event preceding shift that strongly relates to the motor requirements of S2. It is finally suggested that both the P300 and early CNV reflect an orienting response to S1.

Acoustic Stimulation↗
PubMed1989

Changes in contingent-negative variation and reaction time related to precueing of direction and force of a forearm movement.

Scalp-recorded contingent-negative variation was analyzed in a reaction time paradigm with full, partial, or no prior information regarding two dimensions of a forearm response: direction (flexion/extension) and force level (weak/strong). Visual cues (light-emitting diodes) were used for the warning and response signals. The reaction time was shorter when direction, rather than force, was known in advance. Source derivation techniques revealed that the somatosensory arm area was more 'activated' by direction than force information, whereas the precentral cortex seemed to be more strongly influenced by force information. Partial advance information was sufficient to trigger preparatory activities specific for the revealed dimension of the ensuing movement.

Adult↗
PubMed1985

[Contribution of contingent negative variation (CNV) to the study of schizophrenia].

The authors first review neurobiological and psychopathological data supporting the use of Contingent Negative Variation (CNV) for the study of Schizophrenia. Next, results obtained with the method are presented (i.e. with S1-S2 interval = 1 sec, and recording leads = Cz and Fz) comparing 34 control subjects with 29 schizophrenic patients, all diagnosed with the "Present State Examination" test or PSE (Wing and Sartorius). In patients, reduced CNV amplitude (p less than 0.0001), together with reduced CNV resolution (p less than 0.02) and less differentiated topographical spreading (p less than 0.02) were observed relatively to controls. There is also a slower reaction time (p less than 0.02). Such abnormalities are sufficiently frequent as to allow CNV as a helping diagnostic tool, with a sensitivity rate of 83% and a specificity rate of 85%. These results are discussed with respect to the psychopathological and neurobiological problems in relation with schizophrenia.

Contingent Negative Variation↗
PubMed1987

[Value of the study of contingent negative variation in migraine and tension headache].

The aim of this study was to display the result obtained by the contingent negative variation (CNV) recording in patients suffering from headache. Eighty-five patients were taken into account: 59 with migraines (M) and 26 with tension headache (TH). A typical CNV pattern (high CNV amplitude with no habituation) differentiated M from TH. Moreover, psychological data were collected through Rorschach ink blot test among 42 headache sufferers (31 M and 11 TH). The typical Rorschach repressive pattern of alexithymia was found as well in M as in TH while CNV amplitude was significantly higher in the 31 M (-25 microV) than in the 11 TH (-19 microV FP less than 0.04). Biochemical data collected among 28 patients (17 M and 11 TH) revealed a positive correlation between CNV amplitude and plasma level of noradrenaline, regardless of the type of headache (r = 0.58; P less than 0.01). Thus, besides psychological factors, catecholaminergic mechanisms seem implicated in the determination of the CNV pattern in migraine. CNV may help the clinician both to specify diagnosis and to decide between the many therapeutic strategies available.

Adult↗
PubMed1988

[Contingent negative variation and regional cerebral blood flow in senile dementia and cerebral aging].

Relationships between contingent negative variation (CNV) amplitude, regional cerebral blood flow (CBF), mini mental status examination score (MMSE) and reaction time (RT) have been studied in young subjects, non-demented old subjects and patients with primary degenerative senile dementia. Significant correlations have been found between CNV amplitude and global CBF, MMSE score and reaction time. Factorial analysis has shown 3 factors weighted respectively by MMSE and CNV, antero-posterior ratio fort left hemispheric CBF and age, and antero-posterior ratio for right hemispheric CBF and reaction time. Discriminant analysis has shown 2 discriminant functions differentiating young from old subjects with 90% accuracy and demented from non-demented patients with 75% accuracy.

Adult↗