Early Contingent Negative Variation Amplitude Research Articles

Early and late contingent negative variation (CNV) reflect different aspects of deficits in schizophrenia.

Abnormal reward processing and psychomotor slowing are well-known in schizophrenia (SZ). As a slow frontocentral potential, contingent negative variation (CNV) is associated with anticipatory attention, motivation and motor planning. The present study aims to evaluate the early and late amplitude and latencies of CNV in patients with SZ compared to healthy controls during a reward processing task and to show its association with clinical symptoms. We recruited 21 patients with SZ and 22 healthy controls to compare early and late CNV amplitude and latency values during a Monetary Incentive Delay (MID) Task between groups. Patients' symptom severity, levels of negative symptoms and depressive symptoms were assessed. Clinical features of the patients were further examined for their relation with CNV components. In conclusion, we found decreased early CNV amplitudes in SZ during the reward condition. They also displayed diminished and shortened late CNV responses for incentive cues, specifically at the central location. Furthermore, early CNV amplitudes exhibited a significant correlation with positive symptoms. Both CNV latencies were linked with medication dosage and the behavioural outcomes of the MID task. We revealed that early and late CNV exhibit different functions in neurophysiology and correspond to various facets of the deficits observed in patients. Our findings also emphasized that slow cortical potentials are indicative of deficient motivational processes as well as impaired reaction preparation in SZ. To gain a deeper understanding of the cognitive and motor impairments associated with psychosis, future studies must compare the effects of CNV in the early and late phases.

Abnormalities of the contingent negative variation in Huntington's disease: Correlations with clinical features

The contingent negative variation (CNV) is a neurophysiological pattern related to planning of external — paced, voluntary movements. The aim of the study, was to examine the CNV in a cohort of mild demented and non-medicated HD patients, evaluating the CNV amplitude modifications in the light of clinical features and performing Low Resolution Brain Electromagnetic Tomography (LORETA) analysis in order to show the CNV multiple generators. Fourteen HD patients and 25 sex and age-matched controls were studied. All subjects were evaluated by the motor section of UHDRS, MMSE and WAIS. The CNV was recorded by 19 scalp electrodes, with a red light flash as visual warning stimulus (S1), followed by a blue light flash (S2) after a fixed interval of 3 s. The amplitude of early CNV was significantly reduced in HD, compared to controls: the amplitude reduction was significantly correlated with the bradikinesia score. LORETA analysis of early CNV significantly discriminated patients from controls, for a prevalent activation of the posterior part of anterior cingulate cortex in HD. An abnormal activation of the associative cortex devoted to the processing of attention preceding voluntary movement may be supposed in HD, probably mediated by the altered basal ganglia modulation.

Attentional distraction of CNV depending on the spatial focus.

To investigate the distraction of spatial attention to the task-irrelevant visual stimuli, contingent negative variation (CNV) was measured by using a forewarned reaction time task in 20 healthy subjects. The lasting emission of light, irrelevant to the CNV task, at each perimetric angle of 15 degrees, 30 degrees or 45 degrees to the fixated point was presented to the subjects. The amplitude of early CNV was small only under the light-emission at the angle of 30 degrees. Our results indicate that attention is distracted even by the lasting, task-irrelevant stimuli and that distraction is dependent on the focusing function of attention.

Effect of Gumchewing with CNV Paradigm on Event-related Potential

The psychophysiological effects of gumchewing were studied by event-related potential (ERP) in 12 healthy volunteers (six males and six females) aged 20–57 years. ERP was recorded with the Tentwenty electrode system from the contingent negative variation (CNV) paradigm after gumchewing and resting, and 5 event-related potential components (N100, P300, Early CNV, Middle CNV, Rate CNV) were extracted for principle component analysis. N100 peak amplitude after gumchewing was significantly larger than that after resting at F3, FZ, F7, and F8, (p<0.05). Early CNV amplitude after gumchewing was significantly larger than that after resting at FZ, F7, C4, P3, T6 and O2 (p<0.05). Reaction time after gumchewing was significantly shorter than that after resting. These results suggested that gumchewing raises general attention and the arousal level with precision.

Contingent negative variation, extraversion, reaction time and drug effects

Abstract The effect of caffeine and chlordiazepoxide on contingent negative variation (CNV) and on reaction time (RT) was investigated in 44 healthy naive volunteers, in relation to various psychological tests. Early CNV is characterised by a significant interaction between drug effects and extraversion, boredom susceptibility, disinhibition and strength of excitation. Caffeine increased early CNV amplitude for those with high scores and decreased it at low scores. Chlordiazepoxide had the opposite effect. Placebo effect was negligible. At modal scores there was no appreciable difference between either drug and placebo. In consecutive sessions early CNV decreased. Early CNV was not correlated with RT. In contrast, there were no significant drug effects on late CNV or on RT, either with or without an interaction with extraversion. Late CNV showed a strong negative correlation with RT but early CNV had a positive effect on this relationship. RT was also negatively correlated with extraversion. Late CNV was stable over sessions. Only for early CNV the results support the hypothesis that simulation by caffeine would cause a CNV decrease at low scores and an increase at high scores, whereas inhibition by chlordiazepoxide would have the opposite effect.

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.

Effects of reduction in arousal level caused by long-lasting task on CNV.

The present study aimed at investigating an inverted-U relationship between contingent negative variation (CNV) and arousal level by examining the effects on CNV of gradually reduced arousal level by long-lasting task. The subjects conducted a simple reaction time task consisting of warning stimuli (S1) and imperative stimuli (S2). This task consisted of 200 trials and lasted about 40 minutes. During this task, spontaneous EEG before S1 and SPL (skin potential level) were measured as indicators for arousal level. The 200 CNV, EEG and SPL data were classified into 5 blocks each of which included 40 trials of data. Analysis was made in seven subjects in whom reduction in the arousal level in long-lasting task was shown by increase in the relative power values of alpha waves before S1 and decrease in the SPL. As a result, the amplitude of early CNV at Fz was observed to increase from the earlier half phase (block 1) to the middle phase (block 3) and to decrease from the middle phase (block 3) to the latter half (block 5). In the middle phase, the amplitude was the greatest. The low amplitude of early CNV in the early half of the task (block 1) was inferred to have been induced by excessive arousal state because of the low relative power values of alpha waves and the high SPL at this time. On the other hand, the low amplitude in the later phase (block 5) was inferred to have been induced by reduction in arousal level because of the high relative power values of alpha waves and the low SPL. These results suggested that CNV amplitude and arousal level was in an inverted-U relationship.

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.

木質材料 針葉樹材のニオイが随伴性陰性変動（ＣＮＶ）に及ぼす影響

In order to clarify the effect of odors of seven coniferous woods on human, contingent negative variation (CNV) and electroencephalogram (EEG) were measured. Four of the species used, hinoki (Chamaecyparis obtusa), sugi (Cryptomeria japonica), akamatsu (Pinus densiflora), and hiba (Thujopsis dolabrata var. hondai), were grown in Japan, and three of them, Alaska cedar (Chamaecyparis nootkatensis), Douglas fir (Pseudotsuga menziesii), and western red cedar (Thuja plicata), were grown in the United States. The concentrations of their wood odors were analysed by gas-liquid chromatography. The total concentration of monoterpene hydrocarbon in the wood odors was held to less than 3ppb.The amplitudes of early components of CNV and the α/β wave ratio of EEG at the frontal (Fz) and central (Cz) regions between in the presence and absence of wood odors were compared. 5 male and 5 female volunteers ranging in age from 20 to 26 were examinated. The result obtained are summerized as follows:(1) In the presence of wood odors, the early CNV amplitudes at Fz decreased at a statistical level of significance of 5% or better.(2) The α/β wave ratio of EEG increased significantly at Cz with hiba wood odor (p<0.01).(3) The decrease of the early CNV amplitude at Fz is related to the concentration of α-pinene in the wood odors.

Impulsivity, mood and the contingent negative variation in women with and without premenstrual changes in impulsive behaviour

Contingent negative variation (CNV), postimperative variation (PIV) and reaction time (RT) were recorded in a signalled Go/No Go avoidance paradigm, verbal and visuo-spatial versions of a match/mismatch paradigm, and an auditory forewarned RT paradigm at 3 menstrual cycle phases—menstrual, mid-cycle and premenstrual—in 3 samples of women: women without significant premenstrual changes (PMCs) in mood and behaviour; women with documented PMCs in mood and behaviour excluding premenstrual impulsivity; and women with documented PMCs in mood and behaviour including changes in impulsive behaviour. Subjective stress and arousal were also measured at each cycle phase. Recordings were repeated in a small sample of women with PMCs during treatment with fluoxetine/ placebo. There was no relationship between either state or trait measures of impulsivity and Go/No Go CNV, in contrast with previous findings in males. MANOVA revealed significant Group × Phase interactions for early CNV amplitude and laterality in the forewarned RT paradigm, and for subjective stress, supporting a “disordered state regulation” hypothesis of premenstrual syndrome (PMS). Other measures (subjective arousal, PIV in the Go/No Go paradigm) showed significant effects of Group independent of cycle phase, with PMS groups showing lower arousal and greater postimperative positivity than controls.

A correlation study of contingent negative variation, reaction time, and EEG power spectrum in control and psychopathological populations

Contingent negative variation (CNV), reaction time (RT), and EEG power spectrum were measured in a group of 27 neurotics and 26 controls subjects, male and female, aged 18 to 38. CNV was recorded with a 1 sec interstimulus interval and averaged over 48 trials. Two spectral analyses of the EEG were performed, the first during the 1 sec period preceding S1 (spontaneous EEG), the second during the S1–S2 interval (activated EEG). For each group of subjects, we calculated the correlations between four measures of CNV amplitude, RT duration, and the relative powers of the delta, theta, alpha and beta activities during spontaneous and activated EEG. In neurotic subjects there was an absence of correlation between the pre- and post-imperative segments of the CNV, and between early CNV amplitude and per cent alpha power. Both groups shared in common strong correlations relating CNV amplitude and RT length, on the one hand, and the different components of the EEG spectrum, on the other hand, Principal component analysis applied to the pooled data revealed different factors for CNV and EEG parameters, suggesting independence of the neurophysiological mechanisms implied in the two phenomena.