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 307 records · Page 17Linked to original sources
PubMed2000

The effects on auditory neurocognitive evoked responses and contingent negative variation activity of frontal cortex lesions or ablations in man: three new case studies.

Our previous research in patients with extensive surgical ablations of the prefrontal cortex contradict the hypothesis of some authors that the generators of several auditory event-related potentials (ERPs) (N100; P200; N200; P300; SW), recordable in humans with depth/scalp electrodes and MEG over the prefrontal dorsolateral cortical areas, are essentially located in medial prefrontal and anterior cingulate-limbic cortices. Using a standard CNV paradigm, 21 EEG electrodes and topographic mapping analysis, the post-warning (S1) auditory N100a b c, P200, P300 (binaural clicks) and CNV activity were recorded in three additional patients after extensive dorsolateral and/or medial prefrontal cortex ablations, verified through CT/MRI examinations. No true post-S1/CNV components were recordable over the ablated frontal areas, only sporadic volume-conducted ERPs probably generated in the temporo-parietal lobes or posterior cingulate gyrus. For one of these patients, after excision of a vast right frontal epileptogenic cortical region (including extensive dorsolateral areas, but sparing the fronto-medial cortex and anterior/middle cingulate gyrus), no post-S1/CNV components were recordable over the ablated regions. These latest observations again indicate that independent neuronal generators of several post-S1 auditory and CNV components are located in the dorsolateral supramodal premotor/prefrontal cortical areas which are directly, ipsilaterally connected to the uni/multimodal temporo-parieto-occipital sensory and associative regions through the long, two-way, fairly superficial, superior arcuate-longitudinal and deeper superior and inferior occipito-frontal bundles. Clear and almost constant differences in the latency of some post-S1 N100 subcomponents (especially the time-lapses between onset and the highest amplitude of the N100 a and c) over various posterior, central and anterior cortical areas sequentially involved, roughly measured in 10 normal subjects along the scalp and with MRI cerebral imaging, may probably be accounted for by the transcortical homohemispheric conduction time, which varies in our scalp recordings from 1 cm/0.74-1.28 ms, mean approximately 1 cm/1.02 ms ( approximately 9.8 ms).

Adult↗
PubMed1977

The contingent negative variation (CNV) and speech production: slow potentials and the area of Broca.

The lateral distribution of the CNV was investigated during conditions that required normal male and female subjects to vocalize simple English words in a CNV paradigm. In addition to a non-verbal or comparison condition (Tone-Clicks/Button Press), two word conditions presented stimulus words in either S1 or S2 positions (Word-Tone/Speak; Tone-Word/Speak) and a third condition required a one-word association to the stimulus words (Word-Tone/Speak Association). Monopolar scalp activity was collected from sites that included a location approximating Broca's speech area on the left hemisphere, a homologous comparison site on the right hemisphere, frontal sites (F3, F4) and the vertex (Cz). Although several subjects showed some asymmetrical activity in some of the word conditions, amplitude measures based on CNV averages indicated no consistent lateralization effects over the left hemisphere prior to word vocalizaiton. Negative pretrial shifting was suspected in those conditions in which words appeared as S1 signals.

Acoustic Stimulation↗
PubMed1982

An early resolution of contingent negative variation (CNV) in the discrimination.

This study investigates slow potential shifts that occur during a time discrimination task in man. Three experimental series were presented. In series A, each trial included a 5 sec standard interval (SI) followed by a 3 sec SI-TI delay and then by a 4.5, 5.0 or 5.5 sec test interval (TI). The subjects had to estimate whether SI and TI were equal or different and responded by pressing a left or a right button after TI. In series B, the response was postponed after a 3 sec pre-response interval (PRI) succeeding to TI. Series C established an easier discrimination: only 5 or 8 sec TIs were randomly presented in each trial and the subject had to Judge whether he had ben given the "short' or "long' interval. The intervals SI and TI, in which the subject had to collect temporal information, yielded a systematic pattern of slow potential shifts: CNV was followed by an early and prolonged resolution of negativity in the second half of the interval. By contrast, SI-TI delay and PRI only yielded a classical CNV. The "CNV-early resolution' complex appears as a typical feature of temporal tasks. Its possible relation with cognitive processes leading to temporal judgements is discussed, whereas the presence of the only CNV is interpreted as aN indice of expectancy.

Adolescent↗
PubMed1981

Asymmetries of the contingent negative variation (CNV) and its after positive wave (APW) related to differential hemispheric involvement in verbal and non-verbal tasks.

The CNV and the subsequent positive wave (including both the P300 wave and the slow positivity following it) were recorded at left and right frontal and central electrodes during the performance of tasks in which nine right-handed subjects (male and female) had to determine whether S1 and S2 were the same or different. In one task, works had to be matched for meaning while in a second, faces had to be matched for identity. Words elicited CNVs which were more negative over left than right frontal regions. This effect was reversed when the stimuli were faces. Since the CNV is presumed to reflect processes of anticipation rather than stimulus processing, the asymmetry cannot be explained in terms of the lateralisation of neural mechanisms specialised for the analysis of verbal or visuospatial stimuli. Instead the observation is regarded as evidence for mechanisms of lateral activation of a more general nature than would be necessary for the facultative selection of cognitive mode. The amplitude of the CNV relative to baseline was affected by the amplitude of P300 response to S1. This was larger to faces than words in both hemispheres. A small asymmetry in the positive wave following S2 was observed, the amplitude being greater over the right hemisphere for words and over the left for faces. This is interpreted in terms of the subjective probability of the two types of stimulus for a hemisphere ill-equipped to receive them.

Adult↗
PubMed1990

[The anticipatory potential (contingent negative variation) as an indicator of neuronal information processing in relation to changes in slow potentials in the EEG].

The aim of this study was to investigate the interaction between spontaneous Slow Potential Shifts (SPSs) and the probability effect on CNV amplitudes. Fifteen right-handed volunteers participated in this experiment. The presentation of the stimuli was triggered by spontaneous SPSs (duration: 2 seconds, mean-amplitude: 10 microV) in the EEG signal at Cz. Thus, two different S1s (S1a: 1500 Hz, S1b: 2000 Hz) were presented in a random order with a fixed probability of occurrence of 0.8 for S1a and 0.2 for S1b. Each S1 was followed by a light stimulus (S2) with a constant ISI of 4 seconds. According to the cue, the subjects had to push the left (S1a) or the right (S1b) response button as fast as possible with their right index finger. The order of the 4 experimental conditions (stimulus presentation triggered by negative or positive shifts and recording of negative or positive shifts without any stimuli) in which each subject participated was balanced across subjects. Several significant effects could be found by means of a two-way ANOVA for repeated measures (condition x recording site): Negative shifts were accompanied by smaller CNVs as well as PINVs (resolution deficits) at all recording sites; the probability effect was found to be significant in the positive shift condition at F3, F4, and Cz, but not in the negative shift condition except at Cz for the E-wave. CNVs triggered by negative shifts only showed a significant correlation (-.55) with reaction time. These results together favor a two-component model suggesting that SPSs, spontaneous and evoked, are largely generated by glia depolarization, which is evoked by but outlasts neuronal activity.

Adult↗
PubMed1978

The property of contingent negative variation (CNV) in psychiatric patients: schizophrenia and neurosis.

The CNV parameters (amplitude and morphology) and the relationship between CNV parameters and performances (motor response time) were studied on schizophrenics (15 subjects), neurotics (15 subjects) and normal controls (30 subjects divided into 2 groups) in order to clarify the property of CNV in psychiatric patients. Also, the relationship between CNV and personality traits was investigated in neurotics. Since it has been known that age, sex and psychoactive drugs influence the CNV genesis in normal subjects, the control group method was used for these factors in this study. The results obtained were as follows: 1) Mean amplitudes of CNV's for schizophrenics and neurotics in each session of control, nonresponse and recovery tended to be lower than those for normal controls. Significant differences were found between schizophrenics and normal controls. 2) Correlations between CNV amplitude and response time in schizophrenics tended to be positive, while normal controls showed significantly high negative correlations. These findings were discussed from the viewpoint of the arousal theory of CNV genesis. 3) For the neurotic patients, the personality variables appeared to influence CNV amplitude. 4) Type B-CNV was most frequently seen in all sessions for normal controls. Schizophrenics and neurotics tended to show the increment of type P-CNV in nonresponse sessions without a motor response. 5) "Field Dependency" type-CNV was not found in psychiatric patients. This result did not correspond with the data reported by other investigators. 6) Type III- and type IV-prolonged CNV's appeared almost especially in schizophrenics although type II-CNV was observed in all groups. The mechanism of genesis of the prolonged CNV's was discussed.

Adult↗
PubMed1978

The effect of motor-response-deprivation on contingent negative variation (CNV): the morphology.

Eighty-four healthy subjects (47 males and 37 females) ranging in age between 9 and 76 years were employed in a study of the relations of the CNV morphology with the CNV amplitude, the reaction time and the MPI score. The results were as follows: 1. We classified a new type of Plateau (P) in the negative-going limb (NGL) types. 2. There was no sex difference in the NGL types, but the positive-going limb (PGL) types were influenced by age, and the type II tended to increase between the ages of 40--59 years old. 3. As a whole, the type B in the NGL and the type I in the PGL were most prominent regardless of age, session or paradigm. The type FD was very rare and appeared only in the session N. The types III and IV failed to be found in any healthy subjects. 4. Using the matched control study, the relations of the morphology with the CNV amplitude, the reaction time and the MPI score were analyzed. The conventional CNV amplitude in the sessions C and R increased in the sequences of the types B-A-P and the types I-II, and the CNV amplitudes in the session N increased in the sequences of the types A-B-P and II-I. The reaction time in the sessions C and R tended to prolong in the sequences of the types P-B-A and II-I. With the MPI, as the N-score increased with a decrease of the E-score, the NGL types changed from the type P to A through B in the conventional CNV and from the type A to B or P in the session N, while the PGL types changed from the type I to II in the conventional CNV and from the type II to I in the session N. 5. We suggest that there is a twofold arousal process, specific (task-relevant) and general, behind these types and that the dynamic balance of this process may influence psychological manifestations.

Adolescent↗
PubMed1988

Age differences in contingent negative variation activity of healthy young adults and presenile subjects.

20 selected right-handed very healthy subjects (10 young adults and 10 presenile subjects mean age 28.3 and 59.6) were tested for CNV activity with a simple warned reaction time (RT) paradigm. EEG and CNV components (post-S1, N1, P2, P3; early CNV; N1200; late CNV; CNV resolution) were recorded from Fz, C3, Cz, C4, P3, Pz, and P4 referenced to linked mastoid electrodes. EOG, RT and stimuli were also recorded. The presenile group differed significantly from the younger group in the auditory post-S1 N1 and P3, and in the early (O-wave) and late (P-wave) CNV complex components. A progressive amplitude reduction only in frontal leads between O-wave and P-wave with the lowest point being reached in the P-wave was characteristic in the presenile group. Further, presenile subjects showed relatively flat CNV waveshapes of low amplitude and, as a whole, performed a little less well than young persons. This finding suggests that the statistically significant changes in post-S1 EPRs and CNV activity recorded in our presenile subjects, without appreciable deficits in behavioral and mental performance, could be alerting signs of early brain involutional processes related to minimal and subclinical decrement of orienting, attentiveness and response preparation capabilities. If such is the case and it could be confirmed in a larger sample of very healthy subjects, these age-related changes in the presenium could be of considerable practical importance for clinical and research applications.

Adult↗