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 451 records · Page 25Linked to original sources
PubMed2004

Electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task.

OBJECTIVE: The aim was to verify the occurrence of proposed electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task and to support their functional interpretation by using a manipulation intended to enhance subjects' response bias. METHODS: Electroencephalographic activity was recorded during administration of a transformed version of the AX continuous performance task in which cues signaled response alternatives. RESULTS: The previously reported parietal P3, NoGo-N2, NoGo-P3 and contingent negative variation were replicated. Besides, the frontal selection positivity and the lateralized readiness potential were demonstrated. With increasing Go-probability, the parietal P3 to the cue increased without changes in other cue-related correlates. In addition, reaction times decreased, non-parametric measures of sensitivity and bias decreased, the NoGo-N2 increased, and the parietal Go-P3 decreased. CONCLUSIONS: The proposed electrophysiological correlates were identified. Sub-threshold LRPs suggested a central inhibition mechanism. Cue-related correlates revealed that anticipation of a high-probability Go-stimulus involves attention rather than bias. This implies that the increased NoGo-N2 reflected an increase in conflict rather than an increase in inhibition. SIGNIFICANCE: Electrophysiological measures can greatly enhance our understanding of normal and abnormal information processing during continuous performance and related tasks.

Adult↗
PubMedDate not supplied

[The biological basis of suicidal behavior: neuroendocrine and psychophysiological approach to the role of catecholamines].

The current main neurochemical theories of the biological correlates of suicidal behavior principally involve the serotonergic system. Few data are available about the possible role of the catecholaminergic (noradrenergic and dopaminergic) function. In the present study, in a first part, we assessed the growth hormone (GH) response to clonidine, a selective alpha 2-adrenergic agonist, and to apomorphine, a dopaminergic agonist, in 22 DSM-III-R major depressive male inpatients with a history of suicide attempts compared to 22 age-matched major depressive inpatients without history of suicidal behavior. Hormonal responses to clonidine and apomorphine were also compared with 4.00 PM postdexamethasone cortisol levels. The two groups differed significantly in the GH peak response after apomorphine: 6.27 +/- 3.18 ng/ml in suicide attempters vs 17.40 +/- 14.87 ng/ml in nonattempters (F = 11.78, p = 0.001). There was no statistically significant difference between the two groups for GH peak responses after clonidine. Moreover, mean postdexamethasone cortisol levels did not exhibit any significant difference between suicide attempters and nonattempters. Violent and nonviolent attempters did not differ on any of the biological measures. In a second part, P300 and contingent negative variation (CNV) were recorded in 20 depressive inpatients subgrouped into suicide attempters (n = 10) and nonattempters (n = 10). The results showed a significant reduction of both P300 and CNV amplitudes in patients who attempted suicide compared to patients without history of suicide attempts. Moreover, a significant correlation was found between the Suicidal Risk scale and CNV amplitude. In conclusion, these results suggest that a dopaminergic hypoactivity as assessed by a blunted GH response to apomorphine and by a reduction of both P300 and CNV amplitudes, could be considered as a biological correlate of suicidal behavior. In contrast, noradrenergic disturbances, particularly at the level of alpha 2-adrenergic receptors, seem to play a more minor role. Moreover, DST nonsuppression cannot be considered as a biological marker of suicidal behavior.

Adolescent↗
PubMed1998

Topographic differences in CNV amplitude reflect different preparatory processes.

Topographic differences in Contingent Negative Variation (CNV) were recorded while people were preparing for cognitive versus motor tasks in an S1-S2 paradigm. CNV had a frontal distribution when people prepared to encode words into long-term memory, whereas CNV was more centrally distributed when the tasks were predominantly motoric. These topographic differences appeared to be related to the type of task rather than the amount of information extracted from the S2, because a direct manipulation of the level of S2 processing had little effect on CNV amplitude. The topographic differences in CNV suggest that preparation for motor activity is a different psychological process from preparation for stimulus processing and that these two processes are subserved by different neural structures. This experiment also demonstrated that a recognition memory paradigm can be useful in the investigation of the psychological correlates of CNV.

Adolescent↗
PubMed1986

The effects of response parameters on CNV amplitude.

The contingent negative variation (CNV) was recorded using an inter-stimulus interval of 4 sec in the context of variations in the parameters of button press responses to be performed following S2. The response parameters manipulated were response duration, the number of fingers used, the number of discrete movements and the complexity of response sequences. The CNVs were averaged with reference to both the stimuli and the response. Variations in response parameters were apparent only in measures of response averaged CNVs. Negativity following response onset was also related to response parameters, again only for response-locked averages. These results support the contention that the CNV, like the Bereitschaftspotential (BP), is primarily related to response factors, and hence that the CNV and the BP are essentially the same phenomenon. It is suggested that the results indicate that negativity prior to, and possibly following, response onset represents the formulation of response-specific motor programs.

Adult↗
PubMed2000

Policosanol, reaction time and event-related potentials.

The aim of the present study was to compare the results of a 1-week, double-blind placebo-controlled trial investigating the effects of isopolicosanol and octacosanol on reactivity and related brain activity. In particular, reaction time (RT) and event-related potentials such as contingent negative variations (CNV) and P300 (P3) have been studied. Thirty sedentary healthy students were tested before and after treatment (3.6 mg/die for 7 days) with orally administered tablets of placebo (group A), isopolicosanol (B) and octacosanol (C). RT were studied according to three procedures: simple RT (SRT), go/no-go RT (GRT) and choice RT (CRT). Results show that before treatment, there were no significant differences between groups A, B and C. After treatment, the RT of group A was unchanged, while the RT of groups B and C were reduced. In group B, in the SRT test, the reduction of RT was accompanied by electrical data exhibiting increased amplitudes of CNV and shorter latencies of P3. These results show that the main effect on reactivity and event-related potentials can be ascribed to policosanol and is mainly evident in the SRT test.

Administration, Oral↗
PubMed1988

Movement and stimulus preceding negativity.

After a short description of the different premovement potentials it is suggested that readiness potentials (RPs) recorded over different cortical motor areas reflect different functions. Then it is proposed that the late wave of the contingent negative variation (CNV) is a composite of a RP and a stimulus preceding negativity (SPN). Arguments for the existence of a non-motoric SPN are given, based upon our recent experiments. Next, it is suggested that a SPN is found preceding at least three different kinds of stimuli. Finally, it is stated that motor preparation and stimulus anticipation are different processes, reflected in a different distribution of the accompanying Slow Waves and an all or none accompanying change in reflex amplitudes.

Animals↗
PubMed1988

Thyrotropin-releasing hormone enhances event-related brain potentials and growth hormone release in man.

Changes in contingent negative variation (CNV), a brain-evoked potential related in arousal, as well as in serum triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), prolactin (PRL), cortisol and growth hormone (GH) levels were recorded in 12 male volunteers receiving either thyrotropin-releasing hormone (TRH) or saline infusion. Only during TRH administration an increase in CNV (P less than 0.02) and, 30 min later, in GH (P less than 0.05) occurred; thyroid hormones and PRL increased as well, in the absence of any correlation with CNV areas. Cortisol was not affected by TRH. As dopamine (DA) agonistic drugs notoriously increase both CNV areas and GH levels and experimental evidence for prodopaminergic properties of TRH has accumulated in animal models, a possible explanation of the results here presented might be the activation of DA pathways by TRH also in the human.

Adult↗
PubMed2000

Motor and nonmotor event-related potentials during a complex processing task.

Identification of the necessary stimulus properties to elicit the stimulus preceding negativity (SPN) has been the impetus for numerous research studies. The current study was conducted to explore the possibility that the SPN is an index of cognitive resource allocation. An auditory warning stimulus (S1) indicated whether an easy or difficult discrimination would occur at S2. The SPN was collected before a nonmotor discrimination task (S2) that consisted of identifying the higher of two bars. To eliminate the influence of motor processing prior to S2, a button press on the side of the higher bar was held until perception of a response cue (S3). Additionally, P3, contingent negative variation (CNV), and behavioral measures were collected to assist in assessing the SPN. Results indicated that although the SPN exhibited increased negativity, no differences were observed based on task difficulty. However, task difficulty did affect P3 data for both the warning tone and the discrimination task, an effect not observed for the CNV. Overall, the data did not support that hypothesis that the SPN provides an index of cognitive demand.

Adolescent↗
PubMed1990

[The usefulness of event-related negativity in demonstrating the therapeutic effects of nootropic drugs using cerebrolysin as an example].

This study investigated the usefulness of the Contingent Negative Variation (CNV) in the assessment of therapeutic efficacy of a nootropic substance, Cerebrolysin. A total of 41 geriatric patients with the diagnosis of moderate organic brain syndrome of different etiology were included in this randomized placebo-controlled double-blind study. After ten Cerebrolysin- plus multi-vitamins-Infusions, the treatment group of 27 patients showed a significant CNV-amplitude increase as compared to pre-treatment values. In the placebo group of 14 patients CNV-amplitudes even decreased after ten Infusions with multi-vitamins alone. These findings were interpreted in line with the vigilance model of nootropic drug effects as a vigilance-increasing effect of Cerebrolysin, i.e. as an increased neuronal performance readiness. The results confirmed the usefulness of the CNV method by providing an EEG-index of nootropic drug effects.

Aged↗
PubMed1997

[A comparative psychophysiological analysis of anxiety disorders of a permanent and paroxysmal nature].

Observation of patients with panic disorders (PD) and generalized anxious disturbances (GAD) by means of contingent negative variation (CNV) revealed that they significantly differ from healthy individuals. Anxiety, depression and autonomic dysfunction were more pronounced in such patients. Both high amplitude of early CNV component and alteration of its habituation were quite typical for patients with PA in contrast to GAD patients and healthy individuals. There were no differences in CNV indices between the healthy group and the patients with GAD. PA patients differed from GAD ones by smaller manifestation of depression, shorter duration of the disease, shorter time of reaction. The data obtained have demonstrated qualitative psychophysiologic differences between PA and GAD groups of patients. They were mostly pronounced in both amplitude of early CNV and alteration of its habituation. PA patients were characterized by an increase of excitability in brain cortex and by surplus orientation activity. The authors suppose that specific CNV pattern reflects neurodynamics of "paroxysmal brain".

Adult↗
PubMed1992

Relationship between CNV asymmetries and individual differences in cognitive performance, personality and gender.

This study used verbal and spatial variants of a cognitive 'match/mismatch' paradigm to explore relationships between functional brain asymmetries and individual differences in cognitive performance, personality and gender. Contingent negative variation (CNV) elicited in the 'match/mismatch' paradigm was recorded from central (Cz, C3 and C4) derivations in two male and one female samples. Results indicated gender differences in both the degree and direction of CNV asymmetries. Males showed a left hemisphere asymmetry in the verbal task and a right hemisphere asymmetry in the spatial task, with significant laterality (C3-C4) differences between tasks across the foreperiod. Females showed a left hemisphere asymmetry in both tasks with laterality differences between tasks confined to the early part of the foreperiod. CNV amplitude in the verbal task correlated with verbal memory performance and verbal I.Q. CNV amplitude in the spatial task correlated with visuospatial memory performance. Social extraversion was associated with greater left-hemisphere asymmetry in both tasks, while behavioural extraversion was associated with left-hemisphere asymmetry in the verbal task only, and with smaller verbal than spatial CNVs.

Adult↗
PubMed2002

Slow cortical potentials in migraine families are associated with psychosocial factors.

OBJECTIVE: The aim of the study was the determination of the relationships between neurophysiological and psychosocial factors within the pathogenesis of migraine. METHODS: The contingent negative variation (CNV), parent-child interactions and theirs relationship were investigated in 30 families with a migraine child and 20 healthy families. RESULTS: (1) None of the groups of children, independent of diagnosis, differed according to amplitude or habituation of the CNV. (2) Parents from migraine families exerted significantly more control over migraine children compared with interactions with healthy brothers/sisters. (3) The strong relation between CNV habituation/amplitude and abnormal pattern of parent-child interactions (especially overwhelming dominance and control) was found only for young migraineurs. This relation was not seen in healthy families or for healthy siblings of migraine children. CONCLUSION: This study provides significant evidence for a strong influence of family interactions on the development and maintenance of neurophysiological abnormalities in the migraineous headache. The role of psychosocial factors in the etiopathogenesis of migraine has to be investigated in further studies in more detail.

Adult↗
PubMed1996

Latent inhibition effects reflected in event-related brain potentials in healthy controls and schizophrenics.

The present study examined the effects of pre-exposure of an irrelevant stimulus on reaction time and the contingent negative variation (CNV) in healthy controls and schizophrenic patients. In Phase I, subjects were either pre-exposed (PE) or not pre-exposed (NPE) to repeated presentations of an auditory probe stimulus (white noise), while engaged in counting auditory nonsense syllables. In Phase II, all subjects were required to produce a rapid motor response to a visual imperative stimulus that was preceded by the previously irrelevant auditory stimulus. During Phase II in controls, for PE as compared to NPE subjects, the build-up of CNV across trials was delayed. In schizophrenics, for both PE and NPE subjects, there was no pre-exposure effect on the CNV component. These findings indicate that ERPs may be useful in explicating the normal latent inhibition effect (poor associative learning to a stimulus after it has been passively pre-exposed) and its disruption in schizophrenia.

Adult↗
PubMed1981

Opposite hemisphere differences in movement related potentials preceding foot and finger flexions.

Nine right-handed subjects performed an experiment in which the recording of the readiness potential (RP) and of the contingent negative variation (CNV) was combined. A microswitch was pressed by a voluntary foot or finger movement. 4 sec later a visual stimulus was presented, to which the subject had to respond as quickly as possible by making the same movement. Four electrode positions were used: C3, C4, C'3 and C'4, the latter two in between Cz and C3 or C4, respectively. The RPs showed larger amplitudes over the hemisphere, contralateral to the finger movement. Moreover, although not significant, RPs showed larger amplitudes over the hemisphere, ipsilateral to the foot movement. Late CNV waves were larger at C3 prior to a finger response and at C'4 prior to a foot response. This result is an argument for the hypothesis of a common underlying mechanism of RP and CNV late waves. Moreover, it suggests that motor preparation is a selective process which is related to the activation of a specific area in the motor cortex.

Adult↗
PubMed1999

Migraine--evidence for a disturbance of cerebral maturation in man?

The contingent negative variation (CNV), a slow cortical potential between two defined stimuli, was used to record the effect of age in 162 migraine patients and 320 healthy controls aged between 8 and 59 years. The early component (iCNV) and habituation slope of 32 GO-trials are presented. There were no significant differences between healthy controls and migraine patients in iCNV amplitudes or habituation slope up to the age of 19 years. In the age groups from 20-59 years the healthy controls showed a significantly reduced iCNV compared with migraine patients and healthy controls below 20 years of age. While the habituation slope increased in healthy controls, there was no habituation of iCNV in migraine patients. It is suggested that reduced iCNV amplitudes in healthy controls indicate a state of cerebral maturation. This maturation effect is missing in adult migraine patients, leading to pronounced attentional effort in these patients.

Adolescent↗
PubMed1978

A comparison of some physiological and psychological effects of Motival (fluphenazine and nortriptyline) and diazepam in normal subjects.

1 The effects in normal subjects of a single oral dose of Motival (one tablet, containing fluphenazine 0.5 mg and nortriptyline 10 mg) on the contingent negative variation (CNV), reaction time, heart rate, blood pressure and self-rating scales for alertness, anxiety, tension, detachment and depression were compared with those of diazepam (5 mg and 7.5 mg) and placebo or propranolol (60 mg). 2 After diazepam (5 mg: twelve subjects and 7.5 mg: seven subjects) there was a significant decrease in CNV magnitude while after Motival (twelve subjects) there was no significant alteration in CNV magnitude compared to placebo. 3 After diazepam (7.5 mg: seven subjects) there was also a fall in subjective ratings for alertness and tension; this fall was significantly greater than the changes after Motival which did not reduce subjective ratings for alterness or tension below "average" levels. Anxiety ratings did not differ significantly between the two drugs. Changes after propranolol were intermediate in all scales. 4 It is concluded that under these conditions diazepam caused central nervous system depression while Motival did not.

Blood Pressure↗
PubMed2004

Abnormal sensorimotor processing in pianists with focal dystonia.

Focal dystonia is a task-specific sensorimotor disorder that is characterized by sustained muscle contractions, which may cause twisting, repetitive movements, or abnormal postures. In the current study, the contingent negative variation was recorded in a group of professional pianists with focal dystonia (musicians' cramp) and compared to pianist controls. The CNV is composed of an early stimulus processing component and a later response preparation component. The CNV can be elicited in tasks that require movement and nonmovement. A subtractive analysis with a nonmovement condition was used to minimize effects of the CNV not related to response preparation. The current results revealed no group differences for the early CNV (processing of stimulus properties). In contrast, a significant group difference was found in the late CNV (movement preparation) between patients and controls, with the patients showing significantly higher activation prior to movement. The current study demonstrates an increase in overall sensorimotor activity prior to movement in patients with musicians' cramp. This overexcitation of the cortex may be the result of a dysfunction in the globus pallidus, resulting in a lack of inhibition and/or an increase in excitation.

Adult↗
PubMed1994

Chronic tension-type headache: amitriptyline reduces clinical headache-duration and experimental pain sensitivity but does not alter pericranial muscle activity readings.

In a double-blind, placebo-controlled trial, the effect of 75 mg of a slow-release formulation of amitriptyline on the clinical severity of chronic tension-type headache and on headache-associated neurophysiological parameters (EMG activity, exteroceptive suppression of temporal muscle activity, contingent negative variation (CNV) and experimental pain sensitivity) was investigated. All of the patients treated had a history of headaches of many years' standing and many of them had failed attempts at treatment. In the amitriptyline group, a significant reduction in daily headache duration was already found in the 3rd week of treatment, while in the placebo group no significant changes in headache duration were to be seen. In week 6 the amitriptyline group had a significantly shorter daily duration of headache than did the placebo group. Treatment did not result in any significant effects on EMG recordings of pericranial muscle activity either during relaxation or contraction, on exteroceptive suppression of the temporal muscle and on CNV. The sensitivity to suprathreshold experimental pain, however, was significantly reduced. The data show a statistically relevant reduction of daily headache duration. However, they also show that amitriptyline can only partly alleviate chronic headaches but cannot cure them.

Adult↗