Contingent Negative Variation Responses 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.

A Neural Marker of Speech Intention: Evidence From Contingent Negative Variation.

Purpose This study investigated whether changes in brain activity preceding spoken words can be used as a neural marker of speech intention. Specifically, changes in the contingent negative variation (CNV) were examined prior to speech production in three different study designs to determine a method that maximizes signal detection in a speaking task. Method Electroencephalography data were collected in three different protocols to elicit the CNV in a spoken word task that varied the timing and type of linguistic information. The first protocol provided participants with the word to be spoken before the instruction of whether or not to speak, the second provided both the word and the instruction to speak, and the third provided the instruction to speak before the word. Participants (N = 18) were split into three groups (one for each protocol) and were instructed to either speak (Go) or refrain from speaking (NoGo) each word according to task instructions. The CNV was measured by analyzing the difference in slope between Go and NoGo trials. Results Statistically significant effects of hemispheric laterality on the CNV slope confirm the third protocol where the participants know they will speak in advance of the word, as the paradigm that reliably elicits a CNV response related to speech intention. Conclusions The maximal CNV response when the instruction is known before the word indicates the neural processing measured in this protocol may reflect a generalized speech intention process in which the speech-language systems become prepared to speak and then execute production once the word information is provided. Further analysis of the optimal protocol identified in this study requires additional experimental investigation to confirm its role in eliciting an objective marker of speech intention. Supplemental Material https://doi.org/10.23641/asha.14111468.

Trait anxiety on effort allocation to monetary incentives: a behavioral and high-density EEG study

Trait anxiety is an important phenotype in the prediction of stress-induced neuropsychiatric disorders. While the role of trait anxiety in mental effort and cognitive impairment is well documented, much less is known about its influence on motivated behaviors and physical effort. Here, we investigated trait anxiety-related differences in behavioral and neural responses in an effort-related monetary incentive delay task. Participants prompted with different incentive levels could exert handgrip responses to earn monetary rewards while a 256-channel electroencephalography (EEG) was recorded. Participants’ performance was linearly dependent on incentive level, with higher stakes prompting better accuracy and higher grip force. Importantly, we found a striking association between trait anxiety and incentive-related grip force; effort exertion was related to incentive level only in high-anxious individuals. In analyses of neural efficiency associated with effort preparation involving Contingent-negative variation (CNV), we found that the CNV amplitude was sensitive to monetary incentive levels. Source imaging analyses of CNV indicated increased activity in the anterior cingulate cortex (ACC) for the highest incentive level. Importantly, we found a significant interaction between trait anxiety and incentive level on CNV modulation at the interval ranging from −2610 to −2510 ms, with greater CNV responses to the lower monetary incentive sizes in high anxiety. Subsequent mediation analyses supported a mediation of the ACC activation on the association between trait anxiety and incentive-selective grip force. Our study reveals a role for ACC in trait anxiety-related differences on incentive processing, when rewards are dependent on effortful performance.

Differential modulations of reward expectation on implicit facial emotion processing: ERP evidence.

Implicit emotional processing refers to the preferential processing of emotional content even if it is task irrelevant. Given that motivation enhances executive control by biasing attentional resources toward target stimuli, here we investigated the effects of reward expectation on implicit facial emotional processing in two experiments using ERPs. A precue signaling additional monetary reward for fast and accurate response for the upcoming trial (incentive condition; relative to a cue indicating no such additional reward, i.e., nonincentive condition) was followed by the presentation of a happy, angry, or neutral face. Participants had to determine the gender of the face in Experiment 1 and decide whether a number superimposed on the face was even or odd in Experiment 2. In both experiments, incentive cues elicited larger P3 and contingent negative variation responses, and the targets following incentive cues elicited more positive-going ERPs (200-700ms), compared with the nonincentive condition. Importantly, the N2 responses (200-280ms) to the target exhibited differential patterns of Reward × Emotion interaction: relative to the nonincentive condition, the N2 amplitude differences between emotional (i.e., happy and/or angry) and neutral faces increased in the incentive condition in Experiment 1, but diminished in Experiment 2. These results indicate that reward expectation can differentially modulate implicit processing of facial expressions, with increased sensitivity to emotions when the processing of whole faces is required, but with reduced sensitivity when the processing of faces is distractive. This study enriches the evidence for interactions between reward-related executive control and implicit emotional processing.

Hierarchical predictive system for the neural integration of incoming somatosensory stimulations

Hierarchical predictive system for the neural integration of incoming somatosensory stimulations

Event-related brain potentials reflect increased concentration ability after mindfulness-based cognitive therapy for depression: A randomized clinical trial

Mindfulness-based cognitive therapy (MBCT) effectively prevents relapse/recurrence in major depression. The ability to deploy and maintain attention on a particular focus is considered as a prerequisite for ‘mindful’, ‘metacognitive’ awareness, and hence crucial for therapy success. Accordingly, sustained concentration is the skill most extensively taught in MBCT. The goal of the present study was to test whether this ability increases after MBCT, as assumed. The late component of the contingent negative variation (CNV), an event-related brain potential (ERP), known to reflect the allocation of attentional resources, was used as the measure of concentration ability. In the main phase of the study, 91 recurrently depressed patients in remission were randomly assigned to eight-week treatment by either MBCT or waiting (WAIT for delayed MBCT). The CNV response to an auditory test stimulus was measured pre- and post-treatment in a ‘mindfulness task’, in which patients were instructed to focus on their breath, as taught in MBCT. The late CNV (LCNV) was increased only after MBCT (and not after WAIT). This result reflects patients' improved ability to shift their attention toward current moment experience and away from potentially depressogenic thinking or rumination during mild dysphoric states—a known risk factor for depressive relapse/recurrence.

Low frequency oscillations in rat posterior parietal cortex are differentially activated by cues and distractors

The posterior parietal cortex (PPC) is hypothesized to detect visual cues among competing distractors. Anatomical and neurophysiologic evidence indicates that the rat PPC is part of a network of brain areas involved in directed attention, specifically when new task parameters or conditions are introduced. Here, we test the hypothesis that changes in the local field potential (LFP) of the PPC of rats performing a sustained attention task reflect aspects of detection. Two event-related potentials were observed during detection: the P300 response and the contingent negative variation (CNV). Spectrogram analysis also indicated a detection-specific increase in alpha power in the retention interval of this task. This is consistent with observations from human studies, which indicate that tasks requiring a subject to withhold a response produced a pronounced synchronization of alpha rhythms during the delay, and desynchronization during retrieval. We also found cycles of alpha synchrony and desynchrony in response to a periodic distractor. These cycles were most pronounced in the initial trial block of the distractor when the false alarm rate was highest, and as task performance improved these cycles significantly diminished. This result suggests that alpha cycling in the PPC represent neural activity critical for learning to inhibit distractors. The occurrence of alpha synchronization and desynchronization to attention-demanding stimuli, in addition to the P300 and CNV responses observed during detection, is evidence that rat PPC is involved in sustained attention, particularly in the presence of distractors.

Neurophysiological reactivity before a migraine attack

Migraine patients are characterized by increased amplitudes and reduced habituation of the contingent negative variation (CNV) response, especially before a migraine attack. As shown previously, migraine provoking and precipitating agents can cause CNV abnormalities. However, it is unclear whether the temporal relation to the migraine attack determines how the brain reacts to a migraine precipitant. In this study, experimentallyinduced achievement stress, one of the typical precipitants for migraine, was examined for its effects upon the CNV response. CNV was recorded during conditions of rest and stress, both before and after a migraine attack, as well as during a headache-free interval. The neurophysiological reactivity to stress in migraineurs was compared with those of healthy subjects. Before a migraine attack, migraine patients demonstrated significantly more pronounced neurophysiological reactivity to stress: the amplitude of the early CNV component was more increased and its habituation was more reduced in the stress condition, especially 1–3 days before an attack compared with changes of CNV amplitudes and habituation under stress obtained after an attack, during the headache-free interval, or in healthy controls. The study demonstrates that the brain of migraine patients is characterized by increased susceptibility to migraine provoking agents before an actual attack.

Artificial neural network and spectrum analysis methods for detecting brain diseases from the CNV response in the electroencephalogram

Two methods of identifying schizophrenia, Parkinson's disease (PD), and Huntington's disease (HD) are described. The methods are based on the analysis of the contingent negative variation (CNV), an event related potential (ERP) in the electroencephalogram. The first method involves spectrum analysis of the CNV and discriminant analysis of the Fourier harmonic frequency components. The other method involves the application of supervised learning artificial neural networks to the CNV features obtained in the time domain. Additionally, unsupervised artificial neural networks were used to presymptomatically assess the risk of HD. Sensitivities and specificities lie between 0.81 and 1.0 with low false positive rates (0 to 0.13) for differentiating between disease and normal data, and between disease data, dependent on disease and method. The preferred method for disease differentiation for accuracy and ease of application is the multilayer perceptron. Using Kohonen and ART networks for detecting abnormal CNVs in subjects at risk of HD (ARs) eight abnormals are identified in agreement with the prediction of risk derived from a published risk table. In addition, one of the abnormals has since developed symptomatic Huntington's disease. The recommended method is to combine the results of the Kohonen method with an ART2 and a modified ART1 network.

Contingent negative variation in childhood migraine.

Adult migraineurs without aura have an increased amplitude of the Contingent Negative Variation (CNV) between attacks. Given the potential diagnostic importance of this finding and the difficulties associated with diagnosing migraine in childhood it seemed important to assess CNV in children suffering from this disorder. Ninety-seven children aged between 8 and 14 years were recruited. Forty-two suffered from migraine, 34 from tension-type headache. Twenty-one healthy controls were also studied. CNV was recorded from Fz, Cz and Pz referenced to linked earlobes during 20 trials consisting of two tones of moderate intensity with an interstimulus interval (ISI) of 4 sec and an intertrial interval (ITI) of 10 to 14 sec. The second tone of each trial required a button press. EOG was recorded from the left eye. The 10 CNV responses with the least EOG artefact were selected and averaged. Children with migraine had a highly significantly more negative mean CNV amplitude at all three electrode sites than children with tension-type headache and also a more pronounced Post-Imperative-Negative-Variation (PINV). Migrainous children differed from controls only at Cz (ISI). There was also a highly significant increase of mean CNV amplitude and PINV at all three electrode sites in the control group compared to the tension headache group.

Differentiation between subject categories using individual contingent negative variation responses

Differentiation between subject categories using individual contingent negative variation responses

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.

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.

Interaction of electro-ocular potentials with the contingent negative variation.

ABSTRACTThe contingent negative variation (CNV) was recorded from the vertex in forty‐five subjects during a two‐stimulus expectancy paradigm under varying conditions of eye closure and fixation. Simultaneously averaged electro‐oculograms (EOG) were recorded as a measure of eye movement. The amplitude of both CNV and EOG responses was significantly greater for the eyes closed and eyes open unfixated conditions as compared to the eyes fixated condition. CNV and EOG responses were often highly similar in terms of waveform. For the eyes fixated condition three patterns of CNV–EOG interaction were observed. Eighteen subjects demonstrated a CNV response of low amplitude in the absence of detectable EOG responses. Twenty‐three subjects showed a predominant pattern in which CNV responses of high amplitude and EOG responses were present. Four subjects failed to show either a CNV or EOG response. There was considerable within subject variability in the pattern of response with replicated blocks of trials. Thus contamination of the CNV by EOG potentials is reduced by eye fixation but not eliminated because of subject variability in control of eye movement.