Event-related Brain Responses Research Articles

Neural responses to negative outcomes predict success in community-based substance use treatment.

Patterns of brain activation have demonstrated promise as prognostic indicators in substance dependent individuals (SDIs) but have not yet been explored in SDIs typical of community-based treatment settings. Prospective clinical outcome design, evaluating baseline functional magnetic resonance imaging data from the Balloon Analogue Risk Task (BART) as a predictor of 3-month substance use treatment outcomes. Community-based substance use programs in Bloomington, Indiana, USA. Twenty-three SDIs (17 male, aged 18-43years) in an intensive outpatient or residential treatment program; abstinent 1-4weeks at baseline. Event-related brain response, BART performance and self-report scores at treatment onset, substance use outcome measure (based on days of use). Using voxel-level predictive modeling and leave-one-out cross-validation, an elevated response to unexpected negative feedback in bilateral amygdala and anterior hippocampus (Amyg/aHipp) at baseline successfully predicted greater substance use during the 3-month study interval (P≤0.006, cluster-corrected). This effect was robust to inclusion of significant non-brain-based covariates. A larger response to negative feedback in bilateral Amyg/aHipp was also associated with faster reward-seeking responses after negative feedback (r(23) =-0.544, P=0.007; r(23) =-0.588, P=0.003). A model including Amyg/aHipp activation, faster reward-seeking after negative feedback and significant self-report scores accounted for 45% of the variance in substance use outcomes in our sample. An elevated response to unexpected negative feedback in bilateral amygdala and anterior hippocampus (Amyg/aHipp) appears to predict relapse to substance use in people attending community-based treatment.

Subjective craving and event-related brain response to olfactory and visual chocolate cues in binge-eating and healthy individuals

High-sugar/high-fat foods are related to binge-eating behaviour and especially people with low inhibitory control may encounter elevated difficulties to resist their intake. Incentive sensitization to food-related cues might lead to increased motivated attention towards these stimuli and to cue-induced craving. To investigate the combined influence of olfactory and visual stimuli on craving, inhibitory control and motivated attention, 20 healthy controls and 19 individuals with binge-eating viewed chocolate and neutral pictures, primed by chocolate or neutral odours. Subjective craving and electroencephalogram activity were recorded during the task. N2 and Late Positive Potential (LPP) amplitudes were analysed. Patients reported higher craving than controls. Subjective craving, N2 and LPP amplitudes were higher for chocolate versus neutral pictures. Patients showed a higher relative increase in N2 amplitudes to chocolate versus neutral pictures than controls. Chocolate images induced significant increases in craving, motivated attention and measures of cognitive control. Chocolate odour might potentiate the craving response to visual stimuli, especially in patients with binge-eating.

Empathy for pain influences perceptual and motor processing: Evidence from response force, ERPs, and EEG oscillations

ABSTRACTIn the present study we investigated the nature and chronometry of empathy for pain influences on perceptual and motor processes. Thus, event-related brain potentials (ERPs), response force (RF) and oscillatory electroencephalography (EEG) activity were measured while participants were presented with pictures of body parts in painful or neutral situations. Their task consisted in either judging the painfulness of the stimuli or counting the body parts displayed. ERP results supported the assumption of an early automatic component of empathy for pain, as reflected by the early posterior negativity (EPN), and of a late controlled component, as reflected by the late posterior positivity (P3). RF indicated that empathy-evoking stimuli facilitate motor responses if attention is directed toward the pain dimension, whereas EEG oscillations in the mu-and beta-band revealed, independent of the task, an enhanced activation of the sensorimotor cortex after the response to painful compared to neutral stimuli. In conclusion, present findings indicate that empathy-evoking stimuli produce automatic and controlled effects on both perceptual and motor processing.

A preliminary study of longitudinal neuroadaptation associated with recovery from addiction

BackgroundFew studies have explored longitudinal change in event-related brain responses during early recovery from addiction. Moreover, existing findings yield evidence of both increased and decreased signaling within reward and control centers over time. The current study explored reward- and control-related signals in a risky decision-making task and specifically investigated parametric modulations of the BOLD signal, rather than signal magnitude alone. It was hypothesized that risk-related signals during decision-making and outcome evaluation would reflect recovery and that change in specific signals would correspond with improved treatment outcomes. MethodsTwenty-one substance dependent individuals were recruited upon enrollment in community-based substance use treatment programs, wherein they received treatment-as-usual. Participants completed functional neuroimaging assessments at baseline and 3-month follow-up while performing the Balloon Analogue Risk Task (BART). Risk- and reward-sensitive signals were identified using parametric modulators. Substance use was tracked throughout the 3-month study interval using the timeline follow-back procedure. ResultsLongitudinal contrasts of parametric modulators suggested improved formation of risk-informed outcome expectations at follow-up. Specifically, a greater response to high risk (low-likelihood) positive feedback was identified in caudal anterior cingulate cortex (ACC) and a greater response to low risk (low-likelihood) negative feedback was identified in caudal ACC and inferior frontal gyrus. In addition, attenuation of a ventromedial prefrontal cortex (vmPFC) “reward-seeking” signal (i.e., increasing response with greater reward) during risky decisions at follow-up was associated with less substance use during the study interval. ConclusionsChanges in risk- and reward-related signaling in ACC/vmPFC appear to reflect recovery and may support sobriety.

N1 Magnitude of Auditory Evoked Potentials and Spontaneous Functional Connectivity Between Bilateral Heschl's Gyrus Are Coupled at Interindividual Level.

N1 component of auditory evoked potentials is extensively used to investigate the propagation and processing of auditory inputs. However, the substantial interindividual variability of N1 could be a possible confounding factor when comparing different individuals or groups. Therefore, identifying the neuronal mechanism and origin of the interindividual variability of N1 is crucial in basic research and clinical applications. This study is aimed to use simultaneously recorded electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data to investigate the coupling between N1 and spontaneous functional connectivity (FC). EEG and fMRI data were simultaneously collected from a group of healthy individuals during a pure-tone listening task. Spontaneous FC was estimated from spontaneous blood oxygenation level-dependent (BOLD) signals that were isolated by regressing out task evoked BOLD signals from raw BOLD signals and then was correlated to N1 magnitude across individuals. It was observed that spontaneous FC between bilateral Heschl's gyrus was significantly and positively correlated with N1 magnitude across individuals (Spearman's R = 0.829, p < 0.001). The specificity of this observation was further confirmed by two whole-brain voxelwise analyses (voxel-mirrored homotopic connectivity analysis and seed-based connectivity analysis). These results enriched our understanding of the functional significance of the coupling between event-related brain responses and spontaneous brain connectivity, and hold the potential to increase the applicability of brain responses as a probe to the mechanism underlying pathophysiological conditions.

Event-related brain responses while listening to entire pieces of music

Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative deflation occurring around 100 milliseconds after the stimulus onset (N100) and positive deflation occurring around 200 milliseconds after the stimulus onset (P200) ERP responses to peak changes in the acoustic features were distinguishable and were often largest for Tango Nuevo. In addition to large changes in these musical features, long phases of low values that precede a rapid increase – and that we will call Preceding Low-Feature Phases – followed by a rapid increase enhanced the amplitudes of N100 and P200 responses. These ERP responses resembled those to simpler sounds, making it possible to utilize the tradition of ERP research with naturalistic paradigms.

Individual differences in error tolerance in humans: Neurophysiological evidences.

When interacting in error-prone environments, humans display different tolerances to changing their decisions when faced with erroneous feedback information. Here, we investigated whether these individual differences in error tolerance (ET) were reflected in neurophysiological mechanisms indexing specific motivational states related to feedback monitoring. To explore differences in ET, we examined the performance of 80 participants in a probabilistic reversal-learning task. We then compared event-related brain responses (ERPs) of two extreme groups of participants (High ET and Low ET), which showed radical differences in their propensity to maintain newly learned rules after receiving spurious negative feedback. We observed that High ET participants showed reduced anticipatory activity prior to the presentation of incoming feedback, informing them of the correctness of their performance. This was evidenced by measuring the amplitude of the stimulus-preceding negativity (SPN), an ERP component indexing attention and motivational engagement of incoming informative feedback. Postfeedback processing ERP components (the so-called Feedback-Related Negativity and the P300) also showed reduced amplitude in this group (High ET). The general decreased responsiveness of the High ET group to external feedback suggests a higher proneness to favor internal(rule)-based strategies, reducing attention to external cues and the consequent impact of negative evaluations on decision making. We believe that the present findings support the existence of specific cognitive and motivational processes underlying individual differences on error-tolerance among humans, contributing to the ongoing research focused on understanding the mental processes behind human fallibility in error-prone scenarios.

Latency of auditory P300 response is related with cognitive deficits in Obstructive Sleep Apnea Syndrome

Obstructive Sleep Apnea Syndrome (OSAS) is characterized by desaturation in blood oxygen level and sleep fragmentation because of repeated upper airway obstruction. Auditory Event related potentials (AERPs) are scalp recorded voltage fluctuations, which reflect several cognitive processes generated within specific brain regions during auditory stimulus processing. In this study, we aimed to investigate cognitive deficits in OSAS patients with AERPs by taking the effects of aging factor into consideration. AERPs were recorded using an auditory oddball paradigm from 27 OSAS patients (range 28 to 67 years old) and 29 healthy control subjects (range 23 to 60 years old) participated in the study. To evaluate the effects of aging, both the OSAS patients and the controls were divided into two age groups: younger ( 0.05). Our results suggest that negative effects of OSAS on cognitive functions could be observed with event-related brain responses. Changes in the P300 latencies are more robust evidence than other AERP components in evaluating cognitive deficits in OSAS patients.

Event-related brain responses to emotional words, pictures, and faces - a cross-domain comparison.

Emotion effects in event-related brain potentials (ERPs) have previously been reported for a range of visual stimuli, including emotional words, pictures, and facial expressions. Still, little is known about the actual comparability of emotion effects across these stimulus classes. The present study aimed to fill this gap by investigating emotion effects in response to words, pictures, and facial expressions using a blocked within-subject design. Furthermore, ratings of stimulus arousal and valence were collected from an independent sample of participants. Modulations of early posterior negativity (EPN) and late positive complex (LPC) were visible for all stimulus domains, but showed clear differences, particularly in valence processing. While emotion effects were limited to positive stimuli for words, they were predominant for negative stimuli in pictures and facial expressions. These findings corroborate the notion of a positivity offset for words and a negativity bias for pictures and facial expressions, which was assumed to be caused by generally lower arousal levels of written language. Interestingly, however, these assumed differences were not confirmed by arousal ratings. Instead, words were rated as overall more positive than pictures and facial expressions. Taken together, the present results point toward systematic differences in the processing of written words and pictorial stimuli of emotional content, not only in terms of a valence bias evident in ERPs, but also concerning their emotional evaluation captured by ratings of stimulus valence and arousal.

Music and Language Expertise Influence the Categorization of Speech and Musical Sounds: Behavioral and Electrophysiological Measurements

In this study, we used high-density EEG to evaluate whether speech and music expertise has an influence on the categorization of expertise-related and unrelated sounds. With this purpose in mind, we compared the categorization of speech, music, and neutral sounds between professional musicians, simultaneous interpreters (SIs), and controls in response to morphed speech-noise, music-noise, and speech-music continua. Our hypothesis was that music and language expertise will strengthen the memory representations of prototypical sounds, which act as a perceptual magnet for morphed variants. This means that the prototype would "attract" variants. This so-called magnet effect should be manifested by an increased assignment of morphed items to the trained category, by a reduced maximal slope of the psychometric function, as well as by differential event-related brain responses reflecting memory comparison processes (i.e., N400 and P600 responses). As a main result, we provide first evidence for a domain-specific behavioral bias of musicians and SIs toward the trained categories, namely music and speech. In addition, SIs showed a bias toward musical items, indicating that interpreting training has a generic influence on the cognitive representation of spectrotemporal signals with similar acoustic properties to speech sounds. Notably, EEG measurements revealed clear distinct N400 and P600 responses to both prototypical and ambiguous items between the three groups at anterior, central, and posterior scalp sites. These differential N400 and P600 responses represent synchronous activity occurring across widely distributed brain networks, and indicate a dynamical recruitment of memory processes that vary as a function of training and expertise.

Additive effects of affective arousal and top-down attention on the event-related brain responses to human bodies

The early visual event-related ‘N170 response’ is sensitive to human body configuration and it is enhanced to nude versus clothed bodies. We tested whether the N170 response as well as later EPN and P3/LPP responses to nude bodies reflect the effect of increased arousal elicited by these stimuli, or top-down allocation of object-based attention to the nude bodies. Participants saw pictures of clothed and nude bodies and faces. In each block, participants were asked to direct their attention towards stimuli from a specified target category while ignoring others. Object-based attention did not modulate the N170 amplitudes towards attended stimuli; instead N170 response was larger to nude bodies compared to stimuli from other categories. Top-down attention and affective arousal had additive effects on the EPN and P3/LPP responses reflecting later processing stages. We conclude that nude human bodies have a privileged status in the visual processing system due to the affective arousal they trigger.

P300 amplitude and response speed relate to preserved cognitive function in relapsing–remitting multiple sclerosis

ObjectiveTo explore if cognitive impairment in relapsing–remitting multiple sclerosis (RRMS) is associated with abnormal neural function and if there is evidence of neural compensatory mechanisms. MethodsSeventy-two RRMS patients and 89 healthy control subjects were included in a cross-sectional study. Event-related brain potential (P300) and response time (RT) were recorded with visual and auditory choice reaction tasks. Cognitive function was evaluated with an 18 item test battery. ResultsPatients had a decrease in cognitive function (p<0.001 for global score) and increased visual P300 amplitude frontally. P300 amplitude was normal in other brain areas and RT was normal. P300 latency was normal except for an increase in auditory latency occipitally. Cognitive performance correlated positively with parietal P300 amplitude in patients but not in controls. Cognition had stronger correlation (negative) with RT in patients than in controls. ConclusionsPatients with low P300 amplitude and long RT were more often cognitively impaired. This indicates that general factors such as signal amplitude and speed are limiting for cognitive function in RRMS patients. The increase in frontal P300 amplitude may be a compensatory effect. SignificanceOur findings suggest that high amplitude and fast speed may be protective against cognitive impairment.

Voluntary pressing and releasing actions induce different senses of time: evidence from event-related brain responses.

The timing intervals initiated by voluntary pressing actions are subjectively compressed compared with those initiated by voluntary releasing actions. Event-related potentials (ERPs) were employed in the present study to uncover the temporal mechanisms underlying this temporal illusion. The results revealed that the mean amplitude of the P1 component over the frontal-central recording sites, but not the P2 component, was larger in the voluntary pressing condition than in the voluntary releasing condition at the time perception stage. In the fronto-central region, increases in oscillatory activities of delta-theta frequency range (1-7 Hz) were found in the voluntary pressing condition, which corresponded with the emergence of the P1 peak. In addition, the P1 amplitude was negatively related to the corresponding reported time length at the single-trial level. These results are discussed in terms of the functional role of the response-locked P1 in the time perception stage.

Preattentive dysfunction in patients with bipolar disorder as revealed by the pitch-mismatch negativity: a magnetoencephalography (MEG) study.

Mismatch negativity (MMN) and its magnetic counterpart (MMNm) are thought to reflect an automatic process that detects a difference between an incoming stimulus and the sensory memory trace of preceding stimuli. In patients with schizophrenia, an attenuation of the MMN/MMNm amplitude has been repeatedly reported. Heschl's gyrus (HG) is one of the major generators of MMN and the functional alteration of HG has been reported in patients with bipolar disorder. The present study investigated the pitch-MMNm in patients with bipolar disorder using whole-head 306-ch magnetoencephalography (MEG). Twenty-two patients and 22 healthy controls participated in this study. Subjects were presented with two types of auditory stimulus sequences. One consisted of 1,000 Hz standards (probability = 90%) and 1,200 Hz deviants (probability = 10%), and the other consisted of 1,000 Hz standards (90%) and 1,200 Hz deviants (10%). These two tasks were each performed twice. Event-related brain responses to standard tones were subtracted from responses to deviant tones. Patients with bipolar disorder showed a significant bilateral reduction in magnetic global field power (mGFP) amplitudes (p = 0.02) and dipole moments of the MMNm (p = 0.04) compared with healthy controls. Patients with admission experience showed significantly reduced mGFP amplitudes of MMNm compared with patients without admission experience (p = 0.004). Additionally, patients with more severe manic symptoms had smaller mGFP amplitudes of MMNm (ρ = -0.50, p = 0.05). The results of this study suggest that patients with bipolar disorder may exhibit preattentive auditory dysfunction indexed by reduced pitch-MMNm responses. Pitch-MMNm could be a potential trait marker reflecting the global severity of bipolar disorder.

Investigating stream segregation and spatial hearing using event-related brain responses

Several studies have used auditory mismatch negativity (MMN) to study auditory stream segregation. Few of these studies, however, focused on the stream segregation that involves spatial hearing. The present study used MMNs to examine the spatial aspect of stream segregation. Traditional oddball streams were presented in a passive listening paradigm, either in isolation or in the presence of an interfering stream. The interfering streams were engineered so that the deviants were not unexpected if the two streams were heard as perceptually integrated. Interfering streams were either spectrally distant from or close to the oddball stream, and were also spatially separated from the oddball stream. The deviant stimuli differed from the standards in perceived spatial location. For comparison, the MMN paradigm developed by Lepistö et al. (2009) using intensity deviants was repeated on the same group of subjects. For both paradigms, the MMN was strongest when the oddball stream was presented in isolation, less strong but present when the two streams were spectrally separated, and not observable when the streams were spectrally close. These results demonstrate the feasibility of using the MMN to measure spatial stream segregation, especially in populations for whom task-based behavioral experiments cannot be undertaken.

Electrical brain imaging reveals the expression and timing of altered error monitoring functions in major depression.

Major depressive disorder (MDD) is characterized by disturbances in affect, motivation, and cognitive control processes, including error detection. However, the expression and timing of the impairments during error monitoring remain unclear in MDD. The behavior and event-related brain responses (ERPs) of 20 patients with MDD were compared with those of 20 healthy controls (HCs), while they performed a Go/noGo task. Errors during this task were associated with 2 ERP components, the error-related negativity (ERN/Ne) and the error positivity (Pe). Results show that the ERN/Ne-correct-related negativity (CRN) amplitude difference was significantly larger in MDD patients (after controlling for speed), compared with HCs, although MDD patients exhibited overactive medial frontal cortex (MFC) activation. By comparison, the subsequent Pe component was smaller in MDD patients compared with HCs and this effect was accompanied by a reduced activation of ventral anterior cingulate cortex (ACC) regions. These results suggest that MDD has multiple cascade effects on early error monitoring brain mechanisms.

Processing musical form: Behavioural and neurocognitive approaches

Simple melodies and short instrumental pieces largely unfold within the temporal limits of working memory. Within short time-spans (typically from 10 to 15 s), listeners can either subsume form parts into higher-order units (chunking process) or perceive them as sequential, and processes like these can happen while listening or in immediate retrospect. This study investigates the listeners’ chunking abilities as well as their assessment of coherence using two eight-measure theme types in AABB and ABAB forms. Double-letter labels (AA and BB) mark pattern similarity, while two-letter labels (AB) indicate pattern contrast. We measured the event-related brain responses (ERPs) while non-musicians listened to musical themes in real-time. Immediately after presentation, each piece of music had to be evaluated as either sequential or non-sequential (hierarchical). The rating results showed that ABAB compared to AABB forms were significantly more often judged as non-sequential (hierarchical). Independent of form type the tendency to chunk form parts seemed stronger when two aspects coincided: when rhythmical contrast between A-parts and B-parts was high, and when melodic contour was upward-downward. In contrast, the event-related potentials were insensitive to mental chunking processes. They merely reflected the brain’s responses to pattern structure. An anterior negative shift (anterior N300) was observed for immediate (AA) as well as for non-immediate repetition (ABA, ABAB) of similar form parts, suggesting pattern matching at phrase onsets on the basis of rhythmical sameness. To our knowledge, this study is the first neurocognitive approach to musical form perception.

Pitch discrimination without awareness in congenital amusia: Evidence from event-related potentials

Congenital amusia is a lifelong disorder characterized by a difficulty in perceiving and producing music despite normal intelligence and hearing. Behavioral data have indicated that it originates from a deficit in fine-grained pitch discrimination, and is expressed by the absence of a P3b event-related brain response for pitch differences smaller than a semitone and a bigger N2b–P3b brain response for large pitch differences as compared to controls. However, it is still unclear why the amusic brain overreacts to large pitch changes. Furthermore, another electrophysiological study indicates that the amusic brain can respond to changes in melodies as small as a quarter-tone, without awareness, by exhibiting a normal mismatch negativity (MMN) brain response. Here, we re-examine the event-related N2b–P3b components with the aim to clarify the cause of the larger amplitude observed by Peretz, Brattico, and Tervaniemi (2005), by experimentally matching the number of deviants presented to the controls according to the number of deviants detected by amusics. We also re-examine the MMN component as well as the N1 in an acoustical context to investigate further the pitch discrimination deficit underlying congenital amusia. In two separate conditions, namely ignore and attend, we measured the MMN, the N1, the N2b and the P3b to tones that deviated by an eight of a tone (25 cents) or whole tone (200 cents) from a repeated standard tone. The results show a normal MMN, a seemingly normal N1, a normal P3b for the 200 cents pitch deviance, and no P3b for the small 25 cents pitch differences in amusics. These results indicate that the amusic brain responds to small pitch differences at a pre-attentive level of perception, but is unable to detect consciously those same pitch deviances at a later attentive level. The results are consistent with previous MRI and fMRI studies indicating that the auditory cortex of amusic individuals is functioning normally.

Electrocortical evidence for preferential processing of dynamic pain expressions compared to other emotional expressions

Decoding pain in others is of high individual and social benefit in terms of harm avoidance and demands for accurate care and protection. The processing of facial expressions includes both specific neural activation and automatic congruent facial muscle reactions. While a considerable number of studies investigated the processing of emotional faces, few studies specifically focused on facial expressions of pain. Analyses of brain activity and facial responses elicited by the perception of facial pain expressions in contrast to other emotional expressions may unravel the processing specificities of pain-related information in healthy individuals and may contribute to explaining attentional biases in chronic pain patients. In the present study, 23 participants viewed short video clips of neutral, emotional (joy, fear), and painful facial expressions while affective ratings, event-related brain responses, and facial electromyography (Musculus corrugator supercilii, M. orbicularis oculi, M. zygomaticus major, M. levator labii) were recorded. An emotion recognition task indicated that participants accurately decoded all presented facial expressions. Electromyography analysis suggests a distinct pattern of facial response detected in response to happy faces only. However, emotion-modulated late positive potentials revealed a differential processing of pain expressions compared to the other facial expressions, including fear. Moreover, pain faces were rated as most negative and highly arousing. Results suggest a general processing bias in favor of pain expressions. Findings are discussed in light of attentional demands of pain-related information and communicative aspects of pain expressions.

Assessment of chemosensory function using electroencephalographic techniques

Electroencephalographic techniques are widely used to provide an objective evaluation of the chemosensory function and to explore neural mechanisms related to the processing of chemosensory events. The most popular technique to evaluate brain responses to chemosensory stimuli is across trial time-domain averaging to reveal chemosensory event-related potentials (CSERP) embedded within the ongoing EEG. Nevertheless, this technique has a poor signal-to-noise ratio and cancels out stimulus-induced changes in the EEG signal that are not strictly phased-locked to stimulus onset. The fact that consistent CSERP are not systematically identifiable in healthy subjects currently constitutes a major limitation to the use of this technique for the diagnosis of chemosensory dysfunction. In this review, we will review the different techniques related to the recording and identification of CSERP, discuss some of their limitations, and propose some novel signal processing methods which could be used to enhance the signal-to-noise ratio of chemosensory event-related brain responses.