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Rationale Cue avoidance training (CAT) reduces alcohol consumption in the laboratory. However, the neural mechanisms that underlie the effects of this intervention are poorly understood. Objectives The present study investigated the effects of a single session of CAT on event-related and readiness potentials during preparation of approach and avoidance movements to alcohol cues. Methods Heavy drinking young adults (N = 60) were randomly assigned to complete either CAT or control training. After training, we recorded participants’ event-related and motor readiness potentials as they were preparing to respond. Results In the CAT group, N200 amplitude was higher when preparing to approach rather than avoid alcohol pictures. In the control group, N200 amplitudes did not differ for approach and avoidance to alcohol pictures. Regarding the late positive potential (LPP), in the CAT group, the negativity of this was blunted when preparing to avoid alcohol pictures relative to when preparing to avoid control pictures. In the control group, the negativity of the LPP was blunted when preparing to approach alcohol pictures relative to when preparing to approach control pictures. There were no effects on motor readiness potentials. Behavioural effects indicated short-lived effects of training on reaction times during the training block that did not persist when participants were given time to prepare their motor response before executing it during the EEG testing block. Conclusions After a single session of CAT, the enhanced N200 when approaching alcohol cues may indicate the engagement of executive control to overcome the associations learned during training. These findings clarify the neural mechanisms that may underlie the effects of CAT on drinking behaviour.

open access article Odours alter evaluations of concurrently presented visual stimuli, such as faces. Stimulus onset asynchrony (SOA) is known to affect evaluative priming in various sensory modalities. However, effects of SOA on odour priming of visual stimuli are not known. The present study aimed to analyse whether subjective and cortical activation changes during odour priming would vary as a function of SOA between odours and faces. Twenty-eight participants rated faces under pleasant, unpleasant, and no-odour conditions using visual analogue scales. In half of trials, faces appeared one-second after odour offset (SOA 1). In the other half of trials, faces appeared during the odour pulse (SOA 2). EEG was recorded continuously using a 128-channel system, and event-related potentials (ERPs) to face stimuli were evaluated using statistical parametric mapping (SPM). Faces presented during unpleasant-odour stimulation were rated significantly less pleasant than the same faces presented one-second after offset of the unpleasant odour. Scalp-time clusters in the late-positive-potential (LPP) time-range showed an interaction between odour and SOA effects, whereby activation was stronger for faces presented simultaneously with the unpleasant odour, compared to the same faces presented after odour offset. Our results highlight stronger unpleasant odour priming with simultaneous, compared to delayed, odour-face presentation. Such effects were represented in both behavioural and neural data. A greater cortical and subjective response during simultaneous presentation of faces and unpleasant odour may have an adaptive role, allowing for a prompt and focused behavioural reaction to a concurrent stimulus if an aversive odour would signal danger, or unwanted social interaction.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Odours alter evaluations of concurrent visual stimuli. However, neural mechanisms underlying the effects of congruent and incongruent odours on facial expression perception are not clear. Moreover, the influence of emotional faces on odour perception is not established. We investigated the effects of one pleasant and one unpleasant odour paired with happy and disgusted faces, on subjective ratings and ERP responses to faces. Participants rated the pleasantness of happy and disgusted faces that appeared during 3 s pleasant or unpleasant odour pulses, or without odour. Odour pleasantness and intensity ratings were recorded in each trial. EEG was recorded continuously using a 128-channel system. Happy and disgusted faces paired with pleasant and unpleasant odour were rated as more or less pleasant, respectively, compared to the same faces presented in the other odour conditions. Odours were rated as more pleasant when paired with happy faces, and unpleasant odour was rated more intense when paired with disgusted faces. Unpleasant odour paired with disgusted faces also decreased inspiration. Odour-face interactions were evident in the N200 and N400 components. Our results reveal bi-directional effects of odours and faces, and suggest that odour-face interactions may be represented in ERP components. Pairings of unpleasant odour and disgusted faces resulted in stronger hedonic ratings, ERP changes, increased odour intensity ratings and respiratory adjustment. This finding likely represents heightened adaptive responses to multimodal unpleasant stimuli, prompting appropriate behaviour in the presence of danger.

open access article Previous studies demonstrated that pain induced by a noxious stimulus during a distraction task is affected by both stimulus-driven and goal-directed processes which interact and change over time. The purpose of this exploratory study was to analyse associations of aspects of subjective pain experience and engagement with the distracting task with attentionsensitive components of noxious laser-evoked potentials (LEPs) on a single-trial basis. A laser heat stimulus was applied to the dorsum of the left hand while subjects either viewed the Rubin vase-face illusion (RVI), or focused on their pain and associated somatosensory sensations occurring on their stimulated hand. Pain-related sensations occurring with every laser stimulus were evaluated using a set of visual analogue scales. Factor analysis was used to identify the principal dimensions of pain experience. LEPs were correlated with subjective aspects of pain experience on a single-trial basis using a multiple linear regression model. A positive LEP component at the vertex electrodes in the interval 294–351 ms (P2) was smaller during focusing on RVI than during focusing on the stimulated hand. Single-trial amplitude variations of the P2 component correlated with changes in Factor 1, representing essential aspects of pain, and inversely with both Factor 2, accounting for anticipated pain, and the number of RVI figure reversals. A source dipole located in the posterior region of the cingulate cortex was the strongest contributor to the attention-related single-trial variations of the P2 component. Instantaneous amplitude variations of the P2 LEP component during switching attention towards pain in the presence of a distracting task are related to the strength of pain experience, engagement with the task, and the level of anticipated pain. Results provide neurophysiological underpinning for the use of distraction analgesia acute pain relief.

Values are attributed to goods during free viewing of objects which entails multi- and trans-saccadic cognitive processes. Using electroencephalographic eye-fixation related potentials, the present study investigated how neural signals related to value-guided choice evolved over time when viewing household and office products during an auction task. Participants completed a Becker-DeGroot-Marschak auction task whereby half of the stimuli were presented in either a free or forced bid protocol to obtain willingness-to-pay. Stimuli were assigned to three value categories of low, medium and high value based on subjective willingness-to-pay. Eye fixations were organised into five 800 ms time-bins spanning the objects total viewing time. Independent component analysis was applied to eye-fixation related potentials. One independent component (IC) was found to represent fixations for high value products with increased activation over the left parietal region of the scalp. An IC with a spatial maximum over a fronto-central region of the scalp coded the intermediate values. Finally, one IC displaying activity that extends over the right frontal scalp region responded to intermediate- and low-value items. Each of these components responded early on during viewing an object and remained active over the entire viewing period, both during free and forced bid trials. Results suggest that the subjective value of goods are encoded using sets of brain activation patterns which are tuned to respond uniquely to either low, medium, or high values. Data indicates that the right frontal region of the brain responds to low and the left frontal region to high values. Values of goods are determined at an early point in the decision making process and carried for the duration of the decision period via trans-saccadic processes.

Objectives Noxious stimuli capture attention and at the same time, pain is attenuated by a concurrent cognitive task. The present study aimed to elucidate the cortical mechanisms underlying diminution of pain during attentional distraction using single-trial electrocortical and subjective responses. Methods In 24 healthy participants, a laser heat stimulus was applied to the dorsum of the left hand while subjects either viewed Rubin vase-face illusion (RVI), or focused on their pain and associated somatosensory sensations occurring on their stimulated hand. Pain-related sensations occurring on every laser stimulus were evaluated using a set of visual analogue scales. Factor analysis was used to identify the principal dimensions of pain experience. Laser evoked potentials (LEPs) were correlated with subjective aspects of pain experience on a single-trial basis using a multivariate regression model. Results Subjects anticipated and perceived smaller pain whilst focusing on RVI than on their pain-related sensations. A positive LEP component at the vertex electrodes in the interval 294–351 ms was smaller during focusing on RVI than during focusing on the stimulated hand. The attention-related amplitude changes in LEPs were accounted for by an equivalent source dipole located in posterior cingulate cortex (PCC). Single-trial variations of source activity in PCC correlated with changes in Factor 1, representing essential aspects of pain, and inversely with both Factor 2, accounting for anticipated pain, and with the number of RVI figure reversals. Discussion Single-trial analysis of LEPs and subjective responses to a noxious laser stimulus point to the possibility that the attentional switching during a distraction analgesia operates in PCC via three channels: 1. The pain modulation channel which affects the pain experience during the distraction by neural and functional connections of the posterior cingulate cortex with the anterior cingulate cortex. 2. The task engagement channel represented by reduction of the LEP potential in PCC in trials with a large number of RVIs. 3. The anticipation channel representing a contextual, top-down modulation of the distraction effect. Conclusions PCC appears to mediate the attentional switching towards the pain during concurrent, distracting task. Switching between pain and non-pain task is modulated by the strength of engagement in a cognitive-perceptual task, and by the level of anticipated pain. Significance Our findings shed light on the factors underlying distraction analgesia. The level of engagement in the non-pain task and the role of anticipation are the factors which can be boosted to strengthen the analgesia in clinical applications.

Background Previous studies have shown increases in subjective experience and electrophysiological processing of experimental pain during induction of negative emotions with concurrent multi-modal sensory stimuli. The goal of the present study was to analyse spatio-temporal activation patterns underlying processing of acute pain during exposures to affectively valenced odour stimuli. Methods Negative, positive, and neutral (clean air) odour pulses were presented to 17 healthy participants via an olfactometer whilst brief noxious laser stimuli were administered to the dorsum of the left hand. Brain activity was monitored using electroencephalography (EEG) and participants rated the quality and intensity of pain and odour stimuli following each trial using visual analogue scales. Subjective ratings of pain stimuli and laser evoked potentials (LEPs) were analysed to evaluate the influence of valenced odours on subjective and electrophysioloigical aspects of pain processing. Results Analysis of pain ratings revealed no difference in pain intensity, or specific pain qualities across the different odour conditions. Individual LEP components demonstrated expected correlations with specific aspects of pain perception, but did not differ between odour conditions. Conclusions Contrary to research from other sensory modalities, the findings of the present study suggest that affectively valenced odours do not overtly influence aspects of subjective pain perception or electrophysiological processing of acute pain. This may be due to the influence of top-down factors affecting split perception between competing sensory stimuli, which may interact differently for pain and olfactory perception compared to other modalities.

Objectives Previous neuroimaging studies have shown face-specific neural responses to faces compared to objects. The detection of face-specific brain activation in freely behaving and moving people has yet to be accomplished. The purpose of our research was to identify, using wireless multichannel EEG in freely moving participants, eye movement related potentials (EMRPs) during viewing of human faces. Method Mobile EEG and eye tracking was recorded from 19 freely moving participants whilst they freely viewed a mock art gallery. Stimuli were presented on 20 printed poster panels displaying positive, negative and neutral valence images. A head-mounted wearable eye-tracker was used to capture real-world video recordings of gaze locations used to synchronize the EEG and eye-tracking time-series. Results Synchronized EEG and eye-tracking recordings allowed identification of a face-related EMRP component (N185 potential) that was not present whilst participants were viewing non-living objects. Source dipole analysis of the evoked component accounted for the ocular-retinal movement artefact and revealed three additional equivalent current dipoles. In the latency interval from 100 to 300 ms one dipole was located to left extrastriate, one to primary visual cortex and one to the right fusiform gyrus. Discussion Right fusiform gyrus source activity showed sensitivity towards emotional valence suggesting emotional encoding of faces in the fusiform gyrus at a latency interval between 100 and 300 ms. Conclusion We demonstrate the feasibility of recording EMRP’s in freely behaving individuals in a naturalistic setting. Significance These results open new possibilities to BCI as well as clinical, developmental, social or marketing research.

Contains fulltext : 169377.pdf (Publisher’s version ) (Open Access) Misophonia (hatred of sound) is a newly defined psychiatric condition in which ordinary human sounds, such as breathing and eating, trigger impulsive aggression. In the current study we investigated if a dysfunction in the brain’s early auditory processing system could be present in misophonia. We screened 20 patients with misophonia with the diagnostic criteria for misophonia, and 14 matched healthy controls without misophonia, and investigated any potential deficits in auditory processing of misophonia patients using auditory event-related potentials (ERPs) during an oddball task.Subjects watched a neutral silent movie while being presented a regular frequency of beep sounds in which oddball tones of 250 Hz and 4000 Hz were randomly embedded in a stream of repeated 1000 Hz standard tones. We examined the P1, N1 and P2 components locked to the onset of the tones.For misophonia patients, the N1 peak evoked by the oddball tones had a smaller mean peak amplitude than the control group. However, no significant differences were found in P1 and P2 components evoked by the oddball tones. There were no significant differences between the misophonia patients and their controls in any of the ERP components to the standard tones.The diminished N1 component to oddball tones in misophonia patients suggests an underlying neurobiological deficit in misophonia patients. This reduction might reflect a basic impairment in auditory processing in misophonia patients. 6 p.

Introducción: el consumo de alcohol se reconoce como causa importante de accidentes de tránsito por el efecto depresor sobre el sistema nervioso central. Aunque las drogas recreacionales o ilegales tienen una acción similar es poco lo que se conoce sobre su relación con la accidentalidad vial. Objetivo: conocer la situación actual en Colombia y el mundo sobre los efectos del alcohol y las sustancias psicoactivas ilegales en el sistema nervioso central como posibles causas de accidentes de tránsito. Métodos: revisión de la literatura en bases electrónicas utilizando los términos DeCS y MeSH: street drugs, designed drugs, ethanol, cocaine, cannabinoides, amphetamines, injuries, accident traffic y automobile driving. Resultados: algunos estudios en especial en Estados Unidos, se reporta una relación estrecha entre el consumo de sustancias psicoactivas y la accidentalidad vial, con cifras cercanas a las del alcohol. En México también se ha demostrado esta relación. En Colombia la mayoría de publicaciones sobre factores de accidentalidad vial no diferencian el consumo de alcohol de las sustancias psicoactivas, lo cual refleja la falta de programas de promoción y prevención sobre el riesgo de conducir bajo la acción de estas sustancias. Los exámenes para determinar su presencia no se ordenan en forma rutinaria y por los datos existentes no reflejan los costos reales derivados de la atención a víctimas de accidentes de tránsito causados por conducir bajo sus efectos. Conclusiones: la situación actual sobre la accidentalidad vial muestra un preocupante aumento de la mortalidad, morbi­ lidad y discapacidad en países en vías de desarrollo como el nuestro. Se analizaron los efectos del alcohol, cocaína, canabinoides y metanfetaminas sobre el sistema nervioso central que disminuyen las habilidades del individuo para la conducción.