Perception of Prosodic Modulations of Linguistic and Paralinguistic Origin: Evidence From Early Auditory Event-Related Potentials

How listeners handle prosodic cues of linguistic and paralinguistic origin is a central question for spoken communication. In the present EEG study, we addressed this question by examining neural responses to variations in pitch accent (linguistic) and affective (paralinguistic) prosody in Swedish words, using a passive auditory oddball paradigm. The results indicated that changes in pitch accent and affective prosody elicited mismatch negativity (MMN) responses at around 200 ms, confirming the brain’s pre-attentive response to any prosodic modulation. The MMN amplitude was, however, statistically larger to the deviation in affective prosody in comparison to the deviation in pitch accent and affective prosody combined, which is in line with previous research indicating not only a larger MMN response to affective prosody in comparison to neutral prosody but also a smaller MMN response to multidimensional deviants than unidimensional ones. The results, further, showed a significant P3a response to the affective prosody change in comparison to the pitch accent change at around 300 ms, in accordance with previous findings showing an enhanced positive response to emotional stimuli. The present findings provide evidence for distinct neural processing of different prosodic cues, and statistically confirm the intrinsic perceptual and motivational salience of paralinguistic information in spoken communication.

Oxytocin enhances neural approach towards social and non-social stimuli of high personal relevance

Oxytocin (OT) plays a pivotal role in a variety of complex social behaviors by modulating approach-avoidance motivational tendencies, but recently, its social specificity has been challenged. Here, a randomized, double-blind, placebo-controlled study was conducted with forty young adult men, investigating the effect of a single-dose of OT (24 IU) on behavioral and neural approach-avoidance. Frontal alpha asymmetry, indexing neurophysiological approach-avoidance, was obtained from electroencephalographic recordings while participants were presented with a series of pictures, individually rated in terms of personal relevance (i.e., high versus low positive/negative emotional evocativeness) and categorized as social or non-social. Additionally, participants could prolong (approach) or shorten (avoid) the viewing-time of each picture, providing a measure of behavioral approach-avoidance. Intranasal OT enhanced both behavioral and neural approach (increased viewing-time), particularly towards negatively valenced pictures of both social and non-social nature, thus challenging the notion that OT’s effects are specific to social stimuli. Neurally, OT specifically amplified approach-related motivational salience of stimuli that were self-rated to have high personal relevance, but irrespective of their social nature or rated affective valence (positive/negative). Together, these findings provide support to the General Approach-Avoidance Hypothesis of OT, suggesting a role of OT in amplifying the motivational salience of environmental stimuli with high (personal) relevance, but irrespective of their social/non-social nature.Clinical Trial Number: The study design was registered at ClinicalTrials.gov (NCT04443647; 23/06/2020; https://clinicaltrials.gov/ct2/show/NCT04443647).

The neural basis of authenticity recognition in laughter and crying

Deciding whether others’ emotions are genuine is essential for successful communication and social relationships. While previous fMRI studies suggested that differentiation between authentic and acted emotional expressions involves higher-order brain areas, the time course of authenticity discrimination is still unknown. To address this gap, we tested the impact of authenticity discrimination on event-related potentials (ERPs) related to emotion, motivational salience, and higher-order cognitive processing (N100, P200 and late positive complex, the LPC), using vocalised non-verbal expressions of sadness (crying) and happiness (laughter) in a 32-participant, within-subject study. Using a repeated measures 2-factor (authenticity, emotion) ANOVA, we show that N100’s amplitude was larger in response to authentic than acted vocalisations, particularly in cries, while P200’s was larger in response to acted vocalisations, particularly in laughs. We suggest these results point to two different mechanisms: (1) a larger N100 in response to authentic vocalisations is consistent with its link to emotional content and arousal (putatively larger amplitude for genuine emotional expressions); (2) a larger P200 in response to acted ones is in line with evidence relating it to motivational salience (putatively larger for ambiguous emotional expressions). Complementarily, a significant main effect of emotion was found on P200 and LPC amplitudes, in that the two were larger for laughs than cries, regardless of authenticity. Overall, we provide the first electroencephalographic examination of authenticity discrimination and propose that authenticity processing of others’ vocalisations is initiated early, along that of their emotional content or category, attesting for its evolutionary relevance for trust and bond formation.

Effects of system- and media-driven immersive capabilities on presence and affective experience

Virtual reality (VR) is receiving widespread attention as a delivery tool for exposure therapies. The advantage offered by VR over traditional technology is a greater sense of presence and immersion, which magnifies user effects and enhances the effectiveness of exposure-based interventions. The current study systematically examined the basic factors involved in generating presence in VR as compared to standard technology, namely (1) system-driven factors that are exclusive to VR devices while controlling general factors such as field of view and image quality; (2) media-driven factors of the virtual environment eliciting motivational salience through different levels of arousal and valence (relaxing, exciting and fear evoking stimuli); and (3) the effects of presence on magnifying affective response. Participants (N = 14) watched 3 different emotionally salient videos (1 × fear evoking, 1 × relaxing and 1 × exciting) in both viewing modes (VR and Projector). Subjective scores of user experience were collected as well as objective EEG markers of presence (frontal alpha power, theta/beta ratio). Subjective and objective presence was significantly greater in the VR condition. There was no difference in subjective or objective presence for stimulus type, suggesting presence is not moderated by arousal, but may be reliant on activation of motivational systems. Finally, presence did not magnify feelings of relaxation or excitement, but did significantly magnify users’ experience of fear when viewing fear evoking stimuli. This is in line with previous literature showing strong links between presence and generation of fear, which is vital in the efficacy of exposure therapies.

Dopamine-dependent cAMP dynamics in basal amygdala glutamatergic neurons

Dopaminergic inputs to basal amygdala (BA) instruct learning of motivational salience. Here, we investigated the dynamics of dopamine release and downstream signaling during multiple salient events occurring within tens of seconds. We established in vitro and in vivo real-time tracking and manipulation of cAMP - a key intracellular plasticity signal downstream of dopamine receptor activation. Optogenetically-evoked release of dopamine drove proportional increases in cAMP in almost all BA glutamatergic neurons, suggesting widespread actions of dopamine across neurons preferring positive or negative valence. These cAMP responses decayed more slowly than dopamine release, potentially extending the window of plasticity. cAMP levels accumulated following direct photostimulation of cAMP but not repeated stimulation of dopamine axons, due to potent depression of dopamine release. cAMP and protein kinase A (PKA) responses to repeated appetitive or aversive stimuli also exhibited pronounced depression. Thus, history-dependent dynamics of dopamine and cAMP may regulate learning of temporally clustered, salient stimuli.

Reward disturbances in antipsychotic-naïve patients with first-episode psychosis and their association to glutamate levels

Background Aberrant anticipation of motivational salient events and processing of outcome evaluation in striatal and prefrontal regions have been suggested to underlie psychosis. Altered glutamate levels have likewise been linked to schizophrenia. Glutamatergic abnormalities may affect the processing of motivational salience and outcome evaluation. It remains unresolved, whether glutamatergic dysfunction is associated with the coding of motivational salience and outcome evaluation in antipsychotic-naïve patients with first-episode psychosis. Methods Fifty-one antipsychotic-naïve patients with first-episode psychosis (22 ± 5.2 years, female/male: 31/20) and 52 healthy controls (HC) matched on age, sex, and parental education underwent functional magnetic resonance imaging and magnetic resonance spectroscopy (3T) in one session. Brain responses to motivational salience and negative outcome evaluation (NOE) were examined using a monetary incentive delay task. Glutamate levels were estimated in the left thalamus and anterior cingulate cortex using LCModel. Results Patients displayed a positive signal change to NOE in the caudate (p = 0.001) and dorsolateral prefrontal cortex (DLPFC; p = 0.003) compared to HC. No group difference was observed in motivational salience or in levels of glutamate. There was a different association between NOE signal in the caudate and DLPFC and thalamic glutamate levels in patients and HC due to a negative correlation in patients (caudate: p = 0.004, DLPFC: p = 0.005) that was not seen in HC. Conclusions Our findings confirm prior findings of abnormal outcome evaluation as a part of the pathophysiology of schizophrenia. The results also suggest a possible link between thalamic glutamate and NOE signaling in patients with first-episode psychosis.

A neurobehavioral account of differential consumer responses to price and in-store display between un/healthy food

Purpose This paper aims to elucidate some of the complexity around food consumption by drawing from neuroscience research of food as a motivated choice (i.e. a neurobehavioral process sensitive to dopaminergic response to food and environmental cues such as marketing). The authors explore the single and compounded effect of the motivational salience of food’s intrinsic reinforcing value tied to its sugar content and that of two marketing food cues, price and in-store display, on actual consumer purchase behavior. Design/methodology/approach The authors test the above hypotheses in two perceived “healthy” product categories with a wide distribution of sugar content. The authors estimate a within-category model using three years of retail transaction data to test the effect on weekly sales. Findings The authors confirm the single effect of each of food’s and marketing cues’ motivational salience as well as their compounded effect with high-motivational-salience food being less price elastic and more susceptible to in-store display activities. Research limitations/implications This research highlights the need to complement current reliance on unhealthy/healthy perception with finer grained objective evidence linked to the formulation of the food itself and the marketing applied to them. Practical implications The present study findings may help marketing managers and policymakers develop better targeted pricing and display strategies for low- and high-motivational-salience food, attempting to strike a better balance between consumer welfare and commercial performance. Originality/value This paper is one of the few that links real-world market outcomes to predictions derived from a unique combination of consumer neuroscience and neurobiology of food, advancing data-driven decisions.

Motivational Salience Guides Attention to Valuable and Threatening Stimuli: Evidence from Behavior and Functional Magnetic Resonance Imaging

Rewarding and aversive outcomes have opposing effects on behavior, facilitating approach and avoidance, although we need to accurately anticipate each type of outcome to behave effectively. Attention is biased toward stimuli that have been learned to predict either type of outcome, and it remains an open question whether such orienting is driven by separate systems for value- and threat-based orienting or whether there exists a common underlying mechanism of attentional control driven by motivational salience. Here, we provide a direct comparison of the neural correlates of value- and threat-based attentional capture after associative learning. Across multiple measures of behavior and brain activation, our findings overwhelmingly support a motivational salience account of the control of attention. We conclude that there exists a core mechanism of experience-dependent attentional control driven by motivational salience and that prior characterizations of attention as being value driven or supporting threat monitoring need to be revisited.

Salience neural network: another tribute to fashion or the key to all doors?

This review presents an analysis of the literature on studies of the salience neural network, the dynamics of neural network formation during ontogenesis of the brain, and salience dysregulation in neurodegenerative and neuropsychiatric disorders. The role of dopaminergic imbalance in the formation of aberrant salience in schizophrenia is considered. Particular attention is paid to the studies of the significance of motivational salience and reward system in the pathogenesis of addictive disorders.

Motivational salience guides attention to valuable and threatening stimuli: Evidence from behaviour and fMRI

Rewarding and aversive outcomes have opposing effects on behaviour, facilitating approach and avoidance, although we need to accurately anticipate each type of outcome in order to behave effectively. Attention is biased toward stimuli that have been learned to predict either type of outcome, and it remains an open question whether such orienting is driven by separate systems for value- and threat-based orienting or whether there exists a common underlying mechanism of attentional control driven by motivational salience. Here we provide a direct comparison of the neural correlates of value- and threat-based attentional capture following associative learning. Across multiple measures of behaviour and brain activation, our findings overwhelmingly support a motivational salience account of the control of attention. We conclude that there exists a core mechanism of experience-dependent attentional control driven by motivational salience, and that prior characterisations of attention as being value-driven or supporting threat monitoring need to be revisited.