Conditioned cortical reactivity to cues predicting cigarette-related or pleasant images

Food cue reward salience does not explain Hyperphagia in adolescents with Prader-Willi syndrome

Prader-Willi Syndrome (PWS) is characterized by hyperphagia, an extreme and persistent hunger that emerges in early childhood. We used event-related potentials (ERPs) to objectively investigate brain responses to low- and high-calorie foods, animals, and household objects in 20 satiated adolescents with PWS. Late Positive Potential (LPP) responses to food images did not differ from non-food images. Rather, we observed larger ERPs to high-calorie foods relative to animal images (p=.001) in an earlier time window. These responses correlated with greater severity of hyperphagia (p = .01). Thus, hyperphagia associated with PWS may be due to altered satiety regulation rather than increased motivational salience.

Cue-reactivity targeted smoking cessation intervention in individuals with tobacco use disorder: a scoping review

Objectives

Cue-reactivity is a critical step leading to the emergence of addictive psychology and the triggering of addictive behaviors within the framework of addiction theory and is considered a significant risk factor for addiction-related behaviors. However, the effect of cue-reactivity targeted smoking cessation intervention and the cue-reactivity paradigms used in the randomized controlled trials varies, which introduces more heterogeneity and makes a side-by-side comparison of cessation responses difficult. Therefore, the scoping review aims to integrate existing research and identify evidence gaps.

Methods

We searched databases in English (PubMed and Embase) and Chinese (CNKI and Wanfang) using terms synonymous with 'cue' and 'tobacco use disorder (TUD)' to April 2023, and via hand-searching and reference screening of included studies. Studies were included if they were randomized controlled trials taking cue-reactivity as an indicator for tobacco use disorder (TUD) defined by different kinds of criteria.

Results

Data were extracted on each study's country, population, methods, timeframes, outcomes, cue-reactivity paradigms, and so on. Of the 2,944 literature were retrieved, 201 studies met the criteria and were selected for full-text screening. Finally, 67 pieces of literature were selected for inclusion and data extraction. The results mainly revealed that non-invasive brain stimulation and exercise therapy showed a trend of greater possibility in reducing subjective craving compared to the remaining therapies, despite variations in the number of research studies conducted in each category. And cue-reactivity paradigms vary in materials and mainly fall into two main categories: behaviorally induced craving paradigm or visually induced craving paradigm.

Conclusion

The current studies are still inadequate in terms of comparability due to their heterogeneity, cue-reactivity can be conducted in the future by constructing a standard library of smoking cue materials. Causal analysis is suggested in order to adequately screen for causes of addiction persistence, and further explore the specific objective cue-reactivity-related indicators of TUD.

Neuroelectric Correlates of Human Sexuality: A Review and Meta-Analysis

Many reviews on sexual arousal in humans focus on different brain imaging methods and behavioral observations. Although neurotransmission in the brain is mainly performed through electrochemical signals, there are no systematic reviews of the electrophysiological correlates of sexual arousal. We performed a systematic search on this subject and reviewed 255 studies including various electrophysiological methods. Our results show how neuroelectric signals have been used to investigate genital somatotopy as well as basic genital physiology during sexual arousal and how cortical electric signals have been recorded during orgasm. Moreover, experiments on the interactions of cognition and sexual arousal in healthy subjects and in individuals with abnormal sexual preferences were analyzed as well as case studies on sexual disturbances associated with diseases of the nervous system. In addition, 25 studies focusing on brain potentials during the interaction of cognition and sexual arousal were eligible for meta-analysis. The results showed significant effect sizes for specific brain potentials during sexual stimulation (P3: Cohen's d = 1.82, N = 300, LPP: Cohen's d = 2.30, N = 510) with high heterogeneity between the combined studies. Taken together, our review shows how neuroelectric methods can consistently differentiate sexual arousal from other emotional states.

Late positive potential as a candidate biomarker of motivational relevance in substance use: Evidence from a meta-analysis

The objective of the current meta-analysis was to assess the effect size of the Late Positive Potential (LPP) to drug and emotional cues in substance users compared to controls. The secondary objective was to test for moderation by: age, gender, years of use, use status, and substance type. Search was performed in August 2021 using PubMed. Inclusion criteria were: substance use disorder/dependence or validated self-report, LPP means, healthy control comparison, non-acute drug study, data available, peer-reviewed journal, English, and human participants. Selection bias was tested through modified Egger's regression and exploratory 3-parameter selection model tests. Results (k = 11) indicated LPP to drug cues was larger in substance use compared to control group, with a large effect size (Hedges' g=1.66, 95%CI [0.64,2.67], p = 0.005). There were no overall differences for emotional cues. Though threats of selection bias were not severe, inclusion of more studies with larger sample sizes in future meta-analyses will allow more robust tests of publication bias and more accurate measures of effect size.

Automaticity of Early Sexual Attention: An Event-Related Potential Study

A promising line of research on forensic assessment of paraphilic sexual interest focuses on behavioral measures of visual attention using sexual stimuli as distractors. The present study combined event-related potentials (ERPs) with behavioral measures to investigate whether detection of a hidden sexual preference can be improved with ERPs. Normal variants of sexual orientation were used for a proof-of-concept investigation. Accordingly, 40 heterosexual and 40 gay men participated in the study. Within each group, half of the participants were instructed to hide their sexual orientation. The results showed that a match between sexual orientation and stimulus delays responses and influences ERP before motor responses. Late ERP components showed higher potential in differentiating hidden sexual preferences than motor responses, thereby showing how ERPs can be used in combination with reaction time measures to potentially facilitate the detection of hidden sexual preferences.

Internal consistency and test-retest reliability of the P3 event-related potential (ERP) elicited by alcoholic and non-alcoholic beverage pictures

Addiction researchers are interested in the ability of neural signals, like the P3 component of the ERP, to index individual differences in liability factors like motivational reactivity to alcohol/drug cues. The reliability of these measures directly impacts their ability to index individual differences, yet little attention has been paid to their psychometric properties. The present study fills this gap by examining within-session internal consistency reliability (ICR) and between-session test-retest reliability (TRR) of the P3 amplitude elicited by images of alcoholic beverages (Alcohol Cue P3) and non-alcoholic drinks (NADrink Cue P3) as well as the difference between them, which isolates alcohol cue-specific reactivity in the P3 (ACR-P3). Analyses drew on data from a large sample of alcohol-experienced emerging adults (session 1 N = 211, 55% female, aged 18-20 yr; session 2 N = 98, 66% female, aged 19-21 yr). Evaluated against domain-general thresholds, ICR was excellent (M ± SD; r= 0.902 ± 0.030) and TRR was fair (r = 0.706 ± 0.020) for Alcohol Cue P3 and NADrink Cue P3, whereas for ACR-P3, ICR and TRR were poor (r = 0.370 ± 0.071; r = 0.201 ± 0.042). These findings indicate that individual differences in the P3 elicited by cues for ingested liquid rewards are highly reliable and substantially stable over 8-10 months. Individual differences in alcohol cue-specific P3 reactivity were less reliable and less stable. The conditions under which alcohol/drug cue-specific reactivity in neural signals is adequately reliable and stable remain to be discovered.

Enhanced conditioned "liking" of novel visual cues paired with alcohol or non-alcohol beverage container images among individuals at higher risk for alcohol use disorder

RATIONALE/OBJECTIVE

This study used an evaluative conditioning (EC) procedure to assess the affective properties of a CS for ingested drug reward in humans. Specifically, the study tested whether the evaluative response ("liking"/"disliking") to an arbitrary visual stimulus ("CS₂," e.g., a purple hexagon) could be changed through pairings with an alcohol or non-alcohol beverage cue ("CS₁," e.g., a full wine glass, a juice box), which is ostensibly a conditioned visual predictive stimulus for alcohol or non-alcohol liquid reward, respectively.

METHODS

Participants (N = 369, 18-23 years, 66% female, 79% white, 21% reporting no alcohol use ever or in the past year) received 24 CS₁ pairings with each CS₂. CS₂ and CS₁ evaluations were assessed pre- and post-conditioning.

RESULTS

Alcohol and non-alcohol CS₂ "liking" correlated with alcohol use. "Liking" of the alcohol but not non-alcohol CS₁ also correlated with alcohol use. Alcohol CS₁ "liking" also correlated with alcohol and non-alcohol CS₂ 'liking," whereas non-alcohol CS₁ 'liking" correlated with non-alcohol but not alcohol CS₂ "liking."

CONCLUSIONS

Taken together, findings support the idea that drug-related visual stimuli acquire appetitive (hedonic and/or incentive) properties as a function of individual differences in drug use, which entail individual differences in exposure to the conditioning effects of addictive substances like alcohol. Findings also suggest a link between drug use and the propensity to attribute affective/motivational significance to reward-predictive cues in general.

Electrophysiological indexes for impaired response inhibition and salience attribution in substance (stimulants and depressants) use disorders: A meta-analysis

The impairment of inhibitory control and reward system is the core feature underlying substance use disorder (SUD). Previous studies suggested that it can be regarded as impaired response inhibition and salience attribution syndrome (iRISA). The neural substrates of the two deficit functions were widely investigated in neuroimaging studies, and the impaired prefrontal cortex, limbic-orbitofrontal network, and fronto-insular-parietal network were observed. Previous Event-related potential (ERP) studies were also conducted to explore EEG indexes related to abnormal brain function. In the current meta-analysis, we aimed to explore the consistency of ERP indexes that can reflect the two aberrant processes: P300/slow potential (SP) for salience attribution and Error-related negativity (ERN)/Nogo-N200/Nogo-P300 for inhibitory control and conflict monitoring. Subgroup analyses for drug type and drug use conditions were also conducted. According to the 60 research studies, we found significantly enhanced drug-cue-induced P300 amplitude and attenuated Nogo-N200 amplitude in SUD individuals relative to Healthy control (HC), which supports the dual model. Moreover, the drug-cue-induced P300 displayed time-dependence recovery, suggesting a potential index for treatment evaluation. In conclusion, drug-cue-induced P300 and Nogo-N200 demonstrated high consistency, and the drug-cue-induced P300 can be used to track the changes of functional recovery for SUD. The integration of the two ERP components could be regarded as a potential biomarker for SUD, which may provide a new insight for clinical treatment and investigation.

The reality of "food porn": Larger brain responses to food-related cues than to erotic images predict cue-induced eating

While some individuals can defy the lure of temptation, many others find appetizing food irresistible. The goal of this study was to investigate the neuropsychological mechanisms that increase individuals' vulnerability to cue-induced eating. Using ERPs, a direct measure of brain activity, we showed that individuals with larger late positive potentials in response to food-related cues than to erotic images are more susceptible to cue-induced eating and, in the presence of a palatable food option, eat more than twice as much as individuals with the opposite brain reactivity profile. By highlighting the presence of individual brain reactivity profiles associated with susceptibility to cue-induced eating, these findings contribute to the understanding of the neurobiological basis of vulnerability to obesity.

The Late Positive Potentials Evoked by Cigarette-Related and Emotional Images Show no Gender Differences in Smokers

When trying to quit, women are less likely than men to achieve long-term smoking abstinence. Identifying the neuropsychological mechanisms underlying women's higher relapse vulnerability will help clinicians to develop effective tailored smoking cessation interventions. Here we used event-related potentials (ERPs), a direct measure of brain activity, to evaluate the extent to which neurophysiological responses to cigarette-related and other emotional stimuli differ between female and male smokers. Both women and men showed similar patterns of brain reactivity across all picture categories; pleasant and unpleasant images prompted larger Late Positive Potentials (LPPs, a robust measure of motivational relevance) than neutral images in both groups, and cigarette-related images prompted lower LPPs than high arousing emotional images in both groups. Unlike previous studies, there were no differences between male and female smokers with regard to LPP responses to cigarette-related images. This suggests that the LPP may not be ideally suited to discriminate neurophysiological gender differences or that there are simply no gender differences in the neurophysiological responses to cigarette-related stimuli. We collected ERPs from 222 non-nicotine-deprived smokers (101 women) while they watched a slideshow that included high and low emotionally arousing pleasant and unpleasant pictures, cigarette-related, and neutral pictures. We used the mean amplitude of the LPP to assess the affective significance that participants attributed to these pictures.

Brain Responses to Cigarette-Related and Emotional Images in Smokers During Smoking Cessation: No Effect of Varenicline or Bupropion on the Late Positive Potential

Introduction

Varenicline and bupropion are two effective smoking cessation pharmacotherapies. Researchers have hypothesized that they might be effective, in part, because they reduce cue reactivity and cue-induced cravings. Here, we used event-related potentials (ERPs) to directly measure brain responses to cigarette-related and other motivationally relevant images during a pharmacologically aided quit attempt.

Methods

Smokers involved in a 12-week placebo-controlled double-blind clinical trial of smoking cessation medications (varenicline, bupropion, placebo) took part in the study. We assessed participants at two time points: 24 h (n = 140) and 4 weeks (n = 176) after the quit date. At both sessions, we measured the amplitude of the late positive potential (LPP), an ERP component reliably associated with motivational relevance, and self-reported tonic craving using the brief version of the Questionnaire of Smoking Urges (QSU-Brief).

Results

At both sessions, emotional and cigarette-related images evoked significantly larger LPPs than neutral images. Neither drug type nor smoking abstinence altered this effect at either session. At both sessions, varenicline and bupropion significantly reduced self-reported tonic craving relative to the placebo condition.

Conclusions

While both varenicline and bupropion reduced self-reported tonic craving, neither medication altered the amplitude of the LPP to cigarette-related or emotional pictures in smokers attempting to quit. These medications may influence abstinence by means other than by reducing neuroaffective responses to cigarette-related cues. Smokers should be prepared for the likelihood that even after several weeks of successful abstinence, once treatment ends, cigarette-related cues may remain motivationally relevant and trigger cravings that might lead to relapse.

Implications

Bupropion and varenicline do not alter electrophysiological responses, as measured by the LPP, to cigarette-related and emotional images. These findings help explain why cigarette-related cues can trigger relapse when smoking cessation medication treatments end.

Cigarette cues capture attention of smokers and never-smokers, but for different reasons

BACKGROUND

While the notion that smokers reliably show higher reactivity to cigarette-related versus neutral cues is both theoretically and empirically supported, it is unclear why never-smokers also show enhanced brain responses to cigarette-related cues.

METHODS

Using a repetitive picture viewing paradigm, in which responses evoked by affective cues are more resistant to habituation, we assessed the effects of stimulus repetition on event-related potentials (ERPs) evoked by pleasant, unpleasant, cigarette-related, and neutral images in 34 smokers (SMO) and 34 never-smokers (NEV). We examined the early posterior negativity (EPN) and the late positive potential (LPP), two ERP components which are sensitive to a picture's motivational qualities.

RESULTS

Before stimulus repetition, pleasant, unpleasant, and cigarette-related cues produced greater EPN and LPP amplitudes than neutral cues in all subjects. During stimulus repetition, both components were similarly modulated by emotional arousal, such that pleasant, unpleasant, and cigarette-related cues evoked greater EPN and LPP amplitude, relative to neutral. Smoking status did not modulate these effects. While there were no group differences in self-reported stimulus ratings of valence for pleasant, unpleasant, or neutral stimuli, NEV rated cigarette-related cues as unpleasant. We observed a moderate, negative correlation between LPP amplitude and self-reported valence ratings of cigarette-related cues among NEV.

CONCLUSIONS

These data suggest that cigarette-related cues capture attentional resources of both SMO and NEV, but for different reasons. For SMO, cigarette-related cues have acquired motivational significance through repeated associations with nicotine delivery, whereas for NEV, cigarette-related cues are perceived as unpleasant.

Beyond Cue Reactivity: Non-Drug-Related Motivationally Relevant Stimuli Are Necessary to Understand Reactivity to Drug-Related Cues

Neurobiological models of addiction posit that drug use can alter reward processes in two ways: (1) by increasing the motivational relevance of drugs and drug-related cues and (2) by reducing the motivational relevance of non-drug-related rewards. Here, we discuss the results from a series of neuroimaging studies in which we assessed the extent to which these hypotheses apply to nicotine dependence. In these studies, we recorded smokers’ and nonsmokers’ brain responses to a wide array of motivationally relevant visual stimuli that included pleasant, unpleasant, cigarette-related, and neutral images. Based on these findings, we highlight the flaws of the traditional cue reactivity paradigm and we conclude that responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the motivational relevance of cigarette-related cues and to identify smokers attributing higher motivational relevance to drug-related cues than to non-drug-related rewards. Identifying these individuals is clinically relevant as they achieve lower rates of long-term smoking abstinence when attempting to quit. Finally, we show how this approach may be extended beyond nicotine dependence to inform theoretical and clinical research in the study of obesity.

Implications

The cue reactivity paradigm (ie, comparing responses evoked by drug-related cues to those evoked by neutral cues) cannot provide conclusive information about the motivational relevance of drug-related cues. Responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the level of motivational relevance that substance-dependent individuals attribute to drug-related cues.

Individual differences in brain responses to cigarette-related cues and pleasant stimuli in young smokers

BACKGROUND

Decreased sensitivity to pleasant stimuli is associated with a higher vulnerability to nicotine dependence in youths and with difficulty quitting in adult smokers. Recently, we showed that smokers showing lower brain reactivity to non-cigarette-related pleasant images than to cigarette-related ones have lower chances of achieving long-term abstinence during a quit attempt.

METHODS

We tested whether individual differences in brain responses to cigarette-related and pleasant stimuli require a long history of smoking to develop by measuring the late positive potential (LPP) to cigarette cues, emotional, and neutral stimuli in 45 young, light smokers (ages 18-25). k-means cluster analysis was used to partition smokers into two groups based on the magnitude of their LPPs.

RESULTS

Group 1 was characterized by larger LPPs to pleasant pictures than cigarette-related pictures whereas Group 2 showed the opposite pattern.

CONCLUSIONS

Our results suggest that individual differences in brain responses to cigarette-related and pleasant cues do not require a long smoking history to develop.