Blood pressure response to extended-release naltrexone in heroin and prescription opioid users and its implications for cardiovascular morbidity

BACKGROUND

Consuming opioid agonists is a risk factor for cardiovascular disease particularly in intravenous heroin users. The monthly injectable extended-release opioid antagonist, naltrexone (XR-NTX) is an effective treatment for opioid use disorder. The impact of opioid receptor blockade through XR-NTX on blood pressure, a critical risk factor for cardiovascular morbidity, has not yet been characterized.

METHODS

The study evaluated the change in blood pressure during XR-NTX treatment among 14 patients who predominately used intravenous heroin and 24 patients who used prescription oral opioids, all with opioid use disorder. Blood pressure was measured in each patient immediately before the first XR-NTX injection and ∼two weeks after the first injection. The change in diastolic and systolic pressure was compared between the heroin users and the prescription opioids users using analysis of variance.

RESULTS

XR-NTX treatment was associated with significant decreases in diastolic blood pressure in the heroin group, but not in the prescription opioids group. Systolic blood pressure values in the heroin users showed a decline at trend level only.

CONCLUSIONS

Further research is warranted to replicate our findings and to determine whether XR-NTX effect is relatively specific to blood pressure or generalizes to other components of metabolic syndrome. Distinguishing between heroin and prescription opioid users could shed light on the unique clinical and pharmacological profiles of opioid drugs, particularly regarding their cardiovascular safety. This information can be useful in developing personalized therapeutic strategies based on the route of opioid administration.

Delayed effects of cigarette graphic warning labels on smoking behavior

Graphic warning labels (GWLs) on cigarette packs are widely employed to communicate smoking-related health risks. Most GWLs elicit high emotional arousal. Our recent study showed lower efficacy of high-arousal GWLs than low-arousal ones during 4 weeks of naturalistic exposure. Here, we conducted a secondary analysis to investigate the delayed effects of GWLs on smoking severity after the end of the 4- week exposure. In 112 adult smokers (56 high-arousal, 56 low-arousal), there was a significant reduction in the number of cigarettes smoked per day (CPD) from immediately post-exposure to 4 weeks post-exposure. The high-arousal and low-arousal groups did not differ in CPD reduction. Our study suggests lasting impact of GWLs on smoking behavior. The finding may be particularly relevant to the high-arousal GWLs, whose efficacy is not as pronounced during direct and continuous exposure.

Hippocampal volume loss in individuals with a history of non-fatal opioid overdose

Incidence of opioid-related overdoses in the United States has increased dramatically over the past two decades. Despite public emphasis on overdose fatalities, most overdose cases are not fatal. Although there are case reports of amnestic syndromes and acute injury to the hippocampus following non-fatal opioid overdose, the effects of such overdoses on brain structure are poorly understood. Here, we investigated the neuroanatomical correlates of non-fatal opioid overdoses by comparing hippocampal volume in opioid use disorder (OUD) patients who had experienced an opioid overdose (OD; N = 17) with those who had not (NOD; N = 32). Voxel-based morphometry showed lower hippocampal volume in the OD group than in the NOD group, which on post hoc analysis was evident in the left but not the right hippocampus. These findings strengthen the evidence that hippocampal injury is associated with non-fatal opioid overdose, which is hypothesized to underlie overdose-related amnestic syndrome.

Association between body mass index and treatment completion in extended-release naltrexone-treated patients with opioid dependence

Background

Excessive consumption of opioids is associated with impaired metabolic function including increased body mass index (BMI). Opioid antagonist naltrexone (NTX) is an effective treatment for opioid use disorder (OUD) that has the potential to mitigate such metabolic disturbances. Understanding the relationship between treatment adherence and BMI in NTX-treated OUD patients may provide valuable insights into optimizing clinical outcomes.

Methods

Patients with opioid dependence were offered up to three monthly injections of extended-release (XR) NTX. Treatment completers (n = 41) were defined as those who had received all three XR-NTX injections, and non-completers (n = 20) as those missing at least one injection. Logistic regression was performed to examine the association between pre-treatment BMI and treatment completion.

Results

BMI was positively associated with treatment completion. This association remained significant after adjusting for potentially confounding variables.

Conclusion

Our findings suggest that baseline BMI may serve as a potential predictor of XR-NTX treatment adherence in patients with OUD and could help healthcare providers and policy makers alike in developing strategies to improve retention and tailor interventions for specific patient subgroups.

Effects of emotional arousal on the neural impact and behavioral efficacy of cigarette graphic warning labels

BACKGROUND AND AIMS

Graphic warning labels (GWLs) on cigarette packs have been adopted by many jurisdictions world-wide. In the United States, the introduction of GWLs has been delayed by claims that their high level of negative emotional arousal unnecessarily infringed upon the tobacco manufacturers' free speech. This study aimed to provide experimental data on the contribution of emotional arousal to GWL efficacy.

DESIGN

Observational study using long-term naturalistic exposure and functional magnetic resonance imaging.

SETTING

Research university in Philadelphia, PA, USA.

PARTICIPANTS

A total of 168 adult smokers.

MEASUREMENTS

For 4 weeks, participants received cigarettes in packs that carried either high-arousal or low-arousal GWLs (n = 84 versus 84). Smoking behavior, quitting-related cognitions and GWL-induced brain response were measured before and after the 4-week exposure. The amygdala and medial prefrontal cortex served as regions of interest.

FINDINGS

Compared with the high-arousal group, the low-arousal group smoked fewer cigarettes [log10 -transformed, 1.076 versus 1.019; difference = 0.056, 95% confidence interval (CI) = 0.027, 0.085, χ2 (1)  = 14.21, P < 0.001] and showed stronger intention to quit (2.527 versus 2.810; difference = -0.283, 95% CI = -0.468, -0.098, χ2 (1)  = 8.921, P = 0.007) and endorsement of the GWLs' textual component (4.805 versus 5.503; difference = -0.698, 95% CI = -1.016, -0.380, χ2 (1)  = 18.47, P < 0.001). High-arousal GWLs induced greater amygdala response than low-arousal GWLs (0.157 versus 0.052; difference = 0.105, 95% CI = 0.049, 0.161, χ2 (1)  = 23.52, P < 0.001), although the response to high-arousal GWLs declined over time (slope = -0.087 versus 0.016; difference = -0.103, 95% CI = -0.198, -0.009, χ2 (1)  = 6.370, P = 0.046). Greater baseline amygdala response was associated with more smoking at 4 weeks in the high-arousal group, but less smoking in the low-arousal group (slope = 0.179 versus -0.122; difference = 0.287, 95% CI = 0.076, 0.498, χ2 (1)  = 7.086, P = 0.008). Medial prefrontal response did not differ significantly between groups.

CONCLUSIONS

High-arousal cigarette graphic warning labels (GWLs) appear to be less efficacious than low-arousal GWLs. The high emotional reaction that high-arousal GWLs elicit wanes over time. Baseline amygdala response negatively predicts efficacy of high-arousal GWLs and positively predicts efficacy of low-arousal GWLs. High emotional arousal may not be required for sustained GWL efficacy.

Addicted to green: priming effect of menthol cigarette packaging on brain response to smoking cues

INTRODUCTION

Mentholated tobacco cigarettes are believed to be more addictive than non-menthol ones. Packaging of most menthol cigarette brands includes distinctive green hues, which may act as conditioned stimuli (ie, cues) and promote menthol smoking. To examine the cue properties of menthol cigarette packaging, we used a priming paradigm to assess the effect of packaging on the neural substrates of smoking cue reactivity. We hypothesised that menthol packaging will exert a specific priming effect potentiating smoking cue reactivity in menthol compared with non-menthol smokers.

METHODS

Forty-two menthol and 33 non-menthol smokers underwent functional MRI while viewing smoking and neutral cues. The cues were preceded (ie, primed) by briefly presented images of menthol or non-menthol cigarette packages. Participants reported craving for cigarettes in response to each cue.

RESULTS

Menthol packaging induced greater frontostriatal and occipital smoking cue reactivity in menthol smokers than in non-menthol smokers. Menthol packaging also enhanced the mediation by neural activity of the relationship between cue exposure and cigarette craving in menthol but not non-menthol smokers. Dynamic causal modelling showed stronger frontostriatal-occipital connectivity in response to menthol packaging in menthol compared with non-menthol smokers. The effects of non-menthol packaging did not differ between categories of smokers.

CONCLUSIONS

Our findings demonstrate heightened motivational and perceptual salience of the green-hued menthol cigarette packaging that may exacerbate menthol smokers' susceptibility to smoking cues. These effects could contribute to the greater addiction severity among menthol smokers and could be considered in the development of science-based regulation and legal review of tobacco product marketing practices.

Effects of current smoking severity on brain gray matter volume in opioid use disorder - a voxel-based morphometry study

Background: Cigarette smoking (CS) and opioid use disorder (OUD) significantly alter brain structure. Although OUD and cigarette smoking are highly comorbid, most prior neuroimaging research in OUD did not control for smoking severity. Specifically, the combined effect of smoking and OUD on the brain gray matter volume (GMV) remains unknown.Objectives: We used structural magnetic resonance imaging (sMRI) to examine: (1) the GMV differences between OUD and non-OUD individuals with comparable smoking severity; and (2) the differential effect of smoking severity on the brain GMV between individuals with and without OUD.Methods: We performed a secondary analysis of existing sMRI datasets of 116 individuals who smoked cigarettes daily, among whom 60 had OUD (CS-OUD; 37 male, 23 female) and 56 did not (CS; 31 male, 25 female). Brain GMV was estimated by voxel-based morphometry analysis.Results: Compared to the CS group, the CS-OUD group had a higher GMV in the occipital cortex and lower GMV in the prefrontal and temporal cortex, striatum, and pre/postcentral gyrus (whole-brain corrected-p < .05). There was a significant interaction between group and smoking severity on GMV in the medial orbitofrontal cortex (whole-brain corrected-p < .05), such that heavier smoking was associated with lower medial orbitofrontal GMV in the CS-OUD but not CS participants (r=-0.32 vs. 0.12).Conclusions: Our findings suggest a combination of independent and interactive effects of cigarette smoking and OUD on the brain gray matter. Elucidating the neuroanatomical correlates of comorbid opioid and tobacco use may shed the light on the development of novel interventions for affected individuals.

Baseline- and treatment-associated pain in the X:BOT comparative effectiveness study of extended-release naltrexone versus buprenorphine-naloxone for OUD

Chronic pain is highly prevalent among patients with opioid use disorder (OUD). However, little is known about how pharmacological treatments for OUD, for example, extended-release naltrexone (XR-NTX) and buprenorphine-naloxone (BUP-NX), affect pain. To begin addressing this question, we performed a secondary analysis of pain data on a large prospective 24-week, open-label, randomized-controlled comparative effectiveness trial of XR-NTX versus BUP-NX (X:BOT trial). Participants' pain status was measured by the EuroQol (EQ-5D). Based on their responses to the pain question at baseline, participants were dichotomized into "Pain" versus "No Pain" categories. Participant's pain status was evaluated every 4 weeks. A mixed effects longitudinal logistic regression model was fitted to examine the differential effect of XR-NTX versus BUP-NX on pain, modelling pain at all available follow-up assessments, adjusted for age, sex, and baseline pain. A total of 474 individuals who were successfully inducted onto their assigned medications were included in this analysis. Among participants endorsing pain at baseline, substantial reductions in pain were observed over the course of the study in both treatment groups. Howecver reduction in pain was slightly greater in the group treated with XR-NTX than the one treated with BUP-NX (OR = 1.60 [95% CI: 1.07-2.40], P = 0.023). Future research using instruments and design specifically focused on pain could extend the present observations and evaluate their clinical significance.

Sustained brain response to repeated drug cues is associated with poor drug-use outcomes

A threefold increase in fatal cocaine overdoses during the past decade highlights the critical lack of medications for cocaine use disorders. The brain response to drug cues can predict future drug use; however, results have been mixed. We present preliminary evidence that a sustained response to repeated cocaine cues within a single task is a significant predictor of drug-use outcomes. Seventy-three cocaine inpatients were administered a passive-viewing fMRI task, featuring 500 ms novel evocative (cocaine, sexual, aversive) and neutral comparator cues in the first half (Half1), which were then repeated in the second half (Half2). After the baseline scan, patients received eight outpatient treatment weeks with twice-weekly drug screens. Drug-use outcome groups were empirically defined based on cocaine-positive or missing urines averaged across the outpatient phase: GOOD (<40%), POOR (>85%), and Intermediate (INT, between 40% and 85%) outcomes. Differences of response to initial (Half1) and repeated (Half2) cues in a priori (cue-reactive) regions were tested between outcome groups (3 [Group] × 2 [Halves] ANOVA). An interaction was found in the brain response to drug (but not sex or aversive) cues, with a significant difference between the GOOD and POOR outcome groups in Half2, driven by a significant decrease in brain response by the GOOD outcome group and a sustained brain response by the POOR outcome group, to repeated cocaine cues. The brain response to repeated drug cues may be a useful predictor of future drug use, encouraging future intervention studies to restore a "healthy" (decreasing) response to the repeated presentation of drug cues.

Multivariate pattern analysis links drug use severity to distributed cortical hypoactivity during emotional inhibitory control in opioid use disorder

Opioid use disorder (OUD) is characterized by emotional and cognitive impairements that are associated with poor treatment outcomes. The present study investigated the neural mechanism underlying emotion evaluation and inhibitory control using an affective go/no-go (AGN) task and its association with drug use severity and craving in patients with OUD. Twenty-six recently detoxified patients with OUD underwent functional magnetic resonance imaging (fMRI) while performing the AGN task that required response to frequently presented appetitive stimuli ("go") and inhibition of response to infrequently presented aversive stimuli ("no-go"). The fMRI session was immediately followed by an injection of extended-release opioid antagonist naltrexone (XR-NTX). Participants' opioid craving was assessed immediately before fMRI and 10 ± 2 days after XR-NTX injection. Multivariate pattern analysis (MVPA) showed that drug use severity was associated with distributed brain hypoactivity in response to aversive no-go stimuli, with particularly large negative contributions from the cognitive control and dorsal attention brain networks. While drug use severity and its associated MVPA brain response pattern were both correlated with opioid craving at baseline, only the brain response pattern predicted craving during XR-NTX treatment. Our findings point to widespread functional hypoactivity in the brain networks underlying emotional inhibitory control in OUD. Such a distributed pattern is consistent with the multifaceted nature of OUD, which affects multiple brain networks. It also highlights the utility of the multivariate approach in uncovering large-scale cortical substrates associated with clinical severity in complex psychiatric disorders and in predicting treatment response.

The role of withdrawal in mesocorticolimbic drug cue reactivity in opioid use disorder

Opioid use disorder (OUD) is characterized by heightened cognitive, physiological, and neural responses to opioid-related cues that are mediated by mesocorticolimbic brain pathways. Craving and withdrawal are key symptoms of addiction that persist during physiological abstinence. The present study evaluated the relationship between the brain response to drug cues in OUD and baseline levels of craving and withdrawal. We used functional magnetic resonance imaging (fMRI) to examine brain responses to opioid-related pictures and control pictures in 29 OUD patients. Baseline measures of drug use severity, opioid craving, and withdrawal symptoms were assessed prior to cue exposure and correlated with subsequent brain responses to drug cues. Mediation analysis was conducted to test the indirect effect of drug use severity on brain cue reactivity through craving and withdrawal symptoms. We found that baseline drug use severity and opioid withdrawal symptoms, but not craving, were positively associated with the neural response to drug cues in the nucleus accumbens, orbitofrontal cortex, and amygdala. Withdrawal, but not craving, mediated the effect of drug use severity on the nucleus accumbens' response to drug cues. We did not find similar effects for the neural responses to stimuli unrelated to drugs. Our findings emphasize the central role of withdrawal symptoms as the mediator between the clinical severity of OUD and the brain correlates of sensitization to opioid-related cues. They suggest that in OUD, baseline withdrawal symptoms signal a high vulnerability to drug cues.

Multi-View Cluster Analysis with Incomplete Data to Understand Treatment Effects

Multi-view cluster analysis, as a popular granular computing method, aims to partition sample subjects into consistent clusters across different views in which the subjects are characterized. Frequently, data entries can be missing from some of the views. The latest multi-view co-clustering methods cannot effectively deal with incomplete data, especially when there are mixed patterns of missing values. We propose an enhanced formulation for a family of multi-view co-clustering methods to cope with the missing data problem by introducing an indicator matrix whose elements indicate which data entries are observed and assessing cluster validity only on observed entries. In comparison with the simple strategy of removing subjects with missing values, our approach can use all available data in cluster analysis. In comparison with common methods that impute missing data in order to use regular multi-view analytics, our approach is less sensitive to imputation uncertainty. In comparison with other state-of-the-art multi-view incomplete clustering methods, our approach is sensible in the cases of missing any value in a view or missing the entire view, the most common scenario in practice. We first validated the proposed strategy in simulations, and then applied it to a treatment study of heroin dependence which would have been impossible with previous methods due to a number of missing-data patterns. Patients in a treatment study were naturally assessed in different feature spaces such as in the pre-, during-and post-treatment time windows. Our algorithm was able to identify subgroups where patients in each group showed similarities in all of the three time windows, thus leading to the recognition of pre-treatment (baseline) features predictive of post-treatment outcomes.

Reduced cigarette smoking during injectable extended-release naltrexone treatment for opioid use disorder

BACKGROUND

The prevalence of tobacco cigarette smoking in the US has declined to approximately 15%, yet, it remains over 90% among individuals with opioid use disorder regardless of whether they are currently using opioids illicitly or as opioid substitution therapy. This disparity raises the question of whether opioids facilitate smoking among individuals with opioid use disorder and whether opioid antagonists may reduce it.

OBJECTIVES

Determine whether injectable extended-release naltrexone (XR-NTX) treatment of opioid use disorder patients is associated with a spontaneous smoking reduction. We hypothesized that treatment with XR-NTX for would lead to a reduction in smoking in tobacco cigarette smokers with opioid use disorder.

METHODS

We analyzed data from 64 tobacco cigarette smokers (38% female) with opioid use disorder who were induced on XR-NTX for prevention of relapse to opioids. The number of cigarettes smoked per day and opioid-related craving and withdrawal were assessed at baseline and during treatment.

RESULTS

Smoking was reduced from 14.4 ± 1.0 to 9.8 ± 1.0(p < 0.001) cigarettes per day after one month and 8.6 ± 1.1 cigarettes per day after two months of treatment. Daily cigarette consumption was positively correlated with the pre-treatment frequency of opioid use and opioid-related craving during the XR-NTX treatment.

CONCLUSIONS

XR-NTX treatment in smokers with opioid use disorder was associated with a 29% decline in daily cigarette consumption. Together with prior evidence of increased smoking during opioid agonist therapy, our finding suggests a pharmacodynamic interaction between nicotine and opioid systems that could influence treatment choices in this population. Our findings merit confirmation in a prospective controlled study. (NCT02324725 and NCT01587196).

Brain Responses to Anti-Smoking Health Warnings In Youth

Purpose of the Review

Adolescents and young adults are a critical target for smoking prevention efforts. Health education is a key approach to these efforts, yet little is known about how adolescents and young adults process health information. One novel approach to understanding the neurobiological mechanisms of cognitive processing of public health communications is to use neuroimaging techniques to map the brain regions involved and make inferences about the neural systems engaged in the processing of health information. We reviewed recent studies that employed functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to examine the brain responses of adolescents and young adults to anti-smoking health messages and videos.

Findings

This narrative literature review found that the medial prefrontal cortex, amygdala, and hippocampus were the brain regions most commonly engaged in response to health warnings. Developmental factors modulate the relationship between brain regions, regulated emotional reaction, and frontal regions that are responsible for decision making.

Summary

Research that integrates neurophysiology and behavior to study adolescent and young adult neurocognitive responses to health messaging is an important tool for identifying optimal methods to communicate the health hazards of smoking to this vulnerable population.

Connectivity between visual and auditory cortices mediates the influence of argument strength on the effectiveness of smoking-cessation videos among smokers low in sensation seeking

Purpose

Argument strength (AS) is a validated measure of persuasiveness that has been identified as one of the key variables determining the effectiveness of video ads. Smoking-cessation videos with high AS are more effective at reducing smoking behavior than videos with low AS. The neural processes that mediate the effects of AS on subsequent smoking have not been identified. In the present study, we tested whether the efficacy of high-AS smoking-cessation videos is determined by the level of integration of visual and auditory (ie, multisensory) processes. In addition, we tested differences in sensation seeking, which is repeatedly associated with smokers’ sensitivity to cessation interventions.

Patients and methods

Using functional magnetic resonance imaging (fMRI), we recorded the brain response of 66 smokers randomly assigned to view either 16 high-AS or 16 low-AS smoking-cessation videos. Multisensory processing was assessed by the functional connectivity between brain regions that encoded visual and auditory information in the videos. Smoking behavior was indexed by the urine level of cotinine, a nicotine metabolite, immediately before and approximately 30 days after the fMRI session.

Results

We found a significant moderated mediation effect, such that the connectivity between visual and auditory cortices mediated the effect of AS on subsequent smoking, but only for smokers lower in sensation seeking. The prediction performance of the model was confirmed by leave-one-out cross-validation.

Conclusion

Our study suggests that audiovisual integration underlies the greater efficacy of high- vs low-AS smoking-cessation videos for individuals lower in sensation seeking. High-sensation-seeking smokers may be responsive to other characteristics of smoking-cessation videos.

Behavioral and Accumbal Responses During an Affective Go/No-Go Task Predict Adherence to Injectable Naltrexone Treatment in Opioid Use Disorder

Adherence is a major factor in the effectiveness of the injectable extended-release naltrexone as a relapse prevention treatment in opioid use disorder. We examined the value of a variant of the Go/No-go paradigm in predicting extended-release naltrexone adherence in 27 detoxified opioid use disorder patients who were offered up to 3 monthly extended-release naltrexone injections. Before extended-release naltrexone, participants performed a Go/No-go task that comprised positively valenced Go trials and negatively valenced No-go trials during a functional magnetic resonance imaging scan. Errors of commission and neural responses to the No-go vs Go trials were independent variables. Adherence, operationalized as the completion of all 3 extended-release naltrexone injections, was the outcome variable. Fewer errors of commission and greater left accumbal response during the No-go vs Go trials predicted better adherence. These findings support the clinical potential of the behavioral and neurophysiological correlates of response inhibition in the prediction of extended-release naltrexone treatment outcomes in opioid use disorder.

Emotional salience of the image component facilitates recall of the text of cigarette warning labels

Background

Graphic warning labels (GWLs) on cigarette packages, that combine textual warnings with emotionally salient images depicting the adverse health consequences of smoking, have been adopted in most European countries. In the US, the courts deemed the evidence justifying the inclusion of emotionally salient images in GWLs insufficient and put the implementation on hold. We conducted a controlled experimental study examining the effect of emotional salience of GWL's images on the recall of their text component.

Methods

Seventy-three non-treatment-seeking daily smokers received cigarette packs carrying GWLs for a period of 4 weeks. Participants were randomly assigned to receive packs with GWLs previously rated as eliciting high or low level of emotional reaction (ER). The two conditions differed in respect to images but used the same textual warning statements. Participants' recognition of GWL images and statements were tested separately at baseline and again after the 4-week repetitive exposure.

Results

Textual warning statements were recognized more accurately when paired with high ER images than when paired with low ER images, both at baseline and after daily exposure to GWLs over a 4-week period.

Conclusion

The results suggest that emotional salience of GWLs facilitates cognitive processing of the textual warnings, resulting in better remembering of the information about the health hazards of smoking. Thus, high emotional salience of the pictorial component of GWLs is essential for their overall effectiveness.

Reward and aversion processing in patients with post-traumatic stress disorder: functional neuroimaging with visual and thermal stimuli

In patients with post-traumatic stress disorder (PTSD), a decrease in the brain reward function was reported in behavioral- and in neuroimaging studies. While pathophysiological mechanisms underlying this response are unclear, there are several lines of evidence suggesting over-recruitment of the brain reward regions by aversive stimuli rendering them unavailable to respond to reward-related content. The purpose of this study was to juxtapose brain responses to functional neuroimaging probes that reliably produce rewarding and aversive experiences in PTSD subjects and in healthy controls. The stimuli used were pleasant, aversive and neutral images selected from the International Affective Picture System (IAPS) along with pain-inducing heat applied to the dorsum of the left hand; all were administered during 3 T functional magnetic resonance imaging. Analyses of IAPS responses for the pleasant images revealed significantly decreased subjective ratings and brain activations in PTSD subjects that included striatum and medial prefrontal-, parietal- and temporal cortices. For the aversive images, decreased activations were observed in the amygdala and in the thalamus. PTSD and healthy subjects provided similar subjective ratings of thermal sensory thresholds and each of the temperatures. When 46 °C (hot) and 42 °C (neutral) temperatures were contrasted, voxelwise between-group comparison revealed greater activations in the striatum, amygdala, hippocampus and medial prefrontal cortex in the PTSD subjects. These latter findings were for the most part mirrored by the 44 vs. 42 °C contrast. Our data suggest different brain alterations patterns in PTSD, namely relatively diminished corticolimbic response to pleasant and aversive psychosocial stimuli in the face of exaggerated response to heat-related pain. The present findings support the hypothesis that brain sensitization to pain in PTSD may interfere with the processing of psychosocial stimuli whether they are of rewarding or aversive valence.

Effects of extended-release naltrexone on the brain response to drug-related stimuli in patients with opioid use disorder

BACKGROUND

Heightened response to drug-related cues is a hallmark of addiction. Extended-release naltrexone (XR-NTX) is a US Food and Drug Administration-approved pharmacotherapy for relapse prevention in patients with opioid use disorder (OUD). In these patients, XR-NTX has been shown to reduce brain responses to opioid-related visual stimuli. To assess the biomarker potential of this phenomenon, it is necessary to determine whether this effect is limited to opioid-related stimuli and whether it is associated with key OUD symptoms.

METHODS

Using functional MRI (fMRI), we measured the brain responses to opioid-related and control (i.e., sexual and aversive) images in detoxified patients with OUD before, during and after XR-NTX treatment. Craving and withdrawal severity were evaluated using clinician- and self-administered instruments during each session.

RESULTS

We included 24 patients with OUD in our analysis. During XR-NTX treatment, we found reduced responses to opioid-related stimuli in the nucleus accumbens (NAcc) and medial orbitofrontal cortex (mOFC). The reduction in mOFC response was specific to the opioid-related stimuli. The reduced NAcc and mOFC opioid cue reactivity was correlated with reduction in clinician-assessed and self-reported withdrawal symptoms, respectively.

LIMITATIONS

The study was not placebo-controlled owing to ethical, safety and feasibility concerns.

CONCLUSION

Extended-release naltrexone reduces the NAcc and mOFC cue reactivity in patients with OUD. This effect is specific to opioid-related stimuli in the mOFC only. The reduction in neural response to opioid-related stimuli is more robust in patients with greater decline in withdrawal severity. Our results support the clinical utility of mesocorticolimbic cue reactivity in monitoring the XR-NTX treatment outcomes and highlight the link between opioid withdrawal symptomatology and neural opioid cue reactivity.

Increased cocaine and amphetamine-regulated transcript cord blood levels in the newborns exposed to crack cocaine in utero

BACKGROUND

Cocaine and amphetamine-regulated transcript (CART) is an endogenous antioxidant present since the embryonic period. CART is activated by high levels of dopamine and might be of interested in understanding the changes in the REDOX system associated with crack/cocaine intake. The goal of this study was to determine whether exposure to crack in utero is associated with increased CART levels.

METHODS

In this cross-sectional study with consecutive sampling, we compared the umbilical cord blood (UCB) CART levels (μg/mL) of newborns exposed to crack/cocaine in utero (EN, n = 57) to levels in non-exposed newborns (NEN, n = 99). In addition, we compared serum CART levels between EN and NEN mothers, in the immediate postpartum period. Potential confounders, such as perinatal data (e.g., weight, Apgar, etc.), psychopathology (DSM-IV), and use of drugs other than crack (ASSIST) were assessed.

RESULTS

According to general linear model analysis, the adjusted mean CART was significantly higher in EN (0.180, 95% CI 0.088-0.272) than in NEN (0.048, 95% CI 0.020-0.076; p < 0.002; d = 0.68). The difference in CART levels between EN and NEN mothers was not significant (p ≥ 0.05).

CONCLUSION

The increase in CART levels in EN UBC suggests a response to crack/cocaine-induced oxidative stress during gestational period, as a potential attempt of neuroprotection. In adult women in puerperium, however, this endogenous antioxidant recruitment does not seem to operate.

Emotional, physical and sexual abuse are associated with a heightened limbic response to cocaine cues

Drug-reward cues trigger motivational circuitry, a response linked to drug-seeking in animals and in humans. Adverse life events have been reported to increase sensitivity to drug rewards and to bolster drug reward signaling. Therefore, we hypothesized that cocaine-dependent individuals with prior emotional, physical and sexual abuse might have a heightened mesolimbic brain response to cues for drug reward in a new brief-cue probe. Cocaine-dependent human individuals (N = 68) were stabilized in an inpatient setting and then completed an event-related blood-oxygen-level dependent functional magnetic resonance imaging task featuring 500-ms evocative (cocaine, sexual, aversive) and comparator (neutral) cues. Responses to three questions about emotional, physical and sexual abuse from the Addiction Severity Index were used to divide the patients into subgroups (history of Abuse [n = 40] versus No Abuse [n = 28]). When subjects were grouped by the historical presence or absence of emotional, physical or sexual abuse, the Abuse group showed a heightened midbrain, thalamic, caudate, and caudal orbitofrontal cortex response to cocaine cues; a similar result was found in other evocative cues, as well. These findings are the first reported for a 500-ms cocaine-cue probe, and they highlight the ability of very brief evocative cues to activate the brain's motivational circuitry. Although all participants had severe cocaine use disorders, individuals reporting prior abuse had a heightened mesolimbic response to evocative cues. To our knowledge, this is the first study in humans linking a history of abuse to a brain vulnerability (heightened mesolimbic response to drug cues) previously shown to contribute to drug-seeking.

Sustained opioid antagonism modulates striatal sensitivity to baby schema in opioid use disorder

BACKGROUND

Chronic opioid misuse is associated with reduced sensitivity to natural rewards and social motivation deficits that include impaired caregiving. The neurobiological mechanisms underlying these deficits and their response to treatment are not well understood. Baby schema (Kindchenschema) is a set of juvenile physical features, which is perceived as "cute" and triggers motivation for caregiving. Recent studies suggest that the "baby schema effect" is mediated by the brain "reward" network. We studied the impact of opioid antagonist treatment on the baby schema response in patients with opioid use disorder.

METHODS

Forty-seven (24 F) recently detoxified patients with opioid use disorder underwent functional magnetic resonance imaging (fMRI) while viewing infant portraits that were parametrically manipulated for baby schema content and rating them for cuteness, at baseline and during treatment with the injectable extended release opioid antagonist naltrexone (XRNTX). The study was not placebo-controlled.

RESULTS

The behavioral effect of baby schema, indexed by "cuteness" ratings, was present and unaffected by XRNTX. The brain response to baby schema was absent at baseline, but present in the bilateral ventral striatum after two weeks of XRNTX treatment. The decline in self-reported craving for opioids was positively correlated with the brain fMRI response to baby schema in the bilateral ventral striatum.

CONCLUSIONS

Opioid antagonist treatment modulated the brain reward system response to a marker of caregiving motivation in patients with opioid use disorder. Neural response to baby schema may offer a novel probe of social motivation and affiliative behaviors in this population.

Individual differences in the processing of smoking-cessation video messages: An imaging genetics study

Studies testing the benefits of enriching smoking-cessation video ads with attention-grabbing sensory features have yielded variable results. Dopamine transporter gene (DAT1) has been implicated in attention deficits. We hypothesized that DAT1 polymorphism is partially responsible for this variability. Using functional magnetic resonance imaging, we examined brain responses to videos high or low in attention-grabbing features, indexed by "message sensation value" (MSV), in 53 smokers genotyped for DAT1. Compared to other smokers, 10/10 homozygotes showed greater neural response to High- vs. Low-MSV smoking-cessation videos in two a priori regions of interest: the right temporoparietal junction and the right ventrolateral prefrontal cortex. These regions are known to underlie stimulus-driven attentional processing. Exploratory analysis showed that the right temporoparietal response positively predicted follow-up smoking behavior indexed by urine cotinine. Our findings suggest that responses to attention-grabbing features in smoking-cessation messages is affected by the DAT1 genotype.

Oral glucose tolerance test performance in olanzapine-treated schizophrenia-spectrum patients is predicted by BMI and triglycerides but not olanzapine dose or duration

OBJECTIVE

Olanzapine, an atypical antipsychotic, is associated with glucoregulatory abnormalities, but the nature of this link is not fully elucidated. This is the first olanzapine oral glucose tolerance test (oGTT) study to consider treatment dose and duration, and to compare complementary indices respectively assessing insulin sensitivity (Matsuda index) and resistance (homeostasis model assessment).

METHODS

Body mass index (BMI), body composition, plasma lipids, and oGTT were measured in olanzapine-treated nondiabetic patients with DSM-IV-TR diagnosis of schizophrenia or schizoaffective disorder (n = 35).

RESULTS

While only one previously undiagnosed participant met diabetes criteria based on fasting plasma glucose alone (≥126 mg/dL), seven were diagnosed with oGTT (2-hr plasma glucose ≥200 mg/dL). Multiple regression analyses revealed that the Matsuda index correlated with BMI (p < 0.0001) and plasma triglycerides (p = 0.01), but not with age, olanzapine dose, olanzapine treatment duration, or plasma cholesterol. Homeostasis model assessment and fasting plasma glucose correlated with triglycerides only (p < 0.0001 for both).

CONCLUSIONS

Our data suggest that BMI and triglycerides may be implicated in olanzapine-related glucoregulatory abnormalities. The lack of correlation between glucoregulatory abnormalities and olanzapine dose or treatment duration suggests preexisting metabolic disturbances and/or disturbances arising early in the course of treatment. Clinicians prescribing antipsychotics should consider oGTT, especially in patients with obesity and/or hypertriglyceridemia.

Polygraphy and Functional Magnetic Resonance Imaging in Lie Detection: A Controlled Blind Comparison Using the Concealed Information Test

OBJECTIVE

Intentional deception is a common act that often has detrimental social, legal, and clinical implications. In the last decade, brain activation patterns associated with deception have been mapped with functional magnetic resonance imaging (fMRI), significantly expanding our theoretical understanding of the phenomenon. However, despite substantial criticism, polygraphy remains the only biological method of lie detection in practical use today. We conducted a blind, prospective, and controlled within-subjects study to compare the accuracy of fMRI and polygraphy in the detection of concealed information. Data were collected between July 2008 and August 2009.

METHOD

Participants (N = 28) secretly wrote down a number between 3 and 8 on a slip of paper and were questioned about what number they wrote during consecutive and counterbalanced fMRI and polygraphy sessions. The Concealed Information Test (CIT) paradigm was used to evoke deceptive responses about the concealed number. Each participant's preprocessed fMRI images and 5-channel polygraph data were independently evaluated by 3 fMRI and 3 polygraph experts, who made an independent determination of the number the participant wrote down and concealed.

RESULTS

Using a logistic regression, we found that fMRI experts were 24% more likely (relative risk = 1.24, P < .001) to detect the concealed number than the polygraphy experts. Incidentally, when 2 out of 3 raters in each modality agreed on a number (N = 17), the combined accuracy was 100%.

CONCLUSIONS

These data justify further evaluation of fMRI as a potential alternative to polygraphy. The sequential or concurrent use of psychophysiology and neuroimaging in lie detection also deserves new consideration.

True Lies: Delusions and Lie-Detection Technology

Legally relevant lying is an intentional attempt to convince another of the truth of a proposition the liar believes to be false. Delusion is an unintentional product of impaired reality testing that occurs in a range of psychiatric conditions and psychological states, some of which could be clinically subtle. Since deception, truth and delusion differ in the intent rather than reality testing criterion. Deception and delusion are influenced by the degree of congruence between subjective and objective reality and are probably mutually exclusive. Thus, a delusion could lead to an objectively false statement, that could nevertheless be subjectively true and indistinguishable from truth by its psychophysiological (i.e., the polygraph) signature. This article presents a relevant case as a starting point of an examination of the current and future role of neurophysiological (i.e., functional brain imaging) measurements in the detection of deception. The authors incorporate the recent data on functional brain imaging to the neuroanatomical mechanisms of true and false recall, behavioral regulation and deception into a testable model that could redefine deception and separate it from delusions on the basis of objective functional brain imaging measures.

Targeting modulates audiences' brain and behavioral responses to safe sex video ads

Video ads promoting condom use are a key component of media campaigns to stem the HIV epidemic. Recent neuroimaging studies in the context of smoking cessation, point to personal relevance as one of the key variables that determine the effectiveness of public health messages. While minority men who have sex with men (MSM) are at the highest risk of HIV infection, most safe-sex ads feature predominantly Caucasian actors in heterosexual scenarios. We compared brain respons of 45 African American MSM to safe sex ads that were matched (i.e. 'Targeted') to participants' sexual orientation and race, and 'Untargeted' ads that were un matched for these characteristics. Ad recall, perceived 'convincingness' and attitudes towards condom use were also assessed. We found that Targeted ads were better remembered than the Untargeted ads but perceived as equally convincing. Targeted ads engaged brain regions involved in self-referential processing and memory, including the amygdala, hippocampus, temporal and medial prefrontal cortices (MPFC) and the precuneus. Connectivity between MPFC and precuneus and middle temporal gyrus was stronger when viewing Targeted ads. Our results suggest that targeting may increase cognitive processing of safe sex ads and justify further prospective studies linking brain response to media public health interventions and clinical outcomes.

Emotional reaction facilitates the brain and behavioural impact of graphic cigarette warning labels in smokers

BACKGROUND

Warning labels on cigarette packages are an important venue for information about the hazards of smoking. The 2009 US Family Smoking Prevention and Tobacco Control Act mandated replacing the current text-only labels with graphic warning labels. However, labels proposed by the Food and Drug Administration (FDA) were challenged in court by the tobacco companies, who argued successfully that the proposed labels needlessly encroached on their right to free speech, in part because they included images of high emotional salience that indiscriminately frightened rather than informed consumers.

METHODS

We used functional MRI to examine the effects of graphic warning labels' emotional salience on smokers' brain activity and cognition. Twenty-four smokers viewed a random sequence of blocks of graphic warning labels that have been rated high or low on an 'emotional reaction' scale in previous research.

RESULTS

We found that labels rated high on emotional reaction were better remembered, associated with reduction in the urge to smoke, and produced greater brain response in the amygdala, hippocampi, inferior frontal gyri and the insulae.

CONCLUSIONS

Recognition memory and craving are, respectively, correlates of effectiveness of addiction-related public health communications and interventions, and amygdala activation facilitates the encoding of emotional memories. Thus, our results suggest that emotional reaction to graphic warning labels contributes to their public health impact and may be an integral part of the neural mechanisms underlying their effectiveness. Given the urgency of the debate about the constitutional risks and public health benefits of graphic warning labels, these preliminary findings warrant consideration while longitudinal clinical studies are underway.

Neural correlates of adherence to extended-release naltrexone pharmacotherapy in heroin dependence

Injectable extended-release naltrexone (XRNTX) presents an effective therapeutic strategy for opioid addiction, however its utility could be hampered by poor adherence. To gain a better insight into this phenomenon, we utilized blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) in conjunction with a validated cue-induced craving procedure to examine neural correlates of XRNTX adherence. We operationalized treatment adherence as the number of monthly XRNTX injections (range: 0-3) administered to a group of fully detoxified heroin-dependent subjects (n=32). Additional outcomes included urine toxicology screening and self-reported tobacco use. The presented heroin-related visual cues reliably elicited heroin craving in all tested subjects. Nine, five, three and 15 of the participants, respectively, received zero, one, two and three XRNTX injections, predicted by the individual baseline fMRI signal change in response to the cues in the medial prefrontal cortex, a brain region involved in inhibitory self-control and emotional appraisal. The incidence of opioid-positive urines during the XRNTX therapy was low and remained about half the pre-treatment rate after the XRNTX ended. During the treatment, cigarette smoking behaviors followed patterns of opioid use, while cocaine consumption was increased with reductions in opioid use. The present data support the hypothesis that medial prefrontal cortex functions are involved in adherence to opioid antagonist therapy. A potential role of concurrent non-opioid addictive substances consumption during the XRNTX pharmacotherapy warrants further investigation. Our findings set the stage for further bio-behavioral investigations of the mechanisms of relapse prevention in opioid dependence.

Emotional graphic cigarette warning labels reduce the electrophysiological brain response to smoking cues

There is an ongoing public debate about the new graphic warning labels (GWLs) that the Food and Drug Administration (FDA) proposes to place on cigarette packs. Tobacco companies argued that the strongly emotional images FDA proposed to include in the GWLs encroached on their constitutional rights. The court ruled that FDA did not provide sufficient scientific evidence of compelling public interest in such encroachment. This study's objectives were to examine the effects of the GWLs on the electrophysiological and behavioral correlates of smoking addiction and to determine whether labels rated higher on the emotional reaction (ER) scale are associated with greater effects. We studied 25 non-treatment-seeking smokers. Event-related potentials (ERPs) were recorded while participants viewed a random sequence of paired images, in which visual smoking (Cues) or non-smoking (non-Cues) images were preceded by GWLs or neutral images. Participants reported their cigarette craving after viewing each pair. Dependent variables were magnitude of P300 ERPs and self-reported cigarette craving in response to Cues. We found that subjective craving response to Cues was significantly reduced by preceding GWLs, whereas the P300 amplitude response to Cues was reduced only by preceding GWLs rated high on the ER scale. In conclusion, our study provides experimental neuroscience evidence that weighs in on the ongoing public and legal debate about how to balance the constitutional and public health aspects of the FDA-proposed GWLs. The high toll of smoking-related illness and death adds urgency to the debate and prompts consideration of our findings while longitudinal studies of GWLs are underway.

Low message sensation health promotion videos are better remembered and activate areas of the brain associated with memory encoding

Greater sensory stimulation in advertising has been postulated to facilitate attention and persuasion. For this reason, video ads promoting health behaviors are often designed to be high in “message sensation value” (MSV), a standardized measure of sensory intensity of the audiovisual and content features of an ad. However, our previous functional Magnetic Resonance Imaging (fMRI) study showed that low MSV ads were better remembered and produced more prefrontal and temporal and less occipital cortex activation, suggesting that high MSV may divert cognitive resources from processing ad content. The present study aimed to determine whether these findings from anti-smoking ads generalize to other public health topics, such as safe sex. Thirty-nine healthy adults viewed high- and low MSV ads promoting safer sex through condom use, during an fMRI session. Recognition memory of the ads was tested immediately and 3 weeks after the session. We found that low MSV condom ads were better remembered than the high MSV ads at both time points and replicated the fMRI patterns previously reported for the anti-smoking ads. Occipital and superior temporal activation was negatively related to the attitudes favoring condom use (see Condom Attitudes Scale, Methods and Materials section). Psychophysiological interaction (PPI) analysis of the relation between occipital and fronto-temporal (middle temporal and inferior frontal gyri) cortices revealed weaker negative interactions between occipital and fronto-temporal cortices during viewing of the low MSV that high MSV ads. These findings confirm that the low MSV video health messages are better remembered than the high MSV messages and that this effect generalizes across public health domains. The greater engagement of the prefrontal and fronto-temporal cortices by low MSV ads and the greater occipital activation by high MSV ads suggest that that the “attention-grabbing” high MSV format could impede the learning and retention of public health messages.

The effect of naltrexone on body fat mass in olanzapine-treated schizophrenic or schizoaffective patients: a randomized double-blind placebo-controlled pilot study

Olanzapine (OLZ), a commonly prescribed second generation antipsychotic drug, is associated with obesity and metabolic syndrome and may contribute to increased cardiovascular morbidity and mortality. Opioidergic neurotransmission may be implicated in the development of these metabolic disturbances. The objective of this study was to assess the effects of opioid blockade on OLZ-treated patients' metabolic status. Patients with schizophrenia or schizoaffective disorder (n=30) on a stable dose of OLZ were randomized in a double-blind fashion to receive an opioid receptor antagonist, naltrexone (NTX), (n=14) or placebo (n=16). The primary outcome measure was the change in body mass index (BMI) at 12 weeks. Secondary measures included body fat and fat-free mass, along with homeostasis model assessment-estimated insulin resistance (HOMA-IR), plasma lipids and liver function tests (LFTs). There was no significant change in BMI between the treatment arms. However, in comparison to the OLZ + placebo combination, the OLZ + NTX group displayed a significant decrease in the fat and increase in fat-free mass along with a trend towards improvement in HOMA-IR values. There were no significant differences in plasma lipids and LFTs. These findings suggest that addition of NTX to OLZ may attenuate OLZ-induced body fat mass gain. A larger study of longer duration will be needed to confirm these results.

Extended-release naltrexone modulates brain response to drug cues in abstinent heroin-dependent patients

Drug cues play an important role in relapse to drug use. Naltrexone is an opioid antagonist that is used to prevent relapse in opioid dependence. Central opioidergic pathways may be implicated in the heightened drug cue-reactivity, but the effects of the opioid receptors' blockade on the brain responses to drug cues in opioid dependence are unknown. To pursue this question, we studied 17 abstinent i.v. heroin users with brain functional magnetic resonance imaging (fMRI) during exposure to visual heroin-related cues and matched neutral images before and 10-14 days after an injection of extended-release naltrexone (XRNTX). Whole brain analysis of variance of fMRI data showed main effect of XRNTX in the medial frontal gyrus, precentral gyrus, cuneus, precuneus, caudate and the amygdala. fMRI response was decreased in the amygdala, cuneus, caudate and the precentral gyrus and increased in the medial frontal gyrus and the precuneus. Higher plasma levels of naltrexone's major metabolite, 6-beta-naltrexol, were associated with larger reduction in the fMRI response to drug cues after XRNTX in the precentral, caudate and amygdala clusters. The present data suggest that XRNTX pharmacotherapy of opioid-dependent patients may, respectively, decrease and potentiate prefrontal and limbic cortical responses to drug cues and that this effect might be related to the XRNTX metabolism. Our findings call for further evaluation of the brain fMRI response to drug-related cues and of the 6-beta-naltrexol levels as potential biomarkers of XRNTX therapeutic effects in patients with opioid dependence.

Brain trauma, PET scans and forensic complexity

Positron Emission Tomography (PET) is a medical imaging technique that can be used to show brain function. Courts have admitted PET scan evidence in cases involving brain damage, injury, toxic exposure, or illness ("brain trauma") and to support claims of diminished cognitive abilities and impulse control. Despite the limited data on the relationships between PET, brain trauma and behavior, many courts admit PET scan evidence without much critical analysis. This article examines the use of PET as proof of functional impairment and justification of abnormal behavior by explaining its diagnostic use and limitations, the limited support for claims of its relationship to behavior, and evidentiary considerations that should govern its admission into court as evidence. The authors urge courts to consider PET evidence, claims of experts, and the scope of the proposed testimony with greater deference to the clinical scope of PET, as outlined by the American College of Radiology's appropriateness criteria and the Working Group Report of the American Psychiatric Association.

Using Brain Imaging for Lie Detection: Where Science, Law and Research Policy Collide

Progress in the use of functional magnetic resonance imaging (fMRI) of the brain to evaluate deception and differentiate lying from truth-telling has created anticipation of a breakthrough in the search for technology-based methods of lie detection. In the last few years, litigants have attempted to introduce fMRI lie detection evidence in courts. This article weighs in on the interdisciplinary debate about the admissibility of such evidence, identifying the missing pieces of the scientific puzzle that need to be completed if fMRI-based lie detection is to meet the standards of either legal reliability or general acceptance. We believe that the Daubert's "known error rate" is the key concept linking the legal and scientific standards. We posit that properly-controlled clinical trials are the most convincing means to determine the error rates of fMRI-based lie detection and confirm or disprove the relevance of the promising laboratory research on this topic. This article explains the current state of the science and provides an analysis of the case law in which litigants have sought to introduce fMRI lie detection. Analyzing the myriad issues related to fMRI lie detection, the article identifies the key limitations of the current neuroimaging of deception science as expert evidence and explores the problems that arise from using scientific evidence before it is proven scientifically valid and reliable. We suggest that courts continue excluding fMRI lie detection evidence until this potentially useful form of forensic science meets the scientific standards currently required for adoption of a medical test or device. Given a multitude of stakeholders and, the charged and controversial nature and the potential societal impact of this technology, goodwill and collaboration of several government agencies may be required to sponsor impartial and comprehensive clinical trials that will guide the development of forensic fMRI technology.

Depot naltrexone decreases rewarding properties of sugar in patients with opioid dependence

BACKGROUND

Opioid neurotransmission mediates hedonic value of sweet tastants; their intake may be exaggerated by the consumption of exogenous opioids (e.g., opioid dependence). Sweet Taste Test (STT) is a validated quantitative instrument assessing taste perception and hedonic features of sugar (sucrose) using a randomized and double-blind administration at five different sucrose concentrations ranging from 0.05 to 0.83 M.

METHODS

The STT and cue-induced craving procedure were administered to opioid-dependent patients (n = 15) before and 1 week after the injection of a long-acting depot naltrexone (XRNT) preparation.

RESULTS

Analyses of covariance, employing sucrose concentration and its perceived taste as covariates, showed that XRNT therapy significantly reduced the self-reported hedonic and motivational characteristics of sucrose. Greater reductions in both these characteristics were associated with more diminution in the cue-induced opioid craving.

CONCLUSIONS

Opioid antagonism in opioid-dependent subjects leads to a smaller sweet taste reward, which, in turn, may be proportional to decreased opioid craving. These pilot results support the heuristic value of the STT as a potential marker of the XRNT treatment response and call for further inquiry into potential clinical applications of the test.

Relative Function: Nuclear Brain Imaging in United States Courts

Neuropsychological testing—medical imaging of the brain structure and function—allows the expert to inform the court on the brain structure and function of the forensic examinee. Supported by extensive clinical use, neuropsychological testing and structural imaging in the form of computerized tomography and structural magnetic resonance imaging have achieved general acceptance in court. However, functional imaging such as functional MRI and nuclear medicine techniques, such as positron emission tomography (PET), have faced more admissibility challenges. While functional imaging is becoming an increasingly important tool in assessing neuropsychiatric illness, we surmise that evidentiary challenges are largely related to the phase of trial in which the nuclear study is offered as evidence. This article will review the basic science of functional nuclear imaging including PET and single photon emission computed tomography. We will then review cases where admissibility of these techniques has been challenged and consider whether and how nuclear brain imaging can influence the outcome of the trial.

Emerging neurotechnologies for lie-detection: promises and perils

Detection of deception and confirmation of truth telling with conventional polygraphy raised a host of technical and ethical issues. Recently, newer methods of recording electromagnetic signals from the brain show promise in permitting the detection of deception or truth telling. Some are even being promoted as more accurate than conventional polygraphy. While the new technologies raise issues of personal privacy, acceptable forensic application, and other social issues, the focus of this paper is the technical limitations of the developing technology. Those limitations include the measurement validity of the new technologies, which remains largely unknown. Another set of questions pertains to the psychological paradigms used to model or constrain the target behavior. Finally, there is little standardization in the field, and the vulnerability of the techniques to countermeasures is unknown. Premature application of these technologies outside of research settings should be resisted, and the social conversation about the appropriate parameters of its civil, forensic, and security use should begin.

Towards clinical trials of lie detection with fMRI

Recent reports of successful fMRI-based discrimination between lie and truth in single subjects raised the interest of prospective users and a public concern about the potential scope of this technology. The increased scrutiny highlighted the lack of controlled "real life", i.e. prospective clinical trials of this technology that conform to the common standards of medical device development. The ethics of conducting such trials given the paucity of data on fMRI-based lie detection has also been questioned. To probe the potential issues of translating the laboratory research into practice, we conducted a case study in which we adapted the standard Guilty Knowledge Test (GKT), a well-established model of producing deception, to the common scenario of lying on a resume. The task consisted of questions about pertinent items on the subject's resume, three of which could be independently verified as truth (KNOWN) and three that could not be verified and were thus termed UNKNOWN. The subject had an incentive to lie on all UNKNOWN items, and on debriefing confirmed that he had done so. Data was preprocessed, masked with a priori regions of interest, thresholded, and qualitatively evaluated for consistency with the previously reported prefronto-parietal Lie > Truth pattern. Deceptive responses to two out of the three UNKNOWN items were associated with the predicted prefronto-parietal fMRI pattern. In the third UNKNOWN this pattern was absent, and instead, increased limbic (amygdala and hippocampus) response was observed. Based on published prefronto-parietal Lie response pattern, only the first two items could be categorized as Lie. If confirmed, this demonstration of amygdala and hippocampus activation in a Lie > Truth contrast illustrates the need to integrate the limbic system and its emotional and cognitive correlates into the existing model of deception. Our experiment suggests an approach to a naturalistic scenario and the research questions that need to be answered in order to set the stage for prospective clinical trials of fMRI-based lie detection.

Gender differences in the motivational processing of babies are determined by their facial attractiveness

Background

This study sought to determine how esthetic appearance of babies may affect their motivational processing by the adults.

Methodology and Principal Findings

Healthy men and women were administered two laboratory-based tasks: a) key pressing to change the viewing time of normal-looking babies and of those with abnormal facial features (e.g., cleft palate, strabismus, skin disorders, Down's syndrome and fetal alcohol syndrome) and b) attractiveness ratings of these images. Exposure to the babies' images produced two different response patterns: for normal babies, there was a similar effort by the two groups to extend the visual processing with lower attractiveness ratings by men; for abnormal babies, women exerted greater effort to shorten the viewing time despite attractiveness ratings comparable to the men.

Conclusions

These results indicate that gender differences in the motivational processing of babies include excessive (relative to the esthetic valuation) motivation to extend the viewing time of normal babies by men vs. shortening the exposure to the abnormal babies by women. Such gender-specific incentive sensitization phenomenon may reflect an evolutionary-derived need for diversion of limited resources to the nurturance of healthy offspring.

Baby Schema in Infant Faces Induces Cuteness Perception and Motivation for Caretaking in Adults

Ethologist Konrad Lorenz proposed that baby schema ('Kindchenschema') is a set of infantile physical features such as the large head, round face and big eyes that is perceived as cute and motivates caretaking behavior in other individuals, with the evolutionary function of enhancing offspring survival. Previous work on this fundamental concept was restricted to schematic baby representations or correlative approaches. Here, we experimentally tested the effects of baby schema on the perception of cuteness and the motivation for caretaking using photographs of infant faces. Employing quantitative techniques, we parametrically manipulated the baby schema content to produce infant faces with high (e.g. round face and high forehead), and low (e. g. narrow face and low forehead) baby schema features that retained all the characteristics of a photographic portrait. Undergraduate students (n = 122) rated these infants' cuteness and their motivation to take care of them. The high baby schema infants were rated as more cute and elicited stronger motivation for caretaking than the unmanipulated and the low baby schema infants. This is the first experimental proof of the baby schema effects in actual infant faces. Our findings indicate that the baby schema response is a critical function of human social cognition that may be the basis of caregiving and have implications for infant-caretaker interactions.

Reduced prefrontal and temporal processing and recall of high "sensation value" ads

Public service announcements (PSAs) are non-commercial broadcast ads that are an important part of televised public health campaigns. "Message sensation value" (MSV), a measure of sensory intensity of audio, visual, and content features of an ad, is an important factor in PSA impact. Some communication theories propose that higher message sensation value brings increased attention and cognitive processing, leading to higher ad impact. Others argue that the attention-intensive format could compete with ad's message for cognitive resources and result in reduced processing of PSA content and reduced overall effectiveness. Brain imaging during PSA viewing provides a quantitative surrogate measure of PSA impact and addresses questions of PSA evaluation and design not accessible with traditional subjective and epidemiological methods. We used Blood Oxygenation Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) and recognition memory measures to compare high and low MSV anti-tobacco PSAs and neutral videos. In a short-delay, forced-choice memory test, frames extracted from PSAs were recognized more accurately than frames extracted from the NV. Frames from the low MSV PSAs were better recognized than frames from the high MSV PSAs. The accuracy of recognition of PSA frames was positively correlated with the prefrontal and temporal, and negatively correlated with the occipital cortex activation. The low MSV PSAs were associated with greater prefrontal and temporal activation, than the high MSV PSAs. The high MSV PSAs produced greater activation primarily in the occipital cortex. These findings support the "dual processing" and "limited capacity" theories of communication that postulate a competition between ad's content and format for the viewers' cognitive resources and suggest that the "attention-grabbing" high MSV format could impede the learning and retention of an ad. These findings demonstrate the potential of using neuroimaging in the design and evaluation of mass media public health communications.

Acute effect of methadone maintenance dose on brain FMRI response to heroin-related cues

OBJECTIVE

Environmental drug-related cues have been implicated as a cause of illicit heroin use during methadone maintenance treatment of heroin dependence. The authors sought to identify the functional neuroanatomy of the brain response to visual heroin-related stimuli in methadone maintenance patients.

METHOD

Event-related functional magnetic resonance imaging was used to compare brain responses to heroin-related stimuli and matched neutral stimuli in 25 patients in methadone maintenance treatment. Patients were studied before and after administration of their regular daily methadone dose.

RESULTS

The heightened responses to heroin-related stimuli in the insula, amygdala, and hippocampal complex, but not the orbitofrontal and ventral anterior cingulate cortices, were acutely reduced after administration of the daily methadone dose.

CONCLUSIONS

The medial prefrontal cortex and the extended limbic system in methadone maintenance patients with a history of heroin dependence remains responsive to salient drug cues, which suggests a continued vulnerability to relapse. Vulnerability may be highest at the end of the 24-hour interdose interval.

Commentary: the future of forensic functional brain imaging

In "Functional MRI Lie Detection: Too Good to be True?" in this issue of The Journal, Joseph Simpson reviews the merits and the limitations of using fMRI to detect deception. After presenting the gaps in experimental data that stand in the way of translating the laboratory proof of concept to a field application, Simpson surveys the legal, regulatory and ethics concerns facing fMRI, should it emerge as a technologically robust method of lie detection. In our commentary, we update and interpret the data described by Simpson, from the points of view of an experimental scientist and a forensic clinician. We conclude that the current research funding and literature are prematurely skewed toward discussion of existing findings, rather than generation of new fMRI data on deception and related topics such as mind-reading, consciousness, morality, and criminal responsibility. We propose that further progress in brain imaging research may foster the emergence of a new discipline of forensic MRI.