Differences In Subjective Responses Research Articles

Assessment of abuse liability and switching potential of menthol-flavored pod-based electronic nicotine delivery systems among US adults who smoke cigarettes

BackgroundMenthol-flavored electronic nicotine delivery systems (ENDS) are a focus of public health and regulatory policy considerations. The abuse liability of five menthol-flavored pod-based ENDS was compared to combustible cigarettes, and switching potential of ENDS was also evaluated. Methods215 US adults who smoke cigarettes (34.4% female; mean age[SD]=29.60[8.75]; 40.9% non-Hispanic White; mean cigarettes/day[SD]=12.04[8.52]) completed a randomized 6-arm within-person cross-over product-use study. Participants used five pod-based menthol-flavored ENDS (JUUL2 Polar Menthol 1.5%, JUUL2 Prototype Fresh Menthol 3.0%, JUUL Menthol 5.0%, Vuse Alto Menthol 5.0%, NJOY Ace Menthol 5.0%) and their usual brand (UB) cigarette for 20minutes ad libitum. After each product use, subjective reinforcing effects relevant to abuse liability and associated with switching away from cigarettes (e.g., satisfaction, product liking) were assessed. ResultsAll ENDS products were rated substantially and statistically significantly lower than UB cigarette on measures of subjective reinforcing effects (ps<0.001). Satisfying effects of JUUL2 1.5% were rated significantly higher than other ENDS products. JUUL2 Prototype 3.0% and Vuse Alto 5.0% did not significantly differ (ps>0.05), and both were rated significantly higher than JUUL 5.0% and NJOY Ace 5.0% (ps<0.05). Differences in subjective responses to study products did not significantly differ by preference for menthol cigarettes or by current ENDS use. ConclusionsAbuse liability of all menthol-flavored ENDS in this study was substantially lower than combustible cigarettes. Abuse liability of JUUL2 1.5% was within the range of currently marketed pod-based menthol-flavored ENDS products. JUUL2 1.5% likely has high potential for facilitating switching among US adults who smoke.

Gender differences in thermal responses to temperature ramps in moderate environments.

Some studies revealed that steady-uniform thermal environments are not the optimal environmental state to ensure thermal comfort, and temperature ramps offer potential advantages over traditional air conditioning methods. Moreover, when exposed to the same environmental conditions, gender differences in thermal responses were often observed, but the gender differences in the ramped conditions and causal relationships remain unclear. Therefore, an experimental research was conducted in a chamber by controlling the rates and directions to study the gender differences in thermal responses to temperature ramps. Three temperature ramps conditions (A: 26°C-24°C-26°C; B: 26°C-28°C-26°C; C: 26°C-30°C-26°C) were investigated with 60 healthy participants (30 females and 30 males) recruited. The main conclusions indicated that women are more sensitive to temperature ramp-down environments than those of their male counterparts. Direction of temperature ramps had a significant effect on human responses in cool environments but no effect was observed in warm environments. Moreover, there was no significant differences in subjective responses between genders in a 2°C ramp-up environment from 26°C to 28°C. Due to psychological differences, men have a wider range of temperature acceptability than women. Furthermore, the relationships between thermal sensation and thermal comfort, thermal sensation and thermal acceptability were also established, indicating that thermal sensation had significant impacts on other psychological responses. This paper has reference value for related researchers and designers to take temperature ramps and gender differences account in the design of indoor thermal environments, which benefits to improve thermal comfort, health and energy efficiency.

Raw scores on subjective sleepiness, fatigue, and vigor metrics consistently define resilience and vulnerability to sleep loss.

Although trait-like individual differences in subjective responses to sleep restriction (SR) and total sleep deprivation (TSD) exist, reliable characterizations remain elusive. We comprehensively compared multiple methods for defining resilience and vulnerability by subjective metrics. A total of 41 adults participated in a 13-day experiment: 2 baseline, 5 SR, 4 recovery, and one 36 h TSD night. The Karolinska Sleepiness Scale (KSS) and the Profile of Mood States Fatigue (POMS-F) and Vigor (POMS-V) were administered every 2 h. Three approaches (Raw Score [average SR score], Change from Baseline [average SR minus average baseline score], and Variance [intraindividual SR score variance]), and six thresholds (±1 standard deviation, and the highest/lowest scoring 12.5%, 20%, 25%, 33%, and 50%) categorized Resilient/Vulnerable groups. Kendall's tau-b correlations compared the group categorization's concordance within and between KSS, POMS-F, and POMS-V scores. Bias-corrected and accelerated bootstrapped t-tests compared group scores. There were significant correlations between all approaches at all thresholds for POMS-F, between Raw Score and Change from Baseline approaches for KSS, and between Raw Score and Variance approaches for POMS-V. All Resilient groups defined by the Raw Score approach had significantly better scores throughout the study, notably including during baseline and recovery, whereas the two other approaches differed by measure, threshold, or day. Between-measure correlations varied in strength by measure, approach, or threshold. Only the Raw Score approach consistently distinguished Resilient/Vulnerable groups at baseline, during sleep loss, and during recovery‒‒we recommend this approach as an effective method for subjective resilience/vulnerability categorization. All approaches created comparable categorizations for fatigue, some were comparable for sleepiness, and none were comparable for vigor. Fatigue and vigor captured resilience/vulnerability similarly to sleepiness but not each other.

A mixed-reality approach to soundscape assessment of outdoor urban environments augmented with natural sounds

To investigate the effect of augmenting natural sounds in noisy environments, an in-situ experiment was conducted using a mixed-reality head-mounted display (MR HMD). Two outdoor locations close to an expressway were selected for the experiment. A natural sound (birdsong or stream) along with a hologram (sparrow/fountain or loudspeaker) was projected through the MR HMD. Participants were asked to adjust the natural sound levels to their preferred level under ambient traffic noise conditions at each location. Participants also assessed the perceived loudness of traffic (PLN) and overall soundscape quality (OSQ) in conditions with and without the augmented natural sounds. The results showed that both natural sounds significantly reduced the PLN and enhanced the OSQ. No significant differences in subjective responses were found between the loudspeaker and visual representations of the natural sound source as holograms. Analysis on the preferred signal-to-noise ratio (SNR), i.e. ratio of natural sound to traffic levels, indicated a strong negative correlation between the preferred SNRs and ambient traffic noise levels. Overall, the preferred SNR of the birdsong was significantly higher than that of the water sound. Among the acoustic parameters tested, the A-weighted traffic noise level was the strongest predictor for the preferred SNR of both the birdsong and water sound. However, the correlation for the water sound was relatively higher than the birdsong. This was due to the larger variance in the subjective evaluation for the birdsong.

Subjective response to intranasal nicotine administration in oral contraceptive users and naturally-cycling women

IntroductionApproximately half of premenopausal women who smoke cigarettes also use hormonal contraceptives, with most using oral contraceptives (OCs). While research on the effects of endogenous hormones on smoking-related outcomes continues to expand, little is known about the influence of OCs on similar outcomes. We sought to explore differences in the subjective response to nicotine by OC use after stratifying by testing condition (e.g., smoking status). MethodsParticipants were regular (≥5 cigarettes/day) smokers, classified into OC and naturally cycling (NC) groups. All participants completed four total lab sessions by smoking status (ad libitum smoking, acute smoking abstinence) and anticipated progesterone level (low progesterone week (LPW), high progesterone week (HPW)). Each lab session included self-administration of intranasal nicotine (Time 0 min), assessment of subjective response via the Subjective State Scale (−30 and + 5 min). ResultsCompared to the NC group (n = 28), the OC group (n = 14) was younger (26.2 ± 1.1 versus 24.2 ± 1.1; p < 0.001) and had a lower Fagerström Test for Nicotine Dependence score (3.4 ± 0.5 versus 2.6 ± 0.5; p = 0.011). Progesterone-to-estradiol ratios varied significantly by group at three of the four time points (p < 0.05). During ad libitum smoking, the OC group had significantly lower craving after nicotine administration than the NC group (1.93 ± 0.33 versus 2.89 ± 0.23; p = 0.024). No other significant differences in subjective response were identified. ConclusionsDespite significantly different hormone levels, group differences in subjective response to nicotine were relatively few. Additional research is needed to elucidate the mechanisms involved in these observations, as well as explore how they may influence cessation in women.

Greater empathy in MDMA users.

3,4-Methylenedioxymethamphetamine (MDMA) is widely known for its positive acute effects on social behaviour, such as increasing empathy, whilst also attenuating the negative impact of social exclusion. However there is a scarcity of research that investigates the long-term impact of recreational MDMA use on these fundamental social processes. Sixty-seven individuals were split into three groups based on their drug-use history: poly-drug MDMA users ( n = 25), poly-drug users who do not use MDMA ( n = 19), alcohol-only users ( n = 23), and were tested in an independent groups design. Participants completed both a self-report measure of emotional and cognitive empathy, along with the Multifaceted Empathy Task - a computerised assessment of empathy - and the Cyberball Game - a social exclusion paradigm. MDMA users had significantly greater subjective emotional empathy, and greater cognitive empathy on the computer task compared with the poly-drug users who do not use MDMA. There were no significant differences in subjective responses to social exclusion between the groups. Indices of MDMA use did not correlate with empathy. Long-term MDMA users in this sample exhibited normal psychosocial functioning in regard to empathy and social pain and had higher subjective emotional empathy. This conflicts with previous suggestions that moderate, long-term MDMA use may cause heightened social distress, and is further evidence of the safety of the drug, which is relevant to considerations of its therapeutic use.

Comparison of subjective response to alcohol in Caucasian and Hispanic/Latino samples.

Individual differences in subjective response (SR) to alcohol (e.g., stimulation, sedation) are a significant predictor of negative alcohol outcomes. Previous studies have reported ethnic differences in SR (e.g., between some Asian populations and Caucasians), but very few studies have examined SR among Hispanic/Latino individuals. To address this gap in the literature, the present study utilized data from a large-scale, placebo-controlled alcohol administration study to examine differences in SR between Hispanic/Latino and Caucasian individuals. Social drinkers (N = 447) aged 21 to 25 years were randomized to receive either a dose of alcohol targeting a blood alcohol concentration (BAC) of .08 g% or placebo. Only non-Hispanic Caucasian participants (n = 234) and Hispanic/Latino participants (n = 87) were utilized in analyses. SR was assessed at baseline, on the ascending limb of the blood alcohol curve, at peak BAC, and on the descending limb. Repeated measures ANCOVA was utilized to examine interactions between beverage condition, ethnicity, and time predicting SR. The interaction between beverage condition, ethnicity, and time was significant only for low-arousal negative SR (negative sedative effects), such that Hispanic/Latino individuals experienced stronger sedative effects under alcohol (vs. placebo) compared with Caucasian individuals. Caucasians and Hispanic/Latinos showed a similar profile of response with respect to positive aspects of SR (e.g., stimulation). In summary, Hispanic/Latino individuals reported stronger negative SR to alcohol compared with Caucasian individuals, which may be protective against alcohol-related problems. However, future studies are needed to investigate why Hispanic/Latino males remain at relatively high risk for alcohol problems despite stronger negative SR relative to Caucasians. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Striatal activity correlates with stimulant-like effects of alcohol in healthy volunteers.

Individuals who experience greater stimulation and less sedation from alcohol are at increased risk for alcohol-related problems. However, little is known regarding the neurobiological mechanisms underlying subjective response to alcohol. The current study examined the degree to which alcohol-induced brain activation correlates with ratings of stimulation and sedation, using a within-subjects, double-blind, placebo-controlled design. Participants (N = 34 healthy adults with no history of alcohol use disorder) completed three sessions: a calibration session to determine the duration of infusion needed to bring the breath alcohol to 80 mg/dl for each subject, and two counterbalanced fMRI sessions with placebo and alcohol administration. During the fMRI sessions, participants underwent 50 min scans, which included a 10 min baseline period, the IV infusion period needed to bring breath alcohol concentration (BrAC) to a peak 80 mg/dl (on the alcohol session), followed by a post-peak decline period. Participants rated their subjective stimulation and sedation at regular intervals throughout the scan. A priori VOI analyses showed that the time course of stimulation correlated with BOLD signal in the striatum. The time course of sedation did not correlate with BOLD signal in any VOIs. There were no correlations in primary visual cortex, which served as a control. These findings are the first to show that alcohol effects in the striatum are linked to the positive, stimulant-like effects of the drug and advance our understanding of the neurobiological mechanisms underlying individual differences in subjective responses to alcohol, and more broadly, risk for alcohol use disorders.

Autonomic and subjective responsivity to emotional images in people with dissociative seizures.

People with dissociative seizures (DS) report a range of difficulties in emotional functioning and exhibit altered responding to emotional facial expressions in experimental tasks. We extended this research by investigating subjective and autonomic reactivity (ratings of emotional valence, arousal and skin conductance responses [SCRs]) to general emotional images in 39 people with DS relative to 42 healthy control participants, whilst controlling for anxiety, depression, cognitive functioning and, where relevant, medication use. It was predicted that greater subjective negativity and arousal and increased SCRs in response to the affective pictures would be observed in the DS group. The DS group as a whole did not differ from controls in their subjective responses of valence and arousal. However, SCR amplitudes were greater in ‘autonomic responders’ with DS relative to ‘autonomic responders’ in the control group. A positive correlation was also observed between SCRs for highly arousing negative pictures and self‐reported ictal autonomic arousal, in DS ‘autonomic responders’. In the DS subgroup of autonomic ‘non‐responders’, differences in subjective responses were observed for some conditions, compared to control ‘non‐responders’. The findings indicate unaffected subjective responses to emotional images in people with DS overall. However, within the group of people with DS, there may be subgroups characterized by differences in emotional responding. One subgroup (i.e., ‘autonomic responders’) exhibit heightened autonomic responses but intact subjective emotional experience, whilst another subgroup (i.e., ‘autonomic non‐responders’) seem to experience greater subjective negativity and arousal for some emotional stimuli, despite less frequent autonomic reactions. The current results suggest that therapeutic interventions targeting awareness and regulation of physiological arousal and subjective emotional experience could be of value in some people with this disorder.

Developmentally Specific Associations Between CNR1 Genotype and Cannabis Use Across Emerging Adulthood.

Previous studies have found preliminary evidence for associations between common single-nucleotide polymorphisms (SNPs) in the cannabinoid receptor gene CNR1 and cannabis use and dependence. The present study examined a set of eight independent SNPs in or near CNR1 in relation to cannabis use measured longitudinally across emerging adulthood. Using latent growth curve modeling of 10 waves of longitudinal data spanning mean ages 18.4-23.8 years in a sample of non-Hispanic White individuals (n = 334), we tested if genotype at each CNR1 SNP was associated with both level and growth of cannabis use over time. Peer group drug use, a known correlate of individual use, was evaluated as a time-varying predictor of cannabis use and as a moderator of the relationship between SNPs and individual use. After correction for multiple comparisons, one SNP, rs806374, was significantly associated with individual differences in level-but not growth-of cannabis use over time, such that C carriers were more likely to use cannabis more frequently at study onset (around age 18). Peer drug use was a predictor of individual cannabis use that grew in terms of effect size with time, but did not significantly moderate the effect of rs806374 genotype. C carriers at rs806374 may be at specific risk for increased odds of use during the transition out of high school (around age 18). Future studies should investigate potential mechanisms at this developmental stage, including individual differences in subjective response, innate tolerance, reinforcement mechanisms, or general liability for substance misuse.

Autonomic versus perceptual accounts for tactile hypersensitivity in autism spectrum disorder

Tactile atypicality in individuals with autism spectrum disorder (ASD) has harmful effects on their everyday lives including social interactions. However, whether tactile atypicality in ASD reflects perceptual and/or autonomic processes is unknown. Here, we show that adults with ASD have hypersensitivity to tactile stimuli in the autonomic but not perceptual domain. In particular, adults with ASD showed a greater skin conductance response (SCR) to tactile stimuli compared to typically developing (TD) adults, despite an absence of differences in subjective responses. Furthermore, the level of the SCR was correlated with sensory sensitivity in daily living. By contrast, in perceptual discriminative tasks that psychophysically measured thresholds to tactile stimuli, no differences were found between the ASD and TD groups. These results favor the hypothesis that atypical autonomic processing underlies tactile hypersensitivity in ASD.

Acute subjective response to alcohol as a function of reward and punishment sensitivity

Individual differences in subjective response to alcohol play a crucial role in the development of heavy drinking and related problems. In light of this, a growing focus of research has been identifying factors that contribute to differences in response. The aim of the present study was to determine whether individual differences in the subjective experience of rewarding and aversive effects of alcohol are a specific manifestation of general differences in reward and punishment sensitivity. Eighty-nine participants (M age=22.4, SD=1.9; 47.2% women) consumed a moderate dose of alcohol, i.e., peak breath alcohol concentration (BrAC)≈0.080g%, and rated their level of stimulation and sedation at seven timepoints over the BrAC curve. Sensitivity to reward and punishment were assessed by a self-report questionnaire prior to consumption. Multilevel growth models showed that post-consumption changes in stimulation ratings varied as a function of participants' level of reward and punishment sensitivity. Drinkers more sensitive to reward reported feeling more stimulated shortly after drinking and exhibited an attenuated rate of decline in stimulation over the blood alcohol curve, relative to drinkers with less strong reward sensitivity. Reward sensitivity was not related to subjective ratings of sedation, and punishment sensitivity was not related to either stimulation or sedation ratings. Findings suggest that reward sensitivity may increase risk for alcohol misuse among young adult social drinkers by increasing their subjective feelings of stimulation while drinking.

Abstract C39: Optimism and breast cancer risk: Results from a prospective cohort study

Abstract Results from studies of the impact of psychological stress on breast cancer risk have been inconsistent, possibly due to differences in subjective responses to similar stressful events. Dispositional optimism, characterized by the general belief that good things will happen in one's life, is correlated with better adjustment to diverse stressors and psychological wellbeing. Limited numbers of studies suggest that the benefit of optimism may also extend to physical health. The purpose of the present analysis was to examine psychosocial and behavioral correlates of dispositional optimism and to determine whether optimism is a protective factor for breast cancer in a large cohort of women aged 35-74 years. Data came from the Sister Study, a prospective cohort of 50,884 women with a sister with breast cancer. Optimism was assessed among 46,776 women (92%) at the first biennial follow-up interview using the 6-item Life Orientation Test –Revised (LOT-R). After excluding 1,009 women diagnosed with breast cancer prior to the biennial survey, the present analysis comprised 45,767 women. Each item of the LOT-R was scored from 1 (strongly disagree) to 5 (strongly agree). Based on the average score, women were categorized into 3 groups: low (&amp;lt;3); modest (3-&amp;lt;4); and high optimism (&amp;gt;=4). Between the biennial survey and March 2015, 1,398 women were newly diagnosed with breast cancer with an average follow-up duration of 859 days. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for breast cancer were estimated using Cox proportional hazards regression. Approximately half of women (50.9%) fell into the high optimism category, followed by modest (40.4%) and low (8.8%) optimism categories. Women with high optimism were older and reported having higher education and income than those with lower optimism. They were also more likely to exercise, eat healthily, and maintain a healthy weight, and less likely to smoke. Compared with women with modest or high optimism, those with low optimism more frequently reported experience of stressful life events during childhood (mean number of 2.2 in low; 1.3 in modest and 1.0 in high optimism groups) and adulthood (5.2 in low; 4.3 in modest and 3.9 in high optimism groups). Low optimism was also highly correlated with lack of emotional support (14% in low; 4.1% in modest and 1.3% in high optimism group) and increased depression score (14.2 in low; 10.2 in modest and 8 in high optimism group). Compared to the modest optimism group, high optimism was associated with reduced risk of breast cancer, after adjustment for sociodemographic, behavioral, reproductive and psychological variables (adjusted HR: 0.82, 95% CI: 0.72-0.93). Although not statistically significant, low optimism also had a protective association with breast cancer (adjusted HR: 0.84, 95% CI: 0.67-1.06). A sensitivity analysis that excluded 292 breast cancer cases diagnosed within 1 year from the biennial survey yielded similar results. We also performed an exploratory subgroup analysis. The protective association with high optimism appeared to be more evident among women aged &amp;lt;60 years (HR=0.79; 95% CI:0.67-0.92) and minority women (HR=0.69, 95% CI: 0.49-0.96) compared to those aged 60 or older (HR=0.94; 95% CI: 0.81-1.11) and non-Hispanic whites (HR=0.89, 95% CI: 0.79-1.00), but there was no statistical evidence for heterogeneity (p values for heterogeneity = 0.23 for age and 0.26 for race/ethnicity, respectively). No significant interaction with optimism was found for tumor subtype, menopause status, and number of 1st degree family members with breast cancer. In conclusion, we found a reduced breast cancer risk among women with high optimism. High optimism was positively correlated with higher socioeconomic status, healthy behaviors, and reduced stressful life events and depression, but these factors did not explain the protective association between high optimism and breast cancer risk in our data. Citation Format: Sangmi Kim, Fengjiao Hu, Lisa DeRoo, Helen Meier, Christine Parks, Dale Sandler. Optimism and breast cancer risk: Results from a prospective cohort study. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C39.

Subjective Response to Alcohol as a Research Domain Criterion.

Individual differences in the subjective experience of the pharmacological effects of alcohol have long been implicated in the likelihood that one will drink heavily and develop alcoholism. The theme of this conceptual review and perspective article is to synthesize the literature on subjective responses to alcohol and to set an agenda for the next generation of research in the area. Specifically, we contend that in order for subjective response to alcohol to play a prominent role in alcoholism research, it is critical that it be studied as a multimodal phenotype. First, we review the human research on subjective response to alcohol measured under controlled laboratory conditions and draw recommendations for the application of these findings to understanding alcoholism neurobiology in humans. Second, we highlight multimodal approaches, including studies of the genetic and neural substrates of individual differences in subjective response to alcohol. Third, we review treatment implications with a focus on subjective response to alcohol as an intervention target. Upon review of the research on subjective response to alcohol across levels of analyses, we provide recommendations for leveraging these phenotypes in a systematic and methodologically rigorous fashion that can address central questions about alcoholism etiology, disease progression, and personalized treatment. The approach recommended herein is largely consistent with the Research Domain Criteria (RDoC) initiative across the National Institute of Mental Health. The defining feature of such domains is that they inform behavior yet be amenable to examination through multiple units of analysis, such as molecular, genetic, circuit-level, and behavioral measurements. To that end, we contend that subjective response to alcohol represents a behaviorally and biologically plausible phenotype upon which to build using the RDoC framework for understanding alcohol use disorder.

Subjective Responses to Caffeine Are Influenced by Caffeine Dose, Sex, and Pubertal Stage.

Background: Our previous work has shown that there are sex differences in subjective responses to acute caffeine administration in adolescents. The purpose of this study was to determine if these sex differences are dependent on pubertal development. Materials and Methods: We examined subjective responses before and after administration of 0, 1, and 2 mg/kg of caffeine in pre- and postpubertal boys and girls (n = 112). In addition, we examined differences in subjective responses to acute caffeine in both the luteal and follicular phases of the menstrual cycle in postpubertal girls. Results: Caffeine at both doses resulted in greater changes in responses on the Addiction Research Center Inventory and the Brief Assessment of Mood States compared with placebo. Girls reported greater increases from baseline to peak in feeling different and liking the feeling than boys after 2 mg/kg of caffeine regardless of pubertal stage. Postpubertal girls also had a greater decrease from baseline in reports of feeling high and greater increases from baseline in reports of wanting more than postpubertal males. Finally, girls had greater changes (both increases and decreases) in responses on the Brief Mood Questionnaire when in the follicular phase compared with the luteal phase. This was also true for reports of feeling high and feeling different on the Drug Effects Questionnaire. None of these effects varied as a function of usual caffeine use, suggesting that differences are not the result of tolerance or sensitization. Conclusions: These results suggest that subjective responses to caffeine emerge before puberty, but sex differences may be strengthened after pubertal development.

Emotional traits predict individual differences in amphetamine-induced positive mood in healthy volunteers.

Previous research on emotional correlates of individual differences in subjective responses to D-amphetamine has focused on relatively broad personality traits. Yet, emotional functioning is best characterized by several narrow subcomponents, each of which may contribute uniquely to amphetamine response. Here, we examine several specific subdomains of emotional functioning in relation to acute amphetamine response. At a baseline session, healthy stimulant-naive volunteers (N = 97) completed measures of several subdomains of baseline trait emotional functioning and then completed two counterbalanced experimental sessions during which they received a single oral dose of 20mg D-amphetamine or placebo. Acute subjective drug response measures were completed at repeated intervals before and after drug administration. Data from subjective measures that were significantly modulated by amphetamine were reduced using principal component analysis (amphetamine or placebo) into three higher-order factors of "positive mood," "arousal," and "drug high." Amphetamine did not significantly alter any "negative" subjective states. Separate multiple regression analyses were conducted regressing these three drug factors on baseline trait emotional functioning scales. The combined set of trait emotional functioning indicators accounted for approximately 22% of the variance in acute amphetamine-induced positive mood changes. Greater anticipatory pleasure and greater anxious distress each uniquely predicted greater amphetamine-induced positive mood. Trait emotional functioning did not significantly predict amphetamine-induced changes in arousal or drug high. Emotional traits appear to moderate drug-induced positive mood but not other dimensions of amphetamine effects. Different facets of emotional functioning may differentially modulate amphetamine's subjective effect profile.

Subjective response of standing persons exposed to fore-aft, lateral and vertical whole-body vibration

The aims of this study were to propose multiply scale factors for evaluation of discomfort of standing persons and to investigate whether there exist differences between multiplying factors used for evaluation of discomfort of standing persons and those of seated persons exposed to WBV. Twelve male subjects were exposed to twenty-seven stimuli that comprise three acceleration magnitudes (0.2, 0.4, and 0.8 m/s2 r.m.s.) along fore-aft (x), lateral (y) or vertical (z) direction. The subjects with seated or standing posture on the platform of the vibration test rig rated the subjective discomfort for each stimulus that has frequency contents ranging from 1.0 Hz to 20 Hz with a constant power spectrum density. The order of presentation of the test stimuli was fully randomized and each stimulus was repeated three times. The subjective scale for discomfort was calculated by using the category judgment method. The best combinations of multiplying factors were determined by calculating correlation coefficients of regression curves in-between subjective ratings and vibration magnitudes. In all the directions, body posture significantly influenced on subjective discomfort scales. Particularly in the fore-aft and lateral direction, the upper limit of all the categories for the standing posture resulted in higher vibration acceleration magnitudes than those for the seated posture. In contrast, in the vertical direction, only the upper limit of category “1: Not uncomfortable” for standing posture was observed to be higher than that for seated posture. The best agreement for ISO-weighted vibration acceleration occurred at x factor of 1.8 and y factor of 1.8 in the standing posture and x factor of 2.8 and y factor of 1.8 in the seated posture. The results suggest that seated people respond more sensitively and severely in perception of discomfort to fore-aft and lateral vibration than standing people do while standing people respond more sensitively and severely to vertical vibration than seated people do. Thus the effects of body postures on multiplying factors should be considered in evaluation of discomfort caused by whole-body vibration. Relevance to industryThis study reports differences in subjective response of standing persons to fore-aft, lateral and vertical whole-body vibration. The results obtained in this study propose the fundamental data on the sensitivity to whole-body vibration exposed with standing posture.

An evaluation of the differences in subjective responses to the attractiveness of pictures of the opposite sex after a visual presentation

An evaluation of the differences in subjective responses to the attractiveness of pictures of the opposite sex after a visual presentation

Relationships between impulsivity and subjective response in an IV ethanol paradigm

Impulsivity and individual differences in subjective response to alcohol are risk factors for alcohol problems and possibly endophenotypes for alcohol dependence. Few prior studies have addressed relationships between the two constructs. To predict subjective responses to ethanol, we tested self-reported impulsiveness, ethanol dose condition (high dose, low dose, or placebo), and time (seven time points) along with interactions among these variables. The present study is a secondary analysis of data from a within-subject, placebo-controlled, dose-ranging ethanol administration study using IV infusion with a clamping technique to maintain steady-state breath alcohol concentration. The sample consisted of healthy, non-alcohol dependent social alcohol drinkers between the ages of 21 and 30 (N=105). Participants at varying levels of impulsivity were compared with regard to stimulant and subjective responses to three ethanol dose conditions over time. Individuals with higher impulsivity reported elavated stimulant and dampened sedative response to alcohol, particularly at the higher dose. Higher impulsivity was associated with a steeper increase in stimulant effects during the first half of clamped ethanol infusion with the higher dose. These results suggest that impulsive individuals may experience enhanced reinforcing, stimulant effects, and relatively muted aversive sedative effects from alcohol. These subjective responses may relate to enhanced risk of alcohol problems among more impulsive individuals.

Bayesian Semi- and Non-parametric Models for Longitudinal Data with Multiple Membership Effects in R.

We introduce growcurves for R that performs analysis of repeated measures multiple membership (MM) data. This data structure arises in studies under which an intervention is delivered to each subject through the subject's participation in a set of multiple elements that characterize the intervention. In our motivating study design under which subjects receive a group cognitive behavioral therapy (CBT) treatment, an element is a group CBT session and each subject attends multiple sessions that, together, comprise the treatment. The sets of elements, or group CBT sessions, attended by subjects will partly overlap with some of those from other subjects to induce a dependence in their responses. The growcurves package offers two alternative sets of hierarchical models: 1. Separate terms are specified for multivariate subject and MM element random effects, where the subject effects are modeled under a Dirichlet process prior to produce a semi-parametric construction; 2. A single term is employed to model joint subject-by-MM effects. A fully non-parametric dependent Dirichlet process formulation allows exploration of differences in subject responses across different MM elements. This model allows for borrowing information among subjects who express similar longitudinal trajectories for flexible estimation. growcurves deploys "estimation" functions to perform posterior sampling under a suite of prior options. An accompanying set of "plot" functions allow the user to readily extract by-subject growth curves. The design approach intends to anticipate inferential goals with tools that fully extract information from repeated measures data. Computational efficiency is achieved by performing the sampling for estimation functions using compiled C++.