Dataset Information

Trial-by-Trial Fluctuations in Brain Responses to Stress Predict Subsequent Smoking Decisions That Occur Several Seconds Later.

ABSTRACT:

Background

To investigate the neurobiological mechanisms that determine self-regulation of smoking urges when a person encounters stress, we investigated brain network interactions of smoking self-regulation by employing a real-time smoking (nicotine delivery) decision paradigm and a brain-as-predictor neuroimaging approach.

Methods

While in the functional magnetic resonance imaging scanner, 25 cigarette smokers who abstained from smoking overnight made 200 real smoking decisions regarding whether or not to take a puff of an electronic cigarette during 3 different stress conditions (cognitive stress, emotional stress, and no stress). Cognitive stress was induced by a concurrent working memory load, and emotional stress was induced by manipulating a chance of aversive electric shock.

Results

Behaviorally, both cognitive and emotional stress manipulations increased the probability of making a decision to smoke (i.e., taking a puff). In magnetic resonance imaging trial-by-trial analyses, the dorsolateral prefrontal cortex activity measured at the time of the stress cue significantly predicted future smoking decisions that occurred several seconds later. Furthermore, the influence of dorsolateral prefrontal cortex activity on smoking decisions was mediated by the ventral striatum activity at the time of smoking decisions.

Conclusions

Our study demonstrated that brain responses at the time of a stressful moment determine subsequent trial-by-trial smoking decisions by systematically altering brain executive (dorsolateral prefrontal cortex) and reward (ventral striatum) system network activities. Our results further suggest potential translational importance of neuroscientific approaches to predicting self-regulation failures at critical stressful moments.

SUBMITTER: Lim SL

PROVIDER: S-EPMC7655713 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Introduction:Cue reactivity (CR) research has reliably demonstrated robust cue-induced responding among smokers exposed to common proximal smoking cues (eg, cigarettes, lighter). More recent work demonstrates that distal stimuli, most notably the actual environments in which smoking previously occurred, can also gain associative control over craving. In the real world, proximal cues always occur within an environment; thus, a more informative test of how cues affect smokers might be to present these two cue types simultaneously. Methods:Using a combined-cue counterbalanced CR paradigm, the present study tested the impact of proximal (smoking and neutral) + personal environment (smoking and nonsmoking places) pictorial cues, on smokers' subjective and behavioral CR; as well as the extent to which cue-induced craving predicts immediate subsequent smoking in a within-subjects design. Results:As anticipated, the dual smoking cue combination (ProxS + EnvS) led to the greatest cue-induced craving relative to the other three cue combinations (ProxS + EnvN, ProxN + EnvS, and ProxN ± EnvN), ps < .004. Dual smoking cues also led to significantly shorter post-trial latencies to smoke, ps < .01. Overall CR difference score (post-trial craving minus baseline craving) was predictive of subsequent immediate smoking indexed by: post-trial latency to smoke [B = -2.69, SE = 9.02; t(143) = -2.98, p = .003]; total puff volume [B = 2.99, SE = 1.13; t(143) = 2.65, p = .009]; and total number of puffs [B = .053, SE = .027; t(143) = 1.95, p = .05]. Conclusions:The implications of these findings for better understanding the impact of cues on smoking behavior and cessation are discussed. Implications:This novel cue reactivity study examined smokers' reactivity to combined proximal and distal smoking cues. Exposure to a combination of two smoking cues (proximal and environment) led to the greatest increases in cue-induced craving and smoking behavior compared to all other cue combinations. Further, the overall magnitude of cue-induced craving was found to significantly predict immediate subsequent smoking. This work provides new insight on how exposure to various cues and cue combinations directly affect smokers' craving and actual smoking behavior, as well as the relationship between those two indices of reactivity.

Project description:A growing body of evidence indicates a pivotal role of cognition and in particular executive function in gait control and fall prevention. In a recent gait study using electroencephalographic (EEG) imaging, we provided direct proof for cortical top-down inhibitory control in step adaptation. A crucial part of motor inhibition is recognizing stimuli that signal the need to inhibit or adjust motor actions such as steps during walking. One of the EEG signatures of performance monitoring in response to events signaling the need to adjust motor responses, are error-related potential (error-ERP) features. To examine whether error-ERP features may index executive control during gait adaptation, we analyzed high-density (108-channel) EEG data from an auditory gait pacing study. Participants (N = 18) walking on a steadily moving treadmill were asked to step in time to an auditory cue tone sequence, and then to quickly adapt their step length and rate, to regain step-cue synchrony following occasional unexpected shifts in the pacing cue train to a faster or slower cue tempo. Decomposition of the continuous EEG data by independent component analysis revealed a negative deflection in the source-resolved event-related potential (ERP) time locked to 'late' cue tones marking a shift to a slower cue tempo. This vertex-negative ERP feature, localized primarily to posterior medial frontal cortex (pMFC) and peaking 250 ms after the onset of the tempo-shift cue, we here refer to as the step-cue delay negativity (SDN). SDN source, timing, and polarity resemble other error-related ERP features, e.g., the Error-Related Negativity (ERN) and Feedback-Related Negativity (FRN) in (seated) button press response tasks. In single trials, SDN amplitude varied with the magnitude of the cue latency deviation (the time interval between the expected and actual cue onsets). Regression analysis also identified linear coupling between SDN amplitude and the subsequent speed of gait tempo adaptation (as measured by the increase in length of the ensuing adaptation step). The SDN in this paradigm thus seems both to index the perceived need for and the subsequent magnitude of the immediate gait adjustment, consistent with performance-monitoring models. Future research might investigate relationships of these control processes to the impairment of gait adjustment in motor disorders and cognitive decline, for example to develop a biomarker for fall risk prediction in early-stage Parkinson's.

Project description:BackgroundThe prevalence, pathology, and existence of malnutrition-associated diabetes remain uncertain, especially with respect to adult-acquired undernutrition.ObjectiveThe aim was to investigate the association of prior undernutrition (low BMI, in kg/m2), acquired in adulthood and insulin during an oral glucose tolerance test (OGTT).MethodsWe followed up 630 adults recruited 7-14 y previously for other studies. Plasma insulin was measured fasting and at 30 and 120 min during an OGTT. The main exposure was BMI measured 7-14 y prior. The main outcome of interest was plasma insulin, controlling for time during the OGTT using generalized estimating equations, and exploratory outcomes were early insulin response (relative change in insulin and glucose from 0-30 min) and relative insulin and glucose AUCs from 0 to 120 min. Current confounding factors were age, sex, BMI, HIV, socioeconomic status, and physical activity.ResultsIn unadjusted analyses, increasing severity of prior malnutrition was associated with lower insulin concentration. In multivariate adjusted analyses, only current BMI was a strong predictor of overall insulin concentration. Associations with prior BMI of insulin responses accounting for glucose were also seen in unadjusted but not adjusted analyses. For insulin concentration but not the outcomes accounting for glucose, there was a sex interaction with prior BMI such that only men had lower insulin if previously malnourished: insulin (pmol/L) at 120 min was 311 (95% CI: 272, 351) for prior BMI ≥18.5, 271 (95% CI: 221, 321) for prior BMI 17.0-18.5, and 237 (95% CI: 194, 297) for prior BMI <17.0; P = 0.03. HIV status showed limited and variable associations with insulin.ConclusionsInsulin concentration, fasting and during an OGTT, was normalized in women more than in men several years after adult malnutrition. Chronic malnutrition, as indicated by low prior and current BMI, may contribute to diabetes through low insulin secretion.