The Effect Of Abstinence From Smoking On Stress Reactivity

Subjective stress is a well-documented predictor of early smoking relapse, yet our understanding of stress and tobacco use is limited by the reliability of current available measures of stress. Functional magnetic reasoning imaging (fMRI) could provide a much-needed objective measure of stress reactivity. The goal of this dissertation is to contribute to the understanding of abstinence-induced changes in stress reactivity by examining neural, neuroendocrine (cortisol), and subjective measures of stress response during abstinence. In addition, this study investigated the influence of individual variation in nicotine metabolism rates on these measures of stress reactivity. Seventy-five treatment-seeking smokers underwent blood oxygen level dependent (BOLD) fMRI during the Montreal Imaging Stress Task (MIST) on two occasions: once during smoking satiety and once following biochemically confirmed 24-hour abstinence (order counter-balanced). The primary outcome measure was brain response during stress (vs. control) blocks of the MIST. Neural stress reactivity during abstinence (vs. satiety) was associated with significantly increased activation in the left inferior frontal gyrus (IFG), a brain region previously associated with inhibitory control. Greater abstinence-induced change in brain response to stress was associated with greater abstinence-induced change in subjective stress. However, there was no association with abstinence-induced change in cortisol response. In addition, higher rates of nicotine metabolism were associated with increased abstinence-induced change in self-reported stress, but not with brain or cortisol response. This study provides novel evidence that the brain response to stress is altered during the first 24 hours of a quit attempt compared to smoking satiety. These results underscore the importance of stress response during abstinence, and suggest that neuroimaging may provide a useful biomarker of stress response during the early smoking cessation, a period when smokers are most vulnerable to relapse

Addiction: Brain and Cognitive Stimulation for Better Cognitive Control and Far Beyond

Addiction behaviors are characterized by conditioned responses responsible for craving and automatic actions as well as disturbances within the supervisory network, one of the key elements of which is the inhibition of prepotent response. Interventions such as brain stimulation and cognitive training targeting this imbalanced system can potentially be a positive adjunct to treatment as usual. The relevance of several invasive and noninvasive brain stimulation techniques in the context of addiction as well as several cognitive training protocols is reviewed. By reducing cue-induced craving and modifying the pattern of action, memory associations, and attention biases, these interventions produced significant but still limited clinical effects. A new refined definition of response inhibition, including automatic inhibition of response and a more consistent approach to cue exposure capitalizing on the phase of reconsolidation of pre-activated emotional memories, all associated with brain and cognitive stimulation, opens new avenues for clinical research

Exploring the Modulation of Motor Cortical Excitability by Duration of Transcranial Direct Current Stimulation

The motor cortex(MC) was important in human learning and memory, and the level of cortical excitability is a way of assessing its state. To non-invasively modulate cortical excitability, transcranial direct current stimulation (tDCS) is a widely employed technique. tDCS can be utilized to either enhance or inhibit motor MC excitability. However, in most studies, the optimal duration effect of tDCS on cortical excitability has been neglected. Additionally, there are no systematic analysis of tDCS and cortical excitability indexes. To bridge these gaps, we designed an experiment to systematically analyze the duration of tDCS and MC excitability it triggered. We recruited 5 healthy, right-handed subjects. They don’t have history of psychiatric disorders. Throughout the 30-minute tDCS stimulation at 1 mA, we continuously applied TMS to characterize the motor evoked potential. Our experiment revealed the following: applying 1 mA tDCS to the participants for 30 minutes effectively increases cortical excitability, and this effect can last for at least 30 minutes after stimulation. We then analysed cortical excitability by measuring the motor-evoked potentials (MEPs) induced by TMS during the tDCS stimulation process. We found that the relationship between cortical excitability and tDCS duration does not appear to be linear. Instead, two peaks were observed at 2-5 minutes and 15-25 minutes, respectively. A decrease in cortical excitability was observed at 26-28 minutes. Finally, we analysed the response of different participants to tDCS and found that individuals vary in their response to tDCS. Additionally, the relationship between cortical excitability and tDCS duration is inconsistent across different individuals

Effects of single-session transcranial direct current stimulation on reactive response inhibition

Transcranial direct current stimulation (tDCS) is widely used to explore the role of various cortical regions for reactive response inhibition. In recent years, tDCS studies reported polarity-, time- and stimulation-site dependent effects on response inhibition. Given the large parameter space in which study designs, tDCS procedures and task procedures can differ, it is crucial to systematically explore the existing tDCS literature to increase the current understanding of potential modulatory effects and limitations of different approaches. We performed a systematic review on the modulatory effects of tDCS on response inhibition as measured by the Stop-Signal Task. The final dataset shows a large variation in methodology and heterogeneous effects of tDCS on performance. The most consistent result across studies is a performance enhancement due to anodal tDCS over the right prefrontal cortex. Partially sub-optimal choices in study design, methodology and lacking consistency in reporting procedures may impede valid conclusions and obscured the effects of tDCS on response inhibition in some previous studies. Finally, we outline future directions and areas to improve research

Cathodal HD-tDCS above the left dorsolateral prefrontal cortex increases environmentally sustainable decision-making

Environmental sustainability is characterized by a conflict between short-term self-interest and longer-term collective interests. Self-control capacity has been proposed to be a crucial determinant of people’s ability to overcome this conflict. Yet, causal evidence is lacking, and previous research is dominated by the use of self-report measures. Here, we modulated self-control capacity by applying inhibitory high-definition transcranial current stimulation (HD-tDCS) above the left dorsolateral prefrontal cortex (dlPFC) while participants engaged in an environmentally consequential decision-making task. The task includes conflicting and low conflicting trade-offs between short-term personal interests and long-term environmental benefits. Contrary to our preregistered expectation, inhibitory HD-tDCS above the left dlPFC, presumably by reducing self-control capacity, led to more, and not less, pro-environmental behavior in conflicting decisions. We speculate that in our exceptionally environmentally friendly sample, deviating from an environmentally sustainable default required self-control capacity, and that inhibiting the left dlPFC might have reduced participants’ ability to do so

Understanding Antisocial Behavior Through Autonomic Arousal, Nutrition, And Non-Invasive Brain Stimulation

Despite increasing awareness of the contributions of biological sciences in criminology, the extent to which biological variables are incorporated in criminological research and theories remains limited. This dissertation consists of five papers that examine biological factors in conjunction with social environmental and psychological variables to gain a more complete understanding of the etiology of antisocial behavior. Paper 1 examined whether a biological mechanism may help to explain why social environmental factors that are identified in many criminological theories are associated with antisocial behavior. The finding that low heart rate partly mediated the relationship between early social adversity and antisocial behavior in children gives rise to a social neurocriminology perspective whereby social environmental factors influence biology to in turn lead to crime. Paper 2 expanded on this empirical proof of concept by proposing a biopsychosocial model to demonstrate how autonomic arousal can be incorporated into extant criminological theories. Paper 3 employed a biological perspective to explain an important phenomenon in criminology regarding the higher rate of male crime. Using longitudinal mediation analysis, the study is the first to document that lower heart rates in males at age 11 years partly explain their higher levels of offending in adulthood. Findings support the consideration of biological processes in theoretical accounts of the gender gap. Paper 4 examined whether a nutritional factor, vitamin D, confers resilience to childhood antisocial behavior. The finding that meeting vitamin D sufficiency (serum 25-hydroxyvitamin D concentration ≥ 30 ng/mL) nullified the social adversity-antisocial behavior relationship documents for the first time, a protective effect of vitamin D on antisocial behavior. Paper 5 examined the neural mechanisms underlying antisocial behavior using transcranial direct current stimulation. A double-blind, placebo-controlled, stratified, randomized trial on healthy adults provided the first experimental evidence that increasing activity in the prefrontal cortex can reduce intentions to commit aggression. This effect was account for, in part, by enhanced perceptions of moral wrongfulness regarding the aggressive acts. Together, these studies have the potential to advance the field of criminology at conceptual and theoretical levels, as well as knowledge on the development of prevention and intervention programs for such behavior

Inhibitory Control Training

Inhibitory control is a critical neurocognitive skill for navigating cognitive, social, and emotional challenges. It rapidly increases during the preschool period and is important for early cognitive development, as it is a crucial component of executive functioning, self-regulation, and impulsivity. Inhibitory control training (ICT) is a novel intervention in which participants learn to associate appetitive cues with inhibition of behavior. It is being considered a promising approach in the treatment of psychopathology and appetitive behaviors. This book aims to bring together knowledge on the topic, considering research, clinic, and forensic field of intervention. Indeed, this book can be considered an excellent synopsis of perspectives, methods, empirical evidence, and international references