Otsustusprotsesside mõjutamine transkraniaalse magnetstimulatsiooniga

Väitekirja elektrooniline versioon ei sisalda publikatsiooneInimese käitumist kontrollivates otsustusprotsessides on oluline roll dorsolateraalsel prefrontaalkorteksil (DLPFK) ning sellega juhteteede kaudu seotud eemalasuvatel ajupiirkondadel, kuid otsustusprotsesside täpsemate neurobioloogiliste mehhanismide kohta on veel vähe teada. Otsustusprotsesside põhjalik uurimine on oluline nii täidesaatvate funktsioonide ja sihipärase käitumise mõistmiseks kui ka erinevate neuropsühholoogiale tuginevate ravimeetodite väljaarendamiseks. Käesolev väitekiri keskendus mitte-veridikaalsete otsustusprotsesside uurimisele, kasutades selleks transkraniaalse magnetstimulatsiooni (TMS) meetodit. Otsustusprotsessidega seotud DLPFK piirkondi magnetimpulssidega mõjutades on võimalik tuvastada otsustamise neurobioloogilisi korrelaate ning uurida veridikaalseid ja mitte-veridikaalseid otsusi vastandava teoreetilise mudeli paikapidavust. Uuring I näitas, et mitte-veridikaalseid otsustusprotsesse on võimalik TMS-i abil selektiivselt mõjutada, kusjuures vasakpoolne DLPFK näib olevat rohkem spetsialiseerunud mitte-veridikaalsetele kognitiivsetele otsustele kui veridikaalsetele, samas kui parempoolne DLPFK osaleb mõlemat tüüpi otsustes. Tulemused ilmestasid ka seda, et TMS rakendamine avaldab korteksi piirkondadele nii lokaalset kui distaalset, TMS lookusest eemalasuvalt realiseeruvat mõju. Uurimuses II leidis kinnitust parempoolse DLPFK oluline roll impulsiivses ja riskantses käitumises: parempoolse DLPFK neurofüsioloogilise erutuvuse pärssimine madalsagedusliku TMS-iga tõi kaasa käitumise pidurduse vähenemise ning oluliselt riskeerivama käitumisstrateegia. Uuring III kinnitas BDNF geeni olulist mõju nii mitte-veridikaalsetele otsustusprotsessidele kui ka sellele, kuidas prefrontaalsete piirkondade mõjutamine TMS-iga mitte-veridikaalset endofenotüübi mõjuga seotud käitumist muudab. Väitekirja uurimustest järeldub, et TMS meetodil DLPFK piirkondi mõjutades on võimalik otsustusprotsesse mõjutada, kuid vallanduvad käitumuslikud muutused sõltuvad nii ülesande iseloomust, ülesandega seotud kognitiivsete mehhanismide lateralisatsioonist, kui ka inimese neurobioloogilisest endofenotüübist.Human decision-making is known to depend on the prefrontal cortex and distal areas interconnected to it, but its specific neurobiological mechanisms are still largely unknown. Expanding our knowledge of decision-making processes contributes to understanding the neuropsychological principles of executive function and goal directed behaviour, as well as to advancing the clinical application of neurostimulation in this domain. Within empirical studies included in the current dissertation, repeated transcranial magnetic stimulation (rTMS) was applied to the dorsolateral prefrontal cortex (DLPFC) in order to evaluate potential effects on performance across various decision-making tasks. By observing how non-invasive modulation of neural activity in underlying cortical areas affects non-veridical cognition related behavioural choices, the thesis addressed the functional role of the DLPFC in decision-making processes. Results of Study I demonstrated that non-veridical and veridical decision-making both rely on the right DLPFC, whereas the left DLPFC is more specifically committed to non-veridical cognition. Study I findings also emphasised non-focal, distal effects of TMS, when applied to particularly richly interconnected cortical regions such as the DLPFC. Study II revealed that TMS-induced inhibition of the right DLPFC activity affects non-veridical risky behaviour, suggesting that the right DLPFC plays a role in execution and monitoring of performance in risky tasks with a motor response. Study III revealed that non-veridical behaviour is influenced by genetic differences related to the BDNF gene and that TMS stimulation enhances pre-existing genetically determined biases in decision-making preferences. In conclusion, decision-making behaviour can be modulated by applying TMS to the DLPFC, but the resulting behavioural effects depend on the characteristics of the task, the lateralization of task-specific cognitive mechanisms, as well as the neurobiological endophenotypes involved.https://www.ester.ee/record=b522936

Frameworks for Understanding Cultural Variations in Behaviors, Beliefs, and Communication: Implications for Students from Diverse Backgrounds

Services for students with impairments are typically based on the values, beliefs, and communication patterns of dominant, mainstream populations. If services for students and their families from culturally/linguistically diverse backgrounds are to be considered acceptable and effective, they must be designed to account for these cultural variations. Anthropologists and psychologists have developed constructs to explain key behavioral and belief dimensions along which cultures vary, e.g., individualism/collectivism, power distance/hierarchical relationships, analytic/holistic cognition. Researchers in cultural neuroscience are investigating the neurophysiological and neurogenetic associations with these variations in behaviors/beliefs as a means of understanding the mutual influence of cultural and genetic factors on mind, brain, and behavior. This presentation will describe (a) frameworks for understanding cultural variations in values, beliefs, and communication styles, (b) neurophysiological/neurogenetic relationships to these cultural variations in behaviors and beliefs, and (c) implications of these cultural variations on the assessment and intervention of students from diverse backgrounds. Learning Outcomes—at the end of this session, participants will be able to: Describe constructs of cultural variations in behaviors, beliefs, and communication Describe the influence of cultural and genetic factors on mind, brain, and behavior Explain the implications of cultural variations in communication style on the assessment and intervention of culturally/linguistically diverse student

Dispelling urban myths about default uncertainty factors in chemical risk assessment - Sufficient protection against mixture effects?

© 2013 Martin et al.; licensee BioMed Central LtdThis article has been made available through the Brunel Open Access Publishing Fund.Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment. © 2013 Martin et al.; licensee BioMed Central Ltd.Oak Foundatio

Developing systems to control food adulteration

The objective of this study is to explore the current strategies available to monitor and detect the economically and criminally motivated adulteration of food, identifying their strengths and weaknesses and recommend new approaches and policies to strengthen future capabilities to counter adulteration in a globalized food environment. Many techniques are used to detect the presence of adulterants. However, this approach relies on the adulterant, or means of substitution, being "known" and an analytical method being available. Further techniques verify provenance claims made about a food product e.g. breed, variety etc. as well as the original geographic location of food production. These consider wholeness, or not, of a food item and so do not need to necessarily identify the actual adulterant just whether the food is complete. The conceptual framework developed in this research focuses on the process of predicting, reacting and detecting economically and criminally motivated food adulteratio

Using Biomedical Technologies to Inform Economic Modeling: Challenges and Opportunities for Improving Analysis of Environmental Policies

Advances in biomedical technology have irrevocably jarred open the black box of human decision making, offering social scientists the potential to validate, reject, refine and redefine the individual models of resource allocation that form the foundation of modern economics. In this paper we (1) provide a comprehensive overview of the biomedical methods that may be harnessed by economists and other social scientists to better understand the economic decision making process; (2) review research that utilizes these biomedical methods to illuminate fundamental aspects of the decision making process; and (3) summarize evidence from this literature concerning the basic tenants of neoclassical utility that are often invoked for positive welfare analysis of environmental policies. We conclude by raising questions about the future path of policy related research and the role biomedical technologies will play in defining that path.neuroeconomics, neuroscience, brain imaging, genetics, welfare economics, utility theory, biology, decision making, preferences, Institutional and Behavioral Economics, Research Methods/ Statistical Methods, D01, D03, D6, D87,

What's a brain: neuroanatomy and neurochemistry of anxiety disorders in dogs

This review deals with the neurocircuitry of fear and anxiety disorders, with the focus on neuroanatomy and neurochemistry. This knowledge is required to correctly diagnose and treat dogs with anxiety-related behavioral disorders. Research to date has shown the involvement of the frontal cortex, the amygdala, the thalamus and the hippocampus as core regions in regulating fear. Imbalances (hyper- or hypoactivation) in this fear circuitry can trigger inappropriate fear responses, i.e. anxiety disorders. Serotonin, dopamine and norepinephrine are the main neurotransmitters of emotion in the brain, but gamma-aminobutyric acid (GABA), glutamate, and the hypothalamic-pituitary-adrenal (HPA) axis producing glucocorticoids are also important in the neurochemistry of anxiety

The social brain: neural basis of social knowledge

Social cognition in humans is distinguished by psychological processes that allow us to make inferences about what is going on inside other people—their intentions, feelings, and thoughts. Some of these processes likely account for aspects of human social behavior that are unique, such as our culture and civilization. Most schemes divide social information processing into those processes that are relatively automatic and driven by the stimuli, versus those that are more deliberative and controlled, and sensitive to context and strategy. These distinctions are reflected in the neural structures that underlie social cognition, where there is a recent wealth of data primarily from functional neuroimaging. Here I provide a broad survey of the key abilities, processes, and ways in which to relate these to data from cognitive neuroscience

Linking Illness to Food: Summary of a Workshop on Food Attribution

To identify and prioritize effective food safety interventions, it is critical not only to identify the pathogens responsible for illness, but also to attribute cases of foodborne disease to the specific food vehicle responsible. A wide variety of such “food attribution” approaches and data are used around the world, including the analysis of and extrapolation from outbreak and other surveillance data, case-control studies, microbial subtyping and source-tracking methods, and expert judgment, among others. The Food Safety Research Consortium sponsored the Food Attribution Data Workshop in October 2003 to discuss the virtues and limitations of these approaches and to identify future options for the collection of food attribution data in the United States. This discussion paper summarizes workshop discussions and identifies challenges that affect progress in this critical component of a risk-based approach to improving food safety.foodborne illness, food attribution, outbreaks, case-control studies, microbial fingerprinting, microbial subtyping, FoodNet

A framework for cumulative risk assessment in the 21st century

The ILSI Health and Environmental Sciences Institute (HESI) has developed a framework to support a transition in the way in which information for chemical risk assessment is obtained and used (RISK21). The approach is based on detailed problem formulation, where exposure drives the data acquisition process in order to enable informed decision-making on human health safety as soon as sufficient evidence is available. Information is evaluated in a transparent and consistent way with the aim of optimizing available resources. In the context of risk assessment, cumulative risk assessment (CRA) poses additional problems and questions that can be addressed using the RISK21 approach. The focus in CRA to date has generally been on chemicals that have common mechanisms of action. Recently, concern has also been expressed about chemicals acting on multiple pathways that lead to a common health outcome, and non-chemical other conditions (non-chemical stressors) that can lead to or modify a common outcome. Acknowledging that CRAs, as described above, are more conceptually, methodologically and computationally complex than traditional single-stressor risk assessments, RISK21 further developed the framework for implementation of workable processes and procedures for conducting assessments of combined effects from exposure to multiple chemicals and non-chemical stressors. As part of the problem formulation process, this evidence-based framework allows the identification of the circumstances in which it is appropriate to conduct a CRA for a group of compounds. A tiered approach is then proposed, where additional chemical stressors and/or non-chemical modulating factors (ModFs) are considered sequentially. Criteria are provided to facilitate the decision on whether or not to include ModFs in the formal quantitative assessment, with the intention to help focus the use of available resources to have the greatest potential to protect public health