• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 5
  • 2
  • 1
  • 1
  • Tagged with
  • 45
  • 45
  • 22
  • 22
  • 12
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The neural correlates of cognitive reappraisal among post-traumatic stress disorder patients : A systematic review

Nordin, Cecilia, Mattsson, Cecilia January 2023 (has links)
The ability to regulate emotions is essential for human well-being. Among posttraumatic stress disorder (PTSD) patients, the capability to control emotions is impaired. Trauma-focused cognitive behavioral therapy is a recommended treatment for patients diagnosed with PTSD. Usually, cognitive reappraisal is considered the primary regulation technique in cognitive behavioral therapy treatment. The strategy aims to decrease negative or increase positive emotions by changing the interpretation of an event to alter the meaning of the situation. The aim of this thesis was to conduct a systematic review of the neural correlates of cognitive reappraisal among post-traumatic stress disorder patients. Through a systematic search, screening, and selection process out of initial 545 articles, six studies were included for data extraction and discussion. Using functional magnetic resonance imaging, participants utilized the strategy of cognitive reappraisal during an emotion regulation task in the scanner. Using functional magnetic resonance imaging, the neural activity of the participants in the included studies was compared during a cognitive reappraisal task. The result revealed a tendency of decreased activity in prefrontal cortices in PTSD patients during reappraisal compared to controls, indicating deficient recruitment of prefrontal cortices in PTSD patients during reappraisal.
22

A Disorder of The Emotional Brain : Neural Correlates of Body Dysmorphic Disorder

Larsson Torri, Frida January 2022 (has links)
Body Dysmorphic Disorder (BDD) is a mental disorder where the patient is preoccupied with a misperceived deficit in their appearance. It is a common disorder (~2% prevalence worldwide), leaving the patients significantly disabled and distressed. Comorbid disorders such as social phobia, depression, and anxiety disorders appear frequently. Previous neuroimaging studies have found heterogeneous abnormalities in brain regions involved in visual and emotional processing when comparing BDD patients to healthy controls. Some of these areas are involved in limbic structures. The emotional limbic system (involved in emotion recognition, reward, social behaviour, and decision-making) and the memory hippocampal limbic system (involved in episodic memory, information about objects, faces, and spatial locations) have been stated as two separate neural systems. The aim of this systematic review was to analyse the neural correlates of BDD focusing on structural changes in limbic structures, and further investigate whether the emotional limbic circuit exclusively is affected or solely higher influenced than the rest of the limbic structures. Abnormalities in information processing due to aberrant WM connectivity was found, as well as that volumetric alterations in GM and WM tracts correlate with clinical symptomatology. The relationship between visual and emotional processing system abnormalities and BDD severity suggests an involvement of the emotional limbic system in BDD.
23

A Systematic Review of the Neural Correlates and the Psychedelic Experience Induced by Ayahuasca and N, N-Dimethyltryptamine (DMT)

Yonus, Rawad January 2022 (has links)
Background: Ayahuasca is a South American psychoactive brew that contains Dimethyltryptamine (DMT) and monoamine oxidase inhibitors (MAOIs). Research has experienced a resurgence of interest in exploring the potential of these substances in the last decade. Thus, the aim of this review was to systematically review studies that used a placebo-controlled design to explore the neural correlates and psychedelic experience induced by DMT and ayahuasca. Method: The search was conducted using the Web of Science and Scopus databases to select studies published between January 2000 and February 2022 that used neuroimaging techniques and recruited healthy participants. Thus, 7 papers were selected. Results: Ayahuasca alters electrical activity in the brain by decreasing spectralpower in all EEG frequency bands, predominantly in the alpha band. DMT caused a spatially widespread decrease in alpha bands and a more modest decrease in beta bands. Ayahuasca caused an increase in the flow of information in the brain from posterior regions to more frontal regions and an increase in scores in all the Hallucinogen Rating Scale (HRS) subscales. Ayahuasca decreased connectivity in the Default Mode Network (DMN) and increases connectivity between DMN and the salience network. Conclusion: Ayahuasca and DMT can reliably produce profound changes in perception, emotions, and sense of self. Moreover, the decrease in the alpha band, the alteration of information flow between posterior and frontal regions, and the decrease in connectivity in the DMN could be the keystone understanding the neural correlates and the psychedelic experience induced by DMT andayahuasca.
24

Is there support for unattended visual phenomenal consciousness? : A systematic review

Fogelquist, Jennifer, Nilsdotter Swartswe, Johanna January 2023 (has links)
The phenomenal experience of our visual perception, what it is like to be in that state, is something that we might take for granted. However, looking closer at the neural correlates of visual processing in relation to phenomenal experience we recognize that it is a complex issue. Whether our subjective experience of our visual representation of the world is attached to cognitive functions, like working memory and attention, or whether some sort of richness overflows such functions, is an ongoing debate within cognitive neuroscience. Advocates for overflow argue that phenomenal experience is the result of activity in posterior occipito-temporo-parietal areas and is independent of attention, while those within the non-overflow position mean that for phenomenal awareness to arise activity in higher-level areas like the prefrontal lobe is needed. Finding evidence for unattended visual phenomenal consciousness without access consciousness would support the overflow position since it could indicate phenomenal experience as independent of attention. In addition to this debate, researchers need to keep in mind what methods are being used to measure phenomenal experience, since several biases potentially follow studies using introspective measures. Through this systematic review, a search string provided empirical studies based on fMRI that investigated unconscious and conscious visual processing. The results of this review show little or weak evidence for unattended visual phenomenal consciousness and do not seem to overflow cognitive functions.
25

Functional and Structural Neural Correlates of Sensory Discrimination after Stroke

Borstad, Alexandra Lee 24 August 2012 (has links)
No description available.
26

Separating Post-perceptual Processes From Auditory Awareness : An Electrophysiological Study With a No-response Task

Fjordstig, Andréas January 2019 (has links)
Two theories of consciousness have different ideas about when consciousness happens and what neural processes enable conscious experience. The recurrent processing theory supports an early onset of consciousness caused by recurring loops of information between sensory areas. Contrary to this belief, the global workspace theory claims that consciousness appears later, through global recurrent loops of information between sensory and higher order brain areas such as the visual cortex and frontoparietal areas. Electrophysiological studies have found an event-related negativity arising in primary visual areas around 200 ms that correlates to awareness. This activity suits the predictions of an early onset of consciousness made by the recurrent processing theory. It is followed by a later positive amplitude appearing around 400 ms. This activity is in line with predictions made by the global workspace theory. The current study transition from visual to auditory awareness research in order to find the neural correlates of consciousness in audition. A sound detection task with tones calibrated to each participants threshold value was used in the experiment and two electrophysiological measurements of auditory awareness were found. An auditory awareness negativity that appears around 200 ms after stimulus onset and a late positivity appearing around 400 ms. Researchers disagree about if these event-related potentials correlate with awareness or unrelated cognitive mechanisms. In order to solve this problem, the current experiment was devised to test if they were affected by response conditions. A no-response paradigm with reversed response conditions was used to separate pre- and post-conscious mechanisms from the auditory awareness negativity and the late positivity. Results showed that auditory awareness negativity was independent of response condition and thus free from post-perceptual processes. The late positivity amplitude seems to be dependent on response condition but the result was inconclusive.
27

What Facilitates Client Motivation for Change? : A critical look at self-determined behavior change

Fridner, Thomas January 2011 (has links)
Motivational Interviewing (MI) is a client-centered, directive approach for behavior change. Self-Determination Theory (SDT) is a theory of human motivation and self-determined growth. Both of these social-cognitive theories aim to explain motivation and health behavior change and have generated a lot of research on how to increase human motivation. However, MI lacks a definite theory on mechanisms of behavior change and SDT offers a theory of motivation based on extensive research on human interactions. This paper aims to critically look at facilitators of client motivation for behavior change in-session from a social-cognitive perspective on one hand, and neural correlates related to client behavior change on the other hand. MI and SDT somewhat similarly explain what most importantly determines client motivation for change in-session. However, SDT mainly focus on psychological needs such as fostering client autonomy, and MI focus on the therapeutic alliance and on generating client change talk in-session. Efforts to bridge the two methods aim at generating a clearer definition of motivation in MI, and a better framework of practice in SDT. Studies on neural correlates of behavior change support and challenge elements of both approaches, indicating the importance of autonomy and relatedness for motivating positive behavior change.
28

Moral cognition and its neural correlates : Possibilites for enhancement of moral cognition and behavior

Vidlund, Elin January 2018 (has links)
This essay aims to provide an overview of some key theories and frameworks regarding moral cognition and its neural correlates, in order to examine the possibilities of enhancement of moral cognition. Moral cognition arises from the functional integration of several distinct brain regions and networks. These neural systems correspond to different socioaffective abilities, such as empathy and compassion, as well as sociocognitive abilities, such as theory of mind. Due to this neural distinction, these moral abilities, behaviors, and emotions can be targeted and trained separately. Recent research suggests that training sociocognitive and socioaffective abilities increases cortical thickness in corresponding brain regions and networks, hence providing support for adult neural plasticity in relation to moral cognition. Increased cortical thickness also corresponds to enhanced performance in socioaffective and sociocognitive abilities. Training compassion and empathy induce enhanced abilities to pick up emotional cues, as well as strengthen the motivation to alleviate others’ distress. Practicing theory of mind allows for a better understanding of the perspective of others, which has been indicated to reduce biases between individuals or societal groups. Thus, enhanced moral cognition can contribute to an increase in consideration for those affected by our choices and behavior, which may yield more compassionate, just, and safe societies.
29

Does weather affect mental well-being neurologically?

Saldjoughi Tivander, Victoria January 2018 (has links)
Research on well-being is in its infancy and the term lacks a clear definition, yet it is an increasingly popular matter. The neurology underlying well-being is important in such research in order to understand what brain mechanisms are correlated with mental health. Even though objective measures such as brain imaging are increasingly used assessments in well-being and neuroscience studies, self-reports are widely used. Articles viewing such research often state that self-reports could be biased because the subjects may be affected by the weather the day of the self-report. No further explanations are however provided as to why or how those individuals would be affected by the weather, or by which weather conditions. The aim of this thesis is thus to find neurological explanations for how weather can affect well-being. Constituents of well-being will be reviewed together with brain bases of mental health in an attempt to find neural correlations of weather and well-being. How humans are affected by the weather is a limited research area and the findings are diverse on all aspects but the solar influence over the brain and mind. Man-made light was however found to be a substitute for the effect of sunlight on the brain. No strong relationship between weather and well-being were found based on existing literature. No significant neural correlations between mental well-being and different weather conditions was found either.
30

L’impulsivité en toxicomanie : un regard sur les mécanismes neuronaux de la rechute à la nicotine

Bourque, Josiane 08 1900 (has links)
Contexte : Jusqu’à 90% des fumeurs qui tentent d’arrêter de fumer vont rechuter dans l’année suivant la date d’arrêt. L’impulsivité, au même titre que le « craving », a démontré être un bon facteur de prédiction de la rechute tabagique. Ainsi, la présente étude visait à évaluer, à l’aide de la neuroimagerie fonctionnelle, l’influence de l’impulsivité sur les mécanismes neuronaux du « craving » de la cigarette. Parmi les régions cérébrales impliquées dans le « craving » de la nicotine, les cortex préfrontal dorsolatéral, orbitofrontal et cingulaire sont d’importantes structures dans les processus de contrôle de soi. Méthodes : 31 fumeurs chroniques ont passé une session de neuroimagerie durant laquelle ils devaient regarder des images appétitives de cigarettes et des images neutres. Ils ont ensuite dû inscrire le « craving » ressenti à la vue des images et répondre à un questionnaire portant sur les traits de personnalité de l’impulsivité (BIS-11). Résultats : Tel qu’attendu, le score d’impulsivité était positivement corrélé au « craving » rapporté par les participants à la vue d’images de cigarettes. Au niveau cérébral, plus les fumeurs présentaient de forts traits d’impulsivité, moins grande était l’activité du cortex cingulaire postérieur (CCP) durant le « craving ». Enfin, l’activité du CCP présentait une connectivité fonctionnelle négative avec l’insula, le cortex préfrontal dorsolatéral et le cortex cingulaire antérieur. Conclusions : Comme le CCP est le siège des processus de mentalisation et de référence à soi, nous suggérons que plus les fumeurs étaient impulsifs, moins ils prenaient conscience de leur état et moins ils en exerçaient un contrôle, donc plus ils ressentaient de forts « cravings ». En poussant plus loin, nos résultats mettent l’accent sur l’aspect identitaire (le soi, les mémoires autobiographiques) et l’aspect d’introspection en toxicomanie : deux avenues à explorer. / Background: 90% of cigarette smokers attempting to quit smoking relapse by one-year following their quit date. Impulsivity, as well as cue-induced cravings, have been shown to be good predictors of relapse for tobacco smoking; however, no study to date has examined their interaction and its neural substrates. The goal of this study was to determine the neural influence of trait impulsivity during functional imaging of cue-induced cigarette cravings. Among the brain regions involved in nicotine craving, the dorsolateral prefrontal cortex, the orbitofrontal as well as the cingulate cortex all play a significant role in self-control processes. Methods: Thirty-one chronic smokers passively viewed appetitive smoking-related and neutral images while being scanned. Participants also reported their level of craving and completed the BIS-11, a measure of trait impulsivity. Results: As hypothesized, we observed a significant positive relationship between impulsivity scores and reported craving. Impulsivity scores were negatively correlated with activity in the posterior cingulate cortex (PCC). The insula, dorsal anterior cingulate cortex and dorsolateral prefrontal cortex presented a negative connectivity with the PCC. Conclusions: Given that the PCC is involved in mentalization and self-relevant processing, it is possible that greater trait impulsivity in smokers is associated to a lower tendency to understand and use one’s mental and physical state to guide behavior. This may weaken their capacity for self-control and consequently, promotes more automatic and stronger cue-elicited smoking urges. Furthermore, our results highlight the important but undervalued role of identity (the self and autobiographic memories) and mindfulness in addiction.

Page generated in 0.0771 seconds