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No Tingles for You: An Investigation of the Auditory Stimulus Qualities that Elicit AVES (ASMR)Daniels, Aurelia January 2022 (has links)
Audiovisual elicitation of somatosensation (AVES), also more commonly known as autonomous sensory meridian response (ASMR), is a sensory phenomenon in which particular auditory and visual triggers give rise to a static-like physical sensation — usually originating around the back of the head/neck area — called tingles. Those who are susceptible to this type of response typically experience it in association with positive affect and relaxation. In the present study, 64 participants completed an online-experiment in which they rated their perceived tingle intensity and frequency for twelve 60-second video segments displaying AVES content. Each segment was shown to participants twice in a pseudorandomised order of presentation, once with the original audio and once with edited audio (modified by high- and low-pass filtering to make sounds appear more muffled and distant), resulting in a total of 24 trials per participant. Results indicated not only that participants who categorised themselves as experiencing AVES reported both more frequent and intense tingles than those who had reported not experiencing AVES, but also that unedited videos elicited more tingles in both groups as compared to the audio-edited versions of the same clips. These results support the conclusion that the proximal and crisp nature of popular auditory AVES triggers is a key factor of eliciting the tingle response, and that filtering out certain frequency ranges of the audio thus results in a less effective AVES trigger eliciting both a shorter duration and lower intensity of tingles.
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The Neural Correlates of Burnout: A Systematic ReviewFredin, Miranda January 2022 (has links)
Burnout is a condition that results from chronic work-related stress, and it is associated with impairments in cognitive and emotion-related functions, such as impaired executive functions and emotion regulation. This thesis aimed to conduct a systematic review of the neural correlates of burnout. The thesis investigates the following research question: do the neural correlates of burnout involve the same brain regions and/or functions as those implicated in the cognitive functions affected by burnout? The systematic literature search resulted in seven studies which studied either the functional, structural, or electrophysiological correlates of burnout. The results showed that burnout involves functional and structural alterations in regions involved in various higher-order cognitive functions. Structural findings indicate alterations in brain regions involved with emotion processing, memory and attention (i.e., medial prefrontal cortex, caudate, amygdala). Electrophysiological findings indicate differences in alpha power in burnout individuals compared to controls, suggesting that alpha power is reduced when burnout's specific symptoms (i.e., exhaustion) increase. Evident are also findings on functional differences in working memory (dorsolateral prefrontal cortex) and reduced functional connectivity between emotion processing areas (the amygdala and anterior cingulate cortex) and areas such as the motor cortex. The presented findings answer the research question. It can be concluded that the brain regions implicated in the cognitive functions affected by burnout resemble many of the regions affected in the neural correlates of burnout. Future studies should take into account the methodological issues of the existing studies.
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Delusions of body ownership : A systematic review of somatoparaphreniaJohansson, Robin January 2022 (has links)
Somatoparaphrenia (SP) is a disorder where patients deny ownership of their limb and display delusional ideas regarding it. In a review by Vallar and Ronchi (2009), they systematically reviewed the SP literature, and made several conclusions regarding the neural correlates of SP. The current review wanted to investigate whether the brain areas Vallar and Ronchi (2009) associated with SP were still supported today. This was done by systematically reviewing the literature containing lesion data on SP, and then comparing it (with the context of body ownership research) to the findings from Vallar and Ronchi (2009). The results showed extensive damage in the fronto-temporo-parietal regions (most notably the inferior parietal regions) and the underlying white matter. Considerable damage could also be seen at the subcortical level (especially in the insula and basal ganglia), together with extensive white matter damage, mostly in and around the internal capsule. Majority of the lesions were right hemisphere based. These results showed high correspondence with the findings from Vallar and Ronchi (2009). Same could be said when considering body ownership research, because the insula and the inferior parietal region are two areas that have been associated with our sense of body ownership. Although these results had some limitations, they overall contribute to a better understanding of the mechanisms behind both SP and body ownership. Future reviews on SP could try to distinguish between the mechanisms behind the delusional aspect of SP.
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Inhibitory control in adults with ADHDGard, Zoey January 2023 (has links)
Inhibitory control refers to a person’s ability to control responses and impulses. Deficits in inhibitory control have been found in the neurodevelopmental disorder of Attention deficit hyperactivity disorder (ADHD), though this has mainly been studied in children. This thesis is a systematic review of how inhibition is impacted in adults with ADHD and which neural correlates that are associated with inhibitory control. Only peer-reviewed original articles that used adults above the age of 18 were included. All articles used a between subject design, meaning healthy participants were compared to participants with ADHD. To measure inhibitory control, articles which used either the Stroop Task or Go/No-go task were examined. Nine articles were included in this systematic review. Through functional magnetic resonance imaging (fMRI) altered neural activation was seen in several brain regions, such as the dorsolateral prefrontal cortex, fronto-basal ganglia networks, anterior cingulate cortex, posterior cingulate cortex, parietal lobe and inferior frontal gyrus. Many of these regions have previously been linked to inhibitory control, while others hint at possible compensatory pathways for inhibition in ADHD. In summary, subtle impairments in inhibition networks appear to underlie the disorder all the way into adulthood.
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Multiband functional magnetic resonance imaging (fMRI) for functional connectivity assessmentsBjörnfot, Cecilia January 2018 (has links)
During resting state the brain exhibits synchronized activity within all major brain networks. Using blood oxygen level dependent (BOLD) resting state functional magnetic resonance imaging (fMRI) based detection it is possible to quantify the degree of correlation, connectivity, between regions of interest and assess information regarding the integrity of the inter-regional functional integration. A newly available multiband echo planar imaging (EPI) fMRI sequence allows for faster scan times which possibly allows us to better examine large-scale networks and increase the understanding of brain function/dysfunction. This thesis will assess how the newly developed sequence compares to a conventional EPI sequence for detecting resting state connectivity of canonical brain networks. The data acquisitions were made on a 3 Tesla scanner using a 32 channel head coil. The hypothesis was that the multiband sequence would produce a better result since it has faster sampling rate, thus more data points in its time-series to support the statistical analyses. Using Pearson’s linear correlation between the average time-series (approximately 12 minutes long) within a seed-region and all voxels contained in the image volume, correlation maps where created for each of the eight participants using data normalized to Montreal Neurological Institute (MNI) space. The resting state networks (RSN) were then found by performing a one sample T-test on group level. Six seed-coordinates, based on literature, where used revealing the the homotopic connections in anterior Hippocampus, Motor cortex, Dorsal attention, Visual and the Default mode network (DMN) as well for an anterior-posterior connection in the DMN. By comparing the maximum T-values within the regions for the RSN no systematic difference could be found between the multiband and conventional fMRI data. Further tests were conducted to evaluate if the sequences would differentiate in their results if the acquisition time was shortened, i.e shortening the time-series in the voxels. However no such difference could be established.Importantly, the results are specific to the 32 channel head coil used in the current study. Presumably recently available and improved coil designs could better exploit the multiband technique.
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Mind, body, and choice: A review of alexithymia and the somatic-marker hypothesisSnellman, Henrik January 2022 (has links)
This paper examined the claims postulated by the somatic marker hypothesis and compares those claims to the current evidence surrounding the neural basis of alexithymia. The results were then compared to see if they contradict or have a distinct localisation in the brain separate from those behavioural brain regions hypothesized by the somatic marker hypothesis. It was concluded that the somatic marker hypothesis and the neural basis for alexithymia share certain regions of interest, primarily the amygdala and insula, but also potentially the anterior cingulate cortex.
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The wandering mind on music : A review on mind-wandering and musicOlofsson, Simon January 2023 (has links)
It is well known that music can influence our emotions. Research on mind-wandering has revealed that our emotional state can influence the valence of thought content and the prevalence of mind-wandering. Recent behavioural studies have suggested that music can modulate mind-wandering. However, the neural mechanisms to support the claims are unknown. This thesis aim was to explore how music can modulate mind-wandering by reviewing functional neuroimaging studies on the topic. The findings suggest that music induces mind-wandering as it engages the default mode network in a similar fashion that resting does. Music-induced activity from the orbitofrontal cortex and the posterior cingulate cortex seems to be a good neural indicator for mind-wandering content that has a negative valence.
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Sense of Agency and Automation : A Systematic ReviewAlbutihe, Ismael January 2023 (has links)
Technological advancements have resulted in highly automated systems that are featured in many kinds of tools and devices, such as self-driving cars, autopilot in airplanes, and much more. Such systems have enabled tools to plan, decide, and act autonomously. This breakthrough resulted in a new manner of interacting with tools, known as "Human-Robot Joint Action" or "human-AI interaction," in which people and automated tools share control over the tasks that must be performed. However, little is known about the impact of such interactions on people and their sense of agency (SoA) as well as how much autonomy to grant to tools. As a result, the objective of this systematic review is to investigate and understand how automated tools affect human SoA, and if tools with different levels of automation affect our SoA differently. A search in two databases, Scopus, and MEDLINE EBSCO was conducted, and 8 articles were included. The findings suggest that the more automated the tool is, the less SoA participants experience, and that varied levels of automation may impact human SoA depending on the nature of the task. However, this topic is still in its infancy and more research is needed.
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Thumbs Down, Thumbs Down, Thumbs Down : Does the Feedback-Related Negativity (FRN) Habituate?Daniels, Aurelia January 2023 (has links)
The feedback-related negativity (FRN) is a negative event-related potential (ERP) component associated with the presentation of task feedback. The possibility that the FRN may habituate has been briefly mentioned in previous research (Garrido Chaves et al., 2020), but not yet been actively investigated. Thus, the current study is the first one to explicity investigate the possibility of short-term (across trials) and long-term (across blocks) habituation effects on the FRN. This was done by using electroencephalography (EEG) and a time-estimation paradigm during which participants were tasked with guessing the duration of one second. Following each estimate, participants were presented with either positive or negative visual feedback (however, only trials with negative feedback were included in the subsequent statistical analysis). It was hypothesized that mean FRN amplitude would decrease, i.e. habituate, upon increased exposure to negative feedback. Contrary to the expected effect, repeated-measures analyses of variance (ANOVA) and t-tests revealed a stong, significant sensitization effect of FRN mean amplitude in the short-term comparison. However, there appeared to be multiple confounds involved, which made these results ambigous and difficult to interpret. No significant results were found for the long-term comparison, although the ERP waveforms suggested that there might be a (non-significant) habituation effect. This effect may become significant provided a greater sample size. Replication with a greater sample size is thus required before any firm conclusions can be drawn.
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The Origin of the doppelgangers : A review of the neurological explanations of Capgras syndromeOrostica, Sandra, Thorsell, Per January 2024 (has links)
At its core, Capgras syndrome is the delusional belief that someone close to you has been replaced by an identical imposter. Capgras has historically been explained with Freudian psychodynamic theories concerning latent hostility and a sense of personal or professional inadequacy. There is now widespread consensus in the scientific community that Capgras syndrome can arise from brain lesions. Various hypotheses have been proposed to explain its mechanism. The mirror-image-of-prosopagnosia hypothesis posits a disruption of the dorsal visual pathway. Another hypothesis emphasizes the role of a single lesion affecting the functional connectivity of the retrosplenial cortex. Our analysis of 10 case studies reveals inconsistencies with these hypotheses, particularly in accounting for the diverse lesion locations observed in Capgras patients. Our findings suggest that Capgras syndrome likely stems from a multifactorial aetiology involving neurological and neuropsychiatric factors. Lesions may impact multiple areas associated with facial processing and belief evaluation, challenging the notion of a single lesion explanation.
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