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Avkodning, Läshastighet, Motivation & Läsvanor hos Vuxna : En observations- och korrelationsstudie av LäsKedjor-2, DLS Läshastighet, samt SjälvrapportLånghammar, Magdalena January 2018 (has links)
I denna studie undersöktes avkodningsförmåga, läshastighet, motivationsgrad och läsvanor hos 40 vuxna personer, som grupperades utifrån kön, ålder och utbildningsnivå. För att testa avkodningsförmåga användes LäsKedjor-2 (Jacobsson, Läskedjor-2, 2014), för att testa läshastighet användes DLS Läshastighet (Järpsten, DLS läshastighet, 2002) och för att skatta motivationsgrad och läsvanor skapades Självrapport av uppsatsförfattaren själv. Testresultaten omräknades till staninevärden. Ingen signifikant skillnad uppmättes beträffande kön eller ålder på något av testerna. Signifikans beträffande utbildningsnivå uppmättes på alla test utom på det första deltestet i LäsKedjor-2, Bokstavskedjor, samt på läsvanor i Självrapport. Det befanns vara stark korrelation (r=0,62) mellan höga resultat på läshastighet och hög motivationsgrad relaterad till läsning. / In this study decoding skill and reading speed was tested together with level of reading motivation and reading habits in 40 adults, grouped by gender, age and educational level. To test decoding skill LäsKedjor-2 (Jacobsson, Läskedjor-2, 2014) was used, to test reading speed DLS Läshastighet (Järpsten, DLS läshastighet, 2002) was used, and to test level of reading motivation and reading habits the self-assessment questionnaire Självrapport was constructed by the author. The results were transformed into a staninescale. No significant difference was observed regarding gender or age in any of the tests. Significance regarding educational level was observed in all tests except the first part of LäsKedjor-2, Bokstavskedjor, and in reading habits in Självrapport. A strong correlation (r=0,62) was evident in high results in reading speed and high level of reading motivation.
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Prediction of treatment response in Social Anxiety Disorder, what does the brain tell us that questionnaires do not? : Using brain activity related to self- and other-referential criticism to predict treatment response to Internet- delivered Cognitive Behaviour Therapy for Social Anxiety DisorderIsacsson, Nils, Kolbeinsson, Örn January 2016 (has links)
Predicting who will benefit from what in the treatment of psychiatric disorders is incremental to future development of psychological treatments. In the current study functional magnetic resonance imaging (fMRI) data from participants with social anxiety disorder (SAD) was used to elucidate whether neural responses to negative evaluation could predict treatment response in SAD. Nine weeks prior to Internet- delivered Cognitive Behaviour Therapy (ICBT) onset, participants viewed negative social stimuli directed either at themselves or an significant other during fMRI scanning. Regression analyses including the differential activations for other-referential criticism in contrast to self-referential criticism in the posterior mid cingulate cortex (pMCC) and the lingual gyrus (LG) predicted 34% of treatment change as measured by residual gain scores on the Liebowitz Social Anxiety Scale Self-Report (LSAS-SR) in our sample. The final regression model, combining these measures with behavioural measures, which by themselves explained 27% of the variance, resulted in a model explaining 50% of the variance regarding treatment response. This lends additional support to the notion that further elucidating the neurobiological underpinnings of core processes in SAD, as well as the neural correlates of treatment response to CBT, would be of great value in predicting treatment outcome.
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Circadian Rhythms in the Brain - A first stepDadi, Kamalaker Reddy January 2013 (has links)
Circadian Rhythms (CR) are driven by a biological clock called as suprachiasmaticnucleus (SCN), located in a brain region called the hypothalamus. These rhythms are very much necessary in maintaining the sleep and wake cycle at appropriate times in a day. As a starting step towards non-invasive investigation of CR, aim is to study changes in the physiological processes of two Regions of Interest (ROI), the hypothalamus and the visual cortex. This was studied using a functional Magnetic Resonance Imaging (fMRI) technique to investigate for any changes or differences in the Blood Oxygen Level Dependent (BOLD)signals extracted from the ROI during a visual stimulation. We acquired and processed fMRI data to extract BOLD signals from ROI and the extracted signals are again further used to study the correlation with the experimental ON-OFF design paradigm. The extracted BOLD signals varied a lot between the two specified brain regions within the same subject and between three types of fMRI data. These variations were found in terms of number of activated voxels and also Signal to Noise ratio(SNR) level present in the signals. The number of activated voxels and SNR werehigh in visual cortex whereas low number of activated voxels and low SNR were found in hypothalamus. The correlation between BOLD responses from primaryvisual cortex were shown as positive with the experimental stimulation whereas BOLD responses extracted from hypothalamus have shown a negative correlation in time with the experimental stimulation. As a start up of the project, these BOLD responses can provide references for a future use in research studies, especially to further study about change in phase of the BOLD signal extracted exactly from the SCN. These phase responses can then be used to study physiological processing in subjects affected by sleep disorders.
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Validation of a transgenic mouse line with knockdown of mGluR5 selectively in dopamine D1receptor expressing neuronsNasr Esfahani, Ali January 2010 (has links)
One of the main difficulties of addiction treatment is the high risk of relapse even after a longabstinence and fully detoxification. Therefore, discovering the underlying molecular principlesof relapse is essential. The metabotropic glutamate receptor, mGluR5, is considered to beinvolved in this aspect. One of the brain structures expressing mGluR5 is the striatum, an areawith well-established role in addiction which is largely composed of medium-sized spinyneurons (MSNs). These neurons are basically divided into two major subpopulationscharacterized based on their projections and protein properties. It is known that the mGluR5receptor is expressed on both subpopulations of MSNs. Consequently, it can be used to establishthe proportional contribution of each of MSNs subpopulations in relapse to addiction. In ourconstellation, we have generated a mouse line designed to have a selective mGluR5 knock-downin one of these subpopulations – the dopamine D1 receptor (D1R) expressing neurons. It hashowever been unclear if the expression of the transgene is indeed limited to only D1R-expressingneurons. By immunofluorescence technique, I here show that the construct is expressed only inMSNs and is restricted to the D1R-expressing cell population in the striatum. Thus the transgenicmouse line is a good tool for the study of mGluR5 selectively in D1R expressing neurons.
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Event-related potential correlates of visual consciousness : a review of theories and empirical studiesKastrati, Granit January 2012 (has links)
Two influential theories of consciousness disagree about if consciousness initially arises along the occipitotemporal cortex to later engage frontoparietal regions and attentional mechanisms, or if it necessarily requires the latter. Consequently, different predictions are made about the temporal emergence of consciousness. The event-related potential (ERP) technique can be used to resolve the issue. It can temporally track neural activity of consciously perceived stimuli relative to stimuli bypassing consciousness. This essay describes the two theories and reviews ERP studies on visual consciousness and its relationship to attention. Three ERP correlates of consciousness have been proposed. The question is if they should be interpreted as supporting the one or the other theory. Most plausibly, visual consciousness arises along occipitotemporal regions and later incorporates frontal areas engaging higher cognitive functions. Importantly it seems that consciousness cannot arise without spatial attention/parietal regions.
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Measures of Working Memory, Motivation, and Time PerceptionLabbé, Daniel January 2012 (has links)
Recent studies have indicated a further need to investigate the role of motivation in workingmemory (WM) training and that time perception affects motivation. We addressed whethersubjectively perceived time on task in reference to objective time on task could serve as animplicit measure of motivation, while controlling for individual differences in timeperception. Here, the relationship between different measures of time perception, WM, andmotivation was explored in healthy children. Fifty children in three natural groups (ages: 6-7,8-9, 10-11) at a Swedish school participated. WM scores changed with age as expected.However, the absence of correlations between WM performance and intrinsic motivationwere inconsistent with previous findings, presumably due to the low statistical sensitivity.Nevertheless, time perception accuracy (r=0.318, p=0.043) and state motivation (r=0.434,p=0.005) correlated with performance on task interference, but not WM. With somereservations due to low sensitivity, time perception accuracy appears to be linked tocoordinative capacity required for shifting attention, but to a lesser degree sequential working memory capacity.
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CORTICAL PHASE SYNCHRONISATION MEDIATES NATURAL FACE-SPEECH PERCEPTIONBlomberg, Rina January 2015 (has links)
It is a challenging task for researchers to determine how the brain solves multisensory perception, and the neural mechanisms involved remain subject to theoretical conjecture. According to a hypothesised cortical model for natural audiovisual stimulation, phase synchronised communications between participating brain regions play a mechanistic role in natural audiovisual perception. The purpose of this study was to test the hypothesis by investigating oscillatory dynamics from ongoing EEG recordings whilst participants passively viewed ecologically realistic face-speech interactions in film. Lagged-phase synchronisation measures were computed for conditions of eye-closed rest (REST), speech-only (auditory-only, A), face-only (visual-only, V) and face-speech (audio-visual, AV) stimulation. Statistical contrasts examined AV > REST, AV > A, AV > V and AV-REST > sum(A,V)-REST effects. Results indicated that cross-communications between the frontal lobes, intraparietal associative areas and primary auditory and occipital cortices are specifically enhanced during natural face-speech perception and that phase synchronisation mediates the functional exchange of information associated with face-speech processing between both sensory and associative regions in both hemispheres. Furthermore, phase synchronisation between cortical regions was modulated in parallel within multiple frequency bands.
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Theories of Nightmares in Cognitive Neuroscience and PsychologyChamorro, Emilia January 2015 (has links)
Dreaming is a complex, multimodal and sequentially organized model of the waking world (Metzinger, 2003). Nightmares are a category of dreams involving threatening scenarios, anxiety and other negative emotions (Hartmann, 1998; Nielsen & Levin, 2007). Dreams and nightmares are explored in this present thesis in the light of psychology and modern cognitive neuroscience as to their nature, function and neural correlates. The three main dream theories and their leading investigations are reviewed to evaluate their evidence and overall explanatory power to account for the function of dreams and nightmares. Random Activation Theories (RATs) claim dreams are biological epiphenomena and by-products of sleep underlying mechanisms (Crick & Mitchison, 1983; Flanagan, 1995, 2000a, 2000b, Hobson & McCarley, 1997). Mood regulation theories consider that the psychological function of dreams is to regulate mood and help with the adaptation of individuals to their current environment such as solving daily concerns and recovery after trauma exposure (Hartmann, 1996; Levin, 1998; Stickgold, 2008; Kramer, 1991a, 1991b, 2014). Threat Simulation Theories of dreams present the evolutionary function for dreaming as a simulating off-line model of the world used to rehearse threatening events encountered in the human ancestral environment (Revonsuo, 2000a). With the threat-simulation system, threats were likely to be recognized and avoidance skills developed to guarantee reproductive success. TST consider nightmares to reflect the threat-simulation system fully activated (Revonsuo, 2000a). Supported by a robust body of evidence TST is concluded to be the most plausible theory at the moment to account as a theoretical explanation of dreams and nightmares
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The Role of Vision in Attributing the Sense of Part- and Full-Body Ownership During Anomalous ConditionsSavallampi, Mattias January 2015 (has links)
Our bodies are arguably one of the most intimate things we will ever know. But the comfort of our own physical boundaries can be altered in various ways. In this analysis, we will look at how vision contributes to the sense of owning a body by analysing six abnormal conditions: the rubber hand illusion, phantom limbs, somatoparaphrenia, the body-swap illusion, out-of-body experiences, and heautoscopy. Examinations of these experimental or pathological conditions has granted a greater understanding of body-ownership. It was discovered that vision plays different modulatory roles, being more intricately involved in full-body ownership than in part-body ownership. Vision appears to be highly connected to self-location and first-person perspective, which both are contributing factors in projecting the sense of ownership to an external location. In part-body ownership, however, vision can be overruled by other senses, such as proprioception. Though it is still able to contribute to the illusion of projecting ownership and proprioceptive displacement to a rubber hand.
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United in Diversity : A Physiological and Molecular Characterization of Subpopulations in the Basal Ganglia CircuitryViereckel, Thomas January 2017 (has links)
The Basal Ganglia consist of a number of different nuclei that form a diverse circuitry of GABAergic, dopaminergic and glutamatergic neurons. This complex network is further organized in subcircuits that govern limbic and motor functions in humans and other vertebrates. Due to the interconnection of the individual structures, dysfunction in one area or cell population can affect the entire network, leading to synaptic and molecular alterations in the circuitry as a whole. The studies in this doctoral thesis aimed at characterizing restricted subpopulations of neurons in the Basal Ganglia circuitry and their importance in the wider function of the network. To this end, we identified subpopulations of neurons in the subthalamic nucleus (STN), substantia nigra (SN) and ventral tegmental area (VTA), characterized their molecular profile and investigated their physiological role in the circuitry. Within the mouse STN, reduction of glutamatergic neurotransmission in a subpopulation expressing Paired-like homeodomain transcription factor 2 (Pitx2) led to structural alterations in the nucleus as well as biochemical alterations of the dopaminergic system in the Nucleus accumbens (NAc) and changes in reward-related behavior. In the ventral midbrain, we identified and characterized novel marker genes selective to the VTA or SN. Of these, transient receptor potential cation channel subfamily V member 1 (TrpV1) marks a population of mainly glutamatergic neurons in the VTA which project to the NAc, while gastrin releasing peptide (Grp) is expressed in a population of dopaminergic neurons neuroprotected in Parkinson's disease. Furthermore, we discovered that disruption of glutamatergic co-release of dopaminergic neurons expressing dopamine transporter (DAT), diminishes fast EPSCs and glutamate release but does not affect the acquisition of reward-related behavioral tasks. To selectively quantify glutamate release from specific subpopulations, we devised a technique combining glutamate-amperometry and optogenetics. This was used to measure glutamate released from Pitx2-expressing synaptic terminals in the Globus pallidus as well as DAT- or TrpV1-expressing terminals in the NAc. In summary, this doctoral thesis has furthered understanding of the function and importance of specific subpopulations within the Basal Ganglia circuitry and provides a novel means to investigate glutamate in the intact rodent brain within clearly defined, restricted cell populations.
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