• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 1
  • 1
  • Tagged with
  • 16
  • 16
  • 14
  • 7
  • 6
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 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.
11

An fMRI comparison between younger and older adults of neural activity associated with recognition of familiar melodies

Sikka, Ritu 16 September 2013 (has links)
We investigated age-related differences in neural activation associated with recognition of familiar melodies, a process that requires retrieval from musical semantic memory and leads to a feeling of familiarity. We used sparse sampling fMRI to determine the neural correlates of melody processing and familiarity by comparing activation when listening to melodies versus signal-correlated noise, and to familiar versus unfamiliar melodies, respectively. Overall, activity in the bilateral superior temporal gyrus correlated well with melody processing. Familiarity was associated with several frontal regions (bilateral inferior frontal gyrus, superior frontal gyrus, and precentral gyrus; left insular cortex), right superior temporal gyrus; left supramarginal gyrus and cingulate gyrus; bilateral putamen and thalamus; cerebellum and brainstem. No significant differences were found between younger and older adults for either melody processing or familiarity based activation. Assessment of familiarity-related group differences using less stringent criteria identified plausible areas; greater activation was seen bilaterally in the superior temporal gyrus in younger adults and in some left parietal regions in older adults. This study adds to the knowledge of musical semantic memory with results based on a large sample (N = 40) that includes older adults. Our findings for activation associated with melody processing and familiarity support some, but not all, previous results of related studies. We were unable to find conclusive evidence of age-related differences in neural correlates of musical semantic memory, while also being the first study (to the best of our knowledge) to search for these differences. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-09-16 12:38:10.757
12

An fMRI comparison between younger and older adults of neural activity associated with recognition of familiar melodies

Sikka, Ritu 16 September 2013 (has links)
We investigated age-related differences in neural activation associated with recognition of familiar melodies, a process that requires retrieval from musical semantic memory and leads to a feeling of familiarity. We used sparse sampling fMRI to determine the neural correlates of melody processing and familiarity by comparing activation when listening to melodies versus signal-correlated noise, and to familiar versus unfamiliar melodies, respectively. Overall, activity in the bilateral superior temporal gyrus correlated well with melody processing. Familiarity was associated with several frontal regions (bilateral inferior frontal gyrus, superior frontal gyrus, and precentral gyrus; left insular cortex), right superior temporal gyrus; left supramarginal gyrus and cingulate gyrus; bilateral putamen and thalamus; cerebellum and brainstem. No significant differences were found between younger and older adults for either melody processing or familiarity based activation. Assessment of familiarity-related group differences using less stringent criteria identified plausible areas; greater activation was seen bilaterally in the superior temporal gyrus in younger adults and in some left parietal regions in older adults. This study adds to the knowledge of musical semantic memory with results based on a large sample (N = 40) that includes older adults. Our findings for activation associated with melody processing and familiarity support some, but not all, previous results of related studies. We were unable to find conclusive evidence of age-related differences in neural correlates of musical semantic memory, while also being the first study (to the best of our knowledge) to search for these differences. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-09-16 12:38:10.757
13

Funktionelle Konnektivität der Substantia nigra in einem generellen Aufmerksamkeitstest bei idiopathischem Stottern – eine klinische Studie mittels funktioneller Magnetresonanztomografie / Functional connectivity of the substantia nigra in a continuous performance test in persistent developmental stuttering – a clinical study using functional magnetic resonance tomography

Metzger, Friederike Luise 10 November 2020 (has links)
No description available.
14

fMRI exploration of the cerebral mechanisms of the perception of pain in others via facial expression

Budell, Lesley 06 1900 (has links)
No description available.
15

Resting state brain networks in young people with familial risk for psychosis

Jukuri, T. (Tuomas) 16 February 2016 (has links)
Abstract Neuropsychiatric illnesses usually become overtly manifest in adolescence and early adulthood. A critical long-term aim is to be able to prevent the development of such illnesses, which requires instruments to identify subjects at high risk of illness and to offer them effective interventions. There is an indisputable need for more sophisticated methods to enable more precise detection of adolescents and young adults who are at high risk of developing psychosis. Abnormal function in brain networks has been reported in people with schizophrenia and other psychotic disorders. Similar abnormalities have been found also in people at risk for developing psychosis, but it is not known whether this applies also to spontaneous resting state activity in young people with a familial risk for psychosis. We conducted resting-state functional MRI (R-fMRI) in 72 (29 male) young adults with a history of psychosis in one or both parents (FR) but without psychosis themselves, and 72 (29 male) similarly healthy control subjects without familial risk for psychosis. Both groups in the Oulu Brain and Mind study were drawn from the Northern Finland Birth Cohort 1986. All volunteers were 20–25 years old. Parental psychosis was established using the Care Register for Health Care. R-fMRI data was pre-processed using independent component analysis (ICA). A dual regression technique was used to detect between-group differences with p < 0.05 threshold corrected for multiple comparisons at voxel level. FR subjects demonstrated significantly decreased activity compared to control subjects in the default mode network and in the central executive network and increased activity in the cerebellum. The findings clarify previously controversial literature on the subject. The finding suggests that abnormal activity in these brain networks in rest may be associated with increased vulnerability to psychosis. The findings maybe helpful in developing more precise methods for detecting young people at highest risk for developing psychosis. / Tiivistelmä Psykoottisiin häiriöihin sairastutaan yleensä nuoruudessa tai varhaisaikuisuudessa. Psykoositutkimuksen tavoitteena on löytää uusia menetelmiä, joiden avulla kyettäisiin tunnistamaan suurimmassa psykoosiriskissä olevat nuoret, jotta heille voitaisiin tarjota sairautta ennaltaehkäiseviä hoitokeinoja. Skitsofreniaan ja muihin psykoottisiin häiriöihin sairastuneilla on havaittu aivotoiminnan poikkeavuuksia. Samankaltaisia aivotoiminnan poikkeavuuksia on havaittu myös nuorilla, jotka ovat vaarassa sairastua psykoosiin. Toistaiseksi on ollut epäselvää, onko psykoosiin sairastuneiden henkilöiden lapsilla aivohermoverkkojen toiminnan poikkeavuuksia lepotilassa. Suoritimme aivojen lepotilan MRI-tutkimuksen (R-fMRI) 72:lle (29 miestä) nuorelle aikuiselle, joiden jompikumpi vanhempi oli sairastunut psykoosin sekä 72:lle (29 miestä) nuorelle aikuiselle, joiden vanhemmat eivät olleet sairastaneet psykoosia. Molemmat tutkimusryhmät tässä Oulu Brain and Mind -tutkimuksessa olivat Pohjois-Suomen 1986 syntymäkohortin jäseniä. Tutkittavat olivat 20–25 vuoden iässä. Lepotilan toiminnallinen magneettikuvaus suoritettiin 1.5 Teslan Siemensin magneettikuvantamislaitteella. Tutkimuskohteiksi valittiin lepotilan toiminnallinen aivohermoverkko, toiminnan ohjauksesta vastaava aivohermoverkko ja pikkuaivot. Kuvantamisdataan sovellettiin itsenäisten komponenttien analyysia aivohermoverkkojen määrittämistä varten. Ryhmien välisen eron havaitsemiseen käytettiin ei-parametristä permutaatiotestiä, joka kynnystettiin tilastollisesti merkitsevään tasoon (p < 0.05). Lepotilan oletushermoverkossa ja toiminnanohjauksesta vastaavassa aivohermoverkoissa havaittiin vähäisempää aktiivisuutta ja pikkuaivoissa kohonnutta aktiivisuutta perinnöllisessä psykoosiriskissä olevilla nuorilla aikuisilla verrattuna verrokkeihin. Tutkimustulokset selkeyttivät aiempaa ristiriitaista kirjallisuutta tutkimusaiheesta. Tutkimuksessa havaittujen aivoalueiden poikkeava toiminta lepotilassa voi liittyä kohonneeseen psykoosin puhkeamisriskiin. Tutkimuslöydösten avulla voidaan todennäköisesti edesauttaa parempien kuvantamismenetelmien kehittämistä suurimmassa psykoosiriskissä olevien nuorten tunnistamiseen.
16

Responses in left inferior frontal gyrus are altered for speech-in-noise processing, but not for clear speech in autism

Schelinski, Stefanie, Kriegstein, Katharina von 04 June 2024 (has links)
Introduction Autistic individuals often have difficulties with recognizing what another person is saying in noisy conditions such as in a crowded classroom or a restaurant. The underlying neural mechanisms of this speech perception difficulty are unclear. In typically developed individuals, three cerebral cortex regions are particularly related to speech-in-noise perception: the left inferior frontal gyrus (IFG), the right insula, and the left inferior parietal lobule (IPL). Here, we tested whether responses in these cerebral cortex regions are altered in speech-in-noise perception in autism. Methods Seventeen autistic adults and 17 typically developed controls (matched pairwise on age, sex, and IQ) performed an auditory-only speech recognition task during functional magnetic resonance imaging (fMRI). Speech was presented either with noise (noise condition) or without noise (no noise condition, i.e., clear speech). Results In the left IFG, blood-oxygenation-level-dependent (BOLD) responses were higher in the control compared to the autism group for recognizing speech-in-noise compared to clear speech. For this contrast, both groups had similar response magnitudes in the right insula and left IPL. Additionally, we replicated previous findings that BOLD responses in speech-related and auditory brain regions (including bilateral superior temporal sulcus and Heschl's gyrus) for clear speech were similar in both groups and that voice identity recognition was impaired for clear and noisy speech in autism. Discussion Our findings show that in autism, the processing of speech is particularly reduced under noisy conditions in the left IFG—a dysfunction that might be important in explaining restricted speech comprehension in noisy environments.

Page generated in 0.0532 seconds