Search results for "aivotutkimus"

Aerobic fitness, but not physical activity, is associated with grey matter volume in adolescents.

2019

Higher levels of aerobic fitness and physical activity are linked to beneficial effects on brain health, especially in older adults. The generalizability of these earlier results to young individuals is not straightforward, because physiological responses (such as cardiovascular responses) to exercise may depend on age. Earlier studies have mostly focused on the effects of either physical activity or aerobic fitness on the brain. Yet, while physical activity indicates the amount of activity, aerobic fitness is an adaptive state or attribute that an individual has or achieves. Here, by measuring both physical activity and aerobic fitness in the same study, we aimed to differentiate the assoc…

Spatiaalisen ikkunoinnin ja sokean signaalinerottelun menetelmien hyödyntäminen MEG-aineiston analysoinnissa

2018

Sokean signaalinerottelun menetelmät ovat käyttökelpoisia magnetoenkefalografilla mitattujen aivomagneettikäyrien analysoinnissa. Sokean signaalinerottelun menetelmien avulla voidaan selvittää, mistä aivoaktivaatio on peräisin ja millaisiin toimintoihin aktivaatio voidaan yhdistää. MEG-aineiston ajallinen tarkkuus on hyvä, joten lyhytkin mittausaika tuottaa hyvin suuren aineiston. Suuren aineiston tuottamat laskennalliset ongelmat voidaan kiertää ikkunoimalla MEG-aineisto aika- tai tilasuunnassa. Aineiston ikkunointia on sovellettu aiemmissa tutkimuksissa toiminnallisen magneettikuvauksen aineistoon, jolloin ikkunointi on tehty aikasuunnassa. Tässä tutkielmassa ikkunointia sovellettiin MEG-…

Millaista tietoa aivokuvantamisella saadaan ja millaista ei?

2016

Ten-year resistance training background modulates somatosensory P3 cognitive brain resonse in older men : a magnetoencephalograpy study

2020

The brain electrophysiological component P3, associated with good cognitive abilities, deteriorates during healthy aging. Both cognitive functions and P3 component amplitude respond positively to exercise, but the effects of resistance training on P3 are much less studied. Short-term resistance training interventions in older adults indicate modulation towards larger P3 amplitude, but this association has not been studied with a longitudinal study design. We investigated magnetoencephalographically recorded P3 (P3m) in a unique study design of nine aged men (mean age 77.7 y) with quasi-supervised resistance training background over a 10-year period and eight controls of similar age (mean ag…

Event-related potentials to task-irrelevant sad faces as a state marker of depression

2018

Negative bias in face processing has been demonstrated in depression, but there are no longitudinal investigations of negative bias in symptom reduction. We recorded event-related potentials (P1 and N170) to task-irrelevant facial expressions in depressed participants who were later provided with a psychological intervention and in never depressed control participants. Follow-up measurements were conducted for the depressed group two and 39 months later. Negative bias was found specifically in the depression group, and was demonstrated as enlarged P1 amplitude to sad faces, which normalized in the follow-up measurements when the participants had fewer symptoms. Because the P1 amplitude reco…

Longitudinal interactions between brain and cognitive measures on reading development from 6 months to 14 years

2017

Dyslexia is a neurobiological disorder impairing learning to read. Brain responses of infants at genetic risk for dyslexia are abnormal already at birth, and associations from infant speech perception to preschool cognitive skills and reading in early school years have been documented, but there are no studies showing predicting power until adolescence. Here we show that in at-risk infants, brain activation to pseudowords at left hemisphere predicts 44% of reading speed at 14 years, and even improves the prediction after taking into account neurocognitive preschool measures of letter naming, phonology, and verbal short-term memory. The association between infant brain responses and reading …

Rapid changes in brain activity during learning of grapheme-phoneme associations in adults

2020

ABSTRACTLearning to associate written letters with speech sounds is crucial for the initial phase of acquiring reading skills. However, little is known about the cortical reorganization for supporting letter-speech sound learning, particularly the brain dynamics during the learning of grapheme-phoneme associations. In the present study, we trained 30 Finnish participants (mean age: 24.33 years, SD: 3.50 years) to associate novel foreign letters with familiar Finnish speech sounds on two consecutive days (first day ~ 50 minutes; second day ~ 25 minutes), while neural activity was measured using magnetoencephalography (MEG). Two sets of audiovisual stimuli were used for the training in which …

Anodal tDCS over the left prefrontal cortex does not cause clinically significant changes in circulating metabolites

2020

Background: Transcranial direct current stimulation (tDCS), a putative treatment for depression, has been proposed to affect peripheral metabolism. Metabolic products from brain tissue may also cross the blood–brain barrier, reflecting the conditions in the brain. However, there are no previous data regarding the effect of tDCS on circulating metabolites.\ud Objective: To determine whether five daily sessions of tDCS modulate peripheral metabolites in healthy adult men.\ud Methods: This double-blind, randomized controlled trial involved 79 healthy males (aged 20–40 years) divided into two groups, one receiving tDCS (2 mA) and the other sham stimulated. The anode was placed over the left dor…

Early auditory processing in musicians and dancers during a contemporary dance piece

2016

AbstractThe neural responses to simple tones and short sound sequences have been studied extensively. However, in reality the sounds surrounding us are spectrally and temporally complex, dynamic and overlapping. Thus, research using natural sounds is crucial in understanding the operation of the brain in its natural environment. Music is an excellent example of natural stimulation which, in addition to sensory responses, elicits vast cognitive and emotional processes in the brain. Here we show that the preattentive P50 response evoked by rapid increases in timbral brightness during continuous music is enhanced in dancers when compared to musicians and laymen. In dance, fast changes in brigh…

A Deep Learning Model for Automatic Sleep Scoring using Multimodality Time Series

2021

Sleep scoring is a fundamental but time-consuming process in any sleep laboratory. Automatic sleep scoring is crucial and urgent to help address the increasing unmet need for sleep research. Therefore, this paper aims to develop an end-to-end deep learning architecture using raw polysomnographic recordings to automate sleep scoring. The proposed model adopts two-dimensional convolutional neural networks (2D-CNN) to automatically learn features from multi-modality signals, together with a "squeeze and excitation" block for recalibrating channel-wise feature responses. The learnt representations are finally fed to a softmax classifier to generate predictions for each sleep stage. The model pe…