Search results for "MMN"
showing 7 items of 37 documents
Pre-attentive change detection of emotional facial expressions : effects of depression and a short psychological intervention - and ERP study
2012
Tämän tutkimuksen tavoitteena oli tutkia aivojen esitietoista muutoksenhavaitsemiskykyä mittaamalla tapahtumasidonnaisia herätevastepotentiaaleja (ERP) elektroenkefalografiassa (EEG), käyttäen ärsyk-keenä emotionaalisia kasvonilmeitä. Tutkimuksessa verrattiin kahden ryhmän: masentuneiden sekä ei-masentuneiden - ERP vasteista. Lisäksi tutkimme psykologisen lyhyt intervention vaikutuksia koehen-kilöiden ERP vasteisiin. Tutkimuksessa käytettiin ärsykkeinä seitsemään universaalia kasvonilmettä, viidessä eri koeasetelmassa. Yhdessä koeasetelmassa kaikilla seitsemällä kasvonilmeelle oli yhtä suuri todennäköisyys esiintyä (p=0.14). Neljässä muussa koeasetelmassa käytettiin niin sanottua oddball pa…
Somatosensory mismatch response in young and elderly adults
2014
Aging is associated with cognitive decline and alterations in early perceptual processes. Studies in the auditory and visual sensory modalities have shown that the mismatch negativity [or the mismatch response (MMR)], an event-related potential (ERP) elicited by a deviant stimulus in a background of homogenous events, diminishes with aging and cognitive decline. However, the effects of aging on the somatosensory MMR (sMMR) are not known. In the current study, we recorded ERPs to electrical pulses to different fingers of the left hand in a passive oddball experiment in young (22–36 years) and elderly (66– 95 years) adults engaged in a visual task. The MMR was found to deviants as compared to…
Neural Responses to Musical Rhythm in Chinese Children With Reading Difficulties
2020
The perception of the musical rhythm has been suggested as one of the predicting factors for reading abilities. Several studies have demonstrated that children with reading difficulties (RD) show reduced neural sensitivity in musical rhythm perception. Despite this prior evidence, the association between music and reading in Chinese is still controversial. In the present study, we sought to answer the question of whether the musical rhythm perception of Chinese children with RD is intact or not, providing further clues on how reading and music might be interlinked across languages. Oddball paradigm was adapted for testing the difference of musical rhythm perception, including predictable an…
Auditory cortical and hippocampal-system mismatch responses to duration deviants in urethane-anesthetized rats
2013
Any change in the invariant aspects of the auditory environment is of potential importance. The human brain preattentively or automatically detects such changes. The mismatch negativity (MMN) of event-related potentials (ERPs) reflects this initial stage of auditory change detection. The origin of MMN is held to be cortical. The hippocampus is associated with a later generated P3a of ERPs reflecting involuntarily attention switches towards auditory changes that are high in magnitude. The evidence for this cortico-hippocampal dichotomy is scarce, however. To shed further light on this issue, auditory cortical and hippocampal-system (CA1, dentate gyrus, subiculum) local-field potentials were …
Ikääntymisen vaikutus visuaaliseen prosessointiin
2012
Tämän pro gradu -tutkielman tarkoituksena oli selvittää aivojen automaattisen muutoksen havaitsemisjärjestelmän toimintaa visuaalisessa järjestelmässä tapahtumasidonnaisten herätevasteiden (ERP) avulla. Lisäksi tutkielmassa haluttiin selvittää ikääntymisen mahdollisia vaikutuksia tämän järjestelmän toimintaan vertailemalla toisiinsa terveiden nuorten aikuisten (n=19, 22-27 vuotta) ja ikääntyneiden (n=10, 69-95 vuotta) visuaalisia herätevasteita N2- ja P3 -komponenteissa. Visuaalinen herätevaste, jota tutkielmassa tarkasteltiin, oli poikkeavuusnegatiivisuus (mismatch negativity, MMN). Tutkielmassa ERP:t rekisteröitiin elektroenkefalografialla (EEG) ja passiivisen oddball -paradigman avulla. …
Brain's capacity to detect abstract regularities from visual stimuli under different attentive conditions- an ERP study
2010
Many previous studies have applied oddball paradigm to study change detection. Although changes within single features have been investigated a lot, the changes in multiple feature conjunctions have not. The aim of our study was to investigate with event-related potentials by applying oddball paradigm, whether the brain can detect abstract regularities in visual stimulus stream when two different features are combined - semantic meaning and color. Participants were shown adjective words written in red and blue print in quasi-random order on a computer screen. In an oddball paradigm, 90 % of the words (‘standard’) followed the rule “words printed in red have a negative meaning and the words …