Search results for "Negativity"

Kuulotiedon käsittely 5-6-vuotiailla : kuulovasteet, niiden paikantaminen ja yhteys käyttäytymistason testien tuloksiin

2011

Tutkimuksen aiheena oli 5—6-vuotiaiden lasten kuulotiedon käsittely ja sen kehittyminen. Tutkit-tavina oli 25 tyypillisesti kehittynyttä lasta: 13 tyttöä ja 12 poikaa. 5-vuotiaita oli yhdeksän, 6-vuotiaita oli 16. Tutkittavat oli rekrytoitu Jyväskylästä ja sen lähialueilta Väestörekisterikeskukselta saatujen tietojen pohjalta. Tutkimuksessa tehtiin sekä EEG-mittaus että käyttäytymistason testejä. EEG-mittauksessa käytettiin ns. oddball-asetelmaa, jossa taajuudeltaan 500 Hz:n siniäänen seassa soitettiin poikkeavana ärsykkeenä 425 Hz:n siniääntä. Käyttäytymistason testejä oli kaksi: Ensimmäisessä tutkittavien piti kuunnella kolmen siniäänen joukosta, mikä äänistä oli taajuudeltaan korkeampi k…

Hippocampal event-related potentials to pitch deviances in an auditory oddball situation in the cat: experiment I.

1995

Hippocampal event-related potentials (ERP) in the areas CA1, CA3, and dentate fascia (Df) were recorded in cats during an oddball situation when pitch deviant tones occurred in a series of standard tones. When difference waves were calculated by subtracting ERPs to the standard tones from those to the deviant tones, no clear N40d, corresponding to a cat analogue of the human mismatch negativity (MMN) observed in earlier studies, could be detected. Instead, a prominent later negativity (N130d) was observed. A possible extra-hippocampal source of the process reflected by the MMN-like negativity, and a relation between an orienting response (OR) and the N130d are discussed.

Music training enhances rapid neural plasticity of N1 and P2 source activation for unattended sounds

2012

Neurocognitive studies have demonstrated that long-term music training enhances the processing of unattended sounds. It is not clear, however, whether music training also modulates rapid (within tens of minutes) neural plasticity for sound encoding. To study this phenomenon, we examined whether adult musicians display enhanced rapid neural plasticity compared to non-musicians. More specifically, we compared the modulation of P1, N1, and P2 responses to standard sounds between four unattended passive blocks. Among the standard sounds, infrequently presented deviant sounds were presented (the so-called oddball paradigm). In the middle of the experiment (after two blocks), an active task was p…

Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability

2012

Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…

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 …

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 …

Editorial : Visual mismatch negativity (vMMN) : A unique tool in investigating automatic processing

2022

Event-related potentials to task-irrelevant changes in facial expressions

2009

Abstract Background Numerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features. Methods Event-related potentials (ERPs) were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9) were rarely replaced by pictures with a fearful ('fearful deviant', p = .05) or happy ('happy deviant', p = .05) expression. Importantly, facial identities changed from picture to pi…

Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability

2011

Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…

Long-term physical activity modifies automatic visual processing

2019

Electrophysiologically registered visual mismatch negativity (vMMN) is known to represent automatic visual processing in human visual cortex. Since physical activity (PA) is generally beneficial to cerebrovascular function, we wanted to find out if automatic visual processing is affected by PA. We investigated the connection between long-term leisure-time PA and precognitive visual processing in 32 healthy young males. Participants were divided into active (n = 16) and inactive (n = 16) group according to their leisure-time PA records from the past three years. vMMN was recorded with electroencephalogram using passive oddball paradigm with visual bars. Standard (90%) and deviant (10%) stimu…