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Mmn wolff

C Wolff, E Schröger
The functional nature of the pre-attentive automatic auditory feature analysis was investigated using the mismatch negativity (MMN) component of the auditory event-related brain potential. MMNs to ignored sounds deviating in one, two or three dimensions (duration (D), frequency (F), intensity (I)) were recorded. When the corresponding MMN processes elicited by stimuli simultaneously deviating in multiple features are independent from each other, then the empirically measured MMN elicited by multiple deviants equals the sum of the MMINs elicited by the corresponding single deviants...
September 21, 2001: Neuroscience Letters
C Wolff, E Schröger
The human automatic pre-attentive change detection system indexed by the mismatch negativity (MMN) component of the auditory event-related brain potential is known to be highly adaptive. The present study showed that even infrequent repetitions of tones can elicit MMN, independently of attention, when tones of varying frequency are rapidly presented in an isochronous rhythm. This demonstrates that frequency variation can be extracted as an invariant feature of the acoustic environment revealing the capacity for adaptation of the auditory pre-attentive change detection system...
January 2001: Brain Research. Cognitive Brain Research
E Schröger, M H Giard, C Wolff
OBJECTIVE: The aim of this study was to illuminate behavioral and event-related potential (ERP) effects of attentional orienting and reorienting obtained in a newly developed auditory distraction paradigm, to provide more precise indicators about the neural generators of the ERP effects using scalp current density (SCD) analysis, and to evaluate the stability of the distraction effects. METHODS: In two sessions separated by 25 days, 10 subjects were presented with tones being of short (200 ms) and long (400 ms) duration equiprobably; tones were of high-probability standard or of low-probability deviant frequency...
August 2000: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
E Schröger, C Wolff
We investigated event-related potential indications for the orienting towards task-irrelevant, distracting aspects of stimulation and for the subsequent reorienting towards task-related aspects of stimulation. An identical experimental protocol was run in three conditions manipulating the task relevance of the sounds. As to be expected, distractors elicited the MMN (reflecting the brain's pre-attentive change detection) in each condition (even when the sounds were ignored) and subsequent N2b and P3 (reflecting orienting towards the distractor) when the sounds were attended...
October 26, 1998: Neuroreport
E Schröger, C Wolff
A distraction paradigm was utilized that is suited to yield reliable auditory distraction on an individual level even with rather small frequency deviances (7%). Distraction to these tiny deviants was achieved by embedding task-relevant aspects and task-irrelevant, distracting aspects of stimulation into the same perceptual object. Event-related potential (ERP) and behavioral effects of this newly developed paradigm were determined. Subjects received tones that could be of short or long duration equiprobably...
July 1998: Brain Research. Cognitive Brain Research
I Winkler, M Tervaniemi, E Schröger, C Wolff, R Näätänen
Auditory event-related potentials were recorded from reading subjects to frequent and infrequent tones. Frequent tones presented by a loudspeaker in front of the subject were interspersed with infrequent tones delivered either by one of the symmetrically-placed lateral loudspeakers, or by both lateral loudspeakers simultaneously. This latter sound was perceived as originating from a spacious source in the direction of the central loudspeaker. A sizable mismatch negativity (MMN) and P3a were elicited by all three infrequent stimuli, suggesting that infrequent changes in the direction or perceived spaciousness of the sound source were preattentively detected...
February 6, 1998: Neuroscience Letters
E Schröger, C Wolff
Spatial separation of sound sources provides a primary cue for selecting relevant from irrelevant acoustic input. This competence for selective listening is important in every-day life, when several concurrent sound sources are simultaneously active. The present study demonstrated a temporal advantage in the preattentive processing of location information relative to frequency information. This was indicated by shorter latency of the mismatch negativity (MMN), generated by the brain's automatic detection of a sound change, to a location change than to a frequency change...
August 22, 1997: Neuroscience Letters
E Schröger, C Wolff
WE investigated whether the enhanced negativity of the human event-related brain potential elicited by changes in auditory lateralization is due to a higher-order change-detection process or whether it can be explained exclusively in terms of selective sensory adaptation. Infrequent changes in lateralization of a repetitive standard tone, generated by changes in interaural time differences, elicited a frontocentrally distributed negative brain wave in the 100-250 ms range relative to stimulus onset. This brain wave was also elicited when possible sensory adaptation was prevented by controlling for the state of refractoriness of location-specific neurones...
November 25, 1996: Neuroreport
E Schröger, M Tervaniemi, C Wolff, R N Näätänen
The present study demonstrated that the mismatch negativity (MMN), generated by the brain's preattentive detection of a sound change, is elicited by infrequent reversals of two consecutive tones differing in intensity. When tones were presented in a pairwise manner, the MMN was time-locked to the onset of the intensity reversal. When the tones were continuously presented, the MMN was elicited by an irregular loud tone succeeding a regular loud tone but not by an irregular soft tone following a regular soft tone...
September 1996: Brain Research. Cognitive Brain Research
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