The auditory evoked sustained field: origin and frequency dependence

Wilhelms-University of Münster, Institute of Experimental Audiology, Centre of Biomagnetism, Germany.
Electroencephalography and Clinical Neurophysiology 02/1994; 90(1):82-90. DOI: 10.1016/0013-4694(94)90115-5
Source: PubMed


A sound lasting for several seconds is known to elicit a baseline shift in electrical and magnetic records. We have studied the dependence of the magnetic field distribution of this "per-stimulatory" sustained field (SF) on tone frequency. Tone bursts of 2 sec duration and 60 dB nHL intensity were presented to 11 subjects at varying interstimulus intervals between 5 and 7 sec. The carrier frequencies of 250, 1000 and 4000 Hz varied randomly from trial to trial. The field distributions obtained are consistent with the view that the auditory evoked sustained field activity originates in the supratemporal cortex. Differences in the locations of equivalent current dipoles of the SF from those of the M100 wave of the slow auditory evoked field are consistent across subjects. The SF source locations corresponding to stimulus frequencies over an extended frequency range are arranged in a tonotopic manner and support the idea that the sources of the M100 and the SF are current dipole sheets located on the superior surface of the primary auditory cortex.

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Available from: Carsten Eulitz, Sep 29, 2015
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    • "ERPs have provided important insights about age and disease related changes in human cognition by allowing us to study cognitive processes in the brain directly and independently of behavioral measures. EROs can provide additional information about sensory and cognitive functions during stimulus and task evaluation (Başar, 1992; Başar et al., 1997; Pantev et al., 1994). "
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    ABSTRACT: The purpose of this study was to investigate changes in delta event-related oscillations (ERO) in younger and older healthy elderly subjects. We hypothesized that delta ERO were affected by age-related changes, which could be reflected in a visual oddball paradigm. The study included two groups of subjects, 17 younger healthy elderly (mean age: 63.1±2.8years) and 17 gender- and education- matched older healthy elderly (mean age: 79.6±5.2years), who performed a visual oddball paradigm. EEG was recorded from F3, Fz, F4, C3, Cz, C4, P3, Pz, P4, O1, Oz and O2 locations. Peak-to-peak amplitude of delta (0.5-3Hz) target ERO responses during the post-stimulus 0-800msec time window were measured. Repeated measures of ANOVA was used to analyze four locations (frontal, central, parietal, occipital), at three sagittal (left, midline, right) sites. Independent t-tests were applied for post-hoc analyses. The older healthy elderly group had 16-25% lower values for the maximum peak-to-peak amplitudes of delta ERO compared with the younger healthy elderly group over frontal (p<0.003), central (p<0.0001) and parietal (p<0.007) locations [F3.96=4.396, p=0.015]. Furthermore, there was a moderate negative correlation between age and Cz peak-to-peak amplitude of target delta responses [r=-0.401, p<0.02], indicating the notion that peak-to-peak amplitude of Cz decreases as age increases. In the present study younger healthy elderly showed significantly higher event-related delta responses than older healthy elderly at frontal, central and parietal locations. Moreover, delta ERO responses decreased in accordance with age. Copyright © 2015. Published by Elsevier B.V.
    International journal of psychophysiology: official journal of the International Organization of Psychophysiology 02/2015; 94(2). DOI:10.1016/j.ijpsycho.2015.02.006 · 2.88 Impact Factor
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    • "Auditory stimulation with a brief sound elicits several transient evoked responses that are time-locked to the onset of the stimulus. When the sound stimulus is long enough, the transient responses are followed by the stimulus locked DC-shift sustained response, which persists for the duration of the sound [1,2] and returns to baseline shortly after the stimulus offset [2,3]. Sustained response is named as sustained potential (SP) when recorded by electroencephalography and as sustained field (SF) when recorded by magnetoencephalography (MEG). "
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    ABSTRACT: Auditory sustained responses have been recently suggested to reflect neural processing of speech sounds in the auditory cortex. As periodic fluctuations below the pitch range are important for speech perception, it is necessary to investigate how low frequency periodic sounds are processed in the human auditory cortex. Auditory sustained responses have been shown to be sensitive to temporal regularity but the relationship between the amplitudes of auditory evoked sustained responses and the repetitive rates of auditory inputs remains elusive. As the temporal and spectral features of sounds enhance different components of sustained responses, previous studies with click trains and vowel stimuli presented diverging results. In order to investigate the effect of repetition rate on cortical responses, we analyzed the auditory sustained fields evoked by periodic and aperiodic noises using magnetoencephalography. Sustained fields were elicited by white noise and repeating frozen noise stimuli with repetition rates of 5-, 10-, 50-, 200- and 500 Hz. The sustained field amplitudes were significantly larger for all the periodic stimuli than for white noise. Although the sustained field amplitudes showed a rising and falling pattern within the repetition rate range, the response amplitudes to 5 Hz repetition rate were significantly larger than to 500 Hz. The enhanced sustained field responses to periodic noises show that cortical sensitivity to periodic sounds is maintained for a wide range of repetition rates. Persistence of periodicity sensitivity below the pitch range suggests that in addition to processing the fundamental frequency of voice, sustained field generators can also resolve low frequency temporal modulations in speech envelope.
    BMC Neuroscience 01/2012; 13(1):7. DOI:10.1186/1471-2202-13-7 · 2.67 Impact Factor
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    • "Electroencephalographic (EEG) and magnetoencephalographic (MEG) data allow the effective location of current dipoles to be reconstructed, typically one for each hemisphere. A number of studies reported that the dipole's depth below the scalp and its coordinate along the rostrocaudal axis increased with stimulus frequency, and its orientation varied due to gyral morphology (Romani et al. 1982; Pantev et al. 1988; Kuriki and Murase 1989; Cansino et al. 1994; Pantev et al. 1994; Huotilainen et al. 1995; Verkindt et al. 1995; Gabriel et al. 2004; Weisz, Wienbruch, et al. 2004; Wienbruch et al. 2006; Ozaki and Hashimoto 2007). These findings confirm that human auditory cortex is organized tonotopically, with an effective low-to-high-frequency gradient extending in the (antero)lateral-to-(postero)medial direction along HG. "
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    ABSTRACT: Despite numerous neuroimaging studies, the tonotopic organization in human auditory cortex is not yet unambiguously established. In this functional magnetic resonance imaging study, 20 subjects were presented with low-level task-irrelevant tones to avoid spread of cortical activation. Data-driven analyses were employed to obtain robust tonotopic maps. Two high-frequency endpoints were situated on the caudal and rostral banks of medial Heschl's gyrus, while low-frequency activation peaked on its lateral crest. Based on cortical parcellations, these 2 tonotopic progressions coincide with the primary auditory field (A1) in lateral koniocortex (Kl) and the rostral field (R) in medial koniocortex (Km), which together constitute a core region. Another gradient was found on the planum temporale. Our results show the bilateral existence of 3 tonotopic gradients in angulated orientations, which contrasts with colinear configurations that were suggested before. We argue that our results corroborate and elucidate the apparently contradictory findings in literature.
    Cerebral Cortex 10/2011; 22(9):2024-38. DOI:10.1093/cercor/bhr282 · 8.67 Impact Factor
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