PubMed · 5495788
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J Langová, M Morávek, A Novák, M Petrík. 1970. Experimental interference with auditory feedback.. https://doi.org/10.1159/000263396
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
In this paper an attempt was made to describe the basic principles and procedures involved in recording, noninvasively, magnetic fields from the surface of the head and estimating the intracranial sources that give rise to these fields, presumably the same ones that result in time-varying voltages in the scalp that are known as Evoked and Event-Related Potentials. In addition, data from four experiments are briefly described as a means of providing concrete examples of the applicability of Magnetoencephalographic procedures to research issues of interest to cognitive neuroscientists.
The spatio-temporal organization of the human primary auditory response (N19 and P30) was determined by analyzing magnetic fields from the right hemisphere evoked by monaural clicks to the left ear. The magnetic response consisted of peaks corresponding to electrical N19 (N19m) and P30 (P30m) within 40 msec after stimulation. However, the onset of electrical N19 occurred 5-9 msec earlier than that of the magnetic counterpart. Furthermore, the relative amplitude of N19 and P30 (N19/P30) was larger (more than 1) than that (about 0.5) of N19m and P30m (N19m/P30m). The findings suggest an additional contribution from a subcortical source for electrical N19. The estimated equivalent sources for N19m and P30m were localized at the postero-medial part of Heschl's gyrus (the primary auditory cortex). Furthermore, the dipole orientation of N19m was directed postero-ventrally and that of P30m was in the opposite direction, which is compatible with the anatomy of the supratemporal primary auditory cortex. These results resolve a long standing controversy of cortical vs. subcortical structures as the generators of the N19.
Spontaneous otoacoustic emissions (SOAEs) were measured in human monozygotic (MZ) and dizygotic (DZ) twins and in a sample of non-twins. The number of SOAEs exhibited was more highly correlated in MZ co-twins than in same-sex DZ co-twins. Model-fitting to the correlations suggested that about three-quarters of the individual variation in the expression of SOAEs is attributable to genes. There was no convincing evidence for the heritability of specific SOAE frequencies. In accord with past surveys, SOAEs were more numerous in right than left ears, and in female than male subjects. Also investigated were the numbers of SOAEs exhibited by dark-versus light-eyed people and by MZ versus DZ twins. Those differences in our data were small and not statistically significant, but they were in a direction consistent with other studies: more SOAEs in dark-eyed individuals and in MZ twins. The view presented here is that SOAEs themselves are unlikely objects for natural selection, and probably are epiphenomena resulting from selection for those cochlear mechanisms that contribute to good hearing sensitivity - which is related to SOAE expression. It is argued that, in addition to genetics, other factors have the potential to affect the specific numbers of SOAEs that are expressed. For example, some aspects of the complex prenatal process of producing a male fetus are presumed to be responsible for the smaller number of SOAEs seen in males than females.