Forward suppression in the auditory cortex is frequency-specific.
Bottom Line: The temporal order and frequency proximity of sounds influence both their perception and neuronal responses.These effects are larger when the two sounds are spectrally similar.These data are consistent with the idea that cortical neurons receive convergent inputs with a wide range of tuning properties that can adapt independently.
Affiliation: MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, UK.Show MeSH
Related in: MedlinePlus
Mentions: To characterize the locus of suppression (SCF for the tuning of suppression near to threshold or SBF for the conditioner frequency that suppresses most effectively) relative to the single-tone excitatory CF (or BF) and the probe tone frequency, a probe-following index (PFI) was calculated. This characterizes the angle that each data point forms with the horizontal axis of the representation shown in Figs 3 and 4. In the figures, the difference between unit CF and the SCF in octaves [log2(CF/SCF)] is plotted against the difference between the frequency of the probe and CF [log2(CF/Fprobe)]. The PFI for the SCF is given by: (1) where Fprobe is the frequency of the probe. A value of 1 corresponds to points that followed the probe tone frequency perfectly. In such cases SCF = Fprobe, and points lie on the ascending diagonal in the figures. A value of zero indicates that the SCF was identical to the CF (the numerator in Eq. 1 is then a log of 1, which is 0). For the calculation of the PFI associated with the region of maximal suppression, the BF and SBF measures were used.
Affiliation: MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, UK.