Specificity of the Human Frequency Following Response for Carrier and Modulation Frequency Assessed Using Adaptation

Abstract

The frequency following response (FFR) is a scalp-recorded measure of phase-locked brainstem activity to stimulus-related periodicities. Three experiments investigated the specificity of the FFR for carrier and modulation frequency using adaptation. FFR waveforms evoked by alternating-polarity stimuli were averaged for each polarity and added, to enhance envelope, or subtracted, to enhance temporal fine structure information. The first experiment investigated peristimulus adaptation of the FFR for pure and complex tones as a function of stimulus frequency and fundamental frequency (F0). It showed more adaptation of the FFR in response to sounds with higher frequencies or F0s than to sounds with lower frequency or F0s. The second experiment investigated tuning to modulation rate in the FFR. The FFR to a complex tone with a modulation rate of 213 Hz was not reduced more by an adaptor that had the same modulation rate than by an adaptor with a different modulation rate (90 or 504 Hz), thus providing no evidence that the FFR originates mainly from neurons that respond selectively to the modulation rate of the stimulus. The third experiment investigated tuning to audio frequency in the FFR using pure tones. An adaptor that had the same frequency as the target (213 or 504 Hz) did not generally reduce the FFR to the target more than an adaptor that differed in frequency (by 1.24 octaves). Thus, there was no evidence that the FFR originated mainly from neurons tuned to the frequency of the target. Instead, the results are consistent with the suggestion that the FFR for low-frequency pure tones at medium to high levels mainly originates from neurons tuned to higher frequencies. Implications for the use and interpretation of the FFR are discussed.

A novel stimulus paradigm for simultaneous recording of monaural and binaural frequency following response for identification of binaural interaction component

“…They attributed the reduction in the amplitude of the FFR over time to the adaptation of neurons generating the response. Result of the present study was comparable to findings reported by (Gockel et al, 2013;Gockel et al, 2015), where both investigations showed greater amplitude for the FFR at earlier time intervals and a reduction 1 2 in its amplitude over time over time. Therefore, reduced amplitude in the left ear could be attributed to a decrease in neural activity over time due to the adaptation of neurons.…”

“…Thus, the amplitude of the FFR in the left ear was reduced compared to the right ear. Secondly, the reduced amplitude of the FFR in the left ear could be a consequence of the reduction in the neural firing rate over time due to adaptation of neurons contributing to the generation of the FFR (Gockel et al, 2013;Gockel et al, 2015). In the present study, the response of right and left ears were obtained at time intervals between 10 msec and 60 msec and 110 msec and 160 msec post stimulus onset, respectively.…”

On some limitations of the frequency following response

“…The goal of a study by Gockel et al [44] was to determine the characteristic frequency of neurons from which the FFR originates. This was explored using the phenomenon of adaptation, namely the decline of the FFR in response to a steady stimulus.…”

“…Gockel et al [44] measured the FFR for a 100-ms pure tone target (T) that was preceded by a 200-ms pure tone adaptor (A) with either the same or different frequency as T. A and T either had a low frequency (L) of 213 Hz (presented at 80 dB SPL) or a high frequency (H) of 504 Hz (presented at 75 dB SPL), and they were combined in an orthogonal design, leading to four conditions (ALTL, ALTH, AHTL, and AHTH). The FFR was analyzed for five different 50-ms time windows: three over the time course of the adaptor, and two over the time course of the target (see caption of Fig.…”

From Modulated Noise to Natural Speech: the Effect of Stimulus Parameters on the Frequency Following Response

“…These simple stimuli are often unnatural, but they allow for precise manipulation of the acoustic cues. Examples are tonebursts (Clinard et al, 2010; Gardi et al, 1979; Glaser et al, 1976; Tichko and Skoe, 2017), pure tones (Gockel et al, 2015; Holmes et al, 2018), tone sweeps (Billings et al, 2019; Clinard and Cotter, 2015; Krishnan and Parkinson, 2000; Purcell et al, 2004) and (sinusoidally) amplitude modulated (AM) stimuli (Bidelman and Patro, 2016; Dimitrijevic et al, 2016; Van Canneyt et al, 2019). It is unclear whether findings for these non-speech stimuli can be generalized to responses evoked by speech stimuli.…”