Auditory frequency-following response: A neurophysiological measure for studying the “cocktail-party problem”

A comparison of spectral magnitude and phase-locking value analyses of the frequency-following response to complex tones

“…The frequency-following response (FFR), measured as a voltage on the human scalp, reflects how well subcortical portions of the auditory pathway encode periodic portions of an input acoustic stimulus (e.g., Krishnan, 1999;Galbraith et al, 2000;Kraus and Nicol, 2005;Akhoun et al, 2008;Du et al, 2011). Many studies of the FFR focus on those components that are phase locked to the envelope of the input stimulus (FFR ENV ; the portion of the response that is the same for a stimulus and an inverted version of that stimulus), in part because many artifacts and non-neural signals (such as the cochlear microphonic) that can contaminate the measure are canceled when estimating FFR ENV (e.g., see Picton, 2011).…”

“…Here, we directly compare spectral magnitude and PLV measures of the FFR ENV evoked by complex tones to explore whether differences across subjects and conditions are better revealed by PLV analysis than by spectral magnitude analysis (Experiment 1; note that though many studies explore the temporal-finestructure-related component of the FFR, the current study focuses exclusively on the envelope-related component). Past experimental and theoretical studies suggest that FFR ENV is generated primarily by subcortical structures including the cochlea, auditory nerve, cochlear nucleus, and inferior colliculus (Smith et al, 1975;Gardi et al, 1979;Davis and Britt, 1984;Dolphin and Mountain, 1992;Dau, 2003;Wile and Balaban, 2007;Harte et al, 2010;Chandrasekaran and Kraus, 2010;Du et al, 2011). Each peripheral auditory channel will respond to the portion of the acoustic signal falling within its critical band; the observable FFR ENV is a sum of all of this activity, across frequency channels, and therefore depends on the phase locking within each channel as well as the phase and magnitude relationships among the phase-locked activity across all channels.…”

Temporally pre-presented lipreading cues release speech from informational masking

“…Listeners can use various perceptual/cognitive cues to facilitate perceptual segregation between the target speech and the masker by strengthening their selective attention to the target speech (Du et al, 2011). These cues include both viewing a speaker's movements of the speech articulators (simultaneous lipreading) (Summerfield, 1979;Rosenblum et al, 1996;Grant and Seitz, 2000;Rudmann et al, 2003;Helfer and Freyman, 2005) and prior knowledge about part of the target-sentence content (i.e., temporally pre-presented content prime) (Freyman et al, 2004;Yang et al, 2007).…”

Perceived target–masker separation unmasks responses of lateral amygdala to the emotionally conditioned target sounds in awake rats

“…How can the auditory responses specific to the target be isolated? Frequency-following responses (FFRs), which are sustained potentials based on phase-locked firing of neuron populations to low-to-medium-frequency periodical sound waveforms (Worden and Marsh, 1968), are particularly useful for studying attentional modulation of stimulus-specific auditory responses when one or more sound sources are presented simultaneously (Du et al, 2011a). In laboratory rats, FFRs to tonecomplexes can be directly recorded within the LA (Du et al, 2009a) and the auditory midbrain inferior colliculus Du et al, 2009c).…”