Transformation of temporal sequences in the zebra finch auditory system

Abstract

This study examines how temporally patterned stimuli are transformed as they propagate from primary to secondary zones in the thalamorecipient auditory pallium in zebra finches. Using a new class of synthetic click stimuli, we find a robust mapping from temporal sequences in the primary zone to distinct population vectors in secondary auditory areas. We tested whether songbirds could discriminate synthetic click sequences in an operant setup and found that a robust behavioral discrimination is present for click sequences composed of intervals ranging from 11 ms to 40 ms, but breaks down for stimuli composed of longer inter-click intervals. This work suggests that the analog of the songbird auditory cortex transforms temporal patterns to sequence-selective population responses or ‘spatial codes', and that these distinct population responses contribute to behavioral discrimination of temporally complex sounds.DOI: http://dx.doi.org/10.7554/eLife.18205.001

Neural properties of fundamental function encoding of sound selectivity in the female avian auditory cortex

“…Some studies have reported that sequences of syllables and gaps are important for vocal generation and sound recognition on social context or specificity (Araki, Bandi, & Yazaki‐Sugiyama, ; Brainard & Doupe, ; Knowles, Doupe, & Brainard, ; Lim, Lagoy, Shinn‐Cunningham, & Gardner, ; Tanaka, Singh Alvarado, Murugan, & Mooney, ; Van Ruijssevelt et al, ). In this study, the sequence of syllables and gaps corresponded to the temporal modulation of amplitude, which is correlated with neural activity in the vocal motor neurons of male birds (Danish, Aronov, & Fee, ; Lynch, Okubo, Hanuschkin, Hahnloser, & Fee, ).…”

Long-term implicit memory for sequential auditory patterns in humans

“…Agus Kang et al (2017) proposed that incorporating a degree of temporal integration can also account for similar effects observed with random click trains. It is possible that state-dependent neural place maps, as proposed by Kang et al (2017; see also Karmarkar & Buonomano, 2007;Lim, Lagoy, Shinn-Cunningham, & Gardner, 2017) incorporating an integration time of several hundred msec, may also underpin memory for discrete tone sequences. As will be discussed further below, the behavioural pattern reported in the present paper is consistent with sequential information being stored as short sub-sequences, i.e.…”

Auditory memory for random time patterns

“…To simplify, spectral cues may be encoded by the place pattern of spiking rates in frequency-tuned populations of auditory neurons, whereas temporal cues may be encoded by the timing between spikes within a neuron or across neurons in a population. Even though the mapping between acoustic cues and their underlying neural representation is not wellestablished (Cariani and Delgutte, 1996;Lim et al, 2016;Shamma and Lorenzi, 2013), both place (Rothschild et al, 2010) and temporal (Lu et al, 2001;Petkov and Bendor, 2016) cues are abundant along the auditory pathways, from the auditory periphery up to at least the auditory cortex. However, the two types of cue require qualitatively different mechanisms when learning and neural plasticity are considered.…”

“…For temporal cues, however, such a mechanism does not apply directly because what needs to be learnt develops over time. So, neurons would need somehow to encode past and present information simultaneously to learn temporal patterns (Karmarkar and Buonomano, 2007;Lim et al, 2016).…”