Natural ITD statistics predict human auditory spatial perception

A neural code adapted to the statistical structure of sensory cues may optimize perception. We investigated whether interaural time difference (ITD) statistics inherent in natural acoustic scenes are parameters determining spatial discriminability. The natural ITD rate of change across azimuth (ITDrc) and ITD variability over time (ITDv) were combined in a Fisher information statistic to assess the amount of azimuthal information conveyed by this sensory cue. We hypothesized that natural ITD statistics underlie the neural code for ITD and thus influence spatial perception. To test this hypothesis, sounds with invariant statistics were presented to measure human spatial discriminability and spatial novelty detection. Human auditory spatial perception showed correlation with natural ITD statistics, supporting our hypothesis. Further analysis showed that these results are consistent with classic models of ITD coding and can explain the ITD tuning distribution observed in the mammalian brainstem.

Download Full-text

Natural ITD statistics predict human auditory spatial perception

10.1101/303347 ◽

2018 ◽

Cited By ~ 1

Author(s):

Rodrigo Pavão ◽

Elyse S. Sussman ◽

Brian J. Fischer ◽

José L. Peña

Keyword(s):

Spatial Perception ◽

Novelty Detection ◽

Interaural Time Difference ◽

Subject Area ◽

Neural Code ◽

Rate Of Change ◽

Spatial Cues ◽

Sensory Cue ◽

Invariant Statistics ◽

Natural Statistics

A neural code adapted to the statistical structure of sensory cues may optimize perception. We investigated whether interaural time difference (ITD) statistics inherent in natural acoustic scenes are parameters determining spatial discriminability. The natural ITD rate of change across azimuth (ITDrc) and ITD variability over time (ITDv) were combined in a Fisher information statistic for assessing the amount of azimuthal information conveyed by this sensory cue. We hypothesized that natural ITD statistics drive the neural code for ITD and thus influence spatial perception. Human spatial discriminability and spatial novelty detection of sounds with invariant statistics correlated with natural ITD statistics. The lack of natural statistics in the stimuli suggests that this correlation results from natural statistics driving the neural code. Additionally, the density distribution of ITD tuning matching natural statistics is consistent with classic models of ITD coding and can explain the ITD tuning distribution observed in the mammalian brainstem.Impact statementHuman brain has incorporated natural statistics of spatial cues to the neural code supporting perception of sound location.Major subject areaNeuroscience;Research organismHuman;

Download Full-text

The neural code for interaural time difference in human auditory cortex

The Journal of the Acoustical Society of America ◽

10.1121/1.3290744 ◽

2010 ◽

Vol 127 (2) ◽

pp. EL60-EL65 ◽

Cited By ~ 37

Author(s):

Nelli H. Salminen ◽

Hannu Tiitinen ◽

Santeri Yrttiaho ◽

Patrick J. C. May

Keyword(s):

Auditory Cortex ◽

Interaural Time Difference ◽

Neural Code ◽

Time Difference ◽

Human Auditory Cortex

Download Full-text

Adaptive plasticity of the auditory space map in the optic tectum of adult and baby barn owls in response to external ear modification

Journal of Neurophysiology ◽

10.1152/jn.1994.71.1.79 ◽

1994 ◽

Vol 71 (1) ◽

pp. 79-94 ◽

Cited By ~ 30

Author(s):

E. I. Knudsen ◽

S. D. Esterly ◽

J. F. Olsen

Keyword(s):

Spatial Pattern ◽

Optic Tectum ◽

Interaural Time Difference ◽

Rate Of Change ◽

Adaptive Plasticity ◽

Interaural Level Difference ◽

External Ear ◽

Site Location ◽

Physiological Range ◽

Barn Owls

1. This study demonstrates the influence of experience on the establishment and maintenance of the auditory map of space in the optic tectum of the barn owl. Auditory experience was altered either by preventing the structures of the external ears (the facial ruff and preaural flaps) from appearing in baby barn owls (baby ruff-cut owls) or by removing these structures in adults (adult ruff-cut owls). These structures shape the binaural cues used for localizing sounds in both the horizontal and vertical dimensions. 2. The acoustic effects of removing the external ear structures were measured using probe tube microphones placed in the ear canals. In both baby and adult ruff-cut owls, the spatial pattern of binaural localization cues was dramatically different from normal: interaural level difference (ILD) changed with azimuth instead of with elevation, the rate of change of ILD across space was decreased relative to normal, and the rate of change of interaural time difference (ITD) across frontal space was increased relative to normal. 3. The neurophysiological representations of ITD and ILD in the optic tectum were measured before and > or = 3 mo after ruff removal in adults and beginning at 4.5 months of age in baby ruff-cut owls. Multiunit tuning to ITD and to ILD was measured using dichotic stimulation in ketamine-anesthetized owls. The tectal maps of ITD and ILD were reconstructed using visual receptive field location as a marker for recording site location in the optic tectum. 4. Adjustment of the tectal map of ITD to the altered spatial pattern of acoustic ITD was essentially complete in adults as well as in baby ruff-cut owls. This adjustment changed the magnification of ITD across the tectum, with resultant changes in ITD tuning at individual tectal sites of up to approximately 25 microseconds (approximately 5% of the physiological range) relative to normal values. 5. Adaptation of the tectal ILD map to the ruff-cut spatial pattern of acoustic ILD was substantial but clearly incomplete in both adult and baby ruff-cut owls. Although changes of up to approximately 15 dB (approximately 47% of the physiological range) relative to normal tuning were observed at certain tectal sites, the topography of the ILD map was always intermediate between normal and that predicted by the ruff-cut spatial pattern of acoustic ILD.(ABSTRACT TRUNCATED AT 400 WORDS)

Download Full-text

Modulation of the effects of the cannabinoid agonist, ACPA, on spatial and non-spatial novelty detection in mice by dopamine D1 receptor drugs infused into the basolateral amygdala

Behavioural Brain Research ◽

10.1016/j.bbr.2014.11.003 ◽

2015 ◽

Vol 280 ◽

pp. 36-44 ◽

Cited By ~ 11

Author(s):

Meisam Mohammadi ◽

Mohammad Nasehi ◽

Mohammad-Reza Zarrindast

Keyword(s):

Basolateral Amygdala ◽

Novelty Detection ◽

Dopamine D1 Receptor ◽

D1 Receptor ◽

Spatial Novelty ◽

Cannabinoid Agonist

Download Full-text

Reduced temporal processing in older, normal-hearing listeners evident from electrophysiological responses to shifts in interaural time difference

Journal of Neurophysiology ◽

10.1152/jn.00560.2016 ◽

2016 ◽

Vol 116 (6) ◽

pp. 2720-2729 ◽

Cited By ~ 15

Author(s):

Erol J. Ozmeral ◽

David A. Eddins ◽

Ann C. Eddins

Keyword(s):

Cognitive Processing ◽

Temporal Processing ◽

Spatial Perception ◽

Interaural Time Difference ◽

Relative Activity ◽

Time Difference ◽

Asymmetric Distribution ◽

Neural Synchrony ◽

Spatial Cues ◽

Age Related

Previous electrophysiological studies of interaural time difference (ITD) processing have demonstrated that ITDs are represented by a nontopographic population rate code. Rather than narrow tuning to ITDs, neural channels have broad tuning to ITDs in either the left or right auditory hemifield, and the relative activity between the channels determines the perceived lateralization of the sound. With advancing age, spatial perception weakens and poor temporal processing contributes to declining spatial acuity. At present, it is unclear whether age-related temporal processing deficits are due to poor inhibitory controls in the auditory system or degraded neural synchrony at the periphery. Cortical processing of spatial cues based on a hemifield code are susceptible to potential age-related physiological changes. We consider two distinct predictions of age-related changes to ITD sensitivity: declines in inhibitory mechanisms would lead to increased excitation and medial shifts to rate-azimuth functions, whereas a general reduction in neural synchrony would lead to reduced excitation and shallower slopes in the rate-azimuth function. The current study tested these possibilities by measuring an evoked response to ITD shifts in a narrow-band noise. Results were more in line with the latter outcome, both from measured latencies and amplitudes of the global field potentials and source-localized waveforms in the left and right auditory cortices. The measured responses for older listeners also tended to have reduced asymmetric distribution of activity in response to ITD shifts, which is consistent with other sensory and cognitive processing models of aging.

Download Full-text

The modulatory effect of CA1 GABAb receptors on ketamine-induced spatial and non-spatial novelty detection deficits with respect to Ca2+

Neuroscience ◽

10.1016/j.neuroscience.2015.07.083 ◽

2015 ◽

Vol 305 ◽

pp. 157-168 ◽

Cited By ~ 15

Author(s):

A. Khanegheini ◽

M. Nasehi ◽

M.-R. Zarrindast

Keyword(s):

Novelty Detection ◽

Gabab Receptors ◽

Spatial Novelty

Download Full-text

Spatial Stimulus Cue Information Supplying Auditory Saltation

Perception ◽

10.1068/p3293 ◽

2002 ◽

Vol 31 (7) ◽

pp. 875-885 ◽

Cited By ~ 11

Author(s):

Dennis P Phillips ◽

Susan E Hall ◽

Susan E Boehnke ◽

Leanna E D Rutherford

Keyword(s):

Spatial Perception ◽

Interaural Time Difference ◽

Free Field ◽

Spatial Location ◽

Interaural Level Difference ◽

Sound Sources ◽

Interaural Time Differences ◽

Spatial Stimulus ◽

Click Train ◽

Interaural Level Differences

Auditory saltation is a misperception of the spatial location of repetitive, transient stimuli. It arises when clicks at one location are followed in perfect temporal cadence by identical clicks at a second location. This report describes two psychophysical experiments designed to examine the sensitivity of auditory saltation to different stimulus cues for auditory spatial perception. Experiment 1 was a dichotic study in which six different six-click train stimuli were used to generate the saltation effect. Clicks lateralised by using interaural time differences and clicks lateralised by using interaural level differences produced equivalent saltation effects, confirming an earlier finding. Switching the stimulus cue from an interaural time difference to an interaural level difference (or the reverse) in mid train was inconsequential to the saltation illusion. Experiment 2 was a free-field study in which subjects rated the illusory motion generated by clicks emitted from two sound sources symmetrically disposed around the interaural axis, ie on the same cone of confusion in the auditory hemifield opposite one ear. Stimuli in such positions produce spatial location judgments that are based more heavily on monaural spectral information than on binaural computations. The free-field stimuli produced robust saltation. The data from both experiments are consistent with the view that auditory saltation can emerge from spatial processing, irrespective of the stimulus cue information used to determine click laterality or location.

Download Full-text

Dynamic representation of space in the hippocampus: spatial novelty detection and consolidation in CA1 and CA2

10.1101/2021.08.19.456964 ◽

2021 ◽

Author(s):

Guncha Bhasin

Keyword(s):

Novelty Detection ◽

Place Cells ◽

Neuronal Responses ◽

Dynamic Representation ◽

Spatial Novelty ◽

Spatial Coverage ◽

Representation Of Space ◽

Familiar Environment ◽

First Time ◽

Processing Differences

Hippocampal place cells are the functional units of spatial navigation and are present in all subregions- CA1, CA2, CA3 and CA4. Recent studies on CA2 have indicated its role in social and contextual memory, but its contribution towards spatial novelty detection and consolidation remains largely unknown. The current study aims to uncover how CA1 and CA2 detect, process, assimilate and consolidate spatial novelty. Accordingly, a novel 3-day paradigm was designed where the animal was introduced to a completely new environment on the first day and to varying degrees of familiarity and novelty on subsequent days, as the track was extended in length and modified in shape, keeping other environmental constraints fixed. Detection of spatial novelty was found to be a dynamic and complex phenomenon, characterized by different responses from hippocampal place cells, depending on when novelty was introduced. Therefore, the study concludes that early novelty detection (the first time a novel space is introduced in a relatively familiar environment) and subsequent novelty detection are not processed in the same way. Additionally, while neuronal responses to spatial novelty detection (early and subsequent) were found to be the same in CA1 and CA2 ensembles, their responses differed in spatial consolidation mechanisms during subsequent sleep replays. For CA1, spatial coverage of prior behaviour was found to be closely reflected in subsequent sleep for that particular day, but CA2 showed no such coherent response, highlighting mnemonic processing differences between CA2 and CA1 with respect to spatial novelty.

Download Full-text