PubMed Health⌕ Search

PubMed · 15935556

Lights can reverse illusory directional hearing.

Abstract

Adding brief flashes of light to a train of auditory clicks [R. Hari, Illusory directional hearing in humans, Neurosci. Lett. 189 (1995) 29-30] can alter the sounds perceived location within the head. In an experimental procedure adopted from Hari [R. Hari, Illusory directional hearing in humans, Neurosci. Lett. 189 (1995) 29-30], 16 observers listened over headphones to 8 binaural clicks (i.e., 4 left-ear leading followed by 4 right-ear leading) separated by one of three ISIs (8, 64 and 120 ms), then reported the perceived location of each click-pair within the head. Flashing a light rightward across a CRT screen during temporally coincident click-pairs made observers report the location of the sounds in roughly equally spaced steps from left-to-right through the head. In contrast, light flashes originating on the right of the CRT and moving leftward reversed the perceived location of the clicks, so that the sound appeared to originate on the right side of the head and shift leftward. These effects were diminished when the first four lights were all presented on one side of the CRT and the last four lights were all presented on the other side of the CRT. This multimodal phenomenon occurs although the light was perceived external to the head while the sounds presented over headphones were perceived within the head.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ashley Mays, James Schirillo. 2005-08-26. Lights can reverse illusory directional hearing.. https://doi.org/10.1016/j.neulet.2005.05.021

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Sensory filtering phenomenology in PTSD.

Disrupted sensory filtering, or problems with suppressing irrelevant environmental sensory stimuli, has been reported in individuals with posttraumatic stress disorder (PTSD). However, the relationship of sensory filtering deficits to specific PTSD symptoms versus an association with general trauma exposure is unclear. These relationships were examined by administering self-report measures of trauma exposure, PTSD, and sensory gating phenomenology to undergraduate participants with PTSD (n=32), with trauma history but without PTSD (n=144), and with minimal trauma history (n=153). Subjects with PTSD reported greater filtering disruption than individuals in the trauma only and low trauma groups, who did not differ. Individuals endorsing reexperiencing and numbing symptoms, and females endorsing hypervigilance, reported disrupted sensory filtering phenomenology. These results suggest that impaired filtering differentiates between individuals with PTSD symptoms and asymptomatic individuals exposed to multiple traumas and low-trauma controls.

Acoustic Stimulation↗

Hypoglycemia reduces the blood-oxygenation level dependent signal in primary auditory and visual cortex: a functional magnetic resonance imaging study.

Studies of the effects of hypoglycemia on the brain using neurocognitive testing have suggested that mainly complex functions subserved by secondary and tertiary cortex are affected by mild to moderate hypoglycemia and that intensively treated patients with Type I diabetes mellitus (T1DM) may have altered sensitivity to the central nervous system effects of hypoglycemia. Functional magnetic resonance imaging provides a sensitive, regionally-specific probe of possible neurophysiologic changes related to hypoglycemia in the brain. Eleven intensively-treated T1DM patients and 11 matched non-diabetic controls took part in a 2-day protocol in which functional magnetic resonance imaging (MRI) was used to measure changes in the patterns of brain activation produced by simple auditory and visual stimuli in different conditions. On one day, participants were euglycemic the entire time. On the other day, an initial 50-min euglycemic period was followed by a 50-min hypoglycemic period. Results indicated that hypoglycemia reduced the amplitude of the blood-oxygenation level dependent response in primary auditory and visual cortex to simple auditory and visual stimuli. The latency and duration of the transient hemodynamic response function were not affected. Responses to hypoglycemia were similar in diabetic and non-diabetic participants. These results suggest that mild to moderate hypoglycemia may alter the balance of blood flow and oxygen extraction when glucose levels are lowered. Intensively-treated T1DM, with its attendant frequent hypoglycemic episodes, did not seem to alter hypoglycemic responses in primary visual and auditory cortex.

Acoustic Stimulation↗

Song discrimination learning in zebra finches induces highly divergent responses to novel songs.

Perceptual biases can shape the evolution of signal form. Understanding the origin and direction of such biases is therefore crucial for understanding signal evolution. Many animals learn about species-specific signals. Discrimination learning using simple stimuli varying in one dimension (e.g. amplitude, wavelength) can result in perceptual biases with preferences for specific novel stimuli, depending on the stimulus dimensions. We examine how this translates to discrimination learning involving complex communication signals; birdsongs. Zebra finches (Taeniopygia guttata) were trained to discriminate between two artificial songs, using a Go/No-Go procedure. The training songs in experiment 1 differed in the number of repeats of a particular element. The songs in experiment 2 differed in the position of an odd element in a series of repeated elements. We examined generalization patterns by presenting novel songs with more or fewer repeated elements (experiment 1), or with the odd element earlier or later in the repeated element sequence (experiment 2). Control birds were trained with only one song. The generalization curves obtained from (i) control birds, (ii) experimental birds in experiment 1, and (iii) experimental birds in experiment 2 showed large and systematic differences from each other. Birds in experiment 1, but not 2, responded more strongly to specific novel songs than to training songs, showing 'peak shift'. The outcome indicates that learning about communication signals may give rise to perceptual biases that may drive signal evolution.

Acoustic Stimulation↗