Auditory and visual localization performance in a sequential discrimination task

Abstract

Four subjects were tested in a two-alternative, forced-choice, three down-one up adaptive paradigm in which two 200-ms signals were presented sequentially with a 200-ms interstimulus interval. The subject's task was to indicate whether the second stimulus was to the right or left of the first. Tests were conducted with 57 dB (A-weighted), 1.0-kHz high-pass noise, the minimum audible angle (MAA) task, and with lights emitting 620 nm at a luminance level of 200 mL, the minimum visible angle (MVA) task. Localization performance in the MAA task was equal to or better than that obtained in the MVA task for all regions of the frontal field with only one exception, presentations at 0 degrees azimuth. The implications of these results are discussed.

The gradient of spatial auditory attention in free field: An event-related potential study

“…This probably is due to a more refined capability for discriminating between adjacent sound sources centrally than in the periphery. On the basis of earlier studies in cats (Jenkins & Masterton, 1982), it was found that humans can discriminate adjacent sound sources directly in front of them when separated by only 2°_3°, whereas discrimination between peripheral sounds (e.g., at 40°azimuth) was markedly inferior (Perrott, Constantino, & Cisneros, 1993; see also Oldfield & Parker, 1984). Clearly, the sharpness of attentional allocation to a particular sound source among nearby competing sources depends in part on the ability to discriminate the location of the attended source from those of its neighbors.…”

Multisensory stimuli improve relative localisation judgments compared to unisensory auditory or visual stimuli

“…Few studies have attempted to directly compare spatial acuity for auditory and visual stimuli throughout the visual field and focus instead on the spatial capture observed when spatially separated auditory-visual signals are presented (Howard and Templeton, 1966; Bertelson and Radeau, 1981). Two exceptions to this are Perrot et al (1993) and Charbonneau et al (2013). Both determined that both visual and auditory localisation judgments declined as stimuli move from central to peripheral space.…”

“…Both auditory (Mills, 1958; Makous and Middlebrooks, 1990; Charbonneau et al , 2013; Wood and Bizley, 2015; Carlile et al , 2016) and visual localisation acuity declines with eccentricity (Mateeff and Gourevich, 1984; Perrott et al , 1993; Charbonneau et al , 2013). Few studies have attempted to directly compare spatial acuity for auditory and visual stimuli throughout the visual field and focus instead on the spatial capture observed when spatially separated auditory-visual signals are presented (Howard and Templeton, 1966; Bertelson and Radeau, 1981).…”

Relative Localization of Auditory and Visual Events Presented in Peripheral Visual Field

“…While auditory localization also decreases (Makous and Middlebrooks, 1990;Perrott and Saberi, 1990), spatial resolution degrades more slowly than vision (Perrott et ai, 1993). Perrott et al (1993) measured the minimum audible angles (MAA) and minimum visible angles (MVA) over a wide horizontal area (0°-80°) and found that the MAA was equal to or larger than the MVA for all regions beyond a 20°-periphery of the fovea. If the most likely location of an audio-visual target depends on uncertainties individually associated with auditory and visual cues, the dominant modality in localization must be changed by eccentricity.…”