The effect of gaze direction on sound localization in brain-injured and normal adults

Abstract

This study examined the effects of eye position on sound localization in normal and brain lesion subjects. On the assumption that cerebral lesions may disrupt the representation of or attention to auditory space in the contralesional hemispace, we predicted that subjects with brain lesions would be less accurate in localizing sounds in the contralesional hemispace. In Experiment 1 we showed that gazing to the midline subjects with brain lesions were indeed impaired in localizing sounds in the contralesional hemispace. On the assumption that spatial attention is deployed at the site to which gaze is directed, we predicted that sound localization would be better on the side to which subjects directed their gaze. In Experiment 2, brain lesion subjects performed significantly better in the contralesional hemispace when they directed gaze to that hemispace. This improvement was accompanied by deterioration of performance in the ipsilesional hemispace. When subjects directed gaze to the ipsilesional hemispace, performance in the contralesional hemispace was further impaired. The effect of gaze was also observed in normal subjects in Experiments 2 and 3, independently of response mode (verbal versus pointing responses). These findings are consistent with the hypothesis that sound location may be mapped in eye-centered coordinates and that directing gaze to one hemispace reduces attentional allocation to the other hemispace.

Speech intelligibility reduces over distance from an attended location: Evidence for an auditory spatial gradient of attention

“…Second, the gradient was demonstrated while the directions of gaze and attention were dissociated. This confirms that the intelligibility gradient found in Experiment 1A was not simply due to a preference to allocate attentional resources in the direction of gaze (Lie & Branch Coslett, 2006).…”

“…Numerous studies have shown that stimuli at lateralized positions are not as well processed as are those at positions nearer to the midline (e.g., Carlile, Leong, & Hyams, 1997;Mills, 1958). Furthermore, Lie and Branch Coslett (2006) and Rorden and Driver (1999) demonstrated that gaze direction provides a processing advantage, possibly due to an increase in the allocation of attention to the region corresponding to gaze direction. Thus, the apparent gradient of attention could also have been due to observers' gazes being directed forward toward the attended central loudspeaker.…”

Links between eye movement preparation and the attentional processing of tactile events: An event-related brain potential study

“…Similarly, a group of neurons in the frontal eye field becomes active before a saccade is executed either toward an auditory or a visual target (Russo and Bruce, 1994). In addition, behavioural studies have demonstrated improved performance for sounds at fixation (Gopher, 1973; Hublet et al, ​1976, ​1977; Jones and Kabanoff, 1975; Morais et al, 1980; Reisberg et al, 1981), as well as for sounds presented at the destination of an upcoming saccade (Rorden and Driver, 1999; Lie and Coslett, 2006), suggesting that eye gaze may affect auditory processing in a spatially specific fashion.…”

Simultanagnosia: When a Rose Is Not Red

“…'s deficit demonstrated in Experiment 4 is consistent with our hypothesis that he is unable to bind information computed in the ventral and dorsal visual systems. In previous work we have demonstrated that performance on tasks that appear to have no explicit spatial dimension-for example, languagemay be influenced by spatial factors (Coslett, 1999;Coslett, Schwartz, Goldberg, Haas, & Perkins, 1993; see also Lie, McCrae, & Coslett, 2006). On the basis of these data, we argued that stimuli with no apparent spatial dimension are marked for location; furthermore, we argued that a disruption of the binding of this location information to language and other sensorimotor systems may underlie these spatial effects (Coslett, 1999).…”