Visual sensory stimulation interferes with people’s ability to echolocate object size

Abstract

Echolocation is the ability to use sound-echoes to infer spatial information about the environment. People can echolocate for example by making mouth clicks. Previous research suggests that echolocation in blind people activates brain areas that process light in sighted people. Research has also shown that echolocation in blind people may replace vision for calibration of external space. In the current study we investigated if echolocation may also draw on ‘visual’ resources in the sighted brain. To this end, we paired a sensory interference paradigm with an echolocation task. We found that exposure to an uninformative visual stimulus (i.e. white light) while simultaneously echolocating significantly reduced participants’ ability to accurately judge object size. In contrast, a tactile stimulus (i.e. vibration on the skin) did not lead to a significant change in performance (neither in sighted, nor blind echo expert participants). Furthermore, we found that the same visual stimulus did not affect performance in auditory control tasks that required detection of changes in sound intensity, sound frequency or sound location. The results suggest that processing of visual and echo-acoustic information draw on common neural resources.

Human click-based echolocation: Effects of blindness and age, and real-life implications in a 10-week training program

“…We analyzed DFM values at 2000 Hz and 500 Hz test frequencies separately. Overall, performance was in line with values reported elsewhere [38,39], and did not differ between BCs and SCs. Specifically, there was no group difference in DFM values for either 2000 Hz (BCs mean: .438, SD: .233; SCs mean: .541, SD: .151; F(1,23) = 1.236; p = .278; η 2 p : .051) or 500 Hz (BCs mean: .188, SD: .222; SCs mean: .322, SD: .238; F(1,23) = .2.101; p = .161; η 2 p : .084), and DFM was not correlated with age (DFM 2000 :r (N=25) = -.190; p: .368; DFM 500 : r (N=25) = -.320; p = .120).…”

“…. This test has been used previously to determine if an individual's ability to determine changes in spectral frequency sound may be related to their ability to echolocate, e.g., [20,38,39]. The test measures participants' ability to detect a change in the frequency (pitch) of a tone.…”

Neuroplastic Reorganization Induced by Sensory Augmentation for Self-Localization During Locomotion

“…Several lines of evidence demonstrate the involvement of occipital visual, rather than somatosensory, areas in echolocation (Thaler et al, 2011(Thaler et al, , 2014Wallmeier et al, 2015). Furthermore, Thaler and Foresteire (2017) reported that, in sighted individuals, echolocation performance was disrupted by task-unrelated visual, but not tactile, stimuli, also suggesting that there is a lack of involvement of the somatosensory areas in echolocation. The major difference between our findings and those of these previous echolocation studies is in the action demanded for locomotion.…”

Effects of Visual Working Memory on Individual Differences in Echolocation Performance in Sighted Participants

“…(2014), who indicated that echolocation involves spatial cognitive processing (e.g., mental imagery). The visual area may not be involved during other auditory control tasks (e.g., change in the sound location; Thaler & Foresteire, 2017). The present results support these findings regarding visual involvement in echolocation and the spatial component of working memory by sighted participants.…”

“…We hypothesized that visual processing and experience would contribute to the representation of mental images and aid echolocation in sighted subjects. In fact, much effort has been expended on characterizing the relationship between echolocation and visual cognitive processing (Tao et al., 2015; Thaler & Foresteire, 2017; Thaler, Wilson, & Gee, 2014). Thus, we expected that sighted individuals with superior visual working memory capacity would perform better in auditory spatial tasks, such as target search and change detection tasks.…”