Exploring the Effect of Cooperation in Reducing Implicit Racial Bias and Its Relationship With Dispositional Empathy and Political Attitudes

International audienc

Adapting to altered auditory cues: Generalization from manual reaching to head pointing

International audienceLocalising sounds means having the ability to process auditory cues deriving from the interplay among sound waves, the head and the ears. When auditory cues change because of temporary or permanent hearing loss, sound localization becomes difficult and uncertain. The brain can adapt to altered auditory cues throughout life and multisensory training can promote the relearning of spatial hearing skills. Here, we study the training potentials of sound-oriented motor behaviour to test if a training based on manual actions toward sounds can learning effects that generalize to different auditory spatial tasks. We assessed spatial hearing relearning in normal hearing adults with a plugged ear by using visual virtual reality and body motion tracking. Participants performed two auditory tasks that entail explicit and implicit processing of sound position (head-pointing sound localization and audio-visual attention cueing, respectively), before and after having received a spatial training session in which they identified sound position by reaching to auditory sources nearby. Using a crossover design, the effects of the above-mentioned spatial training were compared to a control condition involving the same physical stimuli, but different task demands (i.e., a non-spatial discrimination of amplitude modulations in the sound). According to our findings, spatial hearing in one-ear plugged participants improved more after reaching to sound trainings rather than in the control condition. Training by reaching also modified head-movement behaviour during listening. Crucially, the improvements observed during training generalize also to a different sound localization task, possibly as a consequence of acquired and novel head-movement strategies

Exploring the Effect of Cooperation in Reducing Implicit Racial Bias and Its Relationship With Dispositional Empathy and Political Attitudes

International audienc

Reaching to Sounds Improves Spatial Hearing in Bilateral Cochlear Implant Users

International audienceObjectives: We assessed if spatial hearing training improves sound localization in bilateral cochlear implant (BCI) users and whether its benefits can generalize to untrained sound localization tasks. Design: In 20 BCI users, we assessed the effects of two training procedures (spatial versus nonspatial control training) on two different tasks performed before and after training (head-pointing to sound and audiovisual attention orienting). In the spatial training, participants identified sound position by reaching toward the sound sources with their hand. In the nonspatial training, comparable reaching movements served to identify sound amplitude modulations. A crossover randomized design allowed comparison of training procedures within the same participants. Spontaneous head movements while listening to the sounds were allowed and tracked to correlate them with localization performance. Results: During spatial training, BCI users reduced their sound localization errors in azimuth and adapted their spontaneous head movements as a function of sound eccentricity. These effects generalized to the head-pointing sound localization task, as revealed by greater reduction of sound localization error in azimuth and more accurate first head-orienting response, as compared to the control nonspatial training. BCI users benefited from auditory spatial cues for orienting visual attention, but the spatial training did not enhance this multisensory attention ability. Conclusions: Sound localization in BCI users improves with spatial reaching-to-sound training, with benefits to a nontrained sound localization task. These findings pave the way to novel rehabilitation procedures in clinical contexts

The impact of a visual spatial frame on real sound-source localization in virtual reality

International audienceStudies on audiovisual interactions in sound localization have primarily focused on the relations between the spatial position of sounds and their perceived visual source, as in the famous ventriloquist effect. Much less work has examined the effects on sound localization of seeing aspects of the visual environment. In this study, we took advantage of an innovative method for the study of spatial hearing-based on real sounds, virtual reality and real-time kinematic tracking-to examine the impact of a minimal visual spatial frame on sound localization. We tested sound localization in normal hearing participants (N = 36) in two visual conditions: a uniform gray scene and a simple visual environment comprising only a grid. In both cases, no visual cues about the sound sources were provided. During and after sound emission, participants were free to move their head and eyes without restriction. We found that the presence of a visual spatial frame improved hand-pointing in elevation. In addition, it determined faster first-gaze movements to sounds. Our findings show that sound localization benefits from the presence of a minimal visual spatial frame and confirm the importance of combining kinematic tracking and virtual reality when aiming to reveal the multisensory and motor contributions to spatial-hearing abilities