The lost ability to distinguish between self and other voice following a brain lesion

Abstract

Mechanisms underlying the self/other distinction have been mainly investigated focusing on visual, tactile or proprioceptive cues, whereas very little is known about the contribution of acoustical information. Here the ability to distinguish between self and others' voice is investigated by using a neuropsychological approach. Right (RBD) and left brain damaged (LBD) patients and healthy controls were submitted to a voice discrimination and a voice recognition task. Stimuli were paired words/pseudowords pronounced by the participant, by a familiar or unfamiliar person. In the voice discrimination task, participants had to judge whether two voices were same or different, whereas in the voice recognition task participants had to judge whether their own voice was or was not present. Crucially, differences between patient groups were found. In the discrimination task, only RBD patients were selectively impaired when their own voice was present. By contrast, in the recognition task, both RBD and LBD patients were impaired and showed two different biases: RBD patients misattributed the other's voice to themselves, while LBD patients denied the ownership of their own voice. Thus, two kinds of bias can affect self-voice recognition: we can refuse self-stimuli (voice disownership), or we can misidentify others' stimuli as our own (embodiment of others' voice). Overall, these findings reflect different impairments in self/other distinction both at behavioral and anatomical level, the right hemisphere being involved in voice discrimination and both hemispheres in the voice identity explicit recognition. The finding of selective brain networks dedicated to processing one's own voice demonstrates the relevance of self-related acoustic information in bodily self-representation.

Simulating thoughts to measure and study internal attention in mental health

“…Indeed, thought stimuli were designed to reflect thought content central to theories of cognitive vulnerability in depression 18 , 27 , 66 . The use of one’s voice was grounded in behavioral and phenomenological accounts of inner speech, cognitive neuroscience of own-voice perception and self-representations, and embodied cognition accounts of verbal thought 47 , 49 , 51 , 54 . Future research could, for example, be designed to dissociate internal attentional processing of self-referential thought content from motivationally-salient content or negative- from positive-valenced thought content, or between modes for audio delivery of simulated thought stimuli.…”

“…Own-voice thought stimuli as a means to simulate verbal thought is grounded in work on behavioral and phenomenological accounts of inner speech 47 , 48 and cognitive neuroscience of own-voice perception and self-representations 49 , 50 . Hearing one’s own voice activates right prefrontal brain regions implicated in abstract self-representations and self-referential processes (not activated for example when hearing others’ voices) 49 , 51 , 52 nor when simply reading text 53 . Furthermore, our approach to simulated thought through one’s voice is also informed by embodied or simulated accounts of cognition 54 .…”

Neural representations of own-voice in the human auditory cortex

“…Neural mechanisms underlying the perception of self have been examined using faces 7,[15][16][17][18][19][20][21][22][23][24][25][26][27][28] , as well as voices 18,[29][30][31] . These studies reported higher neural activities in subjects observing their own faces/voices than others' faces/voices.…”

Corticospinal Excitability during a Perspective Taking Task as Measured by TMS-Induced Motor Evoked Potentials

“…The current study further supports lateralized findings by demonstrating that self/other discriminations are significantly different between the hemispheres. These data add to a growing amount of evidence that the RH appears critical in evaluating self/other differences, tested across a number of different modalities in non-patient [ 28 , 80 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 ], and patient populations [ 35 , 105 , 106 , 107 , 108 , 109 ]. Decety and Lamm [ 110 ], have suggested that superior right parietal processing may be critical for both switching and differentiating self/other distinctions.…”