Wearing prisms to hear differently: After-effects of prism adaptation on auditory perception

Abstract

Numerous studies showed that, after adaptation to a leftward optical deviation, pseudoneglect behavior (overrepresentation of the left part compared to the right part of the space) becomes neglect-like behavior (overrepresentation of the right part compared to the left part of the space). Cognitive after-effects have also been shown in cognitive processes that are not intrinsically spatial in nature, but show spatial association as numbers or letters.The space-auditory frequency association (with low frequencies on the left and high frequencies on the right) raises the question of whether prism adaptation can produce aftereffects on auditory perception. We used a new experimental protocol, named the 'auditory interval bisection judgment', where participants had to estimate what limit of an auditory interval (low or high) a target frequency was closer to. We calculated the subjective auditory interval center. In pretest, there was a spontaneous bias of the subjective center of the auditory interval toward the lower limit. That was the first demonstration of pseudoneglect behavior in auditory frequency representation. ANOVA realized on all participants did not show significant results of prism adaptation, but a posteriori analyses on musicians showed that, after adaptation to a leftward optical deviation, there were more target frequencies perceived as closer to the lower limit of the auditory interval. This result corroborates the shift of the subjective center of the auditory interval toward high frequency limit. These innovative results are discussed in terms of putative neural substrates underpinning the transfer of visuomotor plasticity to auditory frequency perception.

How Does Attention Alter Length Perception? A Prism Adaptation Study

“…Because of the asymmetries in interhemispheric inhibition between the left and right parietal cortex (Koch et al, 2011), leftward-and rightward-deviating PA may affect their contralateral parietal cortex differently thereby causing different effects on spatial tasks. In accordance with this explanation, many other cognitive processing involving spatial representation, such as mental number/alphabetic line bisection (Loftus et al, 2008;Nicholls et al, 2008), auditory perception (Michel et al, 2019), and time representation (Anelli and Frassinetti, 2019), is also modulated by leftward-and rightward-deviating PA in different ways.…”

Visuo-motor rotation influences representational acuity but not space representation

“…The lack of representational after-effects following visuo-motor rotation is the first important result of the present study that has strong methodological implications. Indeed, similar to adaptation to force field (Michel et al, 2019), adaptation to visuo-motor rotation reveals to be an appropriate tool to investigate specifically sensorimotor plasticity without producing any change in space representation assessed with line bisection. Therefore, visuo-motor rotation will be particularly appropriate to study sensorimotor plasticity in individuals who exhibit an inherent bias in space representation (e.g., hyperpseudoneglect in patient with schizophrenia or inverse pseudoneglect in children with dyslexia) (Michel, Bidot, Bonnetblanc, & Quercia, 2011; Michel, Cavezian, et al, 2007) while preserving it from any aggravation of their representational bias.…”

“…stimuli that are not intrinsically spatial but considered as activating a mental spatial representation with a left to right continuum. Such examples are the observation of a bias toward small numbers in a series of numbers (Loftus, Nicholls, Mattingley, Chapman, & Bradshaw, 2009; Longo & Lourenco, 2007), towards earlier alphabetic letters (Zorzi, Priftis, Meneghello, Marenzi, & Umilta, 2006) or even toward low auditory frequencies ((Michel, Bonnet, Podor, Bard, & Poulin-Charronnat, 2019).…”

“…Neglect simulation, expressed by a response bias toward the right space, was not only described in peripersonal space representation, but also occurred in extrapersonal (Berberovic & Mattingley, 2003; Michel, Vernet, Courtine, Ballay, & Pozzo, 2008) and bodily space representations (Michel, Rossetti, et al, 2003). Prism adaptation also produces biases toward features with rightward spatial association by shifting the response biases toward large numbers (Loftus, Nicholls, Mattingley, & Bradshaw, 2008), later letters (Nicholls, Kamer, & Loftus, 2008) or higher auditory frequencies (Michel et al, 2019). Furthermore, prism adaptation to a rightward optical deviation is successfully used in neglect rehabilitation (e.g.…”

Boosting Phonological Fluency Following Leftward Prismatic Adaptation: A New Neuromodulation Protocol for Neurological Deficits?

“…For example, in healthy subjects leftward PA induces a sort of left minineglect, counteracting the physiological leftward bias called pseudoneglect 4,5 . PA aftereffects have also been reported in visual search 6 , endogenous and/or exogenous orienting of attention 7 , spatial/temporal representation 8,910,11,12,13,14, visually guided actions 15 , auditory representation 16 , chronic pain 17 , constructional disorders 18 and reward-based learning 19 .…”