Basirat, A. 1, 2 & Schwartz, J. 1
1 GIPSA-Lab, Speech and Cognition Department, UMR 5216 CNRS – Grenoble University, France
2 CEA, DSV/I2BM, NeuroSpin Center, Gif sur Yvette, France
The verbal transformation effect refers to perceptual switches while listening to a speech form repeated rapidly and continuously. It is a specific case of perceptual multistability phenomena, which provide rich paradigms to study the processes underlying the perceptual organization of sensory scenes. The present work aims at integrating the verbal transformation effect into a computational psycholinguistic model of speech perception, while taking into account the recent findings on the role of the multisensory interactions in the emergence and the stability of verbal transformations. It is important to note that psycholinguistic models are not able to explain the verbal transformation effect in their present form. An extension of the TRACE model of speech perception, able to produce verbal transformations in a multisensory framework is presented. Two major behavioral data are considered: firstly, evidence that the speech reading penetrates the verbal transformation effect, secondly, evidence for a possible role of the onset of the visible opening gesture of the jaw and lips. These results are observed with French speaking participants. Three components are added to the TRACE model: a satiation-like mechanism, a temporal binding window and an articulatory bias. The simulation results show the model’s ability to explain the experimental data obtained previously. This work suggests that the psycholinguistic models could take into account, at least partly, the multistable perception of speech. It raises questions about the interactions between the perceptual organization of speech and psycholinguistic processes for lexical access and speech understanding.