Effects of Congenital Visual Deprivation on the Auditory Perception of Anticipatory Labial Coarticulation.

Objective: It has been shown previously that congenitally blind francophone adults had higher auditory discrimination scores than sighted adults. It is unclear, however, if, compared to their sighted peers, blind speakers display an increased ability to detect anticipatory acoustic cues. In this paper, this ability is investigated in both speaker groups.

Silent articulation modulates auditory and audiovisual speech perception.

The concept of an internal forward model that internally simulates the sensory consequences of an action is a central idea in speech motor control. Consistent with this hypothesis, silent articulation has been shown to modulate activity of the auditory cortex and to improve the auditory identification of concordant speech sounds, when embedded in white noise. In the present study, we replicated and extended this behavioral finding by showing that silently articulating a syllable in synchrony with the presentation of a concordant auditory and/or visually ambiguous speech stimulus improves its identification.

Anticipatory lip gestures: a validation of the Movement Expansion Model in congenitally blind speakers.

In this paper, anticipatory co-articulation of the lip protrusion and constriction gestures is investigated in speakers with visual deprivation. Audio-visual recordings of 11 congenitally blind French speakers producing [V-roundC-roundV+round] sequences were measured with a lip shape tracking system. Lip protrusion and constriction values and their relative timings were analyzed.

Test of the movement expansion model: anticipatory vowel lip protrusion and constriction in French and English speakers.

The modeling of anticipatory coarticulation has been the subject of longstanding debates for more than 40 yr. Empirical investigations in the articulatory domain have converged toward two extreme modeling approaches: a maximal anticipation behavior (Look-ahead model) or a fixed pattern (Time-locked model). However, empirical support for any of these models has been hardly conclusive, both within and across languages.

Multistable syllables as enacted percepts: a source of an asymmetric bias in the verbal transformation effect.

Perceptual changes are experienced during rapid and continuous repetition of a speech form, leading to an auditory illusion known as the verbal transformation effect. Although verbal transformations are considered to reflect mainly the perceptual organization and interpretation of speech, the present study was designed to test whether or not speech production constraints may participate in the emergence of verbal representations. With this goal in mind, we examined whether variations in the articulatory cohesion of repeated nonsense words--specifically, temporal relationships between articulatory events--could lead to perceptual asymmetries in verbal transformations.

Multistable representation of speech forms: a functional MRI study of verbal transformations.

We used functional magnetic resonance imaging (fMRI) to localize the brain areas involved in the imagery analogue of the verbal transformation effect, that is, the perceptual changes that occur when a speech form is cycled in rapid and continuous mental repetition. Two conditions were contrasted: a baseline condition involving the simple mental repetition of speech sequences, and a verbal transformation condition involving the mental repetition of the same items with an active search for verbal transformation. Our results reveal a predominantly left-lateralized network of cerebral regions activated by the verbal transformation task, similar to the neural network involved in verbal working memory: the left inferior frontal gyrus, the left supramarginal gyrus, the left superior temporal gyrus, the anterior part of the right cingulate cortex, and the cerebellar cortex, bilaterally.