Linguistic assessment tools for the Digisonic® Dual electric-acoustic speech processor

Interdisciplinary domains LUC

The effects of stimulus complexity on the preattentive processing of self-generated and nonself voices: an ERP study

The ability to differentiate one's own voice from the voice of somebody else plays a critical role in successful verbal self-monitoring processes and in communication. However, most of the existing studies have only focused on the sensory correlates of self-generated voice processing, whereas the effects of attentional demands and stimulus complexity on self-generated voice processing remain largely unknown. In this study, we investigated the effects of stimulus complexity on the preattentive processing of self and nonself voice stimuli. Event-related potentials (ERPs) were recorded from 17 healthy males who watched a silent movie while ignoring prerecorded self-generated (SGV) and nonself (NSV) voice stimuli, consisting of a vocalization (vocalization category condition: VCC) or of a disyllabic word (word category condition: WCC). All voice stimuli were presented as standard and deviant events in four distinct oddball sequences. The mismatch negativity (MMN) ERP component peaked earlier for NSV than for SGV stimuli. Moreover, when compared with SGV stimuli, the P3a amplitude was increased for NSV stimuli in the VCC only, whereas in the WCC no significant differences were found between the two voice types. These findings suggest differences in the time course of automatic detection of a change in voice identity. In addition, they suggest that stimulus complexity modulates the magnitude of the orienting response to SGV and NSV stimuli, extending previous findings on self-voice processing.This work was supported by Grant Numbers IF/00334/2012, PTDC/PSI-PCL/116626/2010, and PTDC/MHN-PCN/3606/2012, funded by the Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) and the Fundo Europeu de Desenvolvimento Regional through the European programs Quadro de Referencia Estrategico Nacional and Programa Operacional Factores de Competitividade, awarded to A.P.P., and by FCT Doctoral Grant Number SFRH/BD/77681/2011, awarded to T.C.info:eu-repo/semantics/publishedVersio

Genetic predisposition and sensory experience in language development: Evidence from cochlear-implanted children

Recent neurobiological studies have advanced the hypothesis that language development is not continuously plastic but is governed by biological constraints that may be modified by experience within a particular time window. This hypothesis is tested based on spontaneous speech data from deaf cochlear-implanted (CI) children with access to linguistic stimuli at different developmental times. Language samples of nine children who received a CI between 5 and 19 months are analysed for linguistic measures representing different stages of language development. These include canonical babbling ratios, vocabulary diversity, and functional elements such as determiners. The results show that language development is positively related to the age at which children get first access to linguistic input and that later access to language is associated with a slower-than-normal language-learning rate. As such, the positive effect of early experience on the functional organisation of the brain in language processes is confirmed by behavioural performance. © 2011 Psychology Press