This study investigates 12 prespeech vocal behaviors which are taken to reflect children's phonological, communicative and early symbolic development. It explores their development (onset, duration and extinction) and their relation to early lexical development. A structured parental questionnaire on prespeech vocalizations was developed, validated and used for the evaluation of 1005 Spanish children's early vocal development (8-30 months). In parallel, the same children's productive vocabulary was assessed using the vocabulary section of the European-Spanish MacArthur-Bates Communicative Development Inventories. Results highlight a global inverted U-shaped developmental pattern which emerges from the asynchronous development of the vocal behaviors examined, relating both their emergence and extinction to advances in linguistic development. Moreover, the protracted coexistence of prespeech vocalizations with early speech and their significant correlations with vocabulary size reveal a gradual transition into language. Overall results reinforce and extend previous findings on the development of prespeech vocalizations and establish their relevance as early indexes of linguistic development. Finally, positive evidence on the use of an assisted parental report method for reliably evaluating these developments is provided. Results are discussed within theoretical frameworks that conceive language as the emergent product of complex developmental processes.
The use of the task-evoked pupillary responses (TEPRs) methodology is emerging in the psycholinguistics literature, as a sensitive, reliable and dynamic psychophysiological measure of the cognitive effort produced by various aspects of language processing. This preliminary study aimed to assess the functionality and effectiveness of a TEPRs design for measuring the cognitive effort required for the processing and spontaneous (non-explicitly prompted) short-term retention of novel phonological forms presented auditorily. Twenty-four young adult participants (aged 19–28 years, M = 20.3, SD = 2.13) were auditorily presented with a series of pseudowords differing in their number of syllables and their syllabic complexity. Then, they were asked to produce a response to a delayed pseudoword–color matching task aimed to induce the short-term retention of the novel forms. Results on the size and timing of the TEPRs reveal a significant pupillary activation, starting immediately after the presentation of the auditory stimuli, peaking at 1080 ms and not subsiding significantly during the protracted retention period. Moreover, the differential complexity of the novel words phonology significantly affected pupillary activation. Overall, these preliminary results point to the effectiveness of pupillometry as a technique for capturing the cognitive effort entailed in the short-term maintenance of novel word forms in the phonological loop, a process deemed crucial in the everyday novel word learning process. Results are discussed in view of future research that could establish and extend their implications.