INtersensory Cooperation in phonological DEvelopment

This proposal investigates the functional role of sensorimotor maturation in two early phonological achievements: phonological specialization (partA) and the emergence of early processing biases (PartB).PartA: Two groups of 10.5-to-12.5-month-olds will undertake two fNIRS experiment following Minagawa-Kawai et al. (2007) with a major modification: one group of infant will complete the task with Early-Learned (own) phonemes (Experiment 1); the other with Late-Learned (non-own) phonemes (Experiment 2).

For each infant, we will collect two indexes of linguistic/oral sensorimotor development.

The statistical analyses (ANOVAs/Linear Mixed Models) will assess whether these indexes predict, for each experiment: (i) early neurofunctional markers of phonological specialization; (b) the degree of activation in frontal-motor areas.PartB: Four groups of 6.30-to-7.30-month-olds will undertake an adapted version of the Conflict Task in Nishibayashi & Nazzi (2016).

Each group will be composed by infants already producing consonants (C-prods) and infants not yet producing consonants (Non-C-prods).

Each group will be assigned to one of the following conditions: (1) test of own sensorimotor knowledge: the participants will perform the conflict task; the analyses will assess whether a difference is observed between C-producers vs Non-C-producers; (2, 3, 4) Test of own and administrated sensorimotor knowledge: the participants will perform the conflict task wearing a mouth-toy that either (2) enhances, (3) inhibits or (4) is neutral with respect to the movements underlying the test items' production.

The statistical analyses (ANOVAs/Linear Mixed Models) will assess if the production-status of the participants predict the emergence of the C-bias.

This will be the first experiment to evaluate the effects of mouth-toys on participants endowed with different levels of sensorimotor development: will mouth-toys have the same effect on infants endowed with higher/lower sensorimotor skills?