Poster A54, Tuesday, August 20, 2019, 10:15 am – 12:00 pm, Restaurant Hall
Dynamics of Word Production in the Transition from Adolescence to Adulthood: an adult-like behaviour in spite of some child-like neurophysiological patterns
Tanja Atanasova1, Raphaël Fargier2, Pascal Zesiger1, Marina Laganaro1;1University of Geneva, 2Aix-Marseille University
To date, studies have been focusing on childhood language development or on language changes related to ageing, while the transition period from childhood to adulthood has only received marginal attention. This is at odds with the knowledge that adolescence reflects a key period in cognitive, social and cortical maturation. A vivid example is the lexical—semantic network, which grows throughout one's entire life, with approximately 40,000 new words learnt from the first decade to adolescence. Lexical selection also becomes more efficient, with production latencies progressively shortening. In fact, variations in the mental processes involved in word production and their time-course are likely to accompany the observed behavioural changes. Previous EEG/ERP studies have shown functional and temporal differences in speech planning processes among school-age children and young adults in picture-naming tasks (Laganaro et al., 2015), with the recruitment of different neural networks in the P100 and the N2/N170 time windows between 10- to 12-year-old children and young adults. The before mentioned N2/N170 component seems to be likely associated with lexical semantic processes in picture naming (Indefrey, 2011). Our aim here was to fill the gap and investigate when and how the youngsters develop an adult-like activation in single word production. We performed a picture-naming experiment under high-density EEG/ERP recording with participants from three age groups: 20 children (10-12 years old), 20 adolescents (15-17 years old) and 20 young adults (20-30 years old). Production latencies and accuracy were not significantly different between adolescents and adults, but differed from those of children for both groups. Waveforms of the three groups were analogous, with boosted and delayed amplitudes in children. We performed microstate analysis of the ERP signal, which allowed us to simultaneously track functional and time-course changes during the development in word encoding processes. Children and adults confirmed their qualitative and quantitative distance and minor topographic differences between adolescents and young adults were shown, however, only some adolescents displayed a similar pattern to that of adults, while others presented a child-like activation pattern in the time-window following the P100 component. The individual factor of chronological age could not be related to any of the presented variations. Our results show mostly adult-like patterns in picture naming in the group of adolescents, but with functional and temporal changes still intervening in specific time-windows underlying the lexical semantic word encoding. The stabilization of production latencies, adult-like in adolescents, and the electrophysiological data illustrate that the acceleration of word production in picture naming occurring in adolescence is not a mere speeding up of mental processes but is also mediated by qualitatively different neural underpinnings. References: Indefrey, P. (2011). The spatial and temporal signatures of word production components: a critical update. Frontiers in Psychology, 2(255). Laganaro, M., Tzieropoulos, H., Fraunfelder U. H. & Zesiger P. (2015). Functional and time-course changes in single word production from childhood to adulthood. Neuroimage, 111, 204-214.
Themes: Language Production, Development
Method: Electrophysiology (MEG/EEG/ECOG)