Effects of concurrent task demands on language planning in fluent children and adults

The aim of the present study was to investigate how children and adults allocate cognitive resources to performing segmental encoding and monitoring in a dual-task paradigm and the response patterns of the primary and secondary tasks in the dual task. Participants were 20 children divided equally into two age groups (7-11 and 12-15 years) and 10 adults. The primary task required participants to monitor phonemic segments in a picture-written word interference paradigm while silently naming the pictures. The picture and distractor word were the same (replica), related (phoneme onset overlap), or unrelated. The secondary task required participants to make pitch judgments on tones presented at short (330 ms) or long (1130 ms) stimulus onset asynchrony (SOA) from picture onset. Developmental differences were observed in both response times and percentage errors in the primary and secondary tasks. Slower responses to the primary task were evident at the long SOA, related condition. Slower response times to the tone decision task were evident at the short rather than the long SOA. The findings support the capacity sharing account of dual-task performance and suggest that dual-task costs during language planning are higher in children than in adults.