(How) Does emotional prosody influence word learning? We attempt to find an answer to this question by conducting word learning experiments with young children.
The objective of our project is to investigate the interaction of emotion, cognition and lan-guage in the early development of children. We focus on the influence of affective prosody on word learning in 14-, 20- and 26-month-old children. We study the role of positive affect (i.e., "happy" intonation) and negative affect (i.e., "warning" intonation), each contrasted with neutral intonation (i.e., like a news speaker). The age groups we test are at different stages in lan-guage acquisition, but each group is capable of fast mapping, that is, all children are able to map a novel word on a novel referent after only a few exposures, thus creating a partial lexical entry. We make use of this ability in the design of our study.
To study the influence of affective prosody on word learning, we combine two different methods: a non-behavioural event-related potentials paradigm and a behavioural object-selection task. During training, in which the EEG is taken, the children are presented with 32 novel objects in combination with novel words. Half of the object-word-pairings are presented with positive (negative) intonation; the other half is presented with neutral intonation. Within each emotion condition, half of the objects are presented in each of the 8 presentations with the same word (= learning possible), the other half of the objects are combined with different words in each of the 8 presentations (= no learning possible). During the behavioural test phase, shortly after the training phase, the children are asked to identify a named object out of a row of 4 objects, which all had been presented with the same affect in the training phase. To investigate the memory for words, this behavioural test phase is repeated on the next day.
The preliminary results of our first study comparing the influence of positive vs. neutral prosody show for the EEG analysis emotion-related processing differences: in the neutral af-fective condition we find the expected components (N200-500 and N400) associated with phonological and lexical-semantic learning. However, in the positive affective condition we do not find these components. That this result is not due to a lack of learning in the children is confirmed by the data from the behavioural test phase. Especially the 20-month-olds benefit, on the first day though not on the second, from emotional prosody: they more often chose the named object correctly when it was presented with positive intonation during training than when it was presented with neutral intonation. The 14- and the 26-month-olds do not seem to benefit from emotional prosody. However, the reasons for this seem to be of a different nature. With the 14-month-olds the reason may lie in their yet limited word learning capacity, whereas the 26-month-olds showed learning in both emotional conditions and on both days, thus demonstrating a greater independence of social-emotional cues.
We recently have begun our second study in which we contrast negative and neutral affect.
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