Thesis defense Sophie De Grauwe (Donders Series 190)
28 October 2015
Promotor: Prof.dr. H. Schriefers, copromotor: Dr. K. Lemhöfer
The Processing of Derivations in Native and Non-Native Speakers of Dutch
In this thesis, the processing of Dutch derivations, i.e., morphologically complex words such as toegeven (‘admit’), was investigated. One of the main questions was whether this type of words is decomposed in its constituent parts (e.g., toe ‘towards’ and geven ‘give’) or processed holistically.
An important factor that could influence this is semantic transparency, i.e., the degree to which the meaning of the complex word as a whole can be derived from the meaning of its parts. For example, a semantically transparent word such as opschrijven (‘write down’, consisting of op- ‘on’ and schrijven ‘write’) may be more easily decomposed than a semantically opaque word such as toegeven. In English, as opposed to German, this has been found to be the case. Dutch, however, has hardly been investigated in this regard.
Another factor that was investigated in this thesis is the motor-relatedness of the stem of the complex word, i.e., the degree to which the stem (e.g., schrijven in opschrijven) refers to an action requiring the use of certain muscles. For example, schrijven (‘write’) refers to an action requiring the use of hand muscles, whereas kiezen (‘choose’, ‘pick’, the stem of uitkiezen ‘pick out’) does not refer to such an action. Previous studies have found differences in processing between morphologically simple motor words such as schrijven and simple non-motor words such as kiezen in terms of processing speed and the brain areas involved. For example, simple motor words, compared to simple non-motor words, have been found to lead to increased activation in the motor and/or premotor cortex, a phenomenon referred to as ‘embodiment’ or ‘embodied language’. However, the effect of motor-relatedness on the processing of morphologically complex words has hardly been studied.
Other factors which were studied in this thesis were language proficiency, by comparing Dutch native and German non-native speakers of Dutch, and experimental context, by comparing different types of morphological priming. The first type of morphological priming investigated was ‘pure’ morphological priming, i.e., priming between a complex word (e.g., toegeven) and its stem (e.g., geven); the second type of morphological priming studied was ‘morpho-semantic priming, i.e., priming between a complex word (e.g., toegeven) and a word semantically related to its stem (e.g., bieden ‘offer’). To investigate the influence of all these factors, both behavioral (morphological priming) and neuroimaging (functional magnetic resonance imaging) methods were used.
The results show that the processing of derivations is influenced not only by semantic transparency, but also by the degree of motor-relatedness of the stem and by the experimental context. Language proficiency, in contrast, did not modulate our results. The effect of motor-relatedness indicates that the degree of motor-relatedness does not only influence the processing of simple words, but also that of morphologically complex words, possibly due to increased semantic activation of motor stems compared to non-motor stems. In addition, our results suggest that morphological priming is not just a neutral tool reflecting how derivations are processed. Instead, the type of morphological priming influences whether or not derivations are decomposed. Finally, semantic and morphological representations seem to be as well developed in advanced German non-native speakers of Dutch as in native speakers, as evidenced by the similarity between the two groups in terms of the activation of brain areas such as the motor cortex and the left inferior frontal gyrus.