The choice of SOAs in priming studies

Here we can note that the choice of SOAs is also very important in the design of a priming paradigm. The choice of the SOA is dependent on the phonological priming effect but its locus is still argued quite a lot. Many studies reported a facilitation effect only when using specific SOAs. The fact that there does not seem to be a universal SOA which would guaranty a priming effect makes it difficult to decide which one to use. In the literature of phonological

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priming, a lot of contrastive results have been reported. Negative SOAs especially have been subjected to a lot of debate. Schriefers, Meyer and Levelt (1990) observed no facilitation effect with a negative SOA of -150 ms in a priming paradigm using auditory distractors while other studies reported a facilitation effect for SOAs varying from -100 ms (Damian & Martin, 1999), -150 ms (Meyers & Schriefers, 1991) and as early SOAs as -300 ms (Starreveld, 2000). It is to note, however, that Starreveld (2000) attributed this very early facilitation effect to a strategy of the participants who might have understood the relationship between distractors and pictures from the previous blocks. Jescheniak and Schriefers (2001) tested this hypothesis but they obtained a facilitation effect at SOA -300ms no matter which block the negative SOAs were tested in. Positive SOAs seem to be slightly more reliable. In her study, Meyer (1996) used four different SOAs (0, +150, +300 and +450 ms). The first three SOAs all led to a facilitation effect on the first word but nothing at SOA +450 ms while no effect was reported on the second word of the pairs but the small inhibitory effect. In the same line, Oppermann et al. (2010) also obtained a facilitation effect at SOA 0 ms, +150 ms, +300 ms but nothing at +400 ms. The choice of SOA is therefore very strategic and we cannot rule out that some studies might have reported different results with the use of different SOA. We will investigate this hypothesis further in the review of the literature.

This brief review of the literature focusing on experimental priming paradigms in the study of encoding processed involved in the production of several words is only shedding light on the many divergences remaining from a methodological and a theoretical point of view. The results of studies using priming paradigms in the production of several words is very confusing varying from facilitation effects (Costa & Caramazza, 2002; Alario & Caramazza, 2002; Miozzo & Caramazza, 1999; Schnur et al, 2006, 2011, Oppermann et al., 2010) to no effect (Meyer, 1996; Wheeldon & Lahiri, 1997) or even to inhibitory effects of phonologically related words (Schriefers & Teruel, 1999a; Jescheniak, Schriefers & Hantsch 2003; Meyer, 2006 and Oppermann et al., 2010) when priming the second or third word of a sequence. We do not seem to find a specific pattern in these results whether we look at the language group (Germanic vs. Romance), the grammatical structure of the utterance tested, the type of SOA selected or even the paradigm chosen. All these studies vary a lot in their format and the interpretation of their results and it is still difficult to see whether the effects obtained are induced by the experimental paradigm used or if they do reflect speech processes.

47 Chapter 2: Different empirical methods to investigate ahead planning Still, although there is not a very clear pattern arising from these results whether we group them according to languages (Germanic vs. Romance) the grammatical structure of the utterance tested or even the paradigm chosen, some trends emerge from the different studies.

It seems indeed that it is more difficult to obtain a strong priming effect beyond the first word for Romance languages such as Spanish (Navarrete & Costa, 2005), French (Schriefers &

Teruel, 1999a, Dumay et al., 1999; Damian et al, submitted) and Italian (Miozzo &

Caramazza, 1999). Only one study by Costa & Caramazza (2002) reports a priming effect for the second word in N+A. While studies on English and German (Damian & Dumay, 2007, 2009, Schnur et al, 2006, Schnur, 2011; Oppermann et al., 2010) very often report a span of encoding comprising the entire message, from simple NPs to verbal sentences. Only one study by Schriefers and Teruel (1999b) failed to report an effect on N in A+N. Whether cross-linguistic differences, syntax or speech production context modulate the span of encoding, it is difficult to say in the light of this review of the literature.

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II.5 Conclusion

The span of encoding of adjective NPs has been investigated in many different languages with different structure and very different results were reported. From the review of the psycholinguistic literature, it is difficult to disentangle what determines the span of encoding.

Syntax and cross-linguistic differences could be potential candidates to account for these results but many counter-examples are reported. To find coherence in the diverging interpretations, we will now integrate some linguistic observations from Chapter 1 into the current conclusion.

On the one hand, part of the linguistic literature on the comparison between A+N and N+A suggests that A+N structures are a “default” structure in French. We recall that A+N NPs are the eldest structure in French while N+A are more recent structures (section I.6.1).

Furthermore, theories of Universal Grammar suggest that A+N structures are the canonical structure while N+A structures are more syntactically complex as they are the result of a syntactic movement with the noun rising higher than the adjective (section I.5.2). These arguments actually converge with the fact that it seems easier to obtain phonological priming on the second word of a A+N NP while encoding of the second word in N+A seems more difficult to obtain. As “default” structures, A+N structures might present easier and faster encoding processes while encoding processes involved in N+A might be less systematic.

Moreover, post-nominal adjectives in French (and probably in other Romance languages for which the adjective can be pre-nominal and post-nominal) are described as being more independent of the noun while pre-nominal adjectives and their nouns form a unique entity (Waugh, 1977). This would be an additional clue to the suggestion of a larger span of encoding for A+N relative to N+A.

It is to note that these diverging results do not only suggest different encoding processes for NPs of different syntactic structures but similar phonological length. What they also suggest is that the minimal unit of encoding might not be the initial word. If the minimal unit of encoding was the initial word, then different syntactic structures of the NP would not influence encoding processes involved in the production of NPs. Chapter 3 will investigate these questions further by first comparing the production of one word versus two words and second compare the production of pre-nominal and post-nominal adjective-noun phrases.

49 Chapter 3: Encoding of simple noun-phrases versus adjective-noun phrases

Chapter 3: Encoding of simple