Design considerations for the present priming study

In order to test the hypotheses of FUL concerning the priming in the present tense of German strong, weak and mixed verbs, an auditory delayed repetition priming was set up. The choice of the auditory modality had specific reasons. First, FUL evolved as a spoken word recognition model and makes specific predictions for the direct mapping of an acoustic signal onto a lexical representation.

Hence, priming predictions within FUL are foremost applicable to the auditory modality. Second, German have a rather opaque relation between the orthographic and the phonological code. Prime presentations in the visual modality may therefore be affected by this opacity. Furthermore, as shown in the review of the priming literature, visual priming may also involve strategic effects. The reason for a delayed priming design stems from the observation that semantic priming may override subtle morphophonological effects in direct (immediate) repetition priming techniques. In contrast, if there are enough intervening items between prime and target on which subjects are required to give lexical decisions, semantic priming can be suppressed (Henderson et al., 1984; Marslen-Wilson et al., 2000;

Marslen-Wilson et al., 1994). That is, a delayed priming taps into genuine morphological relations not affected by concomitant semantic effects. Furthermore, if the strong verb form schläfst in fact primes its infinitive schlafen in a delayed priming setup, the exclusion of semantic priming suggests that schläfst relates to schlafen morphologically, and not, as suggested in the dual route approach, by associative (semantic) links. Thereby, delayed repetition priming provides a stronger argument for a morphemic representation of the corresponding target verb. For that reason, experiment one and three were laid out as auditory delayed repetition priming.

Table 29: Lexical and acoustic representations of strong, weak and mixed German verb forms and predictions for a reversal of the prime-target direction of experiment 1 and 2, i.e. primes are infinitives and targets are 2ND SG PRES forms (experiment 3 and 4). Priming is predicted if there are no feature mismatches between the acoustic signal and the lexical representation of the respective root vowels. The matching score provides an estimation of lexical activation based on matching and nomismatching features. VERB CLASS PRIME (INFINITIVE)

ACOUSTIC ROOT VOWEL FEATURES MATCHING TO THE LEXICON LEXICAL ROOT VOWEL FEATURES

TARGET (2ND SG) MATCHSCORE PRIMING schl/a/fen [DOR]ART [LOW]TH

nomismatch match [ ]ART [LOW]TH

schl//fst ÂsleepÊ 0.66 yes strong s/e/hen [COR]ART []TH

nomismatch nomismatch[ ]ART []TH

s/i/hst ÂseeÊ 0.5 yes m[a]chen[DOR]ART [LOW]TH

match match[DOR]ART [LOW]TH

m/a/chst ÂmakeÊ 1 yes (most) weak l[e]ben[COR]ART [ ]TH

nomismatch nomismatch[ ]ART []TH

l/e/bst ÂliveÊ 0.5 yes b[a]cken[DOR]ART [LOW]TH

nomismatch match [ ]ART [LOW]TH

b//ckst ÂbakeÊ 0.66 yes mixed qu[]llen [COR]ART []TH

nomismatch nomismatch[ ]ART []TH

qu//llst Âsoak, wellÊ 0.5 yes

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On the other hand, most priming studies one finds in the literature involved a crossmodal design.

Especially, the work of Clahsen and colleagues seeking support for a specific dual route model employed a priming setup in which primes were presented auditorily, while targets appeared as visual representations on a computer screen. Therefore, in order to allow for more direct comparisons with ClahsenÊs data, experiment two and four were designed as crossmodal priming experiments with the same data as in experiment one and three. The other motivation of testing the same data in different priming designs has to do with the proposed nature of the lexical representations. As discussed above, it is assumed that the mental lexicon contains featurally core representations onto which speech inputs from the visual and the auditory modality are mapped in a similar way, namely, by virtue of the ternary feature matching process. Once these lexical representations are activated by an appropriate prime, it should not matter whether the target is presented visually or auditorily: In both cases, the behavioural result will reflect the successful activation of the lexical entry based on featural matches and nomismatches. Thus, based on this consideration, the results of the unimodal repetition priming (experiment 1) should be replicated in a crossmodal priming experiment (experiment 2). However, since in such a design, the targets immediately follow their auditory primes, semantic priming will presumably override subtle morphophonological effects. Therefore, the facilitation in mixed [a]-verbs will not be reduced. On the other hand, a reversal of the prime-target direction in the crossmodal setup (experiment 4) should not lead to different results: The predictions are the same as shown in Table 29.

For experiment 1 and 2, primes were always inflected 2ND SG PRES forms of German strong, weak and mixed verbs. Experiment 3 and 4 reversed the prime-target direction and used infinitives as primes, while targets were in the 2ND SG PRES. The advantage of the 2ND SG PRES is that it has an unambiguous person/number suffix –st. In Sonnenstuhl et al.Ês study (Sonnenstuhl et al., 1999), one possibly confound stemmed from the ambiguous 1ST SG forms (e.g. schlaf-e Âsleep.1ST SG PRESÊ) which can be both the inflected 1ST SG IND or the 2NDIMP form. In all four experiments, priming was determined as the lexical decision time advantage on the targets compared to a control condition. The control condition was construed such that there was no relation between the control prime and the relevant target. Additionally, all experiments included a condition in which prime and target had a semantic relation. This semantic condition served as an additional control: The facilitation in the lexical decision on targets semantically related to their primes should be absent in the delayed repetition priming design, but observable in the immediate crossmodal setup. Thereby, genuine morphological effects can be distinguished from combined semantic and morphological priming. Furthermore, the semantic relation between morphological prime-target pairs in an immediate priming design may override subtle morphophonological effects expected to cause reduced priming in mixed [a]-verbs. Hence, while priming in mixed [a]-verbs should be absent or reduced in a delayed auditory setup, it is likely to be observable in the immediate crossmodal design.

Table 30: Design of priming experiments 1-4. While immediate priming types are expected to yield semantic priming, this priming should be suppressed in designs where a certain

amount of fillers intervene between prime and target (delayed priming type).

EXPERIMENT PRIME TARGET TARGET MODALITY PRIMING TYPE

1 2ND SG INFINITIVE auditory delayed

2 2ND SG INFINITIVE visual immediate

3 INFINITIVE 2ND SG auditory delayed

4 INFINITIVE 2ND SG visual immediate