2.3. Stimuli

All items in the four experimental conditions are morphologically complex German noun forms. These are constructed on the basis of sequences of morphological rules in German. In ‘SW’ and in ‘CW,’ all stimuli selected are existing German words that we find in everyday language and in corpora such as CELEX (Baayen, Piepenbrock, & Gulikers, 1995) and the DWDS (Klein & Geyken, 2010). In ‘SW,’ the noun is derived from a base adjective or verb in a single derivational step. Nouns in condition ‘SW’ are therefore morphologically simpler than nouns in ‘CW.’ With the purpose of providing a greater variety of visually dissimilar items, the stimuli in ‘SW’ are formed following one of the two morphological rules given below:

a) base verb > noun in ‐ung as in deuten_V (‘interpret’) > Deutung _N (‘interpretation’)

b) base adjective > noun in ‐igkeit as in müde_A (‘tired’) > Müdigkeit _N (‘tiredness’)

Nouns in ‘CW’ have more morphological complexity as one additional derivational step is required to go back to the base word, which can again be either an adjective or a verb. To illustrate this difference, the complex noun Deutung_N (‘interpretation’) in condition ‘SW’ is 1‐step derived from its verbal base in deuten_V (‘interpret’). The verb heilen (‘to heal’), on the other hand, from which the noun Heilung_N (‘healing’) is derived, is already complex. It is zero‐derived from the base adjective heil (‘whole, intact’) to which an inflectional marker ‐en is added. The constraint that the more complex pseudowords are created in a two‐level process follows from morphological rules of word‐formation in German. As discussed in Fleischer and Barz (1995), nouns in ‐ung can only productively be derived from a verbal, but not an adjectival base. This means that the intermediate step has to be computed ‘on‐line’ in order to satisfy the morphological constraints of the language. In a similar vein, derivations in ‐keit require an adjectival, rather than a verbal base. This gives the following two sequences of morphological rules that derive nouns in condition ‘CW’:

c) base adjective > zero‐derived verb > noun in ‐ung as in heil _A (‘whole, intact’) > heilen_V (‘heal’) > Heilung _N (‘healing’)

d) base verb > adjective in ‐bar > noun in ‐keit as in lesen_V (‘read’) > lesbar_A (‘readable’) > Lesbarkeit _N (‘readability’)

Overall, the nouns presented in the two ‘word’ conditions ‘SW’ and ‘CW’ (such as Deutung and Heilung) look visually similar, but differ in inherent morphological complexity.

Both pseudowords in conditions ‘SP’ and ‘CP’ are formed according to the morphological rules given in (c) and (d). However, they differ in the number of derivational steps that proceed without a lexical representation and thus in the degree of morphological complexity that is expressed through lexical gaps. To illustrate this, *Spitzung in ‘SP’ is formed following the derivational chain in (c) with the final position being filled with a lexical gap as shown in (e):

e) spitz_A (‘sharp’) > spitzen_V (‘sharpen’) > *Spitzung _N (‘sharpening’)

For stimuli in ‘CP’ such as *Hübschung, already the intermediate position (i.e. the zero‐derived verb *hübschen) is a lexical gap. The structural analysis required for *Hübschung can thus be expected to be more complex than for *Spitzung. The derivational chain leading to *Hübschung has the format shown in (f):

f) hübsch_A (‘beautiful’) > *hübschen_V (‘beautify’) > *Hübschung _N (‘beautification’)

To match the types of suffixes presented in the two existing word conditions, half the pseudowords employed in conditions ‘SP’ and ‘CP’ are constructed using the sequence of morphological rules given in (d). For clarity, Table ​Table11 gives an overview of the key characteristics of all four experimental conditions.

Summary stimulus characteristics

Abbreviations: SW = simpler word; CW = complex word; SP = simpler pseudoword; CP = complex pseudoword.

Two filler conditions with 20 items per condition are included to provide a greater variety of visual stimuli. One group consists of existing words that are morphologically complex and matched in length and syllable stress with the two groups of existing items in the experimental conditions. Nonwords in the other filler condition consist of items that are composed of existing stems and suffixes in German, but for which the combination of stem and suffix is not morphologically possible (e.g. *Wirrlein for which the suffix ‐lein would require a nominal, not an adjectival base). 20% of trials consist of fixation crosses to acquire a null‐baseline.

Items in all four experimental conditions, as well as nonword fillers are matched on lexical factors such as base lemma and whole form frequency, orthographic and morphological family size of the base, length, syllable structure, stress pattern and phonological family size (see Table ​Table2).2). Morphological family size measures were obtained by extracting the number of semantically transparent morphologically related words for a given base in CELEX (Baayen et al., 1995). Orthographic and phonological neighbourhood sizes were computed using Clearpond (Marian, Bartolotti, Chabal, & Shook, 2012). In addition to this, lemma and whole word frequencies, as well as ratings of imageability for the complex word were matched between the two conditions containing existing words (all ps > .25). All stimuli in our experimental conditions and fillers are provided in the Supporting Information.

Stimulus matching across word and pseudoword conditions

Abbreviations: SW = simpler word; CW = complex word; SP = simpler pseudoword; CP = complex pseudoword; NW = nonword filler.

Note: Numbers are rounded to the second decimal place.