Morphemes in written word production
8th International Conference of the European Association for
Research on Learning and Instruction (EARLI) Writing Special Interest Group (SIG):
Writing02, 10th to 13th July 2002, Staffordshire University, Stafford, UK,
Vortrag in der AG2 "Cognitive processes in writing".
Guido Nottbusch, Angela Grimm & Rüdiger Weingarten
(University of Osnabrueck): Morphemes in written word production.
Abstract: In previous studies we found that the time course
of typing in written language production correlates closely to the linguistic
structures within words: The duration of inter-keystroke intervals (IKIs) was
significantly longer when a syllable commenced with the following key (S-type) and
was longest when the key at the same time marked the beginning of a new morpheme
(SM-type). The latter were influenced by word frequencies, indicating lexical
dependencies. These effects were stable under various conditions (written, oral
and pictorial stimulus) and in different languages (English, German). Therefore we
conclude that the input into the motor system is composed of sub-word units
instead of fully specified words.
In the present study we concentrate on the SM-type IKIs and explore the influence
of two aspects: In Experiment 1 we investigate possible timing differences in the
access of different types of morphemes. Under the assumption that the duration of
the IKI preceding a combined syllable and morpheme boundary (SM) is affected of
its lexical access, we compared German words (a) containing prefixes (e.g.
<vor-verkaufen> [to sale in advance] and compounds (e.g.
<Natur-volk> [primitive race] and (b) words containing suffixes (e.g.
<Heiter-keit> [cheerfulness]) and again compounds (e.g.
<Wasser-krug> [water jug]). Differences in timing at the start of
stem morphemes and suffixes were significant, the latter being initiated faster.
The slight differences between the initiation of prefixes and stems were
nonsignificant. Our proposal to explain these results is as follows: For prefixes
a following unit is obligatory. ( Prefix+[Prefix+Stem] ). The access to prefixes
seems to be influenced by frame information of the following unit containing a
stem. For suffixes constraints are different: A following unit after a suffix is
only optional. (This can only be another suffix or a new frame containing a stem.)
( [Stem+Suffix] ) In the case of Stem+Suffix constructions the access to the
suffix is faster - no further information is needed.
In our second Experiment we examine the recent results concerning the differences
between absolute and relative word frequencies (see Hay, 2000) adapted to the
field of written word production. Therefore we selected German compounds and
prefixed words that have (a) a high whole word frequency but low base (stem)
frequency (e.g. <Gast-geber> [host]), that are possibly accessed in a
holistic fashion and contrast the measured SM-IKIs with (b) words with a low whole
word frequency but a high frequency of the root morpheme beginning at the
SM-boundary (e.g. <Blut-gruppe> [blood group]), probably composed on-line.
In Experiment 2 the overall comparison between higher whole word and base
frequency did not lead to significant differences. The difference becomes clearer
if the frequency levels of the items are taken into account: Significantly
increased latencies at morpheme onsets were found only in low frequency items with
relatively higher base frequency. This is interpreted as an effect of
compositional word production. There may also be compositional processes in high
frequency items with higher base frequency. Possibly in these cases the
compositional processes are too fast to be detected within the time course of word