The effect of decay and lexical uncertainty on processing long-distance dependencies in reading

Abstract

To make sense of a sentence, a reader must keep track of dependent relationships between words, such as between a verb and its particle (e.g. turn the music down). In languages such as German, verb-particle dependencies often span long distances, with the particle only appearing at the end of the clause. This means that it may be necessary to process a large amount of intervening sentence material before the full verb of the sentence is known. To facilitate processing, previous studies have shown that readers can preactivate the lexical information of neighbouring upcoming words, but less is known about whether such preactivation can be sustained over longer distances. We asked the question, do readers preactivate lexical information about long-distance verb particles? In one self-paced reading and one eye tracking experiment, we delayed the appearance of an obligatory verb particle that varied only in the predictability of its lexical identity. We additionally manipulated the length of the delay in order to test two contrasting accounts of dependency processing: that increased distance between dependent elements may sharpen expectation of the distant word and facilitate its processing (an antilocality effect), or that it may slow processing via temporal activation decay (a locality effect). We isolated decay by delaying the particle with a neutral noun modifier containing no information about the identity of the upcoming particle, and no known sources of interference or working memory load. Under the assumption that readers would preactivate the lexical representations of plausible verb particles, we hypothesised that a smaller number of plausible particles would lead to stronger preactivation of each particle, and thus higher predictability of the target. This in turn should have made predictable target particles more resistant to the effects of decay than less predictable target particles. The eye tracking experiment provided evidence that higher predictability did facilitate reading times, but found evidence against any effect of decay or its interaction with predictability. The self-paced reading study provided evidence against any effect of predictability or temporal decay, or their interaction. In sum, we provide evidence from eye movements that readers preactivate long-distance lexical content and that adding neutral sentence information does not induce detectable decay of this activation. The findings are consistent with accounts suggesting that delaying dependency resolution may only affect processing if the intervening information either confirms expectations or adds to working memory load, and that temporal activation decay alone may not be a major predictor of processing time.

Does entropy modulate the prediction of German long-distance verb particles?

“…Particle verbs and similar complex predicate constructions have previously been used to investigate the presence of long-distance lexical predictions in Dutch (Piai et al, 2013), Hindi (Husain et al, 2014), Persian (Safavi et al, 2016), and German (Stone et al, 2020).…”

“…In reading time studies of Hindi and Persian, it was found that distance, the strength of the predictability of the head-final verb, and the type of intervening information may determine whether or not a lexical prediction is made and whether it can be maintained to facilitate reading (Husain et al, 2014;Safavi et al, 2016). In German, higher certainty about the identity of a particle facilitated early eye fixation times at the particle, but not self-paced reading times (Stone et al, 2020).…”

“…If contextual cues are sufficiently constraining, preactivation may crystallise into prediction of one specific word. Such lexical predictions may benefit readers in processing long-distance dependencies, where key information to interpreting an event is delayed (Husain, Vasishth, & Srinivasan, 2014;Safavi, Husain, & Vasishth, 2016;Stone, von der Malsburg, & Vasishth, 2020). For example, German particle verb constructions allow a large amount of material to separate a verb (e.g.…”

“…Rather than waiting for the particle to appear, readers may predict its identity in order to anticipate the event being described and facilitate processing of the intervening material. However, evidence that readers commit to such specific long-distance content is mixed (Husain et al, 2014;Safavi et al, 2016, Stone et al, 2020 cf. Piai, Meyer, Schreuder, & Bastiaansen, 2013, Stone et al, 2020.…”

“…However, evidence that readers commit to such specific long-distance content is mixed (Husain et al, 2014;Safavi et al, 2016, Stone et al, 2020 cf. Piai, Meyer, Schreuder, & Bastiaansen, 2013, Stone et al, 2020. In this paper, we capitalise on the properties of German particle verbs to test whether readers commit to a specific lexical prediction when the context supports such a prediction.…”