Adrian Staub

The time course of competition for attention: attention is initially labile.

Competition for attention between 2 written words was investigated by presenting the words briefly in a single stream of distractors (Experiment 1) or in different streams (Experiment 2-6), using rapid serial visual presentation at 53 ms/item. Stimulus onset asynchrony (SOA) was varied from 0 to 213 ms. At all SOAs there was strong competition, but which word was more likely to be reported shifted markedly with SOA. At SOAs in the range of 13-53 ms the second word was more likely to be reported, but at 213 ms, the advantage switched to the first word, as in the attentional blink. A 2-stage competition model of attention is proposed in which attention to a detected target is labile in Stage 1. Stage 1 ends when one target is identified, initiating a serial Stage 2 process of consolidation of that target.

Eye movements in reading words and sentences

Publisher Summary The two most robust findings in studies of eye movements and reading are that (1) fixation time on a word is shorter if the reader has a valid preview of the word prior to fixating it, and (2) fixation time is shorter when the word is easy to identify and understand. Word recognition processes seem to be reflected quite straightforwardly in the eye movement record. In contrast, eye movements seem to reflect sentence comprehension processes in a more varied fashion. This chapter reviews the major word identification factors that affect eye movements and describe the role these eye movement phenomena have played in developing theories of eye movements in reading. The chapter tabulates and summarizes 100 reports of how syntactic, semantic, pragmatic, and world-knowledge factors affect eye movements during reading in an initial attempt to identify order in how different types of challenges to comprehension are reflected in eye movements. The chapter reviews findings that have demonstrated effects due to (1) word frequency, (2) word familiarity, (3) age-of-acquisition, (4) number of meanings, (5) morphology, (6) contextual constraint, and (7) plausibility.

Eye movements and processing difficulty in object relative clauses.

It is well known that sentences containing object-extracted relative clauses (e.g., The reporter that the senator attacked admitted the error) are more difficult to comprehend than sentences containing subject-extracted relative clauses (e.g., The reporter that attacked the senator admitted the error). Two major accounts of this phenomenon make different predictions about where, in the course of incremental processing of an object relative, difficulty should first appear. An account emphasizing memory processes (Gibson, 1998; Grodner & Gibson, 2005) predicts difficulty at the relative clause verb, while an account emphasizing experience-based expectations (Hale, 2001; Levy, 2008) predicts earlier difficulty, at the relative clause subject. Two eye movement experiments tested these predictions. Regressive saccades were much more likely from the subject noun phrase of an object relative than from the same noun phrase occurring within a subject relative (Experiment 1) or within a verbal complement clause (Experiment 2). This effect was further amplified when the relative pronoun that was omitted. However, reading time was also inflated on the object relative clause verb in both experiments. These results suggest that the violation of expectations and the difficulty of memory retrieval both contribute to the difficulty of object relative clauses, but that these two sources of difficulty have qualitatively distinct behavioral consequences in normal reading.

Recognition Memory for Briefly Presented Pictures: The Time Course of Rapid Forgetting

When viewing a rapid sequence of pictures, observers momentarily understand the gist of each scene but have poor recognition memory for most of them (M. C. Potter, 1976). Is forgetting immediate, or does some information persist briefly? Sequences of 5 scenes were presented for 173 ms/picture; when yes-no testing began immediately, recognition was initially high but declined markedly during the 10-item test. With testing delays of 2 or 6 s, the decline over testing was less steep. When 10 or 20 pictures were presented, there was again a marked initial decline during testing. A 2-alternative forced-choice recognition test produced similar results. Both the passage of time and test interference (but not presentation interference) led to forgetting. The brief persistence of information may assist in building a coherent representation over several fixations.

The effect of lexical predictability on distributions of eye fixation durations

A word’s predictability in context has a well-established effect on fixation durations in reading. To investigate how this effect is manifested in distributional terms, an experiment was carried out in which subjects read each of 50 target words twice, once in a high-predictability context and once in a low-predictability context. The ex-Gaussian distribution was fit to each subject’s first-fixation durations and single-fixation durations. For both measures, the μ parameter increased when a word was unpredictable, while the τ parameter was not significantly affected, indicating that a predictability manipulation shifts the distribution of fixation durations but does not affect the degree of skew. Vincentile plots showed that the mean ex-Gaussian parameters described the typical distribution shapes extremely well. These results suggest that the predictability and frequency effects are functionally distinct, since a frequency manipulation has been shown to influence both μ and τ. The results may also be seen as consistent with the finding from single-word recognition paradigms that semantic priming affects only μ.

The Effect of Lexical Predictability on Eye Movements in Reading: Critical Review and Theoretical Interpretation

A words predictability in its context has a reliable influence on eye movements in reading. This article reviews the extensive literature that has investigated this influence, focusing on several specific empirical issues. These include assessment of cloze probability as the critical measure of predictability, the form of the relationship between predictability and reading time, the distributional effects of predictability, the interaction between predictability and word frequency, and the interaction between predictability and parafoveal preview. On the basis of this review, two theoretical conclusions are proposed. First, predictability effects in reading result from graded activation of potentially many words, as opposed to discrete prediction of a specific word. Second, this activation has the effect of facilitating either very early stages of lexical processing or pre-lexical processing of visual features or letters.

Parallelism and Competition in Syntactic Ambiguity Resolution

A central issue in sentence-processing research is whether the parser entertains multiple analyses of syntactically ambiguous input in parallel, and whether these analyses compete for selection. In this article, we review theoretical positions for and against such competitive parallelism. We then review empirical evidence, primarily drawing on reading time studies, bearing on the prediction made by parallel competitive models that some cost ought to be associated with processing syntactically ambiguous material. We argue that this prediction is not confirmed by the data, and we discuss recent claims that the models in question do not actually make this prediction. We also emphasize the contrast with lexical ambiguity, where there is clearly a processing cost associated with competition between alternate meanings. Finally, we review a different kind of recent evidence suggesting that two syntactic analyses may indeed coexist under specific circumstances.

Phonological Typicality Does Not Influence Fixation Durations in Normal Reading

Using a word-by-word self-paced reading paradigm, T. A. Farmer, M. H. Christiansen, and P. Monaghan (2006) reported faster reading times for words that are phonologically typical for their syntactic category (i.e., noun or verb) than for words that are phonologically atypical. This result has been taken to suggest that language users are sensitive to subtle relationships between sound and syntactic function and that they make rapid use of this information in comprehension. The present article reports attempts to replicate this result using both eyetracking during normal reading (Experiment 1) and word-by-word self-paced reading (Experiment 2). No hint of a phonological typicality effect emerged on any reading-time measure in Experiment 1, nor did Experiment 2 replicate Farmer et al.s finding from self-paced reading. Indeed, the differences between condition means were not consistently in the predicted direction, as phonologically atypical verbs were read more quickly than phonologically typical verbs, on most measures. Implications for research on visual word recognition are discussed.

The word grouping hypothesis and eye movements during reading

The distribution of landing positions and durations of first fixations in a region containing a noun preceded by either an article (e.g., the soldiers) or a high-frequency 3-letter word (e.g., all soldiers) were compared. Although there were fewer first fixations on the blank space between the high-frequency 3-letter word and the noun than on the surrounding letters (and the fixations on the blank space were shorter), this pattern did not occur when the noun was preceded by an article. R. Radach (1996) inferred from a similar experiment that did not manipulate the type of short word that 2 words could be processed as a perceptual unit during reading when the first word is a short word. As this different pattern of fixations is restricted to article-noun pairs, it indicates that word grouping does not occur purely on the basis of word length during reading; moreover, as the authors demonstrate, one can explain the observed patterns in both conditions more parsimoniously without adopting a word-grouping mechanism in eye movement control during reading.

Individual differences in fixation duration distributions in reading.

The present study investigated the relationship between the location and skew of an individual reader’s fixation duration distribution. The ex-Gaussian distribution was fit to eye fixation data from 153 subjects in five experiments, four previously presented and one new. The τ parameter was entirely uncorrelated with the μ and σ parameters; by contrast, there was a modest positive correlation between these parameters for lexical decision and speeded pronunciation response times. The conclusion that, for fixation durations, the degree of skew is uncorrelated with the location of the distribution’s central tendency was also confirmed nonparametrically, by examining vincentile plots for subgroups of subjects. Finally, the stability of distributional parameters for a given subject was demonstrated to be relatively high. Taken together with previous findings of selective influence on the μ parameter of the fixation duration distribution, the present results suggest that in reading, the location and the skew of the fixation duration distribution may reflect functionally distinct processes. The authors speculate that the skew parameter may specifically reflect the frequency of processing disruption.