Reading in healthy ageing: the influence of information structuring in sentences

In three experiments, we investigated the cognitive effects of linguistic prominence to establish whether focus plays a similar or different role in modulating language processing in healthy ageing. Information structuring through the use of cleft sentences is known to increase the processing efficiency of anaphoric references to elements contained with a marked focus structure. It also protects these elements from becoming suppressed in the wake of subsequent information, suggesting selective mechanisms of enhancement and suppression. In Experiment 1 (using self-paced reading), we found that focus enhanced (faster) integration for anaphors referring to words contained within the scope of focus; but suppressed (slower) integration for anaphors to words contained outside of the scope of focus; and in some cases, the effects were larger in older adults. In Experiment 2 (using change detection), we showed that older adults relied more on the linguistic structure to enhance change detection when the changed word was in focus. In Experiment 3 (using delayed probe recognition and eye-tracking), we found that older adults recognized probes more accurately when they were made to elements within the scope of focus than when they were outside the scope of focus. These results indicate that older adults' ability to selectively attend or suppress concepts in a marked focus structure is preserved.     

Interaction of stimulus and contextual information during reading: Identifying words within sentences

In general, studies on the effects of a sentence context on word identification have focused on how context affects the efficiency of processing a single target word, presented separately from the context. Such studies probably would be incapable of measuring contextual facilitation resulting from cascaded or parallel processing of neighboring words within a sentence. To measure these and other types of facilitation, we presented entire phrases and sentences for subjects to read as fast as possible and to monitor for nonwords. Subjects read at rates representative of natural reading. Experiment 1 demonstrated a large contextual facilitation effect on decision time. Experiment 2 showed that facilitation is caused by specific semantic information and, perhaps to a greater degree, by nonpredictive syntactic information. Experiment 3 showed that the amount of facilitation is greater than could be accounted for by separate contributions from autonomous word level and sentence level processes. These results present difficulties for an autonomous model of reading, but are consistent with interactive models, in which the results of ongoing sentential analyses are combined with stimulus information to identify words.     

Parafoveal preview during reading: effects of sentence position

Two experiments examined parafoveal preview for words located in the middle of sentences and at sentence boundaries. Parafoveal processing was shown to occur for words at sentence-initial, mid-sentence, and sentence-final positions. Both Experiments 1 and 2 showed reduced effects of preview on regressions out for sentence-initial words. In addition, Experiment 2 showed reduced preview effects on first-pass reading times for sentence-initial words. These effects of sentence position on preview could result from either reduced parafoveal processing for sentence-initial words or other processes specific to word reading at sentence boundaries. In addition to the effects of preview, the experiments also demonstrate variability in the effects of sentence wrap-up on different reading measures, indicating that the presence and time course of wrap-up effects may be modulated by text-specific factors. We also report simulations of Experiment 2 using version 10 of E-Z Reader (Reichle, Warren, & McConnell, 2009), designed to explore the possible mechanisms underlying parafoveal preview at sentence boundaries.     

Effects of elaboration and relational distinctiveness on sentence memory

Memory for normal and distinct target sentences in elaborated and isolated contexts was examined in two experiments. Distinctiveness was operationalized as the uniqueness of the stated relation among the elements (words) of the sentence. In both experiments distinct target sentences were recalled significantly better than normal target sentences. Robust elaboration effects emerged only in Experiment 2, however, when care was taken to construct elaborations that were causally related to the target sentences. Further, the positive mnemonic effects of elaboration in Experiment 2 combined additively with the distinctiveness effects. These results demonstrate that text manipulations emphasizing both relational distinctiveness and causal elaboration facilitate memory performance. Several possible theoretical mechanisms underlying this facilitation are outlined.     

Lexical processing and text integration of function and content words: Evidence from priming and eye fixations

The results of two experiments comparing processing of function words and content words are reported. In Experiment 1, priming was present for both related function and related content word pairs, as measured in lexical decision response times. In Experiment 2, participants' eye movements were monitored as they read sentences containing either a high- or a low-frequency function or content target word. Average word length and word frequency were matched across the function and content word conditions. Function words showed frequency effects in first-fixation and gaze duration that were similar to those seen for content words. Clear differences in on-line processing of function and content words emerged in later processing measures. These differences were reflected in reading patterns and reading time measures. There was inflated processing time in the phrase immediately following a low-frequency function word, and participants made more regressions to the target word in this condition than in the other three conditions. The priming effects in lexical decision and the word frequency effects in initial processing measures in silent reading for both word types were taken as evidence of common lexical processing for function and content words. The observed differences in later processing measures in the eye-movement data were taken as evidence of differences in the role that the two word types have in sentence processing beyond the lexical level.     

Incidental formation of episodic associations: The importance of sentential context

The influence of relevant semantic context on the incidental formation of episodic associations between words was probed in two experiments. In Experiment 1, we examined the influence of associations formed incidentally between unrelated words presented either in isolation or embedded in a sentential context on subsequent explicit paired-associate leaning tested by cued recall. The results of Experiment 1 showed that the cued-recall rate of words studied in sentential context was higher than that of words co-occurring in isolated pairs. A subsequent single-items recognition test showed equal item memory for words studied in sentences than for words studied in isolated pairs, suggesting that the sentential context effect in cued recall indeed reflected stronger associations between paired words rather than better memory for single words. In Experiment 2, we ruled out memory for the entire sentence as an alternative explanation for the results of Experiment 1. We suggest two possible mechanisms to account for this advantage: First, pairs embedded in a sentence undergo semantic elaboration that might lead to the incidental formation of an association between them. Second, words embedded in a sentence enjoy the conjoint activation of compatible semantic features, a fact that may also facilitate the formation of an episodic association between them. The implications of these results for computational models using word representations based on co-occurrence data are discussed.     

The influence of lexical and conceptual constraints on reading mixed-language sentences: Evidence from eye fixations and naming times

In two experiments, we explored the degree to which sentence context effects operate at a lexical or conceptual level by examining the processing of mixed-language sentences by fluent Spanish-English bilinguals. In Experiment 1, subjects’ eye movements were monitored while they read English sentences in which sentence constraint, word frequency, and language of target word were manipulated. A frequency × constraint interaction was found when target words appeared in Spanish, but not in English. First fixation durations were longer for high-frequency Spanish words when these were embedded in high-constraint sentences than in low-constraint sentences. This result suggests that the conceptual restrictions produced by the sentence context were met, but that the lexical restrictions were not. The same result did not occur for low-frequency Spanish words, presumably because the slower access of low-frequency words provided more processing time for the resolution of this conflict. Similar results were found in Experiment 2 using rapid serial visual presentation when subjects named the target words aloud. It appears that sentence context effects are influenced by both semantic/conceptual and lexical information.     

Perceptual and response components in repetition priming of spoken words and pseudowords

Two experiments explored repetition priming effects for spoken words and pseudowords in order to investigate abstractionist and episodic accounts of spoken word recognition and repetition priming. In Experiment 1, lexical decisions were made on spoken words and pseudowords with half of the items presented twice (～12 intervening items). Half of all repetitions were spoken in a “different voice” from the first presentations. Experiment 2 used the same procedure but with stimuli embedded in noise to slow responses. Results showed greater priming for words than for pseudowords and no effect of voice change in both normal and effortful processing conditions. Additional analyses showed that for slower participants, priming is more equivalent for words and pseudowords, suggesting episodic stimulus–response associations that suppress familiarity-based mechanisms that ordinarily enhance word priming. By relating behavioural priming to the time-course of pseudoword identification we showed that under normal listening conditions (Experiment 1) priming reflects facilitation of both perceptual and decision components, whereas in effortful listening conditions (Experiment 2) priming effects primarily reflect enhanced decision/response generation processes. Both stimulus–response associations and enhanced processing of sensory input seem to be voice independent, providing novel evidence concerning the degree of perceptual abstraction in the recognition of spoken words and pseudowords.     

A discourse on semantic priming

The processing of a word is sometimes affected if earlier words are semantically related to it (semantic “priming”). Priming phenomena have generally been interpreted as reflecting the organization of the mental lexicon. Past studies have shown that priming effects have a very fast rise time and a relatively rapid decay time. This paper investigates the rate of decay of semantic facilitation in both sentences and lists. It was hypothesized that sentence processing involves the construction of a discourse model in which the main topics stay active. If true, then words referring to related objects or events will be processed rapidly even if they occur later in the input, i.e., there will be no decay of facilitation. Three experiments with college students examined the relative time to process a critical word when it was preceded by either a pair of semantically related words or more neutral words. The materials occurred in either sentences or lists, the latter being word-level anagrams of the sentences. Subjects carried out the phonememonitoring task, responding to a word-initial target phoneme that occurred immediately after the critical word. In Experiments I (N = 58) and II (N = 40) 12 words separated the related/neutral words and the critical items. Facilitation in processing the critical word was present in sentences but not in lists. Experiment III (N = 128) showed that the amount of facilitation in sentences was the same when 12 words separated the related/neutral and critical words as when 1.5 words separated them. Thus, there was no evidence obtained here for decay of facilitation in sentences. The results are taken to be consistent with a discourse-model interpretation of semantic facilitation in sentences.     

Does number data entry rely on the phonological loop?

Two experiments investigated effects of articulatory processing on number data entry. Participants entered four‐digit numbers presented as either words or numerals on a keyboard, either under an articulatory condition or in silence. In Experiment 1, the articulatory condition was articulatory suppression; in Experiment 2, it was vocalisation. In Experiment 1, the articulatory suppression group typed initial digits faster than the silent group, but for subsequent digits, the opposite pattern occurred at least with word stimuli. In Experiment 2, the silent group typed initial digits faster but typed subsequent digits somewhat slower than the vocalisation group. Thus, articulation of numbers, which promotes entry into the phonological loop of working memory, retards processing of initial digits but enhances processing of subsequent digits.     

The influence of contextual constraints on recall for words within sentences

Two experiments examined predictions of the relational-distinctive processing view to account for the influence of sentence constraints on memory of target words. In Experiment 1, congruous expected words were recalled better than incongruous words. Words appearing in high-constraint sentences were recalled better than words appearing in low-constraint sentences. In Experiment 2, word expectancy and sentence constraint interacted so that unexpected congruous words appearing in high-constraint sentences were recalled better than their expected counterparts, but this difference was not present for low-constraint sentences. A hybrid model including aspects of the featural restriction model of sentence constraint and the relational-distinctive processing view is proposed.     

Does number data entry rely on the phonological loop?

Two experiments investigated effects of articulatory processing on number data entry. Participants entered four-digit numbers presented as either words or numerals on a keyboard, either under an articulatory condition or in silence. In Experiment 1, the articulatory condition was articulatory suppression; in Experiment 2, it was vocalisation. In Experiment 1, the articulatory suppression group typed initial digits faster than the silent group, but for subsequent digits, the opposite pattern occurred at least with word stimuli. In Experiment 2, the silent group typed initial digits faster but typed subsequent digits somewhat slower than the vocalisation group. Thus, articulation of numbers, which promotes entry into the phonological loop of working memory, retards processing of initial digits but enhances processing of subsequent digits.     

SEMANTIC AND PHONOLOGICAL CODING PROCESSES IN SKILLED AND LESS SKILLED READERS' READING OF TEXT

Abstract

Two experiments examine the memory coding processes of skilled and less skilled readers during the reading of connected text. In experiment 1, students read several paragraphs which required a lexical decision about an underlined letter string within a sentence. Underlined letter strings were either synonyms, repeated words, or control words in reference to items in the sentence. Students were later asked to recall words related to their lexical decision, as well as verify the occurrence of sentences from the text. Skilled readers recalled more synonyms than poor readers, whereas no differences emerged between groups in their recall of other types of words related to the lexical task or for the verification of sentences. Experiment 2 procedures were similar to Experiment 1, except that synonyms were replaced with homophones and the sentence verification task included phrases related to the homophones. When compared to less skilled readers, skilled readers recalled more homophones and repeated words, but were more likely to be disrupted in correct verification of sentences with homophones. Taken together, the experiments suggest that along with phonological coding, semantic processing contributes an important amount of variance to deficiencies in the reading of connected text.     

Pronominal Resolution and Gap Filling in Agrammatic Aphasia: Evidence from Eye Movements

This paper reports the results of three studies examining comprehension and real-time processing of pronominal (Experiment 1) and Wh-movement (Experiments 2 and 3) structures in agrammatic and unimpaired speakers using eyetracking. We asked the following questions: (a) Is off-line comprehension of these constructions impaired in agrammatic listeners?, (b) Do agrammatic, like unimpaired, listeners show eye movement patterns indicative of automatic pronominal reference resolution and/or gap-filling?, and (c) Do eyetracking patterns differ when sentences are correctly versus incorrectly interpreted, or do automatic processes prevail in spite of comprehension failure? Results showed that off-line comprehension of both pronoun and Wh-movement structures was impaired in our agrammatic cohort. However, the aphasic participants showed visual evidence of real-time reference resolution as they processed binding structures, including both pronouns and reflexives, as did our unimpaired control participants. Similarly, both the patients and the control participants showed patterns consistent with successful gap filling during processing of Wh-movement structures. For neither pronominal nor movement structures did we find evidence of delayed processing. Notably, these patterns were found for the aphasic participants even when they incorrectly interpreted target sentences, with the exception of object relative constructions. For incorrectly interpreted sentences, we found end of sentence lexical competition effects. These findings indicate that aberrant lexical integration, rather than representational deficits or generally slowed processing, may underlie agrammatic aphasic listener’s comprehension failure.     

The homophone effect in semantic access tasks using kanji words: Its relation to the articulatory suppression effect

The present study examined whether articulatory suppression influences homophone effects in semantic access tasks using Japanese kanji words. In Experiment 1, participants were required to decide whether visually presented word pairs were synonyms. This experiment replicated the homophone effect observed in previous research that showed more false positive errors in response to nonsynonym homophone pairs than to controls. The present study found that this homophone effect was also obtained under an articulatory suppression condition. In Experiment 2, participants performed a semantic decision task, in which they had to judge whether a visually presented target word was an exemplar of a definition that was shown immediately before presentation of the target word. The homophone effect observed in previous studies was replicated—that is, longer response times and more false positive errors were associated with homophones of correct exemplars than with nonhomophone control words. This homophone effect was also obtained under an articulatory suppression conditions. These results suggest that the phonological processing that produces the homophone effects in semantic access tasks using Japanese kanji words does not include articulatory mechanisms.     

Focus identification during sentence comprehension: evidence from eye movements

Three eye movement experiments investigated focus identification during sentence comprehension. Participants read dative or double-object sentences (i.e., either the direct or indirect object occurred first), and a replacive continuation supplied a contrast that was congruous with either the direct or the indirect object. Experiments 1 and 2 manipulated focus by locating only adjacent to either the direct or indirect object of dative (Experiment 1) or double-object (Experiment 2) sentences. Reading-time effects indicated that the surface position of the focus particle influenced processing. In addition, Experiment 1 reading times were longer when the replacive was incongruous with the constituent that only adjoined, and particle position modulated a similar effect in Experiment 2. Experiment 3 showed that this effect was absent when only was omitted. We conclude that the surface position of a focus particle modulates focus identification during on-line sentence comprehension.     

The homophone effect in semantic access tasks using kanji words: its relation to the articulatory suppression effect

The present study examined whether articulatory suppression influences homophone effects in semantic access tasks using Japanese kanji words. In Experiment 1, participants were required to decide whether visually presented word pairs were synonyms. This experiment replicated the homophone effect observed in previous research that showed more false positive errors in response to nonsynonym homophone pairs than to controls. The present study found that this homophone effect was also obtained under an articulatory suppression condition. In Experiment 2, participants performed a semantic decision task, in which they had to judge whether a visually presented target word was an exemplar of a definition that was shown immediately before presentation of the target word. The homophone effect observed in previous studies was replicated--that is, longer response times and more false positive errors were associated with homophones of correct exemplars than with nonhomophone control words. This homophone effect was also obtained under an articulatory suppression conditions. These results suggest that the phonological processing that produces the homophone effects in semantic access tasks using Japanese kanji words does not include articulatory mechanisms.     

Distinctiveness effects in recall:

Unusual information is generally recalled better than common information (the distinctiveness effect). Differential processing accounts propose that the effect occurs because unusual material elicits encoding processes that are different from those elicited by common material, and strong versions of these accounts predict distinctiveness effects in between-list as well as within-list designs. Experiment 1 employed a between-list design and manipulated presentation rate. Contrary to differential processing predictions, no distinctiveness effect emerged, nor did recall patterns for atypical versus common sentences differ as a function of presentation rate. Experiment 2 further tested differential processing accounts as well as representation accounts via a within-list manipulation and conditions that included experimenter-provided elaborations. Distinctiveness effects emerged in all conditions and, contrary to differential processing predictions, the pattern of recall in the elaborated conditions did not differ from that in the unelaborated conditions. Taken together, the results of this study lend more support to a representation view that suggests mechanisms related to the representation and subsequent retrievability of elements in the memory record play a major role in the distinctiveness effect.     

Spatial distance effects on incremental semantic interpretation of abstract sentences: Evidence from eye tracking

A large body of evidence has shown that visual context information can rapidly modulate language comprehension for concrete sentences and when it is mediated by a referential or a lexical-semantic link. What has not yet been examined is whether visual context can also modulate comprehension of abstract sentences incrementally when it is neither referenced by, nor lexically associated with, the sentence. Three eye-tracking reading experiments examined the effects of spatial distance between words (Experiment 1) and objects (Experiment 2 and 3) on participants’ reading times for sentences that convey similarity or difference between two abstract nouns (e.g., ‘Peace and war are certainly different...’). Before reading the sentence, participants inspected a visual context with two playing cards that moved either far apart or close together. In Experiment 1, the cards turned and showed the first two nouns of the sentence (e.g., ‘peace’, ‘war’). In Experiments 2 and 3, they turned but remained blank. Participants’ reading times at the adjective (Experiment 1: first-pass reading time; Experiment 2: total times) and at the second noun phrase (Experiment 3: first-pass times) were faster for sentences that expressed similarity when the preceding words/objects were close together (vs. far apart) and for sentences that expressed dissimilarity when the preceding words/objects were far apart (vs. close together). Thus, spatial distance between words or entirely unrelated objects can rapidly and incrementally modulate the semantic interpretation of abstract sentences.