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Eye tracking has indicated that older and young adults process distracters similarly when reading single sentences. The present study extended this approach by presenting short paragraphs, sentence by sentence. Eye tracking measures included reading times per word, and the duration of the first fixation and total fixations to the distracters and target words. Comprehension was tested following each paragraph, and recognition of distracters and target words was assessed. The results indicated that young adults were able to learn to ignore the distracters as they read through the paragraphs, whereas older adults were less successful at learning to ignore the distracters.

Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults' speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults' speech, like young adults' speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults., ((c) 2010 APA, all rights reserved).)

The eye movements of young and older adults were tracked as they read sentences varying in syntactic complexity. In Experiment 1, cleft object and object relative clause sentences were more difficult to process than cleft subject and subject relative clause sentences; however, older adults made many more regressions, resulting in increased regression path fixation times and total fixation times, than young adults while processing cleft object and object relative clause sentences. In Experiment 2, older adults experienced more difficulty than young adults while reading cleft and relative clause sentences with temporary syntactic ambiguities created by deleting the that complementizers. Regression analyses indicated that readers with smaller working memories need more regressions and longer fixation times to process cleft object and object relative clause sentences. These results suggest that age-associated declines in working memory do affect syntactic processing., (((c) 2007 APA, all rights reserved).)

The authors used eye-tracking technology to examine young and older adults' online performance in the reading in distraction paradigm. Participants read target sentences and answered comprehension questions following each sentence. In some sentences, single-word distracters were presented in either italic or red font. Distracters could be related or unrelated to the target text. Online measures, including probability of fixation, fixation duration, and number of fixations to distracting text, revealed no age differences in text processing. However, young adults did have an advantage over older adults in overall reading time and text comprehension. These results provide no support for an inhibition deficit account of age differences in the reading in distraction paradigm, but are consistent with J. Dywan and W. E. Murphy's (1996) suggestion that older adults are less able than the young to distinguish target and distracter information held in working memory., (((c) 2006 APA, all rights reserved).)

Young and older adults' eye fixations were monitored as they read sentences with temporary ambiguities such as "The experienced soldiers warned about the dangers conducted the midnight raid." Their fixation patterns were similar except that older adults made many regressions. In a 2nd experiment, high- and low-span older adults were compared with high- and low-span young adults. Pint-pass fixations were similar, except low-span readers made many regressions and their total fixation times were longer. High-span readers also used the focus operator "only" (e.g., "Only experienced soldiers warned about the dangers.") to immediately resolve the temporary ambiguities. No age group differences were observed. These results are discussed with reference to theories of the role of working memory in sentence processing.

Young and older adults provided language samples in response to questions while walking, finger tapping, and ignoring speech or noise. The language samples were scored on 3 dimensions: fluency, complexity, and content. The hypothesis that working memory limitations affect speech production by older adults was tested by comparing baseline samples with those produced while the participants were performing the concurrent tasks. There were baseline differences: Older adults' speech was less fluent and less complex than young adults' speech. Young adults adopted a different strategy in response to the dual-task demands than older adults: They reduced sentence length and grammatical complexity. In contrast, older adults shifted to a reduced speech rate in the dual-task conditions.

Mixed modeling was used to examine longitudinal changes in linguistic ability in healthy older adults and older adults with dementia. Language samples, vocabulary scores, and digit span scores were collected annually from healthy older adults and semiannually from older adults with dementia. The language samples were scored for grammatical complexity and propositional content. For the healthy group, age-related declines in grammatical complexity and propositional content were observed. The declines were most rapid in the mid 70s. For the group with dementia, grammatical complexity and propositional content also declined over time, regardless of age. Rates of decline were uniform across individuals. These analyses reveal how both grammatical complexity and propositional content are related to late-life changes in cognition in healthy older adults aswell as those with dementia. Alzheimer's disease accelerates this decline, regardless of age.

Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an "extension" analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency.

The present study examines language samples from the Nun Study. Measures of grammatical complexity and idea density were obtained from autobiographies written over a 60-year span. Participants who had met criteria for dementia were contrasted with those who did not. Grammatical complexity initially averaged 4.78 (on a 0-to-7-point scale) for participants who did not meet criteria for dementia and declined .04 units per year; grammatical complexity for participants who met criteria for dementia initially averaged 3.86 and declined .03 units per year. Idea density averaged 5.35 propositions per 10 words initially for participants who did not meet criteria for dementia and declined an average of .03 units per year, whereas idea density averaged 4.34 propositions per 10 words initially for participants who met criteria for dementia and declined .02 units per year. Adult experiences, in general, did not moderate these declines.

Three studies evaluated different varieties of elderspeak using a referential communication task. Experiment 1 compared the effects of syntactic simplifications and semantic elaborations. Experiment 2 contrasted syntactic simplifications and prosodic exaggerations. Experiment 3 contrasted 2 different syntactic simplification strategies and 2 different prosodic exaggerations. Providing semantic elaborations and reducing the use of subordinate and embedded clauses benefit older adults and improve their performance on the referential communication task, whereas reducing sentence length, slowing speaking rate, and using high pitch do not. The use of short sentences, a slow rate of speaking, and high pitch resulted in older adults' reporting more communication problems. These experiments validate a version of elderspeak that benefits older adults without sounding patronizing and insulting.

Off-line studies of younger and older adults' processing of syntactically complex sentences have shown that there is a consistent negative relationship between task performance and working memory for older adults. However, it is not evident from these studies whether working memory affects the immediate syntactic analysis of a sentence, off-line processes, or both. In the current study an online reading paradigm was used to examine the working memory capacity-constrained sentence processing model from M.C. MacDonald, M.A. Just, and P.A. Carpenter (1992). Working memory span, type of syntactic ambiguity (ambiguous vs. unambiguous), and type of syntactic ambiguity resolution (main verb vs. relative clause) interacted to influence younger and older adults' on-line reading times and off-line sentence comprehension.

Caregivers of patients diagnosed with Alzheimer's disease (AD) are often advised to modify their speech to facilitate the patients' sentence comprehension. Three common recommendations are to (a) speak in simple sentences, (b) speak slowly, and (c) repeat one's utterance, using the same words. These three speech modifications were experimentally manipulated in order to investigate their individual and combined effects on sentence comprehension in AD. Fifteen patients with mild to moderate AD and 20 healthy older persons were tested on a sentence comprehension task with sentences varying in terms of (a) degree of grammatical complexity, (b) rate of presentation (normal vs. slow), and (c) form of repetition (verbatim vs. paraphrase). The results indicated a significant decline in sentence comprehension for the AD group. Sentence comprehension improved, however, after the sentence was repeated in either verbatim or parapharsed form. However, the patients' comprehension did not improve for sentences presented at the slow speech rate. This pattern of results is explained via-à-vis the patients' working memory loss. The findings challenge the appropriateness of several clinical recommendations.