Tracking reading: dual task costs of oral reading for young versus older adults.

A digital pursuit rotor was used to monitor oral reading costs by time-locking tracking performance to the auditory wave form produced as young and older adults were reading out short paragraphs. Multilevel modeling was used to determine how paragraph-level predictors of length, grammatical complexity, and readability and person-level predictors such as speaker age or working memory capacity predicted reading and tracking performance. In addition, sentence-by-sentence variation in tracking performance was examined during the production of individual sentences and during the pauses before upcoming sentences. The results suggest that dual tasking has a greater impact on older adults' reading comprehension and tracking performance. At the level of individual sentences, young and older adults adopt different strategies to deal with grammatically complex and propositionally dense sentences.

Learning to ignore distracters.

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.

Older adults with and without stroke reduce cadence to meet the demands of talking.

PURPOSE: Cognitive tasks performed while walking can be challenging for older adults, especially for those with stroke. Conversational speech requires attention and working memory. The purpose of this study was to examine how older adults with and without stroke meet the demands of walking while talking. METHODS: Community-dwelling older adults, 12 without stroke and 24 with, were videotaped walking an irregular elliptical pathway. Audio recordings were made as subjects discussed topics such as describing a memorable vacation. Each participant performed in single and dual task conditions: speaking, walking, and speaking while walking. Primary measures of interest included cadence and speech rate. Components of language including measures of fluency, grammatical complexity, and semantic content were analyzed to examine additional changes in speech. Paired t-tests were used to compare single and dual task performance for each group. Group differences for dual task effects were examined with independent sample t tests. RESULTS: Cadence decreased with the addition of talking for those without stroke, P < .007, and those with stroke, P < .001. Speech rates did not change with walking for either group; those without stroke did not alter the language components. Participants with stroke reduced the grammatical complexity and semantic content of speech when walking, P's < .013. Those without stroke spent more time doing both tasks at once than those with stroke, P < .023. CONCLUSION: Clinicians can expect older adults to reduce walking speed to meet the demands of walking and talking. Older adults with stroke may use additional strategies to walk and talk simultaneously.

Dual-task demands of hand movements for adults with stroke: a pilot study.

UNLABELLED: For adults with stroke, walking while performing a cognitive task can be challenging, resulting in slower walking, poorer cognitive performance, or decreased performance on both tasks. It is not known if dual-task deficits are also present for upper limb movements for adults with stroke. PURPOSE: To determine if unilateral movements of the affected and less affected hand are compromised when walking or talking. METHODS: Nineteen community-dwelling adults with stroke were video- and audiotaped while performing in single- and dual-task conditions. Tasks included repeated, rhythmic hand movements with the affected and less affected hand, walking a narrow pathway, and speaking. For dual-task conditions, movements of each hand were done while walking and while talking. The rate of hand movement, cadence, and speech rate were analyzed using repeated measures analyses of variance. RESULTS: Affected hand movement rate was the same for single- and dual-task conditions. The rate of less affected hand movement was affected by dual-task conditions; this was due to an increase in hand movement rate while talking. Examination of cadence and speech rates revealed that cadence was decreased when moving the affected hand. Speech rate increased when accompanied by hand movements, but post hoc analyses were not significant. CONCLUSION: For those with stroke, dual-task deficits are seen with slower walking while moving the affected hand. In contrast, hand movements while speaking may have a more complex relationship, with possible faster speech rates in dual-task conditions.

The effects of varying task priorities on language production by young and older adults.

The present study compared how varying task priorities affected young and older adults' language production. Both young and older adults responded to monetary incentives to vary their performance when simultaneously talking and tracking a pursuit rotor. Tracking performance improved when they were rewarded for tracking and declined when they were rewarded for talking. Both young and older adults also spoke more slowly when rewarded for tracking and more rapidly when rewarded for talking. Young produced less complex sentences when rewarded for tracking and produced more complex sentences when rewarded for talking. However, older adults did not vary their grammatical complexity as a function of monetary incentives. These results are consistent with prior studies suggesting that older adults use a simplified speech register in response to dual-task demands.

Understanding verbal fluency in healthy aging, Alzheimer's disease, and Parkinson's disease.

OBJECTIVE: Verbal fluency measures are frequently part of batteries designed to assess executive function (EF), but are also used to assess semantic processing ability or word knowledge. The goal of the present study was to identify the cognitive components underlying fluency performance. METHOD: Healthy young and older adults, adults with Parkinson's disease, and adults with Alzheimer's disease performed letter, category, and action fluency tests. Performance was assessed in terms of number of items generated, clustering, and the time course of output. A series of neuropsychological assessments were also administered to index verbal ability, working memory, EF, and processing speed as correlates of fluency performance. RESULTS: Findings indicated that regardless of the particular performance measure, young adults performed the best and adults with Alzheimer's disease performed most poorly, with healthy older adults and adults with Parkinson's disease performing at intermediate levels. The exception was the action fluency task, where adults with Parkinson's disease performed most poorly. The time course of fluency performance was characterized in terms of slope and intercept parameters and related to neuropsychological constructs. Speed of processing was found to be the best predictor of performance, rather than the efficiency of EF or semantic knowledge. CONCLUSIONS: Together, these findings demonstrate that the pattern of fluency performance looks generally the same regardless of how performance is measured. In addition, the primary role of processing speed in performance suggests that the use of fluency tasks as measures of EF or verbal ability warrants reexamination.

Tracking sentence planning and production.

OBJECTIVE: To assess age differences in the costs of language planning and production. METHODS: A controlled sentence production task was combined with digital pursuit rotor tracking. Participants were asked to track a moving target while formulating a sentence using specified nouns and verbs and to continue to track the moving target while producing their response. The length of the critical noun phrase (NP) as well as the type of verb provided were manipulated. RESULTS: The analysis indicated that sentence planning was more costly than sentence production, and sentence planning costs increased when participants had to incorporate a long NP into their sentence. The long NPs also tended to be shifted to the end of the sentence, whereas short NPs tended to be positioned after the verb. Planning or producing responses with long NPs was especially difficult for older adults, although verb type and NP shift had similar costs for young and older adults. DISCUSSION: Pursuit rotor tracking during controlled sentence production reveals the effects of aging on sentence planning and production.

Tracking talking: dual task costs of planning and producing speech for young versus older adults.

A digital pursuit rotor was used to monitor speech planning and production costs by time-locking tracking performance to the auditory wave form produced as young and older adults were describing someone they admire. The speech sample and time-locked tracking record were segmented at utterance boundaries and multilevel modeling was used to determine how utterance-level predictors such as utterance duration or sentence grammatical complexity and person-level predictors such as speaker age or working memory capacity predicted tracking performance. Three models evaluated the costs of speech planning, the costs of speech production, and the costs of speech output monitoring. The results suggest that planning and producing propositionally dense utterances is more costly for older adults and that older adults experience increased costs as a result of having produced a long, informative, or rapid utterance.

Aging and the vulnerability of speech to dual task demands.

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.

Interventions to reduce cognitive decline in aging.

As the population ages, risks for cognitive decline threaten independence and quality of life for older adults and present challenges to the health care system. Nurses are in a unique position to advise older adults about cognitive health promotion and to develop interventions that optimize cognition in older adults. A literature review was conducted to provide nurses in mental health and geriatric care with an overview of research related to the promotion of successful cognitive aging for older adults. Research evaluating cognitively stimulating lifestyles and the effects on cognitive function in older adults of interventions targeting cognitive training, physical activity, social engagement, and nutrition were reviewed. Overall research findings support positive effects of cognitive and physical activity, social engagement, and therapeutic nutrition in optimizing cognitive aging. However, the strength of the evidence is limited by research designs. Applications for health promotion to optimize cognitive aging and future directions for research are discussed.

Comprehension of Health-related Written Materials by Older Adults.

This study examined how Flesch Reading Ease and text cohesion affect older adults' comprehension of common health texts. All older adults benefited when high Flesh Reading Ease was combined with high cohesion. Older adults with small working memories had more difficulty understanding texts high in Flesch Reading Ease. Additionally, older adults with low verbal ability or older than 77 years of age had difficulty understanding texts high in text cohesion but low in Flesch Reading Ease. These results imply that writers must increase Flesch Reading Ease without disrupting text cohesion to ensure comprehension of health-related texts.

The use of illustration to improve older adults' comprehension of health-related information: is it helpful?

OBJECTIVE: To examine whether explanatory illustrations can improve older adults' comprehension of written health information. METHODS: Six short health-related texts were selected from websites and pamphlets. Young and older adults were randomly assigned to read health-related texts alone or texts accompanied by explanatory illustrations. Eye movements were recorded while reading. Word recognition, text comprehension, and comprehension of the illustrations were assessed after reading. RESULTS: Older adults performed as well as or better than young adults on the word recognition and text comprehension measures. However, older adults performed less well than young adults on the illustration comprehension measures. Analysis of readers' eye movements showed that older adults spent more time reading illustration-related phrases and fixating on the illustrations than did young adults, yet had poorer comprehension of the illustrations. CONCLUSION: Older adults might not benefit from text illustrations because illustrations can be difficult to integrate with the text. PRACTICE IMPLICATIONS: Health practitioners should not assume that illustrations will increase older adults' comprehension of health information.

The effects of aging and dual task demands on language production.

A digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. After training on the pursuit rotor, participants were asked to track the moving target while providing a language sample. When simultaneously engaged, young adults experienced greater dual task costs to tracking, fluency, and grammatical complexity than older adults. Older adults were able to preserve their tracking performance by speaking more slowly. Individual differences in working memory, processing speed, and Stroop interference affected vulnerability to dual task costs. These results demonstrate the utility of using a digital pursuit rotor to study the effects of aging and dual task demands on language production and confirm prior findings that young and older adults use different strategies to accommodate to dual task demands.

Young and Older Adults' Reading of Distracters.

We used eye-tracking technology to examine young and older adults' performance in the reading with distraction paradigm. One-, 2- and 4-word distracters that formed meaningful phrases were used. There were marked age differences in fixation patterns. Young adults' fixations to the distracters and targets increased with distracter length, suggesting that they were attempting to integrate the distracters with the sentence and had more and more difficulty doing so as the distracters increased in length. Young adults did have better comprehension of the sentences than older adults and also better recognition memory for target words and distracters.

Automatic measurement of propositional idea density from part-of-speech tagging.

The Computerized Propositional Idea Density Rater (CPIDR, pronounced "spider") is a computer program that determines the propositional idea density (P-density) of an English text automatically on the basis of part-of-speech tags. The key idea is that propositions correspond roughly to verbs, adjectives, adverbs, prepositions, and conjunctions. After tagging the parts of speech using MontyLingua (Liu, 2004), CPIDR applies numerous rules to adjust the count, such as combining auxiliary verbs with the main verb. A "speech mode" is provided in which CPIDR rejects repetitions and a wider range of fillers. CPIDR is a user-friendly Windows .NET application distributed as open-source freeware under GPL. Tested against human raters, it agrees with the consensus of two human raters better than the team of five raters agree with each other [r(80) = .97 vs. r(10) = .82, respectively].

Eye movements of young and older adults during reading.

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.

Age differences in memory-load interference effects in syntactic processing.

The effects of a memory load on syntactic processing by younger and older adults were examined. Participants were asked to remember a noun phrase (NP) memory load while they read sentences varying in syntactic complexity. Two types of NPs were used as memory loads: proper names or definite descriptions referring to occupations or roles. The NPs used in the sentence and memory load either matched (e.g., all proper names or all occupations), or they mismatched. Participants read complex sentences more slowly than they did simpler sentences; for young adults, this complexity effect was exacerbated when memory interference was generated by matching NPs in the sentence and memory load, whereas for older adults, memory-load interference did not vary with sentence complexity or memory-load matching. These results suggest that a general reduction in older adults' processing capacity was produced by the memory load, whereas the matching memory loads and sentence NPs produced a more specific form of interference that affected young adults' online processing.

Revealing language deficits following stroke: the cost of doing two things at once.

The costs of doing two things were assessed for a group of healthy older adults and older adults who were tested at least 6 months after a stroke. A baseline language sample was compared to language samples collected while the participants were performing concurrent motor tasks or selective ignoring tasks. Whereas the healthy older adults showed few costs due to the concurrent task demands, the language samples from the stroke survivors were disrupted by the demands of doing two things at once. The dual task measures reveal long-lasting effects of strokes that were not evident when stroke survivors were assessed using standard clinical tools.

Eye movements of young and older adults while reading with distraction.

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.

Aging, encoding, and word retrieval: distinguishing phonological and memory processes.

Word retrieval deficits are one of the most common complaints among older adults. The Transmission Deficit Hypothesis predicts that phonologically similar names would be harder for older adults to encode and retrieve. Results indicated that overall older adults encoded and recalled fewer words than younger adults when given only one trial and when given multiple trials to criterion. For both experiments, proper names were more difficult to retrieve than common nouns, and phonologically similar words were more difficult to retrieve than phonologically different words for both older and younger adults. Age differences were not evident for retrieving phonologically similar items or names but older adults did need more trials to encode phonologically similar items and names. Age differences for phonologically similar items and names appear related to encoding processes with retrieval of these items consistently hard for both older and younger adults.