Different effects of dual task demands on the speech of young and older adults

Young and older adults provided language samples in response to elicitation questions while concurrently performing 3 different tasks. The language samples were scored on three dimensions: fluency, grammatical complexity, and content. Previous research had suggested the hypothesis that the restricted speech register of older adults is buffered from the costs of dual task demands. This hypothesis was tested by comparing language samples collected during a baseline condition with those produced while the participants were performing the concurrent tasks. The results indicate that young and older adults adopt different strategies when confronted with dual task demands. Young adults shift to a restricted speech register when confronted with dual task demands. Older adults, who were already using a restricted speech register, became less fluent although the grammatical complexity and informational content of their speech was preserved. Hence, some but not all aspects of older adults' speech are buffered from dual task demands.     

The costs of doing two things at once for young and older adults: talking while walking,finger tapping,and ignoring speech or noise

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.     

The benefits and costs of repeated memory tests for young and older adults

Repeated and prolonged searches of memory can lead to an increase in how much is recalled, but they can also lead to memory errors. These 3 experiments addressed the costs and benefits of repeated and prolonged memory tests for both young and older adults. Participants saw and imagined pictures of objects, some of which were physically or conceptually similar, and then took a series of repeated or prolonged recall tests. Both young and older adults recalled more on later tests than on earlier ones, though the increase was less marked for older adults. In addition, despite recalling less than did young adults, older adults made more similarity-based source misattributions (i.e., claiming an imagined item was seen if it was physically or conceptually similar to a seen item). Similar patterns of fewer benefits and more costs for older adults were seen on both free and forced recall tests and on timed and self-paced tests. Findings are interpreted in terms of age-related differences in binding processes.     

Prospective memory in young and older adults: The effects of task importance and ongoing task load

Remembering to perform an action in the future, called prospective memory, often shows age-related differences in favor of young adults when tested in the laboratory. Recently Smith, Horn, and Bayen (2012; Aging, Neuropsychology, and Cognition, 19, 495) embedded a PM task in an ongoing color-matching task and manipulated the difficulty of the ongoing task by varying the number of colors on each trial of the task. Smith et al. found that age-related differences in PM performance (lower PM performance for older adults relative to young adults) persisted even when older adults could perform the ongoing task as well or better than the young adults. The current study investigates a possible explanation for the pattern of results reported by Smith et al. by including a manipulation of task emphasis: for half of the participants the prospective memory task was emphasize, while for the other half the ongoing color-matching task was emphasized. Older adults performed a 4-color version of the ongoing color-matching task, while young adults completed either the 4-color or a more difficult 6-color version of the ongoing task. Older adults failed to perform as well as the young adults on the prospective memory task regardless of task emphasis, even when older adults were performing as well or better than the young adults on the ongoing color-matching task. The current results indicate that the lack of an effect of ongoing task load on prospective memory task performance is not due to a perception that one or the other task is more important than the other.     

Inhibitory processes in young and older adults in a picture-word task

Abstract

The present study examines changes in healthy young and healthy older adults in the ability to inhibit partially activated information in a picture/word interference paradigm. On each trial, subjects received a cue (i.e., the word PICTURE or WORD) indicating which of two stimuli the subject should attend to in an upcoming picture/word display. the display always contained a superimposed picture and word (e.g., a picture of a DEER with the word TEA printed on it). Following display offset, and depending upon the initial precue, either a test picture (e.g., KETTLE) or a test word (e.g., MOOSE) was presented. the subject's task was to determine as quickly and as accurately as possible whether the test stimulus was related to the cued dimension of the earlier picture/word display. the speed to reject an unrelated test item (e.g., picture of a KETTLE when the precue was PICTURE) that was related to the ignored dimension of the picture/word display (e.g., the word TEA in the picture/word display) was used as an index of the efficiency of the inhibitory system. the results indicated that older adults had more difficulty than younger adults inhibiting a to-be-ignored word when it was related to a picture test item, but did not have more difficulty inhibiting a to-be-ignored picture when it was related to a word test item. the results indicate that an age-related deficit in the control of interfering information is dependent upon the fluency of the processing routes.     

The roles of private speech and inner speech in planning during middle childhood: Evidence from a dual task paradigm

Children often talk themselves through their activities, producing private speech that is internalized to form inner speech. This study assessed the effect of articulatory suppression (which suppresses private and inner speech) on Tower of London performance in 7- to 10-year-olds, relative to performance in a control condition with a nonverbal secondary task. Experiment 1 showed no effect of articulatory suppression on performance with the standard Tower of London procedure; we interpret this in terms of a lack of planning in our sample. Experiment 2 used a modified procedure in which participants were forced to plan ahead. Performance in the articulatory suppression condition was lower than that in the control condition, consistent with a role for self-directed (private and inner) speech in planning. On problems of intermediate difficulty, participants producing more private speech in the control condition showed greater susceptibility to interference from articulatory suppression than their peers, suggesting that articulatory suppression interfered with performance by blocking self-directed (private and inner) speech.     

Orienting task effects on memory for presentation modality in children, young adults, and older adults.

Children (7 to 10 years), young adults (17 to 24 years), and older adults (55 to 77 years) were asked to learn three lists of words that were of mixed modality (half the words were visual, and half the words were auditory). With one list the subjects were asked a semantic orienting question; with another, a nonsemantic orienting question; and with a third, no orienting question. Half the subjects in each age group were also asked to remember the presentation modality of each word. Older adults remembered less information about modality than children and young adults did, and the variation in the type of orienting question--or the lack of one--affected modality identification. However, there was no Orienting Task x Age interaction for modality identification. The results of this study suggest that encoding modality information does not take place automatically--in any age group--but that explanations focusing on encoding strategies and effort are not likely to account for older adults' difficulties in remembering presentation modality.     

How scenes containing visual errors affect speech fluency in young and older adults

We compared young and older adults’ speech during an error detection task, with some pictures containing visual errors and anomalies and other pictures error-free. We analyzed three disfluency types: mid-phrase speech fillers (e.g., It’s a little, um, girl), repetitions (e.g., He’s trying to catch the- the birds), and repairs (e.g., She- you can see her legs). Older adults produced more mid-phrase fillers than young adults only when describing pictures containing errors. These often reflect word retrieval problems and represent clear disruptions to fluency, so this interaction indicates that the need to form and maintain representations of novel information can specifically compromise older adults’ speech fluency. Overall, older adults produced more repetitions and repairs than young adults, regardless of picture type, indicating general age-related increases in these disfluencies. The obtained patterns are discussed in the context of the Transmission Deficit Hypothesis and other approaches to age-related changes in speech fluency.     

Perception of alternated speech operates similarly in young and older adults with age-normal hearing

When speech is rapidly alternated between the two ears, intelligibility declines as the rate of alternation approaches 3 to 5 switching cycles per second, and then, paradoxically, returns to a good level beyond that point. We tested intelligibility when shadowing was used as a response measure (Experiment 1), when recall was used as a response measure (Experiment 2), and when time-compression was used to vary the speech rate of the presented materials (Experiment 3). In spite of claims that older adults are generally slower in switching attention, younger and older adults did not differ in the critical alternation rates producing minimal intelligibility. We suggest that the point of minimal intelligibility in alternated speech reflects an interaction between (1) the rate of disruption induced by breaking the speech stream between two sound sources, (2) the amount of contextual information per ear, and (3) the size of the silent gaps separating the speech elements that must be perceptually bridged.     

Relational and imageric recall in young and older adults under conditions of high task demand

Research indicates the presence of an age-related pictorial processing deficit, for which the elderly may attempt to compensate through the use of relational information. Cognitive asynchrony theory, a recent synthetic formulation which unites elements of the generalized slowing hypothesis, environmental support theory, and the item-specific/relational information distinction, has proven useful in a number of experiments in explaining these aspects of visual cognitive aging. The present experiments tested this theoretical formulation under high processing demand conditions in both the relational and the pictorial/item-specific realm. Young and older adults yielded a complex pattern of results consistent with the cognitive asynchrony synthesis of these theoretical considerations. The present experiments add to the growing body of findings indicating that the cognitive subsystems of memory decline at different rates, that the differences in cognitive processing between young and older adults tend to be more quantitative than qualitative, and that the global age-related memory deficits of popular belief are in fact relatively circumscribed and specific. This research was supported by grant AG11605 from the National Institute on Aging, and by a grant from the College of Science and Mathematics, California State University.     

Relational and imageric recall in young and older adults under conditions of high task demand

Research indicates the presence of an age-related pictorial processing deficit, for which the elderly may attempt to compensate through the use of relational information. Cognitive asynchrony theory, a recent synthetic formulation which unites elements of the generalized slowing hypothesis, environmental support theory, and the item-specific/relational information distinction, has proven useful in a number of experiments in explaining these aspects of visual cognitive aging. The present experiments tested this theoretical formulation under high processing demand conditions in both the relational and the pictorial/item-specific realm. Young and older adults yielded a complex pattern of results consistent with the cognitive asynchrony synthesis of these theoretical considerations. The present experiments add to the growing body of findings indicating that the cognitive subsystems of memory decline at different rates, that the differences in cognitive processing between young and older adults tend to be more quantitative than qualitative, and that the global age-related memory deficits of popular belief are in fact relatively circumscribed and specific. This research was supported by grant AG11605 from the National Institute on Aging, and by a grant from the College of Science and Mathematics, California State University.     

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.     

Divided attention in younger and older adults: effects of strategy and relatedness on memory performance and secondary task costs

Divided attention at encoding leads to a significant decline in memory performance, whereas divided attention during retrieval has relatively little effect; nevertheless, retrieval carries significant secondary task costs, especially for older adults. The authors further investigated the effects of divided attention in younger and older adults by using a cued-recall task and by measuring retrieval accuracy, retrieval latency, and the temporal distribution of attentional costs at encoding and retrieval. An age-related memory deficit was reduced by pair relatedness, whereas strategy instructions benefited both age groups equally. Attentional costs were greater for retrieval than for encoding, especially for older adults. These findings are interpreted in light of notions of an age-related associative deficit (M. Naveh-Benjamin, 2000) and age-related differences in the use of self-initiated activities and environmental support (F. I. M. Craik, 1983, 1986).     

Replicating distinctive facial features in lineups: identification performance in young versus older adults

Criminal suspects with distinctive facial features, such as tattoos or bruising, may stand out in a police lineup. To prevent suspects from being unfairly identified on the basis of their distinctive feature, the police often manipulate lineup images to ensure that all of the members appear similar. Recent research shows that replicating a distinctive feature across lineup members enhances eyewitness identification performance, relative to removing that feature on the target. In line with this finding, the present study demonstrated that with young adults (n = 60; mean age = 20), replication resulted in more target identifications than did removal in target-present lineups and that replication did not impair performance, relative to removal, in target-absent lineups. Older adults (n = 90; mean age = 74) performed significantly worse than young adults, identifying fewer targets and more foils; moreover, older adults showed a minimal benefit from replication over removal. This pattern is consistent with the associative deficit hypothesis of aging, such that older adults form weaker links between faces and their distinctive features. Although replication did not produce much benefit over removal for older adults, it was not detrimental to their performance. Therefore, the results suggest that replication may not be as beneficial to older adults as it is to young adults and demonstrate a new practical implication of age-related associative deficits in memory.     

Planning and task management in older adults: Cooking breakfast

The article describes a simulated "cooking breakfast" task in which participants must remember to start and stop cooking five foods so that all the foods are "ready" at the same time. In between starting and stopping operations, the participants also carried out a "table-setting" task as a filler activity. The breakfast task yields various measures of multitasking and executive control. Groups of younger and older adults performed the task; half of the participants in each group were bilinguals and the other half were monolinguals. The results showed substantial age-related decrements in most measures of executive control. Additionally, older bilinguals showed some advantages in task management over their monolingual peers.     

An emotional Stroop task with faces and words. A comparison of young and older adults

AntecedentsGiven the contradictions of previous studies on the changes in attentional responses produced in aging a Stroop emotional task was proposed to compare young and older adults to words or faces with an emotional valence.MethodThe words happy or sad were superimposed on faces that express the emotion of happiness or sadness. The emotion expressed by the word and the face could agree or not (cued and uncued trials, respectively). 85 young and 66 healthy older adults had to identify both faces and words separately, and the interference between the two types of stimuli was examined.ResultsAn interference effect was observed for both types of stimuli in both groups. There was more interference on positive faces and words than on negative stimuli.ConclusionsOlder adults had more difficulty than younger in focusing on positive uncued trials, whereas there was no difference across samples on negative uncued trials.     

Walking and talking: dual-task effects on street crossing behavior in older adults

The ability to perform multiple tasks simultaneously has become increasingly important as technologies such as cell phones and portable music players have become more common. In the current study, we examined dual-task costs in older and younger adults using a simulated street crossing task constructed in an immersive virtual environment with an integrated treadmill so that participants could walk as they would in the real world. Participants were asked to cross simulated streets of varying difficulty while either undistracted, listening to music, or conversing on a cell phone. Older adults were more vulnerable to dual-task impairments than younger adults when the crossing task was difficult; dual-task costs were largely absent in the younger adult group. Performance costs in older adults were primarily reflected in timeout rates. When conversing on a cell phone, older adults were less likely to complete their crossing compared with when listening to music or undistracted. Analysis of time spent next to the street prior to each crossing, where participants were presumably analyzing traffic patterns and making decisions regarding when to cross, revealed that older adults took longer than younger adults to initiate their crossing, and that this difference was exacerbated during cell phone conversation, suggesting impairments in cognitive planning processes. Our data suggest that multitasking costs may be particularly dangerous for older adults even during everyday activities such as crossing the street.     

Specific effects of the Trier Social Stress Test on speech fluency in young and older adults

The notion that speech becomes less fluent during stressful speaking conditions has received little empirical test, and no research has tested this relationship in older adult participants. We analyzed speeches produced during the Trier Social Stress Test (TSST) or during a less stressful placebo (pTSST) version of the task. We measured young and older adults’ speech fillers (e.g., um), unfilled pauses (at least 1 s in duration), and other disfluencies (e.g., repetitions, repairs). Neither young nor older adult participants rated themselves as having greater stress in the TSST than pTSST condition, but behavioral effects were obtained. Participants in the TSST condition produced more mid-phrase speech fillers and unfilled pauses than participants in the pTSST condition. Young adults produced more unfilled pauses than older adults overall, and older adults produced more mid-phrase fillers than young adults. Critically, age group interacted with experimental condition, such that older speakers produced disproportionately more mid-phrase fillers than young adults in the TSST compared to the pTSST condition. In sum, the negative effects of the TSST on fluency were generally similar across age, but this specific age-related increase in mid-phrase fillers indicates that older adults’ word retrieval may have been particularly negatively affected. Findings are generally consistent with previous research and add to understanding of how factors internal to the speaker (i.e., demographic, personality, and cognitive variables) and factors external to the speaker (i.e., variables regarding the situation, context, or content of speech) combine to affect speech fluency.     

Relational frameworks for recall in young and older adults

Recent research indicates the presence of an age-related visual processing deficit, for which the elderly may attempt to compensate through the use of relational information. This hypothesis was tested, using the category superiority effect as a model system. In studies of young adults, the category superiority effect has been shown to be confined to relatively abstract stimulus materials, such as verbal items, and to be absent for pictures. However, it was predicted that a category superiority effect would be present in elderly adults both for verbal and for pictorial stimuli, since the elderly would be expected to utilize category information to compensate for imagerie deficits. This prediction was confirmed, consistent with the hypothesis advanced above. It was further suggested that the establishment of a prior framework for recall, based on relational information, would reduce this effect significantly. This prediction was also confirmed. This research was supported by Grant AGI 1605, National Institute on Aging, and by a grant from the School of Natural Sciences, California State University, Fresno.