Age-related differences in resolving semantic and phonological competition during receptive language tasks

Receptive language (e.g., reading) is largely preserved in the aging brain, and semantic processes in particular may continue to develop throughout the lifespan. We investigated the neural underpinnings of phonological and semantic retrieval in older and younger adults during receptive language tasks (rhyme and semantic similarity judgments). In particular, we were interested in the role of competition on language retrieval and varied the similarities between a cue, target, and distractor that were hypothesized to affect the mental process of competition. Behaviorally, all participants responded faster and more accurately during the rhyme task compared to the semantic task. Moreover, older adults demonstrated higher response accuracy than younger adults during the semantic task. Although there were no overall age-related differences in the neuroimaging results, an Age×Task interaction was found in left inferior frontal gyrus (IFG), with older adults producing greater activation than younger adults during the semantic condition. These results suggest that at lower levels of task difficulty, older and younger adults engaged similar neural networks that benefited behavioral performance. As task difficulty increased during the semantic task, older adults relied more heavily on largely left hemisphere language regions, as well as regions involved in perception and internal monitoring. Our results are consistent with the stability of language comprehension across the adult lifespan and illustrate how the preservation of semantic representations with aging may influence performance under conditions of increased task difficulty.

Aging and Language Production

Experimental research and older adults' reports of their own experience suggest that the ability to produce the spoken forms of familiar words declines with aging. Older adults experience more word-finding failures, such as tip-of-the-tongue states, than young adults do, and this and other speech production failures appear to stem from difficulties in retrieving the sounds of words. Recent evidence has identified a parallel age-related decline in retrieving the spelling of familiar words. Models of cognitive aging must explain why these aspects of language production decline with aging whereas semantic processes are well maintained. We describe a model wherein aging weakens connections among linguistic representations, thereby reducing the transmission of excitation from one representation to another. The structure of the representational systems for word phonology and orthography makes them vulnerable to transmission deficits, impairing retrieval.

Aging in two languages: Implications for public health

With the population aging and a dramatic increase in the number of senior citizens, public health systems will be increasingly burdened with the need to deal with the care and treatment of individuals with dementia. We review evidence demonstrating how a particular experience, bilingualism, has been shown to protect cognitive function in older age and delay onset of symptoms of dementia. This paper describes behavioral and brain studies that have compared monolingual and bilingual older adults on measures of cognitive function or brain structure and reviews evidence demonstrating a protective effect of bilingualism against symptoms of dementia. We conclude by presenting some data showing the potential savings in both human costs in terms of demented patients and economic considerations in terms of public money if symptoms of dementia could be postponed.

Mood congruity and episodic memory in young children

Although mood congruity effects on episodic memory have been reported extensively in adults, they have not been reported for children younger than 10 years. The current research investigated mood congruity effects in story recall using an embodied approach to mood induction involving a facial manipulation task with 3- and 4-year-old children. Participants held a chopstick or a popsicle stick in their mouths in a way to either produce or inhibit a smile while they listened to a story featuring happy events for a happy character and sad events for a sad character. Children's mood ratings before and after mood induction indicated that mood became more positive in the smile condition, with no change in the no smile condition. Children in the smile condition, but not in the no smile condition, remembered more about the happy character than the sad character in the story. These results extend mood congruity effects to 3- and 4-year olds, suggesting that at this age representations of emotion interact with basic memory processes. Moreover, the efficacy of reenactment of sensorimotor components of emotion in modifying mood is consistent with embodied representation of emotion during early childhood.

Age-related differences in the neural bases of phonological and semantic processes

Changes in language functions during normal aging are greater for phonological compared with semantic processes. To investigate the behavioral and neural basis for these age-related differences, we used fMRI to examine younger and older adults who made semantic and phonological decisions about pictures. The behavioral performance of older adults was less accurate and less efficient than younger adults' in the phonological task but did not differ in the semantic task. In the fMRI analyses, the semantic task activated left-hemisphere language regions, and the phonological task activated bilateral cingulate and ventral precuneus. Age-related effects were widespread throughout the brain and most often expressed as greater activation for older adults. Activation was greater for younger compared with older adults in ventral brain regions involved in visual and object processing. Although there was not a significant Age × Condition interaction in the whole-brain fMRI results, correlations examining the relationship between behavior and fMRI activation were stronger for younger compared with older adults. Our results suggest that the relationship between behavior and neural activation declines with age, and this may underlie some of the observed declines in performance.

Stroke experiences in weblogs: a feasibility study of sex differences

Background

Research on cerebral stroke symptoms using hospital records has reported that women experience more nontraditional symptoms of stroke (eg, mental status change, pain) than men do. This is an important issue because nontraditional symptoms may delay the decision to get medical assistance and increase the difficulty of correct diagnosis. In the present study, we investigate sex differences in the stroke experience as described in stories on weblogs.

Objective

The goal of this study was to investigate the feasibility of using the Internet as a source of data for basic research on stroke experiences.

Methods

Stroke experiences described in blogs were identified by using StoryUpgrade, a program that searches blog posts using a fictional prototype story. In this study, the prototype story was a description of a stroke experience. Retrieved stories coded by the researchers as relevant were used to update the search query and retrieve more stories using relevance feedback. Stories were coded for first- or third-person narrator, traditional and nontraditional patient symptoms, type of stroke, patient sex and age, delay before seeking medical assistance, and delay at hospital and in treatment.

Results

There were 191 relevant stroke stories of which 174 stories reported symptoms (52.3% female and 47.7% male patients). There were no sex differences for each traditional or nontraditional stroke symptom by chi-square analysis (all Ps>.05). Type of narrator, however, affected report of traditional and nontraditional symptoms. Female first-person narrators (ie, the patient) were more likely to report mental status change (56.3%, 27/48) than male first-person narrators (36.4%, 16/44), a marginally significant effect by logistic regression (P=.056), whereas reports of third-person narrators did not differ for women (27.9%, 12/43) and men (28.2%, 11/39) patients. There were more reports of at least 1 nontraditional symptom in the 92 first-person reports (44.6%, 41/92) than in the 82 third-person reports (25.6%, 21/82, P=.006). Ischemic or hemorrhagic stroke was reported in 67 and 29 stories, respectively. Nontraditional symptoms varied with stroke type with 1 or more nontraditional symptoms reported for 79.3% (23/29) of hemorrhagic stroke patients and 53.7% (36/67) of ischemic stroke patients (P=.001).

Conclusions

The results replicate previous findings based on hospital interview data supporting the reliability of findings from weblogs. New findings include the effect of first- versus third-person narrator on sex differences in the report of nontraditional symptoms. This result suggests that narrator is an important variable to be examined in future studies. A fragmentary data problem limits some conclusions because important information, such as age, was not consistently reported. Age trends strengthen the feasibility of using the Internet for stroke research because older adults have significantly increased their Internet use in recent years.

Aging increases inattentional blindness to the gorilla in our midst

When engaged in an attention-demanding task, people are surprisingly vulnerable to inattentional blindness--the failure to notice an unexpected event. Two theories of cognitive aging, attentional capacity models and inhibitory deficit models, make opposite predictions about age differences in susceptibility to inattentional blindness. We tested these predictions using an inattentional blindness paradigm developed by Simons and Chabris (1999) and found that older adults were more likely to experience inattentional blindness than young adults. These results are compatible with attentional capacity models of cognitive aging but not with current inhibitory deficit models.

On the tip-of-the-tongue: neural correlates of increased word-finding failures in normal aging

Tip-of-the-tongue (TOT) experiences are frustrating word-finding failures where people are temporarily unable to produce a word they are certain they know. TOT frequency increases with normal aging during adulthood, and behavioral evidence suggests that the underlying deficit is in retrieving the complete phonology of the target word during production. The present study investigated the neural correlates of this phonological retrieval deficit. We obtained 3-D T1-weighted structural magnetic resonance images (MRI) for healthy participants between 19 and 88 years old and used voxel-based morphometry to measure gray matter density throughout the brain. In a separate session, participants named celebrities cued by pictures and descriptions, indicating when they had a TOT, and also completed Raven's Progressive Matrices (RPM), a task that does not involve phonological production. The number of TOTs increased with age and also with gray matter atrophy in the left insula, an area implicated in phonological production. The relation between TOTs and left insula atrophy cannot be attributed to the correlation of each variable with age because TOTs were related to insula atrophy even with age effects removed. Moreover, errors on the RPM increased with age, but performance did not correlate with gray matter density in the insula. These results provide, for the first time, an association between a region in the neural language system and the rise in age-related word-finding failures and suggest that age-related atrophy in neural regions important for phonological production may contribute to age-related word production failures.

Cherry pit primes Brad Pitt: Homophone priming effects on young and older adults' production of proper names

This study investigated why proper names are difficult to retrieve, especially for older adults. On intermixed trials, young and older adults produced a word for a definition or a proper name for a picture of a famous person. Prior production of a homophone (e.g., pit) as the response on a definition trial increased correct naming and reduced tip-of-the-tongue experiences for a proper name (e.g., Pitt) on a picture-naming trial. Among participants with no awareness of the homophone manipulation, older but not young adults showed these homophone priming effects. With a procedure that reduced awareness effects (Experiment 2), prior production of a homophone improved correct naming only for older adults, but speeded naming latency for both age groups. We suggest that representations of proper names are susceptible to weak connections that cause deficits in the transmission of excitation, impairing retrieval especially in older adults. We conclude that homophone production strengthens phonological connections, increasing the transmission of excitation.

Do alternative names block young and older adults' retrieval of proper names?

This study evaluates whether tip of the tongue experiences (TOTs) are caused by a more accessible word which blocks retrieval of the target word, especially for older adults. In a "competitor priming" paradigm, young and older adults produced the name of a famous character (e.g., Eliza Doolittle) in response to a question and subsequently named a picture of a famous actor or actress depicting this character (e.g., Audrey Hepburn as Eliza Doolittle). Older adults produced more TOTs than young adults, but prior production of a related character name did not affect TOTs, although it did reduce incorrect responses. There were no age differences in knowledge of films and TV and thus the age-related increase in TOTs is not because older adults have more relevant knowledge. The findings are compatible with models in which alternate words are a consequence not a cause of TOT.

Asymmetric aging effects on semantic and phonological processes: naming in the picture-word interference task

In 2 experiments, participants named pictures while ignoring auditory word distractors. For pictures with homophone names (e.g., ball), distractors semantically related to the nondepicted meaning (e.g., prom) facilitated naming by top-down phonological connections for young but not for older adults. Slowing from unrelated distractors and facilitation from phonologically related distractors were age invariant except in distractors that were both semantically and phonologically related. Only distractors semantically related to the picture interfered more for older than younger adults. These results ar einconsistent with age-linked deficits in inhibition of irrelevant information from either internal or external sources. Rather, aging affects priming transmission in a connectionist network with asymmetric effects on semantic and phonological connections involved in comprehension and production, respectively.

Asymmetric aging effects on semantic and phonological processes: naming in the picture-word interference task

In 2 experiments, participants named pictures while ignoring auditory word distractors. For pictures with homophone names (e.g., ball), distractors semantically related to the nondepicted meaning (e.g., prom) facilitated naming by top-down phonological connections for young but not for older adults. Slowing from unrelated distractors and facilitation from phonologically related distractors were age invariant except in distractors that were both semantically and phonologically related. Only distractors semantically related to the picture interfered more for older than younger adults. These results ar einconsistent with age-linked deficits in inhibition of irrelevant information from either internal or external sources. Rather, aging affects priming transmission in a connectionist network with asymmetric effects on semantic and phonological connections involved in comprehension and production, respectively.

The community-based morbidity of flexible cystoscopy

OBJECTIVE

To evaluate patients' experience after flexible cystoscopy (FC), particularly concentrating on the prevalence and degree of symptoms, the frequency of visits to their General Practitioner (GP), subsequent antibiotic rates and the actual incidence of urinary tract infection (UTI).

PATIENTS AND METHODS

Consecutive patients (420) presenting for FC were audited prospectively. A pain score for the procedure was recorded immediately afterward (linear scale 0-10) and a self-administered questionnaire completed at 7 days, to assess the objective and subjective symptoms and their duration, and the incidence of GP visits and subsequent antibiotic provision noted. An interim analysis was conducted on the initial 274 datasets received. To estimate the incidence of FC-induced UTI, the final 110 patients were asked not to consult their GP but to present to the urology department at 3 days after FC (or the emergency department if clinically necessary). These patients had initially provided a mid-stream urine (MSU) sample before FC and were assessed symptomatically with a subsequent sample obtained if a urinary dipstick test 3-days after FC was abnormal.

RESULTS

In all, 384 (91%) evaluable forms were returned. The median (range) pain score for FC was 1.1 (0-8.5), with seven patients (1.8%) recording a pain score of > 5 (all men); 382 patients (99.5%) declared they would be happy to undergo an identical procedure in the future if medically indicated. Pain on voiding was reported in 190 patients (50%), urinary frequency in 142 (37%) and gross haematuria in 73 (19%). Eighteen of the initial 274 patients (6.6%) visited their GP, with 15 (5.5%) of these receiving antibiotics. The MSU data from the final 110 patients showed a FC-mediated infection in three (2.7%).

CONCLUSION

Although FC is well tolerated, gross haematuria, urinary frequency and dysuria occur afterward much more frequently than expected. Patients should be thoroughly counselled before FC about these potential symptoms, to reduce their concern, any unnecessary GP visits and the use of antibiotics.

Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults

In a repetition priming paradigm, young and older participants read aloud prime words that sometimes shared phonological components with a target word that answered a general knowledge question. In Experiment 1, prior processing of phonologically related words decreased tip-of-the-tongue states (TOTs) and increased correct responses to subsequent questions. In Experiment 2, the priming task occurred only when the participant could not answer the question. Processing phonologically related words increased correct recall, but only when the participant was in a TOT state. Phonological priming effects were age invariant, although older adults produced relatively more TOTs. Results support the transmission deficit model that the weak connections among phonological representations that cause TOTs are strengthened by production of phonologically related words. There was no evidence that phonologically related words block TOT targets.

Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults

In a repetition priming paradigm, young and older participants read aloud prime words that sometimes shared phonological components with a target word that answered a general knowledge question. In Experiment 1, prior processing of phonologically related words decreased tip-of-the-tongue states (TOTs) and increased correct responses to subsequent questions. In Experiment 2, the priming task occurred only when the participant could not answer the question. Processing phonologically related words increased correct recall, but only when the participant was in a TOT state. Phonological priming effects were age invariant, although older adults produced relatively more TOTs. Results support the transmission deficit model that the weak connections among phonological representations that cause TOTs are strengthened by production of phonologically related words. There was no evidence that phonologically related words block TOT targets.

Production and perception of "verbosity" in younger and older adults

Older adults produced more off-topic speech (OTS) than younger adults during autobiographical interviews in previous studies, a finding attributed to age-related deficits in inhibiting irrelevant information. In this study, older adults produced more OTS than younger adults for autobiographical topics, but not for picture descriptions. A 2nd sample of younger and older participants rated older adults' story quality more positively than that of younger adults, a problematic finding for the inhibitory deficit explanation. Rater age affected ratings of how focused the speech was on the topic, suggesting age differences in criteria for OTS. These findings are consistent with the Pragmatic Change hypothesis, which maintains that older adults adopt communicative goals that emphasize the significance of life experiences rather than conciseness in their personal narratives.

Production and perception of "verbosity" in younger and older adults

Older adults produced more off-topic speech (OTS) than younger adults during autobiographical interviews in previous studies, a finding attributed to age-related deficits in inhibiting irrelevant information. In this study, older adults produced more OTS than younger adults for autobiographical topics, but not for picture descriptions. A 2nd sample of younger and older participants rated older adults' story quality more positively than that of younger adults, a problematic finding for the inhibitory deficit explanation. Rater age affected ratings of how focused the speech was on the topic, suggesting age differences in criteria for OTS. These findings are consistent with the Pragmatic Change hypothesis, which maintains that older adults adopt communicative goals that emphasize the significance of life experiences rather than conciseness in their personal narratives.

H.M. revisited: relations between language comprehension, memory, and the hippocampal system

Three studies tested the claim that H.M. exhibits a "pure memory deficit" that has left his ability to comprehend language unimpaired relative to memory-normal controls. In Study 1, H.M. and memory-normal controls of comparable intelligence, education, and age indicated whether sentences were ambiguous or unambiguous, and H. M. detected ambiguities significantly less often than controls. In Study 2, participants identified the two meanings of visually presented sentences that they knew were ambiguous, and relative to controls, H.M. rarely discovered the ambiguities without help and had difficulty understanding the first meanings, experimenter requests, and his own output. Study 3 replicated these results and showed that they were not due to brain damage per se or to cohort effects: Unlike H.M., a patient with bilateral frontal lobe damage detected the ambiguities as readily as young and same-cohort older controls. These results bear on two general classes of theories in use within a wide range of neurosciences and cognitive sciences: The data favor "distributed-memory theories" that ascribe H.M.'s deficit to semantic-level binding processes that are inherent to both language comprehension and memory, over "stages-of-processing theories," where H.M.'s defective storage processes have no effect on language comprehension.

Memory, language, and ageing

This overview provides both theoretical and empirical reasons for emphasizing practice and familiar skills as a practical strategy for enhancing cognitive functioning in old age. Our review of empirical research on age-related changes in memory and language reveals a consistent pattern of spared and impaired abilities in normal old age. Relatively preserved in old age is memory performance involving highly practised skills and familiar information, including factual, semantic and autobiographical information. Relatively impaired in old age is memory performance that requires the formation of new connections, for example, recall of recent autobiographical experiences, new facts or the source of newly acquired facts. This pattern of impaired new learning versus preserved old learning cuts across distinctions between semantic memory, episodic memory, explicit memory and perhaps also implicit memory. However, familiar verbal information is not completely preserved when accessed on the output side rather than the input side: aspects of language production, namely word finding and spelling, exhibit significant age-related declines. This emerging pattern of preserved and impaired abilities presents a fundamental challenge for theories of cognitive ageing, which must explain why some aspects of language and memory are more vulnerable to the effects of ageing than others. Information-universal theories, involving mechanisms such as general slowing that are independent of the type or structure of the information being processed, require additional mechanisms to account for this pattern of cognitive aging. Information-specific theories, where the type or structure of the postulated memory units can influence the effects of cognitive ageing, are able to account for this emerging pattern, but in some cases require further development to account for comprehensive cognitive changes such as general slowing.

Language, aging, and inhibitory deficits: evaluation of a theory

This article evaluates the success of Inhibitory Deficit theory in addressing two basic functions of a theory: explaining available results and predicting new findings. The review focuses on language comprehension and production, domains of cognition vulnerable to age-linked inhibitory deficits under the theory. Considerable research, however, reports remarkable age constancy in many aspects of language performance, contrary to the predictions of Inhibitory Deficit theory. For conditions that do produce age differences in language comprehension and production, evidence for inhibitory deficits is controversial at best. In predicting new findings, Inhibitory Deficit theory is constrained by lack of a well specified model, producing confusion between inhibition that occurs at a behavioral level versus a theoretical level. Modification of the theory is required to bring it in line with empirical findings on language and aging, and greater specification of underlying processes is required to reduce contradictions in predictions.

Why do semantic priming effects increase in old age? A meta-analysis

This study reports a meta-analysis comparing the size of semantic priming effects on young and older adults' lexical decision and pronunciation latency. The analysis included 15 studies with 49 conditions varying the semantic relatedness of a prime stimulus (single word or whole sentence) and a target word. An effect-size analysis on the difference between young and older adults' semantic priming effect (unrelated minus related latency) indicated that semantic priming effects are reliably larger for older than for young adults. There was no evidence for nonhomogeneity in this age difference across the different conditions. The relationship between young and older adults' semantic priming effects was described by a function with a positive intercept and a slope of 1.0. This pattern of findings favors aging models postulating process-specific slowing rather than general cognitive slowing.

Why do semantic priming effects increase in old age? A meta-analysis

This study reports a meta-analysis comparing the size of semantic priming effects on young and older adults' lexical decision and pronunciation latency. The analysis included 15 studies with 49 conditions varying the semantic relatedness of a prime stimulus (single word or whole sentence) and a target word. An effect-size analysis on the difference between young and older adults' semantic priming effect (unrelated minus related latency) indicated that semantic priming effects are reliably larger for older than for young adults. There was no evidence for nonhomogeneity in this age difference across the different conditions. The relationship between young and older adults' semantic priming effects was described by a function with a positive intercept and a slope of 1.0. This pattern of findings favors aging models postulating process-specific slowing rather than general cognitive slowing.

Semantic priming in young and older adults: Evidence for age constancy in automatic and attentional processes

Automatic and attentional components of semantic priming and the relation of each to episodic memory were evaluated in young and older adults. Category names served as prime words, and the relatedness of the prime to a subsequent lexical decision target was varied orthogonally with whether the target category was expected or unexpected. At a prime-target stimulus-onset asynchrony (SOA) of 410 ms, target words in the same category had faster lexical decision latencies than did different category targets. This effect was not significant at a 1,550-ms SOA and was attributed to automatic processes. Expected category targets had faster latencies than unexpected category targets at the 410-ms SOA, and the magnitude of the effect increased at the 1,550-ms SOA. This effect was attributed to attentional processes. These patterns of priming were obtained for both age groups, but in a surprise memory test older adults had poorer recall of primes and targets. We discuss the implications of these results for the hypothesis that older adults suffer deficits in selective attention and for the related hypothesis that attentional deficits impair semantic processing, which causes memory decrements in old age.

Word associations in old age: Evidence for consistency in semantic encoding during adulthood

Word associations of 80 young and 80 older adults were compared for 113 stimulus words. The proportion of paradigmatic responses varied with the grammatical class of the stimulus word and with the vocabulary level of the subject, but not with age. The same proportion of young and older adults gave the most common responses. Although older adults had a greater number of unique responses, this seems to reflect age differences in vocabulary level, as vocabulary but not age was a good predictor. Within-subject variability was also comparable across age, as on a retest young and older adults gave the same proportion of responses that were identical to those on the original test. Both age groups were more likely to repeat common than uncommon responses on the retest. This, together with analyses of response latency, suggests equivalent use of strategic processes across age. The results indicate that semantic structure and semantic encoding in adults are related to verbal ability, but not to age.

Word associations in old age: evidence for consistency in semantic encoding during adulthood

Word associations of 80 young and 80 older adults were compared for 113 stimulus words. The proportion of paradigmatic responses varied with the grammatical class of the stimulus word and with the vocabulary level of the subject, but not with age. The same proportion of young and older adults gave the most common responses. Although older adults had a greater number of unique responses, this seems to reflect age differences in vocabulary level, as vocabulary but not age was a good predictor. Within-subject variability was also comparable across age, as on a retest young and older adults gave the same proportion of responses that were identical to those on the original test. Both age groups were more likely to repeat common than uncommon responses on the retest. This, together with analyses of response latency, suggests equivalent use of strategic processes across age. The results indicate that semantic structure and semantic encoding in adults are related to verbal ability, but not to age.

Copper and zinc utilization in elderly adults

Elderly adults were provided with 2.33 mg of copper and either 7.80 or 23.26 mg of zinc daily during a 30-day metabolic study. Excretions of both minerals were measured throughout the study. The subjects were able to maintain apparent positive balance for copper, but were in negative balance for zinc on both levels off intake. Copper retention was significantly reduced by intake of the higher amount of zinc. These results support other reports indicating antagonism between the two nutrients. The hair content of zinc and copper was higher in females than in males and was in the ranges indicative of long-term adequate intakes. Recumbent length was significantly greater than standing height and should be investigated further as a more accurate measure of body height in the elderly.