The problem of naming in SDAT: A relative deficit

Abstract

Research relating to language disorder in senile dementia of the Alzheimer type (SDAT) has focused primarily on naming impairment, formally termed anomia or nominal aphasia/dysphasia. Data resulting from this research have been insufficiently informed by a comparative linguistic framework in which performance on naming tasks is contrasted with performance on other forms of language tasks. The present study involves the comparison of 21 adults with SDAT and 18 demographically controlled normal elderly adults on the Test for Syntactic Complexity and fifteen subtests of the Western Aphasia Battery. Performance on naming is compared with performance on oral language variables of repetition, yes/no response, auditory word recognition, sequential commands, syntactic processing, as well as with performance on reading tasks and non-verbal tasks. Findings relating to oral language tasks show that structured syntactic processing requiring explicit interpretation and sequential commands are significantly more difficult for the SDAT sample than are three of four naming tasks. Further, significant SDAT performance variability is found across naming tasks. The generative categorical naming task is found to be significantly more difficult for the SDAT patient than are the other three naming tasks. It is concluded that the generative categorical naming task should be regarded as a meta-naming task. In sum, it is found that although language dysfunction in SDAT has anomic components, the essential character of the language disorder is not best conceptualized as a problem of naming.     

Breathe Easy,Speak Easy: Pulmonary Function and Language Performance in Aging

Background: This study explored the association between pulmonary function (PF) and older adults’ language performance accuracy. Study rationale was anchored in aging research reporting PF as a reliable risk factor affecting cognition among the elderly.

Methods: 180 adult English native speakers aged 55 to 84 years participated in the study. PF was measured through forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio (FFR). Language performance was assessed with an action naming test and an object naming test, and two tests of sentence comprehension, one manipulating syntactic complexity and the other, semantic negation. Greater PF was predicted to be positively associated with all tasks.

Results: Unadjusted models revealed FVC and FEV1 effects on language performance among older adults. Participants with higher FVC showed better naming on both tasks and those with higher FEV1 had better object naming only. In covariate-adjusted models, only a positive FVC-object naming association remained.

Conclusion: Findings were discussed in terms of brain oxygenation mechanisms, whereby good PF may implicate efficient oxygenation, supporting neurotransmitter metabolism that protects against neural effects of cerebrovascular risk. Effects on object naming were linked to putative differential oxygenation demands across language tasks.     

Language deficits in depression: comparisons with SDAT and normal aging

In order to contribute to the definition of the structure of cognitive deficits in major depression/unipolar, language processing was studied in 20 elderly persons with major depression/unipolar, 23 elderly with SDAT, and 20 normal elderly. Measures administered included the Western Aphasia Battery, Test for Syntactic Complexity, and Chomsky Test of Syntax. Results indicate that depressed elderly performance on structural language variables of repetition, naming, auditory verbal comprehension, syntax, and reading is significantly better than performance of the SDAT sample. In contrast, results suggest that in comparing normal and depressed elderly, the normal elderly have the edge. On three measures of eleven, there are significant differences between depressed and normal elderly language processing. In analyzing the measures of significant difference, it is determined that complexity is an intervening variable. It is concluded that although the reason for language deficits in major depression/unipolar is as yet unknown, it is not justifiable at present to rule out an organic hypothesis.     

The Effect of Plausibility on Sentence Comprehension Among Older Adults and its Relation to Cognitive Functions

Background/Study Context: Older adults show age-related decline in complex-sentence comprehension. This has been attributed to a decrease in cognitive abilities that may support language processing, such as working memory (e.g., Caplan, DeDe, Waters, & Michaud, 2011,Psychology and Aging, 26, 439–450). The authors examined whether older adults have difficulty comprehending semantically implausible sentences and whether specific executive functions contribute to their comprehension performance.

Methods: Forty-two younger adults (aged 18–35) and 42 older adults (aged 55–75) were tested on two experimental tasks: a multiple negative comprehension task and an information processing battery.

Results: Both groups, older and younger adults, showed poorer performance for implausible sentences than for plausible sentences; however, no interaction was found between plausibility and age group. A regression analysis revealed that inhibition efficiency, as measured by a task that required resistance to proactive interference, predicted comprehension of implausible sentences in older adults only. Consistent with the compensation hypothesis, the older adults with better inhibition skills showed better comprehension than those with poor inhibition skills.

Conclusion: The findings suggest that semantic implausibility, along with syntactic complexity, increases linguistic and cognitive processing loads on auditory sentence comprehension. Moreover, the contribution of inhibitory control to the processing of semantic plausibility, particularly among older adults, suggests that the relationship between cognitive ability and language comprehension is strongly influenced by age.     

Language in dementia of recent referral

Twenty-four recently referred patients with dementia were assessed on a range of language tests and a mental status test. The tasks which appeared to present the most difficulties for the patients were written spelling, pragmatic processing tasks like sentence disambiguation and proverb interpretation. 'Straight' linguistic processing tasks sensitive to aphasia, like oral reading, serial identification of objects, naming and correction of semantically incorrect sentences, appeared to present fewer problems. It is concluded that certain language tasks may be useful and sensitive detectors of developing dementia, and that in early dementia those aspects of language which depend on straight linguistic processing can be relatively preserved.     

Temporal dynamics of verbal object comprehension

Knowledge of the stage composition and the temporal dynamics of human cognitive operations is critical for building theories of higher mental activity. This information has been difficult to acquire, even with different combinations of techniques such as refined behavioral testing, electrical recording/interference, and metabolic imaging studies. Verbal object comprehension was studied herein in a single individual, by using three tasks (object naming, auditory word comprehension, and visual word comprehension), two languages (English and Farsi), and four techniques (stimulus manipulation, direct cortical electrical interference, electrocorticography, and a variation of the technique of direct cortical electrical interference to produce time-delimited effects, called timeslicing), in a subject in whom indwelling subdural electrode arrays had been placed for clinical purposes. Electrical interference at a pair of electrodes on the left lateral occipitotemporal gyrus interfered with naming in both languages and with comprehension in the language tested (English). The naming and comprehension deficit resulted from interference with processing of verbal object meaning. Electrocorticography indices of cortical activation at this site during naming started 250–300 msec after visual stimulus presentation. By using the timeslicing technique, which varies the onset of electrical interference relative to the behavioral task, we found that completion of processing for verbal object meaning varied from 450 to 750 msec after current onset. This variability was found to be a function of the subject’s familiarity with the objects.     

Differences between two types of dual tasks according to the educational level in older adults

IntroductionFor dual-task paradigms, the timed up and go (TUG) test along with other cognitive or motor tasks has been used to evaluate and predict the risk of falling in older adults. However, the interference between motor-cognitive tasks can differ by the cognitive task.ObjectiveTo evaluate the performance of the TUG test under a single task condition and two dual-task conditions in older adults and to explore the effect of educational level on task performance.MethodsA total of 418 older adults (328 females) voluntarily participated in this study. The TUG test was administered as a single task and a dual task with one secondary simultaneous task: counting aloud backward from 100 or naming animals. Comparisons were performed to determine the interference caused by each cognitive task on the motor task, and correlation analysis was performed to explore the role of educational level.ResultsThe animal task led to a poorer TUG performance and a higher dual-task cost than did the counting task. Furthermore, the motor task led to a higher percentage of errors and cognitive stops in the animal task. Educational level plays a significant role in the interaction between tasks.ConclusionsBetween-task interference differs by the type of cognitive task performed and the educational level of the participants. The results of the present study should be considered when dual-task assessments are planned for older adults.     

Aging and memory for self-performed tasks: effects of task difficulty and time pressure

An increase in task difficulty or time pressure during the performance of cognitive tasks decreased the ability of older adults to recall the tasks. In Experiments 1 and 2, adult age differences in recall of cognitive tasks were smaller for easier than for more difficult tasks, and, in Experiment 3, adult age differences were smaller for recall of cognitive tasks without time pressure than for recall of cognitive tasks with time pressure. During difficult or time-pressured cognitive tasks, older adults may become anxious about their performance, and they may have trouble inhibiting negative self-evaluative thoughts about their performance. Older adults may thus devote less attention to aspects of the cognitive tasks that would be beneficial for task recall.     

The Role of Executive Functions in Object- and Action-Naming among Older Adults

Background/Study Context: Lexical retrieval abilities and executive function skills decline with age. The extent to which these processes might be interdependent remains unknown. The aim of the current study was to examine whether individual differences in three executive functions (shifting, fluency, and inhibition) predicted naming performance in older adults.

Methods: The sample included 264 adults aged 55–84. Six measures of executive functions were combined to make three executive function composites scores. Lexical retrieval performance was measured by accuracy and response time on two tasks: object naming and action naming. We conducted a series of multiple regressions to test whether executive function performance predicts naming abilities in older adults.

Results: We found that different executive functions predicted naming speed and accuracy. Shifting predicted naming accuracy for both object and action naming while fluency predicted response times on both tests as well as object naming accuracy, after controlling for education, gender, age, working memory span, and speed of processing in all regressions. Interestingly, inhibition did not contribute to naming accuracy or response times on either task.

Conclusion: The findings support the notion that preservation of some executive functions contributes to successful naming in older adults and that different executive functions are associated with naming speed and accuracy.     

Task specificity in age-related slowing: word production versus conceptual comparison

We analyzed age-related slowing in 29 younger (M = 22 years) and 30 older adults (M = 70 years) who performed a conceptual comparison task, a naming task, and a simple reaction time task. Both vocal and manual responses were elicited in all except the naming task. Results did not support the hypothesis that there is greater age-related slowing in comparison tasks than in production tasks. In contrast, we found an interaction between age and response modality in the conceptual comparison task. Response latencies of younger participants were shorter in the manual modality whereas those of older participants were shorter in the vocal modality. In the simple reaction time task manual responses were faster in the two age groups. These findings are discussed in relation to models assuming task-specific slowing factors.     

From the Cover: Brain signatures of artificial language processing: Evidence challenging the critical period hypothesis

Adult second language learning seems to be more difficult and less efficient than first language acquisition during childhood. By using event-related brain potentials, we show that adults who learned a miniature artificial language display a similar real-time pattern of brain activation when processing this language as native speakers do when processing natural languages. Participants trained in the artificial language showed two event-related brain potential components taken to reflect early automatic and late controlled syntactic processes, whereas untrained participants did not. This result challenges the common view that late second language learners process language in a principally different way from native speakers. Our findings demonstrate that a small system of grammatical rules can be syntactically instantiated by the adult speaker in a way that strongly resembles native-speaker sentence processing.     

Age and planning tasks: the influence of ecological validity

Planning ability is important in many everyday tasks, such as cooking and shopping. Previous studies have investigated aging effects on planning, looking at either widely used laboratory-based neuropsychological tasks such as the Tower of London (TOL) or more naturalistic planning tasks, such as organizing shopping errands. In the current study, we compare the effects of normal adult aging on both the TOL and a more ecologically valid planning task, the Plan-a-Day (PAD) task. There was a reliable decline in TOL planning performance with age, but no significant correlation between age and PAD planning performance. Age-related variance was partly explained by variance in information processing speed and education. It is proposed that in more ecologically valid planning tasks, age changes in processing speed can be compensated for by task-related knowledge. Implications for everyday planning performance by older adults are considered.     

Do you see what I see? The impact of age differences in time perspective on visual attention

In young adults, having a relatively long time perspective has been associated with a more abstract, holistic approach to cognitive tasks, as opposed to the more concrete, detailed approach associated with having a more limited or near-future focus ( Trope & Liberman, 2003). Here we studied the impact of age differences in temporal perspective on performance on a classic visual attention task ( Navon, 1977) that allowed for an orientation toward either detailed or holistic processing. Consistent with views on temporal perspective and cognition ( Liberman, Sagristano, & Trope, 2002), we found that younger adults were more likely than older adults to orient toward holistic processing.     

Timed instrumental activities of daily living tasks: relationship to cognitive function and everyday performance assessments in older adults

BACKGROUND: We live in a world where information is presented in a time-limited fashion and successful adaptation is dependent on time-limited responses. Slowed visual-processing speed is common among older adults. Its impact on everyday task performance is not clearly understood. OBJECTIVE: The goal was to determine whether visual-processing speed, as well as memory and inductive reasoning, are independently associated with the time required by older adults to complete instrumental activities of daily living typical of everyday life. METHODS: Five timed instrumental activities of daily (TIADL) tasks were administered to 173 older adults (ages 65-90 years) along with assessments of visual-processing speed, memory, and inductive reasoning. The dependent variable was the time required to perform the task (e.g., finding a telephone number, making change, finding and reading the ingredients on a can of food, finding food items on a shelf, reading instructions on medicine container). Medical and functional comorbidities known to affect task performance were measured in order to adjust for their impact on the dependent variable. Other measures of everyday task competence (Everyday Problems Test, Observed Tasks of Daily Living, questionnaire on IADL difficulties) were also administered in order to determine to what extent existing measures of everyday performance are associated with TIADL performance. Test-retest reliability of the TIADL score was assessed in a separate sample. RESULTS: Although memory and reasoning were crudely related to the time needed to perform the TIADL tasks, only processing speed was independently associated with TIADL scores. Those older adults with slow processing speed were more likely to require longer times to complete everyday tasks. Previously developed measures of everyday task competence (e.g., Everyday Problems Test, Observed Tasks of Daily Living) based on accuracy scoring did not strongly predict TIADL performance. CONCLUSION: These results suggest a unique role for an everyday competence test that focuses on the timely completion of everyday tasks, rather than on an assessment of accuracy alone. TIADL measures may prove useful in evaluating the everyday effectiveness of cognitive interventions targeted at increasing information-processing speed.     

Effects of processing style and age on schema acquisition.

Age differences in schema acquisition were examined using a task in which participants read paragraphs about a character and learned to predict his behavior. Successful performance depended on learning which information in the paragraphs was related to the behavior. Because these predictive traits were arbitrarily selected, prior experience was of no benefit. Twenty-eight young adults (ages 18 to 25) and 28 older adults (ages 60 to 80) participated in this experiment. The young adults performed better overall than the older adults. However, when we reexamined the data by considering processing style (i.e., whether individuals relied on a data-driven or conceptually driven processing style), we found that young and older adults who tested specific hypotheses were similar, whereas the older adults who tried to rely on general impressions performed poorly. Findings indicate that it is critical to determine how people approach cognitive tasks and that some older adults are likely to engage in conceptually driven processing regardless of its relevance to a particular task.     

Age-related differences in dual-task visual search: are performance gains retained?

Older and young adults practiced a verbal/spatial dual task and were tested for retention performance 1 month later. Participants first practiced each component task separately to individually determine component processing time. Thus, age-related differences in single-task detection sensitivity were minimized prior to performing the dual task. Participants practiced the dual task for two 1.5-hour sessions. Following the retention interval, they were retested on the single-task components and on the dual task. Correct detection as well as signal detection parameters were examined. Older adults demonstrated decreased sensitivity as well as a more conservative response bias during acquisition. Retention performance for the single tasks replicated previous retention studies, demonstrating age-related performance declines when stimulus-specific learning is assessed. Dual-task retention capability declined for both older and young adults equally when detection accuracy, but not perceptual sensitivity, was measured. Response bias changed differentially for older and young adults across the retention interval.     

Adult age differences in the storage of information in working memory.

The performance of 97 young and 91 old persons were compared to determine if a deficiency in working memory resources for processing, storage, or allocation could be detected. Persons simultaneously performed a storage and one of two processing tasks while instructed to allocate resources to processing, storage, or both tasks. The storage task involved remembering the names of one, three, or five persons. Processing tasks involved solving addition problems presented on flashcards or answering common knowledge questions. Results showed increased age differences on the storage task as demands for resources increased but no differences on processing tasks. Individuals seemed unable to allocate resources as instructed. A comparison of young-old and old-old groups showed the same results as those obtained comparing young and old groups and support the hypothesis of a deficiency of storage, but not processing, resources in working memory for old, especially old-old, adults.     

A visual recognition memory test for the assessment of cognitive function in aging and dementia

Young, non-demented elderly, and elderly demented subjects were administered a computerized visual recognition memory task. In the task, subjects were instructed to point out the new object from a group of objects whose number was progressively incremented. The test was subject-paced and made use of face-valid stimulus materials; it is closely comparable to tests developed for memory assessment in non-human primates that are sensitive to the effects of hippocampal ablation. The present task was found to elicit significant differences in performance between young and non-demented aged subjects, between the non-demented and demented elderly, and between demented subjects in the early and more advanced stages of senile dementia of the Alzheimer type (SDAT). In a discriminant analysis, the visual recognition memory test scores correctly classified 72.6% of the aged subjects and early SDAT patients. No significant difference in task performance was found between SDAT patients and demented patients with a significant cerebrovascular etiological component. Thus, although the task does not appear to be suitable for diagnostic purposes it would be useful for the assessment of treatment effects upon age-related cognitive dysfunction.     

Reliance on visible speech cues during multimodal language processing: individual and age differences

The current study demonstrates that when a strong inhibition process is invoked during multimodal (auditory-visual) language understanding: older adults perform worse than younger adults, visible speech does not benefit language-processing performance, and individual differences in measures of working memory for language do not predict performance. In contrast, in a task that does not invoke inhibition: adult age differences in performance are not obtained, visible speech benefits language performance, and individual differences in working memory predict performance. The results offer support for a framework for investigating multimodal language processing that incorporates assumptions about general information processing, individual differences in working memory capacity, and adult cognitive aging.     

Towards a deterioration of the structural and perceptive representations of objects in physiological aging?

Previous data collected in healthy elderly participants by our laboratory suggested impairment of visual and auditory object processing in normal aging. This impairment seemed not to be related to simple perceptual deficits. The aim of the present study was to identify the mechanism of this disorder according to serial models of object recognition, by dissociating the recognition abilities using naming tasks from a visual and from auditory stimuli, perceptual representations (visual and auditory), and semantic knowledge on the same 62 objects. Fifty three healthy participants were divided in three groups according to age (20-30 years, n = 17; 40-50 years, n = 14; 60-95 years, n = 22). They performed a battery assessing visual and auditory naming, judgement on semantic knowledge and perceptual visual properties, and matching of perceptual auditory properties of the same objects. The aged participants had lower performance on the naming tasks in both modalities, and worse perceptual properties performances again for both modalities than the other two groups. However, no significantly statistical difference was found on the semantic task. A significant correlation was found between age and the scores on each of the four tasks on which aged participants had lower scores than the youngest ones. No statistical difference was found between the two younger groups, but a trend was shown for the perceptual properties. Thus a degradation of perceptual representations of objects seems to be present in normal aging, but the nature of this degradation has to be specified.