Age-related differences in lexical access, spreading activation, and simple pronunciation.

An experiment was conducted to address age-related differences in lexical access, spreading activation, and pronunciation. Both young and older adults participated in a delayed pronunciation task to trace the time course of lexical access and a semantic priming task to trace the time course of spreading activation. In the delayed pronunciation task, subjects were presented a word and then, after varying delays, were presented a cue to pronounce the word aloud. Older adults benefited considerably more from the preexposure to the word than did the younger adults, suggesting an age-related difference in lexical access time. In the semantic priming pronunciation task, semantic relatedness (related vs. neutral), strength of the relationship (high vs. low), and prime–target stimulus onset asynchrony (200 ms, 350 ms, 500 ms, 650 ms, and 800 ms) were factorially crossed with age to investigate age-related differences in the buildup of semantic activation across time. The results from this task indicated that the activation pattern of the older adults closely mimicked that of the younger adults. Finally, the results of both tasks indicated that older adults were slower at both their onset to pronounce and their actual production durations (i.e., from onset to offset) in the pronunciation task. The results were interpreted as suggesting that input and output processes are slowed with age, but that the basic retrieval mechanism of spreading activation is spared by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploring the Identification-Production Hypothesis of Repetition Priming in Young and Older Adults.

The identification-production hypothesis of age-related differences in repetition priming predicts reduced priming in older adults on indirect memory measures that require stimulus production (production priming) together with age constancy on indirect measures that require stimulus identification, verification, or classification processes (identification priming). Although some evidence is consistent with this hypothesis, comparisons of identification and production priming in young and older adults often confound stimulus, subject, and dependent measure factors across tasks. Consequently, repetition priming has yet to be assessed in healthy young and healthy older adults using identification and production tasks that control for these factors. The identification-production hypothesis was tested using verb generation as a measure of production priming (Experiments 1-3) and semantic classification (Experiment 1) or semantic verification (Experiments 2 and 3) as the measure of identification priming. Contrary to the identification-production hypothesis, no age-related diminutions in identification or production forms of priming were found. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related slowing and the time course of semantic priming in visual word identification.

Investigated, in 4 experiments, the time course of semantic priming effects during 2 forms of visual word identification, lexical decision and pronunciation. On each trial, a target letter string was preceded by a single-word priming context. The effects of varying the stimulus onset asynchrony between the prime and the target indicated that the time course of semantic priming was equivalent for young and older adults. There were no consistent differences between lexical decision and pronunciation in the time course of semantic priming. The age differences associated with response selection were greater than would be predicted by generalized age-related slowing. The semantic priming effects were also inconsistent with a generalized slowing model, but the reliability of these effects was substantially lower than the reliability of the other task-related variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in young and older adults.

In three experiments, young and older adults were compared on both implicit and explicit memory tasks. The size of repetition priming effects in word completion and in perceptual identification tasks did not differ reliably across ages. However, age-related decrements in performance were obtained in free recall, cued recall, and recognition. These results, similar to those observed in amnesics, suggest that older adults are impaired on tasks which require conscious recollection but that memory which depends on automatic activation processes is relatively unaffected by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

Word associations of 80 young (aged 17–33 yrs) and 80 older (aged 62–87 yrs) adults were compared for 113 stimulus words. Results indicate that the proportion of paradigmatic responses varied with the grammatical class of the stimulus word and with the vocabulary level of the S, but not with age. The same proportion of young and older Ss gave the most common responses. Although older Ss had a greater number of unique responses, this seemed to reflect age differences in vocabulary level, as vocabulary but not age was a good predictor. Within-S variability was also comparable across age, as on a retest young and older Ss 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. It is concluded that 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. (49 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct and indirect tests of memory for category exemplars in young and older adults.

Young and older adults were compared on direct (cued recall) and indirect (exemplar generation) tests of memory for category members. Because category names served as cues in both tasks, amount of retrieval support was constant across tasks. Although older adults produced fewer category members in cued recall, priming of category exemplars in the generation task did not vary with age. These results suggest that age constancy in priming tasks does not depend on physical similarity between study materials and retrieval cues provided at test and point to the importance of deliberate recollection as a factor in determining the extent of age differences in memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and rate of activation in semantic memory.

Two word-primed picture-naming experiments were carried out to test the hypothesis that rate of activation in semantic memory is slower for older adults than for young adults. The presence of priming effects, both positive and negative, was taken as evidence of activation. In Exp 1 there was no age difference in the time of onset of either facilitation or inhibition by primes. A computer simulation, based on a simple connectionist model, showed that slower processing would have only a minimal effect on the time of onset of priming effects under the assumptions of the model; however, offset of inhibition by primes would be delayed if processing rate were reduced. In Exp 2 older adults showed inhibition by primes over a longer interval than did young adults, which was taken as evidence that the general slowing associated with aging extends to the transmission of activation at the earliest levels of cognitive processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations between procedural and episodic memory: Effects of time and aging.

The issue of multiple memory systems is explored. Young and older adults (mean ages?=?20 and 71, respectively) named pictures and were tested immediately, 1, 7, or 21 days later. Episodic memory (recognition) for pictures was significantly lower in older relative to young adults and declined systematically across all retention intervals in both age groups. In contrast, procedural memory (repetition priming in picture naming) revealed no reliable age differences. In both age groups, priming declined within the first 24 hr, but unlike recognition, there was no further decrement from 1 to 21 days. There were also within-subject dissociations: The magnitude of priming was equivalent for remembered and forgotten items, and the relation between recognition and priming across intervals was nonmonotonic, revealing a reversed association. The findings were interpreted within a multiple-memory-systems framework. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in integrated semantic memory.

Used J. D. Bransford and J. J. Franks's (1971) paradigm of linguistic abstraction to examine age differences in the nature of stored semantic information. 20 young (mean age 18.7 yrs) and 18 old adults (mean age 67.3 yrs) served as Ss. Specifically, age differences on 2 dimensions of memory were examined: (a) integration of related content from separate sentences and (b) retention of precise semantic content. Young and old Ss were not found to differ in the precision of retained semantic information. Furthermore, while both age groups evidenced integration of information as indexed by a strong linear trend of recognition rate across sentence complexity, this trend did not interact with age, supporting the idea that both age groups showed comparable integration of linguistic information into holistic ideas. Implications for current conceptualizations of age differences in memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming in major depressive state

We studied semantic priming in 20 major depressive subjects. The methodology used was a visual lexical decision task. Semantic priming is the facilitation of target word recognition (shortening of response time) by the prior presentation of a semantically related context (a prime word). It relies on semantic processing of words and context, facilitating early cognitive stages of response. Varying the temporal interval between prime and target words onset allows us to distinguish between two priming mechanisms, relying on more automatic (test 1) or more controlled (i.e. attention dependent) (test 2) information processing. We observe a significant retardation for words and pseudo-words in depressives (in relation to controls) in both tests. In spite of a general retardation and increase of response times in depressives, semantic priming is evident in both groups and both tests, and does not differ significantly between depressive and control groups in either automatic or controlled conditions. Theses results confirm that semantic processing is not impaired in depression, and are discussed with regard to the hypothesis of an effortful processing impairment in depression, and to depressive retardation.     

Aging and the inhibition of spatial location.

Two experiments compared the performance of older and younger adults on a task assessing suppression (or negative priming) for location of distractors. A 3rd experiment compared the 2 age groups on suppression for location and identity of distractors such that location was irrelevant to selection and response. Older and younger adults showed location suppression across all experiments. In Exp 3, identity suppression was found for younger but not older adults. In addition, younger adults revealed an additive effect for suppression of identity and location. Consistent evidence of inhibition of return was not found for either age group. The findings are discussed in terms of the L. Hasher and R. T. Zacks (1988) theory of reduced inhibitory efficiency in the elderly and in terms of neurophysiological evidence that inhibition of identity and location may function separately within the 2 cortical visual systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic semantic priming: Effect of category exemplar level and word association level.

Evaluated semantic priming when the prime was masked below naming threshold and the target was named in 4 experiments with 263 undergraduates. Exp I showed that when word primes were masked and word targets were named, prior knowledge of the related pairs did not alter semantic priming. Semantic priming within categories occurred only when the prime stimulus was the 1st category exemplar. Findings of Exp II indicate that when masked pictures were used as primes, semantic priming for word targets was sensitive to the category exemplar level of the prime but not to the category exemplar level of the target. Word association norms collected in Exp III did not support the hypothesis that the effect of category exemplar level was mediated by the strength of word association. Exp IV revealed significant semantic priming for masked picture primes and within-category word targets, regardless of the level of word association between prime and target. Exp IV also demonstrated semantic priming for high word association targets that were not members of the same semantic category. For all experiments, Ss with the longest average reaction times (RTs) also showed the largest semantic priming effect for naming word targets. It is suggested that viewing one of the highest ranking category exemplars activates the memory representation of the category, perhaps because such prototypic exemplars are contained within the category concept itself. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immunohistochemical localisation of alpha1B-adrenergic receptors in the rat iris

This article reports results from a meta-analysis on adult age differences in the negative priming effect (21 studies on identity negative priming and 8 on location negative priming). Both younger and older adults were found to be susceptible to the negative priming effect in identity and location tasks. Effect sizes were homogeneous for both tasks, indicating that the data are adequately described without reference to moderator variables. State trace analysis on identity tasks, in which mean latencies in negative priming conditions were regressed onto mean latencies in baseline conditions, showed (a) that in both age groups the negative priming effect is proportional rather than additive and (b) that the negative priming effect is smaller in older adults as compared with younger adults.     

A test of the frontal lobe functioning hypothesis of age deficits in production priming.

Older adults have been hypothesized to show reduced priming relative to younger adults on implicit memory tests that require production of a response because these tasks place high demands on attentional processes associated with frontal lobe function, which are often reduced with age (see D. A. Fleischman & J. D. E. Gabrieli, 1998). The current study directly tested this frontal lobe hypothesis of age effects in production priming. Younger adults and older adults who differed in their attentional abilities as measured by a battery of neuropsychological tests were given two production priming tasks, word stem completion and category production, followed by explicit free recall tests. Results showed that explicit memory performance was reduced by age and older adults' frontal functioning. Age and frontal functioning influenced category production priming but not word stem completion priming. Results failed to support the frontal account of age reductions in production priming. Instead, results implicate the influence of other processes often involved in production priming tasks, such as explicit memory strategies and response competition, as critical for understanding age effects in implicit memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How many memory systems? Evidence from aging.

The present research tested Tulving's (1985) ternary memory theory. Young (ages 19–32) and older (ages 63–80) adults were given procedural, semantic, and episodic memory tasks. Repetition, lag, and codability were manipulated in a picture-naming task, followed by incidental memory tests. Relative to young adults, older adults exhibited lower levels of recall and recognition, but these episodic measures increased similarly as a function of lag and repetition in both age groups. No age-related deficits emerged in either semantic memory (vocabulary, latency slopes, naming errors and tip-of-the-tongue responses) or procedural memory (repetition priming magnitude and rate of decline). In addition to the age by memory task dissociations, the manipulation of codability produced slower naming latencies and more naming errors (semantic memory), yet promoted better recall and recognition (episodic memory). Finally, a factor analysis of 11 memory measures revealed three distinct factors, providing additional support for a tripartite memory model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and the negative priming effect: A meta-analysis.

This article reports results from a meta-analysis on adult age differences in the negative priming effect (21 studies on identity negative priming and 8 on location negative priming). Both younger and older adults were found to be susceptible to the negative priming effect in identity and location tasks. Effect sizes were homogeneous for both tasks, indicating that the data are adequately described without reference to moderator variables. State trace analysis on identity tasks, in which mean latencies in negative priming conditions were regressed onto mean latencies in baseline conditions, showed (a) that in both age groups the negative priming effect is proportional rather than additive and (b) that the negative priming effect is smaller in older adults as compared with younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflict and collaboration in middle-aged and older couples: II. Cardiovascular reactivity during marital interaction.

Marital strain confers risk of cardiovascular disease (CVD), perhaps though cardiovascular reactivity (CVR) to stressful marital interactions. CVR to marital stressors may differ between middle-age and older adults, and types of marital interactions that evoke CVR may also differ across these age groups, as relationship contexts and stressors differ with age. The authors examined cardiovascular responses to a marital conflict discussion and collaborative problem solving in 300 middle-aged and older married couples. Marital conflict evoked greater increases in blood pressure, cardiac output, and cardiac sympathetic activation than did collaboration. Older couples displayed smaller heart rate responses to conflict than did middle-aged couples but larger blood pressure responses to collaboration—especially in older men. These effects were maintained during a posttask recovery period. Women did not display greater CVR than men on any measure or in either interaction context, though they did display greater parasympathetic withdrawal. CVR to marital conflict could contribute to the association of marital strain with CVD for middle-aged and older men and women, but other age-related marital contexts (e.g., collaboration among older couples) may also contribute to this mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of age and task demands on visual selective attention.

We investigated whether young and older adults differ on measures of interference (INT), negative priming (NP), and inhibition of return (IOR) on a spatial selective attention task that gradually increased in cognitive demand, from simple perceptual matching to letter identification. For both groups, INT increased and IOR decreased with task demand; while NP remained stable. We found age-related increases in INT, NP, and IOR, independent of task demand. However, only between-groups differences in IOR remained after correcting for age-related slowing in response times. Finally, we found no association between our measures of attention across groups, suggesting negligible overlap between INT, NP, and IOR. Our results indicate that attention is selectively and independently influenced by age and task demands, with both effects dependent on how attention is measured. These findings shed light on the “frontal hypothesis of aging.” (PsycINFO Database Record (c) 2010 APA, all rights reserved)