Word frequency effects in priming performance in young and older adults

The present study examined word frequency effects on implicit priming in older adults compared with younger adults. In Experiment 1 participants performed a spelling test consisting of primed and unprimed homophones (e.g., mourning) and nonhomophones (e.g., militant). Older adults spelled more unprimed, low-frequency homophones than did younger adults, suggesting that there are age-related differences in base-rate spelling of lower frequency homophones. Experiment 2 involved a word-fragment completion task that primed both high- and low-frequency words. Young adults showed larger priming effects for low-frequency words, whereas older adults showed smaller and similar priming effects for high- and low-frequency words. Experiment 3 replicated the finding that word frequency has no effect on priming performance in older adults on a word-fragment completion task. These studies found differential word frequency effects on priming performance between young and older adults.     

Spatial knowledge of young and elderly adults: Scene recognition from familiar and novel perspectives

To determifie whether older adults experience particular problems with retrieval, groups of young and elderly adults were given free recall and recognition tests of supraspan lists of unrelated words. Analysis of number of words correctly recalled and recognized yielded a significant age by retention test interaction: greater age differences were observed for recall than for recogni- tion. In a second analysis of words recalled and recognized, corrected for guessing, the interaction disappeared. It was con- cluded that previous interpretations that age by retention test interactions are indicative of retrieval problems of the elderly may have been confounded by methodological problems. Furthermore, it was suggested that researchers in aging and memory need to be explicit in identifying their underlying models of error processes when analyzing recognition scores: different error models may lead to different results and interpretations.     

Adult age differences in visual word recognition: semantic encoding and episodic retention

The present experiment examined adult age differences in semantic priming effects and subsequent episodic retention for visually presented words. Twenty-four young (18-22 years) and 24 older (58-74 years) adults participated. In a lexical decision task, each of the word targets was presented as the final item of a sentence context (i.e., a prime) that was either semantically congruous, incongruous, or neutral with regard to the target. The perceptual difficulty of the target was also varied. The semantic priming effects in lexical decision RT were equivalent in magnitude for the young and older adults. The RT data appeared to represent a generalized, age-related slowing in the speed of information processing. In unexpected tests of recall and recognition for the target words, the older adults performed significantly worse than the young adults. The present results indicate that age-related deficits in episodic memory are not accompanied by substantial changes in semantic encoding ability.     

Age differences in processing relevant versus irrelevant stimuli in multiple-item recognition learning

Age differences in the processing of relevant stimuli were examined under two levels of irrelevant stimulation. The relevant stimuli were the right words of a multiple-item recognition learning task; the two levels of irrelevant stimulation were provided by the pairing of one wrong word (two-alternative items) versus three wrong words (four-alternative items) with each right word. Elderly subjects were inferior to young adults in the learning of four-alternative items, but not in the learning of two-alternative items. This finding supports the hypothesis, derived from previous research on perceptual tasks, that elderly adults direct greater amounts of attention to irrelevant stimuli than do young adults, thus reducing the amount of processing available for the accompanying relevant stimuli. However, despite their presumed greater attention to irrelevant stimuli, elderly subjects recognized fewer individual wrong words on a subsequent memory test than did young adults. This age-related effect was interpreted in terms of depth of processing theory.     

Memory for topics of conversation: adult age differences and intentionality

Young adults and elderly adults received a series of topics for discussion, followed by a recall test of the topics per se and a recognition memory test of the questions asked during the conversations. Half of the participants in each age group were forewarned of the subsequent recall test (intentional memory); the remaining participants were not forewarned (incidental memory). Null effects for instructional variation were found at both age levels for all memory scores. For recall, an age difference, favoring young adults, was found. However, no age difference was found for either the recognition of old questions as old or the recognition of new questions as new. The results were interpreted in terms of an age deficit for the retrieval of memory traces established by the comprehension of conversational content.     

Introduction to A.T. Welford's “between bodily changes and performance: Some possible reasons for slowing with age”

Abstract

The present experiment examined adult age differences in semantic priming effects and subsequent episodic retention for visually presented words. Twenty-four young (18-22 years) and 24 older (58-74 years) adults participated. In a lexical decision task, each of the word targets was presented as the final item of a sentence context (i.e., a prime) that was either semantically congruous, incongruous, or neutral with regard to the target. The perceptual difficulty of the target was also varied. The semantic priming effects in lexical decision RT were equivalent in magnitude for the young and older adults. The RT data appeared to represent a generalized, age-related slowing in the speed of information processing. In unexpected tests of recall and recognition for the target words, the older adults performed significantly worse than the young adults. The present results indicate that age-related deficits in episodic memory are not accompanied by substantial changes in semantic encoding ability.     

Implicit and explicit measures of memory for perceptual information in young adults,healthy older adults,and patients with Alzheimer's disease

In this study, we examined how implicit and explicit memory for perceptual information (modality and voice) and lexical information varied across three subject groups: healthy young adults, healthy older adults, and age-matched older adults with dementia of the Alzheimer's type (DAT). These groups exhibited cross-modality (abstract) priming of the same magnitude. However, young adults produced greater modality- and voice-specific priming than the other two groups, whose performance was equivalent, suggesting that aging, but not DAT, reduced form-specific priming. Young adults demonstrated better recognition memory than healthy older adults, who in turn exhibited better recognition memory than older adults with DAT. In young adults, recognition memory was also sensitive to perceptual information. These findings indicate that aging can affect implicit memory for perceptual information, whereas DAT magnifies the effect of aging on explicit memory.     

The effects of aging and degree of association on the semantic priming of lexical decisions

Adults completed a lexical decision task in which they saw two strings of letters on each trial and were asked to respond "yes" only if both strings were words. Later, participants were tested for incidental free recall and incidental forced-choice recognition of the words presented in the lexical decision task. These tasks were given to 20 young (mean age = 31.1 years) and 20 old (mean age = 69.5 years) non-student adults in Experiment 1, and to 20 young college students in Experiment 2. In both experiments, semantic priming occurred, i.e., lexical decisions were faster when the words within a pair were related than when they were not. For the college students in Experiment 2, but not for the non-students in Experiment 1, this effect was greater for high-dominance pairs (e.g., BIRD-ROBIN) than for low (e.g., BIRD-DUCK). Experiment 1 revealed no age differences in priming, but significant age differences favoring the young in both free recall and recognition. The results are interpreted in light of theories that distinquish between automatic and effortful activation of semantic memory.     

Temporal memory and content memory for actions: adult age differences in acquisition and retention

Young adult and elderly adult subjects were tested under incidental memory conditions for recognition memory of content and temporal memory for the order of a series of actions performed in the laboratory. The tests were conducted both shortly after completion of the series and 24 hours later, with different sets of actions tested on each occasion. Recognition memory of content showed no forgetting for the young subjects, but significant forgetting for the elderly subjects. Memory for temporal information was substantially greater for the young subjects than for the elderly subjects. Both age groups showed substantial forgetting of temporal information over the 24-hour retention interval.     

An adult developmental study of the encoding of spatial location.

The present study was designed to test the hypothesis that there is a differential deficit in the ability to encode contextual information with increasing age. Young, middle-aged, and elderly adults were shown target words in various quadrants of a computer screen (contexts) and were told to either (a) remember the words and their locations, (b) remember the words, or (c) tell whether the words referred to something that was alive or not. Following presentation of the words, subjects were given a recognition test for the words and were asked to identify the quadrant in which each word had been presented. If older adults have a contextual encoding deficit, than an interaction between age and instruction condition would be expected in memory for quadrants. Older adults would be expected to perform better relative to younger adults when the locations were target information (intentionally learned) than when they were contextual (not intentionally learned). Since such an interaction was not obtained, the results provide no support for the hypothesis that the elderly have an encoding deficit that is specific to contextual information.     

Age differences in the vulnerability of facial recognition memory to proactive interference

A facial recognition memory task was administered to 16 young subjects (age range 18-30) and 28 elderly subjects (age range 63-83). A continuous recognition paradigm was used, in which subjects were instructed to identify the repeated faces in an ongoing series of faces presented on a video monitor screen. A signal detection analysis of the data revealed a mild recognition memory deficit in the elderly, due mainly to an increase in false positives during the second half of the test session. This age-specific increase in late-session false alarms may be a result of increased sensitivity of the aged subjects to proactive interference from previously presented faces. Increasing the length of the delay between the initial and repeat presentation of a face decreased recognition accuracy in both groups, but the young subjects were more sensitive to the delay interval effect than the elderly. Multiple presentations of faces produced a comparable improvement in the recognition accuracy of both young and old subjects. The elderly subjects exhibited a more liberal response bias than the young subjects, indicating that impaired memory task performance of the aged subjects cannot be attributed to a more conservative test-taking strategy.     

Priming in episodic memory

Young and old adults studied related and unrelated word pairs and were given both cued recall and recognition tests. The recognition test required speeded responses to single words. The test order was constructed so that half of the B items from each A-B pair were preceded by its paired A item whereas the other half of the B items were preceded by some other old item. Priming was measured as the difference in reaction time between these two types of items. Significant age differences were found in both recall and recognition accuracy, but young and old adults showed equal amounts of priming. There were significant main effects of relatedness on all three dependent measures, but only in cued recall was there a larger age deficit for unrelated items. The results are inconsistent with an age-related deficit for integrating pairs of words at encoding and suggest, instead, an impairment of effortful retrieval processes.     

The effects of orienting tasks on adult age differences in recall and recognition

This research examined the type of recognition errors made following orienting task instructions in order to investigate possible age differences in the depth of processing of information to be learned. Eighteen young, 18 middle-aged, and 18 elderly adults viewed 48 words, each of which was accompanied by learning instructions or a phonological or semantic orienting task. Subjects were then presented previously-seen items paired with a synonym, rhyme, or unrelated word. Analyses revealed no age differences in the number or pattern of recognition errors. Middle-aged and elderly adults recalled fewer items than young adults and their recall scores were less affected by orienting task instructions. Results are discussed in the context of possible age differences in the depth and elaboration of processing during study.     

Age-related differences in the use of contextual information in recognition memory: a global matching approach

Age differences in the processing of contextual information were investigated using the Item, associated Context, and Ensemble (ICE) model (K. Murnane, M. P. Phelps, & K. Malmberg, 1999), a general global matching model of recognition memory. In two experiments, young and older adults studied words in environmental contexts and were tested in both the same and different contexts. Patterns of context effects for hit rate, false alarm rate, and d' suggest that older adults process associated context, but have difficulties integrating items and context into an ensemble. Thus, older adults appear to have a specific, rather than a general, deficit in processing contextual information. A deficiency in ensemble processing may be responsible for the prevalent finding that older adults show poorer recognition memory performance than young adults.     

An adult development study of contextual memory

This study tested the hypothesis that there is a relatively greater decrease in memory for contextual features than in memory for target information with increasing age. Young, middle-aged, and elderly adults were presented with a number of slides, each of which contained a word centered on a background composed of either a landscape/cityscape or a border design. One third of the subjects were told to remember the words, one third were told to remember the backgrounds, and one third were told to remember the word-and-background pairs. Recognition memory for both words, backgrounds, and word-and-background pairings was tested in all subjects. The interaction between age, instruction condition, and type of information tested was not significant. Thus, there was no support for the hypothesis that older adults have a greater deficit in contextual memory than in memory for target information when compared to younger adults.     

Adult age differences in memory for modality attributes

Young and elderly subjects performed on two memory tasks. The first task involved recognition of word content and identification of each word's sex of voice in the study list. An additional independent variable consisted of intentional versus incidental learning instructions. An age difference favoring young adults was found for both word recognition and sex of voice recognition, confirming earlier evidence found with a more difficult sentence recall task. Comparable age deficits were found on the second task involving word recognition and identification of each word's case format in the study list. Encoding of modality attributes does appear to be an effortful process and is susceptible to age deficits. However, contrary to the age differentiation hypothesis, the cross-task correlation between modality recognition scores was no greater for elderly adults than for young adults.     

Effects of aging and education on false memory

This study examined the effects of aging and education on participants' false memory for words that were not presented. Three age groups of participants with either a high or low education level were asked to study lists of semantically related words. Both age and education were found to affect veridical and false memory, as indicated in the recall and recognition of the studied word and nonstudied lures. A low education level had a negative effect on memory performance for both young and middle-aged adults. Older adults with a high level of education had a higher level of false memory than those with a lower education level. The results of this study are discussed in terms of the importance of education on false memory and mechanisms that create false memory of words in older adults.     

Context utilization in young and old adults

Two experiments examined adult age differences in the spontaneous use of context to study and retrieve information. Young and old adults were presented with a series of homographs (targets) that were paired with two context words which biased a specific meaning of the target. Recognition memory for targets was then tested by presenting them in the same context or removing or varying the context. In general, recognition decreased in both groups as the retrieval context became more dissimilar to the study context, suggesting that both young and old adults utilize context and that congruent study and retrieval information facilitates retrieval. However, it appeared that older primarily encoded general semantic information relating to the association between target and context, whereas younger adults encoded distinctive information about individual targets. Such encoding differences could account for observed age differences in false recognitions for lures in old contexts and correct recognitions for targets in new contexts.     

The effects of age-stereotype priming on the memory performance of older adults

The effects of age-stereotype priming on the memory performance of older adults were investigated through a conceptual replication and extension of Levy's (1996. Journal of Personality and Social Psychology, 71, 1092-1107) study. Sixty young and 60 older adults were subliminally primed with a positive age stereotype, a negative age stereotype, or neutral primes. Memory performance on two tasks (a photo recall task and a dot location task) was measured before and after the priming intervention. Although the study does not provide unequivocal support for Levy's (1996) findings, results did show that priming a negative age stereotype undermined memory performance for a small sample of older adults who were "unaware" of the primes. However, contrary to Levy's findings, priming a positive age stereotype did not increase older adults' memory performance. There were no significant effects of priming positive or negative age stereotypes on the memory performance of young adults.     

Adult age differences in free recall as a function of basis of organization and method of presentation.

To examine age-related differences in the discovery of intralist relationships, young and elderly adults were presented a free-recall list in either the conventional successive single-item format or in a whole-list display. A list that could be organized by associative or rhyming intralist relationships was used to test the levels-of-processing model of memory as an explanation of age differences in recall. Young adults recalled more base-words, associates, and rhymes than elderly subjects on immediate free and cued tests and on an uncued test one week later. Elderly subjects showed less utilization of both semantic and nonsemantic intralist relationships. Age did not interact with method of presentation. Recall and organization deficits occurred for elderly adults even though they were less anxious than young adults.