Accuracy and qualities of real and suggested memories: nonspecific age differences.

This study examined adult age differences in the accuracy, confidence ratings, and vividness ratings of veridical and suggested memories. After seeing either one or two exposures of a vignette depicting a theft, young adults (M = 19 years) and older adults (M = 73 years) were given misleading information that suggested the presence of particular objects in the episode. Memory accuracy was higher for younger adults than for older adults, and the frequency of falsely reporting the presence of suggested objects was greater for older adults than for young adults. Further, levels of confidence and vividness ratings of the perceptual attributes (colors, locations) of falsely recognized items were higher for older adults than for young adults. Both young adults and older adults used more perceptual references when describing veridical memories than when describing suggested memories. Age differences in the suggestibility of memory were attributed to nonspecific or nondissociated memory aging effects.

Cognitive skill acquisition and transfer in younger and older adults.

The acquisition of cognitive skills often depends on 1 of (or a combination of) 2 processes, the execution of an algorithm, and the retrieval of problem instances. This study examined the effects of age and repetition of problem instances on the production and verification of solutions to 2 serially presented sets of alphabet arithmetic problems. Analyses of the parameters derived from power-function fits for individuals revealed age differences favoring young adults in improvement span, learning rate, and asymptote. For both age groups, the beneficial effects of repetitions on 1st-set response times were attributable to algorithmic speedup and to the retrieval of instances, whereas improvements in the speed of 2nd-set response times were attributable primarily to item retrieval.

Instance-based automaticity and aging: acquisition, reacquisition, and long-term retention.

This research examined age differences in the acquisition and reacquisition of instance-based automaticity. In 2 experiments, young and older adults were trained to enumerate targets presented in otherwise empty displays or in displays that contained distractors. Experiment 1 revealed that older adults required more practice to reach asymptote than young adults. For both age groups, modifications of the identities and locations of targets produced substantial disruptions in performance, whereas modifications of the identities or locations of distractors produced little interference. However, no age differences in the representations of instances in memory were obtained in participants who reached asymptote. Experiment 2 revealed age deficits in the long-term retention and rate of reacquisition of instance-based automaticity 18 months after initial training.

An examination of the effects of adult age on explicit and implicit learning of figural sequences.

Memory for previously learned figural sequences and item-to-item covariations within figural sequences was examined under explicit and implicit instructional conditions in three age groups: young adults (17-23 years); middle-aged adults (35-45 years); and older adults (55-65 years). In Phase 1 of the experiment, the acquisition phase, half the subjects in each age group learned sequences of three to eight items in which the item-to-item changes conformed to an artificial grammar, and the other half of the subjects in each age group learned strings in which the item-to-item changes were nongrammatical. In Phase 2, the implicit/explicit test phase, subjects made forced-choice judgments about parts of the strings that they learned in Phase 1, under either explicit or implicit instructions. Analyses of Phase 2 data revealed that subjects in both instructional conditions used item-to-item covariations in making decisions about grammatical strings. However, use of previously learned covariations as well as the number of correct judgments about previously learned strings was greater in the explicit condition than in the implicit condition. An age-related deficit was found for explicit recognition of grammar-following sequences.

Age and the ability to inhibit distractor information in visual selective attention.

Adult age differences in the effects of different types of distractor interference on visual search were examined. Young adults (mean age = 18.5 years) and older adults (mean age = 69.5 years) performed a target-counting task that required a complete search of a visual display in each trial. Varying numbers of targets were presented alone in displays or were interspersed among eight distractor items that were either categorically related (letters) or conceptually related (numbers representing either the correct number or the incorrect number of targets in the display) to the target item (letter Q). An adult age difference in the speed of target enumeration was observed when targets were presented alone in the display. In addition, when targets appeared with distractors, both younger and older adults were penalized more by conceptually interfering distracters than by categorically related distractors. Results did not suggest an age-related decline in inhibitory processes.

Skill and hemispheric specialization in detecting featural differences in visual images.

Visual asymmetry patterns related to skill were examined during a target-probe matching task in 24 skilled medical technologists and 24 matched controls. On each of 240 test trials, digitized replicas of specimens commonly encountered in medical laboratory diagnostics were shown centrally for 500 msec. Each target was immediately followed by a lateralized probe item for 120 msec that was either an exact copy (positive probe) or a distorted version (negative probe) of the target. Difficulty level of target-probe matching was manipulated on negative probe trials; half of the negative items consisted of difficult discriminations which were selected to assess the effects of domain-specific experience on detecting small differences in salient morphological features. Medical technologists exhibited a right visual field advantage, but were not different from the control subjects in speed or accuracy to positive probes or to easy negative probes. The observed left-hemisphere advantage in skilled visual processing is attributed to the beneficial effects of experience on the development of domain-specific visual analysis skills.

Age and visual field differences in computing visual-spatial relations.

Age and brain hemispheric differences in visual-spatial performance were investigated using 2 versions of categorical and coordinate (metric) spatial relations tasks. Thirty-two young adults (M = 19.2 years) and 32 older adults (M = 68.8 years) participated. An overall age-related decrement in computing visual-spatial relations was obtained for lateralized presentations and when items were presented centrally. In contrast to some previous findings, there was no evidence to suggest differential aging of the right hemisphere in computing visual-spatial relations.

Aging and shifts of visual spatial attention.

Three experiments examined adult age differences in the efficiency of endogenous (voluntary) and exogenous (involuntary) attention shifts. Younger and older subjects performed a spatial cuing task in which abruptly onset peripheral cues (Experiment 1) or central, symbolic cues (Experiments 2 and 3) were presented before a target stimulus at intervals ranging from 50 to 250 ms. With peripheral cues, the magnitude of cuing effects was at least as great for older as for younger adults and followed a similar time course. Similar results were obtained with symbolic cues, although cuing effects for older adults varied with cue difficulty. The results suggest that cue encoding may decline with advancing age but that the efficiency of the shift process is preserved.

Hemispheric specialization for categorical and coordinate spatial representations: a reappraisal.

The purpose of the present study was to examine Kosslyn's (1987) claim that the left hemisphere (LH) is specialized for the computation of categorical spatial representations and that the right hemisphere (RH) is specialized for the computation of coordinate spatial representations. Categorical representations involve making judgements about the relative position of the components of a visual stimulus (e.g., whether one component is above/below another). Coordinate representations involve calibrating absolute distances between the components of a visual stimulus (e.g., whether one component is within 5 mm of another). Thirty-two male and 32 female undergraduates were administered two versions of a categorical or a coordinate task over three blocks of 36 trials. Within each block, items were presented to the right visual field-left hemisphere (RVF-LH), the left visual field-right hemisphere (LVF-RH), or a centralized position. Overall, results were more supportive of Kosslyn's assertions concerning the role played by the RH in the computation of spatial representations. Specifically, subjects displayed an LVF-RH advantage when performing both versions of the coordinate task. The LVF-RH advantage on the coordinate task, however, was confirmed to the first block of trials. Finally, it was found that males were more likely than females to display faster reaction times (RTs) on coordinate tasks, slower RTs on categorical tasks, and an LVF-RH advantage in computing coordinate tasks.

Object recognition by component features: are there age differences.

This study extended aspects of Biederman's (1987) recognition-by-components (RBC) theory to the analysis of age differences in the recognition of incomplete visually-presented objects. RBC theory predicts that objects are recognizable or recoverable under conditions of fragmentation if a sufficient amount of essential structural information remains available. Objects are rendered nonrecoverable by the omission or obstruction of essential structural features at vertices and areas of concavity. Fifteen young adults and 15 older adults participated in a study of the effects of amount (25%, 45%, 65%) and type of fragmentation (recoverable, nonrecoverable) on object naming. Age-related declines in recognizing incomplete objects were associated with the amount of fragmentation, but type of fragmentation did not affect the performance of older adults. For the young adults, accuracy of performance was affected by both amount and type of fragmentation, consistent with Biederman's RBC theory. These results were interpreted as suggesting that age-related declines in perceptual closure performance have to do with non-structural factors such as the ability to inferentially augment degraded or missing visual information.

Adult age differences in implicit and explicit memory: time course and encoding effects.

Young and older adults were tested at three delays on word-stem completion or cued recall following semantic or structural word judgments. Identical three-letter stems were present at retrieval for both implicit (completion) and explicit (cued recall) tasks; only the intention to recall list words differed. The young adults outperformed the older adults on both implicit and explicit tasks at all test delays. Under some conditions, the older but not the young adults performed more poorly on cued recall than on stem completion, suggesting a possible failure to use implicitly available information to support explicit remembering. These results suggest that some forms of implicit memory decline with normal aging.

Age and the selectivity of visual information processing.

Two experiments were conducted to assess age differences in the selectivity of visual information processing. Selectivity was measured by the amount of interference caused by nontarget letters when subjects detected a target letter in a visual display. In both experiments, young and elderly groups participated in search and nonsearch conditions; in the search condition targets appeared anywhere in the display, whereas in the nonsearch condition targets were confined to the center position of the display. In the first experiment, subjects were assigned to either condition for two sessions of testing, and in the second experiment each subject participated in both conditions. In both experiments nontargets produced larger interference effects for old compared to young adults in the search condition but not in the nonsearch condition. The obtained pattern of age effects could not be explained by age-related reductions in parafoveal acuity. The findings indicate that the magnitude of divided-attention deficit increases with age, whereas focused-attention deficits are unaffected by aging.

Aging and the use of sentential structure to facilitate word recognition.

The ability of younger adults (mean age = 35.4 years) and older adults (mean age = 74.12 years) to use syntactic-semantic structure to identify words was examined by presenting word strings in random order and sentence order at subnormal speech rate, and at the speech reception threshold of the participant. Significant facilitation of word recognition occurred in the sentence strings in both age groups. Further, although the younger participants recognized more words in both the scrambled and sentences strings than the elderly, there was no significant difference in the percent benefit to word recognition in the sentence strings. The total pattern of results suggests that the deficit in the elderly participants was due either to age differences in memory and attention, high frequency hearing loss, response bias, or the application by the younger participants of linguistic rules not directly deriving from the presence of sentential structure.

Age and openness to experience in autobiographical memory.

Adult age and openness to experience were examined as predictors of autobiographical memory in a group of men and women ranging from 25 to 85 years of age. The remoteness of autobiographical memories retrieved in response to prompt words was more dependent on the age of the respondent than on his or her tendency to be receptive to new experiences as measured by Costa and McCrae's (1978) Experience Inventory. Older adults were more past-oriented in their recollections than younger adults, and experientially-open individuals regardless of age recalled more events from their recent pasts than from their distant pasts. Number of memories recalled, while not related to age, was positively associated with experiential openness.

Automatic and controlled semantic priming: accuracy, response bias, and aging.

Adult age differences in automatic and controlled semantic priming were investigated by varying the probability of valid primes in a lexical decision task. Tachistoscopic parafoveal stimulus presentation was used to assess age differences in accuracy and response bias as well as latency. Both age groups showed the expected findings of benefits without costs under automatic priming and benefits and costs under controlled priming. Errors for young adults were distributed equally among word and nonword stimuli, whereas older adults displayed a strong tendency to commit errors on nonword trials.

Research practices in the psychology of aging: a survey of research published in the Journal of Gerontology, 1975-1982.

The aim of this paper was to describe current research practices in the study of the psychology of aging. A total of 263 articles published in the Psychological Sciences Section of the Journal of Gerontology was examined in terms of subject-selection procedures, sample characteristics, author characteristics, data analysis techniques, research design, and specific area of research. Compared with an earlier survey, it was observed that research practices have improved with regard to sample representativeness of the age variable and the appropriate use of statistics, especially use of multivariate and regression analyses. Fifty-six percent of the studies surveyed were classified as cognitive investigations, and many of these studies were conducted from an information-processing perspective. A need for more detailed description by authors of subject-selection procedures and subject characteristics was noted.

Responses to moral dilemmas involving self versus others.

Forty older adults were administered the standard version (i.e. Other-orientation) of Rest et al.'s Defining Issues Test (DIT) and a modified version (i.e., Self-orientation) of the same instrument on two separate occasions. Contrary to the results of previous studies with children and young adults, the self/other manipulation in the present study failed to influence significantly older adults' moral judgments. The role of cognitive/perspective-taking and personal/affective factors in the moral reasoning abilities of the elderly, as well as those of children and young adults, are discussed.

Age, response complexity, and target consistency in visual search.

Adult age differences in visual search were examined under manipulations of target set consistency (fixed versus varied), response complexity (2 versus 4 sorting categories), display size (1, 4, or 8 letters/card), and sessions (2). Mean card sorting times of 20 young (mean = 22 years) and 20 elderly (mean = 62 years) adults were compared. Significant main effects of age, complexity, consistency, sessions, and display size were obtained. A consistent target set facilitated search independent of response complexity. As predicted, significant interactions indicated that age differences in search were eliminated under the fixed set procedure but not under the varied set procedure.

Adult age differences in visual search as a function of stimulus mapping and processing load.

Previous research has indicated age-related declines in visual search and memory search performance. Recent nondevelopmental evidence suggests that after extensive practice with a consistent stimulus set, performance in search tasks becomes independent of information load. Eight volume (mean age 23.55 years) and eight elderly (mean age 74.92 years) females searched for either two or four target letters which appeared individually in displays of one, four, or nine letters using either an unchanging memory set (consistent mapping) or changing memory sets (varied mapping); subjects performed over six sessions. Under the varied mapping condition the traditional pattern of age-associated decrement in search was obtained, while in the consistent mapping condition adult age differences were attenuated. These findings supported the hypothesis that age-related decrements in visual search can be eliminated, or at least minimized, when various control processes such as selective attention are short-circulated by automatic information processing.