Biomedical subjects

Lynn Hasher

Publications and source records attributed to Lynn Hasher.

14 recordsLinked to original sources

PubMed2006

The influence of emotional valence on age differences in early processing and memory.

This study examined older and younger adults' attentional biases and subsequent incidental recognition memory for distracting positive, negative, and neutral words. Younger adults were more distracted by negative stimuli than by positive or neutral stimuli, and they correctly recognized more negative than positive words. Older adults, however, attended equally to all stimuli yet showed reliable recognition only for positive words. Thus, although an attentional bias toward negative words carried over into recognition performance for younger adults, older adults' bias appeared to be limited to remembering positive information.

Adolescent↗

PubMed2006

Attentional disregulation: a benefit for implicit memory.

The authors investigated the effect of age and time of testing on the ability to control attention and addressed the possibility that older adults' susceptibility to distraction may sometimes facilitate performance on a later cognitive task. Using a modification of a G. Rees, C. Russell, C. D. Frith, and J. Driver (1999) procedure, the authors asked the participants to make same or different judgments on line drawings superimposed with task-irrelevant letter strings. Memory for the distractors was subsequently tested with an implicit memory task. Both older and young adults demonstrated greater memory for distractors at nonoptimal times of day than at optimal times of day; however, older adults showed considerably better memory for the distractors than did young adults.

Adolescent↗

PubMed2006

Age differences in implicit interference.

We assessed age differences in interference effects in priming by using fragment completion. In Experiment 1, noninterfering filler words preceded critical targets at study, and priming was age invariant. In Experiment 2, the same target items had interfering competitors at the beginning of the list, such that both the target and the competitor were legitimate solutions to a fragment. Having two responses to a cue was disruptive for older adults, but not for younger adults. Younger and older adults differ in their susceptibility to interference in implicit tasks, and interference may play a role in influencing the magnitude of age differences in priming.

Adolescent↗

PubMed2006

Distraction as a determinant of processing speed.

Processing speed is often described as a fundamental resource determining individual (e.g., I.Q.) and group (e.g., developmental) differences in cognition. However, most tests that measure speed present many items on a single page. Because many groups with slowed responding are also distractible, we compared younger and older adults on high-distraction (i.e., standard) versus low-distraction versions of two classic speed tasks. Reducing distraction improved the performance of older adults but had little or no effect on younger adults, suggesting that the ability to limit attentional access to task-relevant information can affect performance on tests designed to measure processing speed.

Adult↗

PubMed2005

The attraction effect in decision making: superior performance by older adults.

Previous work showed that older adults' choice performance can be wiser than that of younger adults (Tentori, Osherson, Hasher, & May, 2001). We contrasted two possible interpretations: a general expertise/wisdom view that suggests that older adults are generally more skilled at making decisions than younger adults and a domain-specific expertise view that suggests that older adults are more skilled decision makers only in domains in which they have greater knowledge. These hypotheses were contrasted using attraction effect tasks in two different domains: earning extra credit in a course and grocery shopping, domains presumed to be of different levels of knowledge to younger and older adults. Older adults showed consistent choice for both domains; younger adults showed consistent choice only for the extra credit problem. Several explanations of these findings are considered, including Damasio's somatic marker theory and age differences in reliance on heuristic versus analytic styles.

Adolescent↗

PubMed2005

Framing effects in younger and older adults.

A growing literature on decision making in older adults suggests that they are more likely to use heuristic processing than are younger adults. We assessed this tendency in the context of a framing effect, a decision-making phenomenon whereby the language used to describe options greatly influences the decision maker's choice. We compared decision making under a standard ("heuristic") condition and also under a "justification" condition known to reduce reliance on heuristics. In the standard condition, older adults were more susceptible than younger adults to framing but the two groups did not differ when participants were asked to provide a justification. Thus, although older adults may spontaneously rely more on heuristic processing than younger adults, they can be induced to take a more systematic approach to decision making.

Adolescent↗

PubMed2005

Age and inhibition: the retrieval of situation models.

We present a test of whether age-related differences in the management of interference during memory retrieval can be explained, at least in part, by decreased inhibitory mechanisms in older adults. We conducted this test by measuring the ease of retrieval of situation model representations that were sources of interference on the preceding trial but that contained the target information for the current trial. Prior research has shown that situation model retrieval under these conditions exhibits inhibition relative to an unrelated control. This effect was replicated in the current study for younger but not older adults; at the same time, the older adults showed greater overall retrieval interference than the younger adults. This pattern is consistent with the idea that there are declines in inhibitory processing in older adults, and that this applies to memory retrieval.

Adolescent↗

PubMed2005

Implicit memory, age, and time of day: paradoxical priming effects.

Memory retrieval can occur by at least two routes: a deliberate one, as when one attempts to retrieve an event or fact, and an unintentional one, as when one's behavior is triggered by the past without one's knowledge or awareness. We assessed the efficacy of these retrieval systems as a function of circadian arousal and time of day. Evening-type younger adults and morning-type older adults were tested at either peak (morning for old; evening for young) or off-peak times on implicit and explicit stem completion (Experiment 1) or on implicit category generation (Experiment 2). Results for explicit stem-cued recall replicated better performance for each age group at its peak time. In stark contrast, implicit performance was better at off-peak than at peak times of day, raising the possibility that the processes that serve explicit and implicit retrieval are on different circadian schedules, and highlighting the need to consider individual differences in circadian arousal when assessing either memory system.

Adolescent↗

PubMed2004

Age and time-of-day effects on learning and memory in a non-matching-to-sample test.

This study provides further evidence that the time-of-day (TOD) when testing is conducted affects cognitive performance in old rats and, for the first time in an animal model, in young adult rats as well. Groups of young and old rats were entrained to a 12-h light-dark schedule and administered tests of learning and memory in a non-matching-to-sample (NMTS) task in a water maze. Testing was conducted at the beginning of the rats' activity cycle (AM) or at the end of the cycle (PM). In addition to age differences in performing the task, there were major findings with respect to time of testing: (1) young rats tested in the PM were better than young rats tested in the AM at learning the NMTS rule and in the delayed-NMTS (DNMTS) task; (2) old rats tested in the AM were better than PM-tested old rats on the DNMTS task, with the former attaining performance levels that approximated those of young rats; (3) the TOD effect in old rats extended to a DNMTS reversal (DNMTS-R) condition in which rats, originally tested in the AM, subsequently were administered the test in the PM, and vice versa; (4) the TOD effects in young and old rats in the DNMTS and DNMTS-R tests were strongest at relatively long delays, suggesting that hippocampal function may be particularly vulnerable to such effects; (5) there was evidence in the old rats of a relationship between diurnal drinking patterns and performance at the longest delay in the DNMTS test. These results, which parallel similar findings with human subjects, emphasize a linkage between circadian rhythmicity and cognitive performance throughout adulthood, and indicate the importance of circadian disruption in old age as a contributing factor to age differences in learning and memory performance.

Aging↗

PubMed2003

Inhibitory attentional control in patients with frontal lobe damage.

The performance of a group of frontal lobe lesion and a group of frontal lobe dementia patients was compared with the performance of their respective matched normal control groups on two tests of inhibitory attentional control-the stop-signal reaction time task and a negative priming task. Both patient groups responded significantly slower than their respective normal control groups, but they showed only marginally significant selective impairments on the measures of inhibition. The data suggest that the specific inhibitory processes evaluated by these two tests are, in general, spared in patients with focal frontal lobe lesions or frontal lobe degeneration.

Adult↗

PubMed2002

Age, time of testing, and proactive interference.

A four-list version of a release from proactive interference paradigm was used to assess the degree to which older and younger adults tested at optimal and nonoptimal times of day are vulnerable to interference effects in memory, effects that may increase at nonoptimal times. Morning type older adults and Evening type younger adults were tested either early in the morning or late in the afternoon. Standard buildup and release effects were shown for all age groups except for older adults tested in the afternoon; they failed to show release. Recall and intrusion data suggested that older adults are more vulnerable to proactive interference than younger adults and that for older adults at least, interference effects are heightened at nonoptimal times of day. The data are discussed in terms of an inhibitory model of control over the contents of working memory (Hasher, Zacks, & May, 1999).

Adolescent↗

PubMed2002

Truth and character: sources that older adults can remember.

Are age differences in source memory inevitable? The two experiments reported here examined the hypothesis that the type of source information being tested mediates the magnitude of age differences in source memory. In these studies, participants listened to statements made by two different speakers. We compared younger and older adults' source memory in a traditional perceptual source task (memory for voice) and in two affective, conceptually based source tasks (truth of the statements, character of a person in a photo). In both studies, the perceptual and conceptual source information were conveyed in the same manner, as one speaker was associated with one type of information (e.g., female voice speaks truth). Age differences were robust for decisions regarding who said each statement but were negligible or truth or character decisions. These findings are provocative because they suggest that the type of information can influence age-related patterns of performance for source-conveyed information.

Adult↗

PubMed2002

Working memory span: the effect of prior learning.

Recent work suggests that working memory span (WMS) tasks are not simple measures of the capacity to simultaneously store and process new information. Instead, these measures may be influenced by numerous factors, including proactive interference (PI). The current study examined whether WMS, like other memory tasks, is also influenced by PI from prior memory experiments. Experimentally experienced and naive participants completed a speaking span task. Span scores were lower for experienced than for naive participants, but other cognitive scores were not. In combination with other work, these results suggest that WMS estimates are not pure measures of capacity and may be partially determined by PI.

Adult↗

PubMedDate not supplied

How feelings of stereotype threat influence older adults' memory performance.

The purpose of the present research was to explore the role of stereotype threat as a mediator of older people's memory performance under different instructional sets. In three studies, younger and older participants completed a memory test that was either framed as a memorization or as an impression formation task. Across these studies, memory performance was greater for younger than for older adults and was higher in the impression formation than memorization condition, but was not different for older adults in the two instruction conditions. These results also showed that age differences in memory performance were mediated by participants' feelings of stereotype threat, such that age was positively related to stereotype threat and stereotype threat was negatively related to memory performance. These data demonstrate that concerns about being negatively stereotyped influence age differences in memory performance, and that the effects of these feelings on performance are not easily reduced by reframing the task instructions.

Adolescent↗