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S Hashtroudi

Publications and source records attributed to S Hashtroudi.

17 recordsLinked to original sources
PubMed1996

d-Cycloserine enhances implicit memory in Alzheimer patients.

We tested the ability of d-cycloserine, a partial glycine agonist acting at the N-methyl-D-aspartate (NMDA) receptor complex, to improve implicit memory in Alzheimer patients in a parallel-group, placebo-controlled, double-blind study. One-hundred eight patients with probable Alzheimer's disease of mild to moderate severity received d-cycloserine (5, 15, or 50 mg) or placebo twice daily for 10 weeks. We then evaluated their ability to identify perceptually degraded words, some of which were repeated over multiple trials across 3 days. Implicit memory performance of words repeated across trials was significantly enhanced for the patients who received 15 mg d-cycloserine compared with those who received placebo. These findings support development of NMDA receptor-mediated glutamatergic interventions for the treatment of Alzheimer-related memory disorders.

Aged↗
PubMed1995

Aging and single versus multiple cues in source monitoring.

Participants heard words said by 2 speakers and later decided who said each word. The authors varied the perceptual distinctiveness of the speakers and the distinctiveness of the cognitive operations participants performed on the words. Relative to younger adults, older adults had significantly lower source monitoring scores when perceptual or cognitive operations conditions were similar but not when either cue was more distinctive. Combining cues did not affect source monitoring of younger adults but hurt older adults' performance relative to the distinctive perceptual condition. Evidently, older adults generate cognitive cues at the expense of encoding perceptual cues; any deficit in binding perceptual and semantic information disadvantages them more in source monitoring than in old/new recognition. There was no correlation between neuropsychological tests assessing frontal function and source monitoring in older adults.

Adolescent↗
PubMed1994

Aging and the effects of affective and factual focus on source monitoring and recall.

Pairs of young and elderly Ss participated in a short play and were then instructed to talk about factual or affective aspects of the play or to talk about the play without any particular focus suggested. In both the affective and control condition, older adults' ability to discriminate what they had said from what the other person had said was poorer than that of young adults. In contrast, when induced to focus on the factual content of the events, older Ss' source monitoring improved, and the age difference was reduced. The pattern was similar when Ss' ability to discriminate what they had said from what they had thought was examined. Furthermore, affective focus lowered the overall level of recall for both young and older Ss and led older Ss, in particular, to introduce more elaborations into their recall. The possibility that age difference in remembering content and source are related to type of focus is discussed.

Adolescent↗
PubMed1993

Source monitoring.

A framework for understanding source monitoring and relevant empirical evidence is described, and several related phenomena are discussed: old-new recognition, indirect tests, eyewitness testimony, misattributed familiarity, cryptomnesia, and incorporation of fiction into fact. Disruptions in source monitoring (e.g., from confabulation, amnesia, and aging) and the brain regions that are involved are also considered, and source monitoring within a general memory architecture is discussed. It is argued that source monitoring is based on qualities of experience resulting from combinations of perceptual and reflective processes, usually requires relatively differentiated phenomenal experience, and involves attributions varying in deliberateness. These judgments evaluate information according to flexible criteria and are subject to error and disruption. Furthermore, diencephalic and temporal regions may play different roles in source monitoring than do frontal regions of the brain.

Attention↗
PubMed1992

Age differences in using source-relevant cues.

Subjects heard words originating from 2 speakers and later decided which of the 2 speakers said the words. Older adults had difficulty with source monitoring when perceptual cues from 2 sources were similar (2 female speakers), but this difficulty was overcome when perceptual cues were distinctive (a male and a female speaker) and were the only salient cues to source. Older adults also benefited from distinctive spatial cues when these were the only salient cues to source. Older adults, however, experienced difficulties in using multiple cues (both perceptual and spatial) to source effectively, whereas younger adults were able to use multiple cues to enhance their source-monitoring performance. It is suggested that age differences in source monitoring result from differential cue utilization.

Adult↗
PubMed1992

The effects of milacemide on item and source memory.

Prior research has shown that memory for facts and items (item memory) and memory for where one has learned these items (source memory) can be dissociated under certain conditions. In this study, we examined the effects of milacemide, a derivative of glycine, on memory for item and source information in healthy young and older adults. These results pointed to a dissociation between source memory and item memory: Milacemide administration seemed to facilitate memory for source information but did not affect recognition memory.

Acetamides↗
PubMed1991

Does organization improve priming?

In five experiments, the effects of organization on implicit memory or priming tests were compared with its effects on the explicit memory tests of free and cued recall. Organization was manipulated by varying list structure (blocked vs. random presentation of categorized items) and by instructions. The results showed that organization had parallel effects on the category-production priming test and free- and cued-recall tests; performance was enhanced by organization on both types of tests. It was also demonstrated that the effect of organization on priming was limited to the category-production test and was not obtained with the word-identification priming test. These results suggest that performance on implicit and explicit memory tests is similarly affected by experimental manipulations when both types of tests rely on conceptually driven processing. In addition, performance on two implicit tests is dissociated when one test relies on conceptually driven processing and the other on data-driven processing.

Adult↗
PubMed1991

Priming is independent of skill learning.

This study examined the relation between repetition priming and skill learning. Priming refers to facilitation in processing a specific item as a result of previous exposure to that item. Skill learning refers to general improvement in task performance as a function of practice. In Experiment 1 (N = 60), skill acquisition occurred in partial-word identification and inverted reading tasks but not in a word-fragment completion task. However, the amount of priming was the same in all three tasks. In Experiment 2 (N = 52), priming effects in partial-word identification did not vary as a function of practice with degraded words. In Experiment 3 (N = 40), skill learning was greater with high- than with low-frequency words, whereas priming was unaffected by word frequency. Experiment 4 (N = 20) ruled out the possibility that explicit retrieval was involved in the implicit memory tasks. These results suggest that priming can be independent of skill learning.

Humans↗
PubMed1991

Effects of aging on priming and skill learning.

This study examined the effects of aging on 2 kinds of implicit memory; repetition priming and skill learning. In Experiment 1, older adults showed less improvement in the skill of reading inverted words than did young adults, but priming performance did not differ for the 2 age groups. Similarly, in Experiment 2, in a partial-word identification task, skill learning was observed only for young adults, whereas there was no age difference in priming. Experiments 1a and 2a, however, showed that when older adults were presented with more perceptual information than were young adults, the age deficit in skill learning was eliminated. These results indicate that skill learning is impaired under data-limited conditions, whereas priming is unaffected under these conditions. It is proposed that the age deficit in skill learning is related to a deficit in perceptual organization and reorganization.

Adolescent↗
PubMed1991

Glycine prodrug facilitates memory retrieval in humans.

Modulation of glycine concentrations in the brain influences learning and memory functions in experimental animals. We administered milacemide, a glycine prodrug, or placebo to young and older healthy adults, who performed a word-retrieval task. Milacemide administration increased the number of words retrieved and decreased the latency with which these words were retrieved for both young and older adults.

Acetamides↗
PubMed1990

Aging and qualitative characteristics of memories for perceived and imagined complex events.

Older and younger adults' memory for perceived and imagined events was examined with a procedure in which everyday situations are simulated in the laboratory. Subjects perceived some situations and imagined others. Later, they were asked to rate their memory for various aspects of these situations (e.g., amount of perceptual detail, thoughts and feelings). A recall test followed the ratings. On the rating scale, for both perceived and imagined events, older subjects reported better memory for their thoughts and feelings than did younger subjects. In addition, on the recall test, older subjects produced more thoughts and feelings than did younger subjects, whereas younger subjects produced more perceptual and spatial information. These results suggest that older subjects may not inhibit personal information (e.g., thoughts and feelings), and this information may interfere with memory for other aspects of information, such as perceptual and contextual details (Hasher & Zacks, 1988).

Adolescent↗
PubMed1989

Aging and source monitoring.

This experiment was designed to examine the ability of older and younger adults to remember the source of information. Three types of source monitoring tasks were investigated: discriminating between externally derived and internally generated memories, discriminating between two types of internally generated memories, and discriminating between two types of externally derived memories. Relative to younger adults, older adults had more difficulty discriminating between memories of the same class (external-external and internal-internal), but they did not have more difficulty discriminating between memories of different classes (external-internal). These findings indicate that the age-related difficulty in remembering the source of information should not be characterized as a general deficit. Factors that may account for age deficits in source monitoring are discussed drawing upon the Johnson-Raye (1981) reality monitoring framework.

Adult↗
PubMed1988

Data-driven and conceptually driven processes in partial-word identification and recognition.

Three experiments examined priming in partial-word identification (Warrington & Weiskrantz, 1968) and its relation to recognition memory. The results showed that changes in modality of presentation between study and test reduced performance on both identification and recognition. In contrast, changes in elaborative processing enhanced recognition but had no effect on identification. Furthermore, when explicit memory instructions were given, identification was changed to a cued recall test and was consequently affected by elaborative processing. We also found that the time course of forgetting in priming was different from that in recognition; priming in identification did not change over a 24-hr interval, whereas recognition declined rapidly during this interval. Overall, these results suggest that identification relies primarily on data-driven processing, whereas recognition can rely on both data-driven and conceptually driven processing.

Adult↗
PubMed1987

Cognitive effort and the word frequency effect in recognition and lexical decision.

Cognitive effort requirements for high and low frequency words were assessed during study for a recognition test and during the performance of a lexical decision task. Recognition for these words was tested following each task. Low frequency words received greater effort than high frequency words during study for recognition, and these words were subsequently recognized better than high frequency words. Cognitive effort requirements during performance of an incidental lexical decision task were similar to those during study for recognition. Moreover, recognition performance following the lexical decision task resembled performance following a recognition expectancy. Overall, the results indicate that low frequency words require more extensive processing than high frequency words and that this difference in processing may be a factor in recognition word frequency effects.

Attention↗
PubMed1984

Intact retention in acute alcohol amnesia.

Research on alcohol amnesia has focused on memory processes that are disrupted during intoxication. The present experiment examined the possibility that certain memory processes might be resistant to the amnesic effects of alcohol. Intoxicated and sober subjects studied a list of 29 words. They were then given one of three different retention tests: free recall, identification of degraded words based on the procedure used by Warrington and Weiskrantz (1970), and yes/no recognition. As expected, free recall was significantly impaired by alcohol intoxication. In contrast, in the identification test, intoxicated subjects benefited to the same degree as sober subjects from prior exposure to the items. The two groups did not differ in immediate recognition memory. The results of the free-recall and identification tasks are similar to findings with chronic amnesic patients and suggest that perceptual fluency is not affected by alcohol, whereas elaborative processes supporting recall are particularly sensitive to disruption during intoxication. The failure to find recognition impairment at the level of intoxication used in this study distinguishes temporary alcohol amnesia from chronic amnesia.

Adult↗
PubMedDate not supplied

Generation and elaboration in older adults.

This study examined the effects of elaborative processing in older adults using the same technique employed in an earlier study (Hashtroudi, Parker, DeLisi, & Wyatt, 1983) on acute alcohol amnesia. Older and younger adults either generated elaborators or were provided with elaborators. Elaborators were either precise or imprecise. Generation, in particular generation of precise elaborators, was effective in enhancing older subjects' level of recall and reducing age differences in memory. It is suggested that active involvement in elaborative processing enables older adults to take advantage of elaboration. Similarities and differences between memory decrements associated with aging and with alcohol intoxication are discussed.

Adult↗