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L Hasher

Publications and source records attributed to L Hasher.

14 recordsLinked to original sources
PubMed1992

Age and the availability of inferences.

Age differences in inference availability and memory were investigated using a speeded decision procedure and cued recall. Younger and older adults read passages that directly suggested either a target inference or an incorrect, competing inference before finally supporting the target inference. At critical points in a passage, subjects judged whether each of a series of words, including either the target or competing inference, was consistent with their current interpretation. Although both groups agreed on the final target inference, younger and older adults showed different patterns of inference availability and revision. Older adults showed broader and more sustained activation of alternative interpretations and also showed lower levels of inference recall. These findings are interpretable by a framework that proposes age-related breakdowns in inhibitory mechanisms that control the contents of working memory (Hasher & Zacks, 1988).

Adolescent↗
PubMed1991

Age and inhibition.

Two experiments assess adult age differences in the extent of inhibition or negative priming generated in a selective-attention task. Younger adults consistently demonstrated negative priming effects; they were slower to name a letter on a current trial that had served as a distractor on the previous trial relative to one that had not occurred on the previous trial. Whether or not inhibition dissipated when the response to stimulus interval was lengthened from 500 ms in Experiment 1 to 1,200 ms in Experiment 2 depended upon whether young subjects were aware of the patterns across trial types. Older adults did not show inhibition at either interval. The age effects are interpreted within the Hasher-Zacks (1988) framework, which proposes inhibition as a central mechanism determining the contents of working memory and consequently influencing a wide array of cognitive functions.

Adolescent↗
PubMed1991

Age and reading: the impact of distraction.

Older and younger adults read aloud and answered questions about texts that did or did not have distracting material interspersed amid target text. When present, distracting material occurred in a different type font from that of target material. Across 2 experiments, distracting material was meaningless, meaningful but unrelated to the text, or meaningful and text related. Subjects were instructed to attend only to the target text. Reading time measures indicated that compared with younger adults, older adults have a more difficult time ignoring the distracting information, particularly information meaningfully related to target text. Verbal ability differences among older, but not younger, adults moderated distraction effects. Age differences in inhibitory attentional mechanisms were considered as processes influencing distraction effects.

Adolescent↗
PubMed1991

Aging and suppression: memory for previously relevant information.

In the 1st part of the experiment, older and younger adults read a series of high-cloze sentence frames, each missing its final word (e.g., "She ladled the soup into her____."). Subjects were instructed to predict the ending for each. For critical sentences, the predicted final word (bowl) was not shown. Instead, an unexpected but acceptable ending (lap) was provided as the target. On a subsequent indirect memory test in which subjects generated endings to medium-cloze sentences, older adults showed reliable retention of both the disconfirmed (bowl) and target (lap) endings. Younger adults showed retention of only the targets. Results are consistent with the Hasher and Zacks (1988) view that the impaired inhibitory mechanisms of older adults impede the abandonment of no-longer-relevant thoughts.

Adolescent↗
PubMed1991

Age deficits in retrieval: the fan effect.

The fan effect paradigm was used to investigate age-related changes in the effects of different levels of interference on retrieval. Younger and older adults learned a list of person-activity "facts" in which each person and each activity occurred in 1, 2, or 3 different facts (fan level). A subsequent speeded recognition test required the participants to distinguish the learned facts from foils constructed by recombining the same concepts. On this recognition test, both groups showed an increase in response time and errors as the fan level of the probe increased. For older adults these effects were larger, however, indicating an age-related increase in interference effects in retrieval. These results are consistent with a theoretical framework (Hasher & Zacks, 1988) which proposes an age-related decline in the ability to screen irrelevant information out of working memory. The findings also have implications for age differences in discourse processing and other cognitive tasks that crucially depend on the timely and accurate retrieval of stored information.

Adult↗
PubMed1990

Younger and older adults' use of mental models as representations for text materials.

Recent work suggests that formation and use of mental model (representations of situations described) is an integral part of discourse comprehension. In an experiment comparing younger and older adults on this aspect of text comprehension, subjects heard readings of a list of sentences and took a forced-choice recognition test. The test contained 2 types of distractors with an equal degree of verbatim similarity to the target sentences. One type described the same situation as the corresponding target sentence; the other did not. If mental models are an integral part of text representation formed at encoding, then a large number of confusions of the first, but not the second, type of distractor with the target sentence would be obtained. Younger and older adults showed this pattern to equal degrees. These data are consistent with those indicating that linguistic competence remains stable over the adult years (cf. Light, 1988).

Adolescent↗
PubMed1987

Encoding and memory of explicit and implicit information.

The usefulness of a general capacity model for predicting age differences in memory for critical information in text was assessed. Passages that either explicitly stated or implied, in either a predictable or unpredictable manner, a fact central to understanding were read to study participants. No age differences were obtained in the recall of explicit central facts, but the younger adults outperformed the older adults when these facts had to be inferred. A revised capacity model, which implicates encoding processes in the breakdown of inference formation, is outlined to account for these and other data.

Adolescent↗
PubMed1987

Human learning and memory.

There have been several notable recent trends in the area of learning and memory. Problems with the episodic/semantic distinction have become more apparent, and new efforts have been made (exemplar models, distributed-memory models) to represent general knowledge without assuming a separate semantic system. Less emphasis is being placed on stable, prestored prototypes and more emphasis on a flexible memory system that provides the basis for a multitude of categories or frames of reference, derived on the spot as tasks demand. There is increasing acceptance of the idea that mental models are constructed and stored in memory in addition to, rather than instead of, memorial representations that are more closely tied to perceptions. This gives rise to questions concerning the conditions that permit inferences to be drawn and mental models to be constructed, and to questions concerning the similarities and differences in the nature of the representations in memory of perceived and generated information and in their functions. There has also been a swing from interest in deliberate strategies to interest in automatic, unconscious (even mechanistic!) processes, reflecting an appreciation that certain situations (e.g. recognition, frequency judgements, savings in indirect tasks, aspects of skill acquisition, etc) seem not to depend much on the products of strategic, effortful or reflective processes. There is a lively interest in relations among memory measures and attempts to characterize memory representations and/or processes that could give rise to dissociations among measures. Whether the pattern of results reflects the operation of functional subsystems of memory and, if so, what the "modules" are is far from clear. This issue has been fueled by work with amnesics and has contributed to a revival of interaction between researchers studying learning and memory in humans and those studying learning and memory in animals. Thus, neuroscience rivals computer science as a source of interdisciplinary stimulation. Research on topics such as memory for spatial location, the relation between memory and affect, and autobiographical memory reminds us that general theories of memory based on studies of verbal materials alone are limited. Investigating how people remember complex natural events should provide us with a larger set of memory phenomena to explain and consequently insight into a wider range of memory principles or a deeper understanding of the ones we already accept (e.g. the role of repetition, encoding specificity), including their functional significance for human behavior.(ABSTRACT TRUNCATED AT 400 WORDS)

Affect↗
PubMed1987

Truly incidental encoding of frequency information.

Four experiments demonstrated that adults can reliably remember frequency of occurrence information about items they have been exposed to under truly incidental memory conditions. Subjects neither knew that the ultimate test task would concern item frequency nor that they had any reason to remember the items. This was accomplished by presenting items under the guise of one of three cover tasks: anagram solving, sentence completion, and picture naming in a Stroop-like task. In addition, one experiment found that subjects who were prewarned for either a nonspecific memory test or a frequency test were no better able to judge frequency than were subjects operating under truly incidental conditions.

Attention↗
PubMed1986

Frequency discrimination: assessing global-level and element-level units in memory.

Subjects' knowledge of how often various events occur was used to assess the retention of memory units for word-like strings of letters. A series of strings was presented at one of three exposure durations. Within the series, the frequencies of occurrence of different strings and of the letters composing the strings were varied orthogonally. At relatively long exposure durations, subjects could discriminate the frequency of occurrence for both strings and their constituent letters. The formation of global-level (string) memory units was indicated by judgments of string frequency being unaffected by either the frequencies of their component letters or experimental conditions (brief exposures) that prohibited accurate judgment of letter frequency. Although judgments of letter frequency were sometimes biased by the frequency of the strings containing the letters, the success with which the judgments discriminated different levels of letter frequency did not depend on the activation of string-level memory units. Furthermore, subjects' frequency judgments for letters were not predictable from their recall of the strings containing the letters. These results, which could not be explained by Tversky and Kahneman's (1973) "availability heuristic," provided evidence for the formation of element-level (letter) memory units. A converging experiment established that element-level frequency information could be abstracted from words as well as nonwords, and further, that this information was stored in long-term memory.

Adolescent↗
PubMed1985

Mood, recall, and selectivity effects in normal college students.

In three experiments we explored the relation between normal variation in depressed mood and memory in college students. Subjects read and subsequently recalled stories whose protagonists experienced good, bad, and neutral events. Contrary to predictions arising independently from capacity theory and from schema theory, the recall of depressed and nondepressed subjects did not differ in either overall level or in affective content. The results are not easily handled by a conceptualization of depression, tied to schema theory, which proposes that negative cognitions are important for the initiation and maintenance of depression. The general usefulness of induction procedures in research on the depressive syndrome is discussed.

Adult↗
PubMed1983

Processing of occurrence-rate and item information by children of different ages and abilities.

Two experiments compare the performance of children who vary in both age and learning ability. In the first experiment, learning disabled and nondisabled children from three age groups were tested for their incidental memory for frequency of occurrence information. In the second experiment, learning disabled and nondisabled children from two age groups were tested for their intentional memory of item information on a free recall test. In agreement with the notion that frequency is automatically encoded, all groups extracted frequency information and neither age nor learning ability influenced performance. However, both age and ability influenced performance on the recall test.

Age Factors↗