Biomedical subjects

A Wingfield

Publications and source records attributed to A Wingfield.

At least 37 records · Page 2Linked to original sources

PubMed1993

Selective preservation of a lexical category in aphasia: dissociations in comprehension of body parts and geographical place names following focal brain lesion.

The selective dissociation of memory for proper names is discussed in the context of a review of dissociations involving broadly defined vs narrowly defined semantic categories in brain damaged adults. Two narrowly defined categories for which dissociations have been reported are body parts (selectively impaired in comprehension) and geographical place names (selectively preserved in comprehension). In this study, 167 aphasic patients were tested for their ability to correctly identify body parts and map locations from spoken names, relative to a baseline for correct responses on general word discrimination (object identification). Wernicke's aphasics and Global aphasics both had significantly more success in pointing to named map locations and significantly worse performance in pointing to named body parts than they had in selecting other objects from multiple choice. Anomic aphasics showed precisely the opposite pattern of results. Other aphasic subgroups (Broca's aphasics, Mixed Nonfluent aphasics, Conduction aphasics, Transcortical Motor and Transcortical Sensory aphasics, and Mixed Fluent aphasics) did not show significant deviations in either direction. We suggest that the selective preservation for place names may be related to their status as proper names.

Adult↗

PubMed1992

The use of pronoun anaphora and speaker mood in the interpretation of conversational utterances by right hemisphere brain-damaged patients.

Understanding utterances in conversations requires a listener to weigh the disparate pieces of information present in a discourse. In this study, we examined how right hemisphere brain-damaged (RHD) patients and non-brain-damaged control subjects interpreted responses to questions concerning the location of a person (e.g., "Where's Dad?"). Stimulus vignettes included variation on three factors relevant to discourse comprehension: the mood of a speaker, the plausibility of the answer to a question, and whether the answer contained an anaphoric pronoun linking the response to the preceding question. Relative to the control subjects, the RHD patients made greater than normal use of the presence/absence of an anaphoric pronoun in their utterance interpretations, less than normal use of the speaker's mood, and marginally less than normal use of a response's plausibility. These data show how RHD patients rely on their largely intact linguistic abilities when understanding discourse and how their comprehension goes awry due to their reduced appreciation of other essential aspects of natural communication. The discussion focuses on the variable roles of speaker mood, plausibility, and pronoun anaphora in supporting inferences about a speaker's intended meaning and on the selective nature of RHD patients' impairment in this domain.

Affect↗

PubMed1992

Rapid speech processing and divided attention: processing rate versus processing resources as an explanation of age effects.

The authors conducted a dual-task study to examine age differences in speech processing under varying loads. Younger and older adults listened to and immediately recalled spoken passages presented at various speech rates (140-280 words per min). This task was performed alone as well as in a divided-attention condition in which subjects concurrently performed a picture recognition task. Consistent with the slowing hypothesis, older adults' immediate memory performance was differentially depressed when speech rates were very fast. The Age x Speech Rate interaction, however, was not exacerbated in the divided-attention condition. This suggests that aging may reduce the rate at which the processing operations underlying memory for speech are completed, but this is conceptually distinct from an age-related reduction in attentional capacity.

Adolescent↗

PubMed1992

Adult age differences in the use of prosody for syntactic parsing and recall of spoken sentences.

In this experiment, young and elderly adults listened to and recalled sentences that were varied in speech rate through computer-controlled time compression. Half of the sentences at each speech rate were presented with a normal prosodic pattern that reinforced the lexically defined syntactic structure of the sentences, and half were presented with a prosodic contour that conflicted with that structure. Both young and elderly subjects showed better recall for slower speech rates and when prosody was consistent with syntactic structure, but these effects were larger for elderly subjects. When syntax and prosody were placed in conflict, elderly subjects were more likely than the young to reconstruct the lexical content of the presented sentences to produce responses with a syntactic structure consistent with the prosody marking. Although elderly adults may be disadvantaged by rapid speech input rates, we show that they rely on normal prosody to aid syntactic parsing as a step toward language comprehension.

Acoustic Stimulation↗

PubMed1991

Speech-processing capacity in young and older adults: a dual-task study.

Adult age differences in processing speech were examined with a dual-task paradigm. Subjects listened to spoken passages for later recall while performing a concurrent reaction time task intended to index cognitive capacity usage on the speech memory task. Age differences in secondary task decision latencies were eliminated when subgroups of young and older subjects were matched on working memory span. These findings are interpreted as showing that an age-related reduction in working memory efficiency contributes to age differences in processing discourse for memory.

Adolescent↗

PubMed1991

Word onset gating and linguistic context in spoken word recognition by young and elderly adults.

Young and elderly adults heard recorded words that increased in word-onset duration ("gated" words). Without context, both age groups could recognize spoken words after hearing only 50% to 60% of word onset information. When these words were embedded in sentence contexts, subjects required only 20% to 30% of word onset for recognition. An analysis of pre-recognition responses was used to examine use of linguistic context by both age groups to produce correct word recognition in the absence of a complete, or completely processed, acoustic input.

Adolescent↗

PubMed1990

Effects of word-onset cuing on picture naming in aphasia: a reconsideration.

When an aphasic is unable to name an object, giving the patient the opening sounds of the target name will often trigger the correct response. Eighteen aphasic subjects were tested using a gating paradigm to compare word onset durations necessary to elicit correct names after an initial naming failure with those necessary for recognizing the same words when spoken in isolation with no picture present. Prerecognition errors were also examined. Results suggested that the facilitation of naming found when examiners supply word-onset sound cues may be due in part to a two-stage process consisting of stem-completion followed by matching the picture with the potential name as generated.

Aged↗

PubMed1990

Age differences in processing information from television news: the effects of bisensory augmentation.

Younger and older adults listened to segments of television news under one of three conditions: (a) Listen, in which they heard the auditory portion of the segment without its visual track; (b) Listen + Read, in which they listened to the auditory track only while reading along with a written transcript; and (c) Listen + Television, in which they heard the original televised segment complete with audio and visual track. Younger adults showed better free recall for the spoken information when it was augmented by the written transcript or video track; older adults did not show this benefit of bisensory augmentation. Subjects were also tested on a Daneman and Carpenter (1980) style measure of working memory processing. This measure accounted for virtually all age variance in memory performance in the unaugmented Listen condition. In the Listen + TV condition, however, there was a substantial proportion of age variance in performance which could not be accounted for in terms of working memory processing. Results are discussed in terms of the varying involvement of working memory processing in age differences as a function of input modality.

Adolescent↗

PubMed1989

The nature of prolonged word search.

Two alternative hypotheses were considered concerning the process of prolonged search for an uncommon word in response to hearing its definition. One alternative is that a conscious retrieval effort brings the target progressively closer to threshold. The second is that the retrieval process is a random neural exploration outside of conscious control. A tachistoscopic probe was devised to compare word recognition thresholds after 10 sec versus 30 sec of presumed search time. Results failed to show a difference between the two delay conditions and were interpreted as inconsistent with the first alternative but consistent with the second.

Humans↗

PubMed1989

Age and decision strategies in running memory for speech: effects of prosody and linguistic structure.

Young and elderly adults heard recorded passages of English prose spoken with and without normal prosody, and passages that were devoid of either linguistic or prosodic structure. Subjects were instructed to interrupt the speech input at points of their choosing for immediate recall on a segment-by-segment basis. For both age groups segmentation strategies varied with type of speech materials as did their levels of recall accuracy. Age differences in recall performance were diminished by the presence of normal prosody, an effect only partially attributable to the use of prosody to detect linguistic boundaries at the surface level.

Age Factors↗

PubMed1988

Memorability functions as an indicator of qualitative age differences in text recall.

An analysis in which the probability of text unit recall for older adults [p(Re/O)] is plotted as a function of this probability for the young [p(Re/Y)] is considered as one way to assess whether there are qualitative differences in text recall for young and old. The application of this relative memorability analysis to previously reported data dealing with the immediate recall of spoken sentences (Stine, Wingfield, & Poon, 1986) revealed that although older adults show qualitative recall similar to younger adults when informational density is low, they show less discrimination among text elements when informational density is increased.

Adult↗

PubMed1987

Process and strategy in memory for speech among younger and older adults.

Younger and older adults listened to and immediately recalled short passages of speech that varied in the rate of presentation and in the degree of linguistic and prosodic curing. Although older adults showed a differential decrease in recall performance as a function of increasing speech rate, age differences in recall were reduced by the presence of linguistic and prosodic cues. Under conditions of optimum linguistic redundancy, older adults were also found to add more words and to make more meaning-producing reconstructions in recall. Differences in overall performance are accounted for in terms of age-related changes in working memory processing and strategy utilization.

Adult↗

PubMed1987

Levels upon levels: predicting age differences in text recall.

Younger and older adults read and recalled narrative and expository prose passages of varying propositional density. Age differences in recall were smaller when text units were from higher levels in a coherence graph and when the young and elderly groups compared were higher in verbal ability. The extent to which age differences were moderated by these factors varied, however, as a function of text characteristics. These results reinforce the position that the extent of age differences in text recall depends on both text and reader characteristics.

Adolescent↗

PubMed1986

Category specific dissociations in naming and recognition by aphasic patients.

Two studies examined category specific retrieval deficits in aphasic patients. The first study tested naming performance of 24 aphasic patients for pictures of objects representing 16 semantic categories. Instances of deviantly high and low naming scores relative to a patient's general level of naming ability were encountered, most notably for letters, body parts and colors. The second study compared name production versus name recognition for 117 aphasic patients across six stimulus categories. Although a general superiority of name recognition over name production was found, thirteen patients, predominantly fluent aphasics, accounted for most instances of correct naming in the absence of correct name recognition. Letters, body parts and colors were again most notable. Several issues in lexical access for name recognition versus name production are discussed.

Adult↗

PubMed1986

How much and how fast: rapid processing of spoken language in later adulthood.

Speech processing involves rapid decoding and construction of meaning from a transitory acoustic signal. Because older adults have been found to be slower in performing many cognitive tasks, we hypothesized that they may have difficulty in immediate recall for speech of increasing input rate. Two experiments are reported in which both older and younger participants listened to and immediately recalled sentences that were systematically varied in speech rate and number of propositions. Although recall performance of the older adults showed a disproportionate decline when speech rate was increased, older adults, as well as the younger adults, were able to recall sentences of increasing propositional densities. We also found that the tendency to recall a greater proportion of main ideas than details (the levels effect) was enhanced by increased propositional density, and depressed by increased speech rate and increased age. These results are discussed in terms of an age-related change in the rate at which information can be processed in working memory.

Adolescent↗

PubMed1986

Organizational strategies in immediate recall of rapid speech by young and elderly adults.

Young and elderly adults heard recorded passages of meaningful prose with instructions to interrupt the speech at points of their choosing for immediate recall on a segment by segment basis. At normal speech rates both young and elderly subjects segmented passages primarily at coherent syntactic boundaries and showed equivalent recall performance. Increasing the passages' speech rate produced a significant reduction in recall performance for the elderly subjects relative to the young even though their segmentation strategies remained the same. Results were attributed to an age-sensitive encoding difficulty at a level higher than surface syntactic parsing.

Adolescent↗

PubMed1985

Speed of processing in normal aging: effects of speech rate, linguistic structure, and processing time.

Young and elderly adults heard three types of speech materials varying in both length and degree of semantic and syntactic constraints. Time compression was used to vary speech rates systematically to test a speed of processing hypothesis as one explanation of performance deficits associated with normal aging. In addition to segment length effects, the elderly participants showed significantly steeper rates of performance decline with increasing speech rate, with slope constants dependent on the structural constraints of the speech materials. The results are discussed in terms of processing rate hypotheses and context utilization.

Adolescent↗

PubMed1984

Prosodic features and the intelligibility of accelerated speech: syntactic versus periodic segmentation.

An experiment is reported in which subjects heard paragraph-length samples of time-compressed speech which were interrupted for intermediate reports either on a simple periodic basis or at points corresponding to sentence and major clause boundaries. The passages were spoken in a normal prosodic pattern, in list intonation, or were electronically processed to produce otherwise normal speech specifically deprived of pitch variation. Decrease in intelligibility scores with increasing speech rate was accompanied by a significant effect of place of interruption for report and of the prosodic pattern in which the passages were heard. Interactions among these variables were interpreted to suggest ways in which prosody ordinarily facilitates the determination of syntactic structure in connected speech.

Humans↗