Biomedical subjects

L K Obler

Publications and source records attributed to L K Obler.

18 recordsLinked to original sources

PubMed1995

Variability in aphasia research: aphasia subject selection in group studies.

Subject selection criteria and descriptive data were compiled from 15 consecutive aphasia group studies published in Brain and Language from its inception (1974-1976) and two decades later. While some measures remain constant (aphasia type and lesion site are most commonly used in both periods), additional measures are reported only or more frequently in the recent period (e.g., age, handedness, bilingualism, language spoken, multiple vs. single lesions). Of interest is the decrease in the total number of subjects included in aphasia group studies from the early to the current period.

Aphasia↗

PubMed1994

Wernicke and Alzheimer on the language disturbances of dementia and aphasia.

Signs of language dysfunction in dementia of the Alzheimer's type (DAT) and in the aphasic syndromes of transcortical sensory aphasia and Wernicke's aphasia are superficially similar. The unresolved question concerning the extent to which the language disturbances of DAT are "aphasic" is linked to a more fundamental question concerning the relation of language to thought, given that aphasia is often defined as language disturbance without disturbance of intellect, and dementia as dissolution of intellectual function, of which language forms an integral part. In this paper we explore the historical roots of today's debate by analyzing the original case studies of Wernicke (1874) and Alzheimer (1907, 1911). Although each of these neurologists described similar patterns of language disturbance, they drew different conclusions. Wernicke argued for a distinction between language and thought and between the language disturbances of aphasia and those of dementia. Alzheimer continued the then dominant paradigm of aphasia in describing the language disturbances of his demented patients as aphasic. Paradoxically his conclusion makes him appear, in contrast to Wernicke, to argue for the identity of the language disturbances of aphasia and dementia. Yet he himself acknowledged that the presence of focal language symptoms arising from diffuse degenerative pathology was indeed problematic. We conclude that today's discussion could profitably be refocused on the question which emerges from the original works of Wernicke and Alzheimer, which Alzheimer himself asked, and which remains unanswered: How can diffuse cerebral pathology give rise to a pattern of language deficit virtually identical to that of a focal lesion?

Aged↗

PubMed1994

Special talents in Geschwind's and Galaburda's theory of cerebral lateralization: an examination in a female population.

Geschwind and Galaburda (1985) proposed that delayed growth of posterior left hemisphere sites in male dyslexics are associated with markers of anomalous dominance (AD) and special cognitive talents. We found that talent in a female population was related to the strength of nonright-handedness, and was elevated in right-handed individuals with histories of familial left-handedness. Subjects reporting a history of dyslexia tended to be musically talented. While immune disorders were not related to talent for the whole population, they did co-occur with talents in a group of 10 individuals reporting 7 or more AD markers.

Adult↗

PubMed1993

Suppression and facilitation of pragmatic performance: effects of emotional content on discourse following right and left brain damage.

This study examines the effect of emotional content on the verbal pragmatic aspects of discourse production in right-brain-damaged (RBD), left-brain-damaged (LBD), and normal control (NC) right-handed adults. Subject groups were matched for gender, age, education, and occupation; brain-damaged groups did not differ on months post CVA onset and lesion location. Subjects were screened to ensure that they demonstrated adequate cognitive and visual perceptual skills to participate in the study. Pictorial stimuli were used to elicit discourse that contained emotional and nonemotional (procedural, visuospatial) content. Trained raters evaluated each discourse for appropriateness on seven verbal pragmatic features (e.g., conciseness, quantity, relevancy). Across all three conditions, the brain-damaged groups were impaired relative to NCs. In the nonemotional conditions, LBDs were particularly impaired in pragmatics, whereas in the emotional condition, RBDs demonstrated pragmatic deficits. Emotional content appeared to facilitate pragmatic performance among LBD aphasics and to suppress pragmatic performance among RBDs.

Aphasia↗

PubMed1992

Right hemisphere specialization for the identification of emotional words and sentences: evidence from stroke patients.

This study examines the contribution of the lexical/verbal channel to emotional processing in 16 right brain-damaged (RBD), 16 left brain-damaged (LBD) and 16 normal control (NC) right-handed adults. Emotional lexical perception tasks were developed; analogous nonemotional tasks were created to control for cognitive and linguistic factors. The three subject groups were matched for gender, age and education. The brain-damaged groups were similar with respect to cerebrovascular etiology, months post-onset, sensory-motor status and lesion location. Parallel emotional and nonemotional tasks included word identification, sentence identification and word discrimination. For both word tasks, RBDs were significantly more impaired than LBDs and NCs in the emotional condition. For all three tasks, RBDs showed a significantly greater performance discrepancy between emotional and nonemotional conditions than did LBDs or NCs. Results were not affected by the valence (i.e. positive/negative) of the stimuli. These findings suggest a dominant role for the right hemisphere in the perception of lexically-based emotional stimuli.

Aged↗

PubMed1992

Speech monitoring skills in Alzheimer's disease, Parkinson's disease, and normal aging.

We examined the abilities of 15 patients with dementia of the Alzheimer type (DAT), 22 patients with Parkinson's Disease (PD), and 141 healthy subjects (ranging in age from 30 to 79 years) to detect and correct their own speech errors. Each subject was shown the Cookie Theft picture of the BDAE (Goodglass & Kaplan, 1972. The assessment of aphasia and related disorders. Philadelphia: Lea & Febiger.) and instructed to tell the examiner the "...story of what's happening in the picture." Self-monitoring performance was assessed by tabulating the number of uncorrected errors as well as repaired errors. We divided repairs into two types based on the psycholinguistics literature (van Wijk & Kempen, 1987. Cognitive Psychology, 19, 403-440). Speech corrections were judged to be lemma repairs when the reparandum was a single word, and reformulation repairs when a new syntactic constituent was added to the reparandum. Patients with DAT corrected only 24% of their total errors and patients with PD only 25%. Healthy subjects, by contrast, corrected from 72 to 92% of their total errors. Patients with DAT tended to rely on reformulation repairs while patients with PD used both repair types about equally often. While healthy elderly Ss (in the 70s group) utilized lemma repairs more often than the reformulation strategy, all other healthy Ss used both strategies about equally often. Across all groups naming performance correlated negatively with numbers of undetected errors. Results point to a previously unrecognized communication disorder associated with PD and DAT and manifested by an impairment in the ability to correct output errors. This impairment may be related to attentional and frontal dysfunction in the two patient groups.

Adult↗

PubMed1992

Impact of emotional content on discourse production in patients with unilateral brain damage.

A picture story task was developed to examine expression of emotion via the verbal/lexical channel. The task elicited discourse with either emotional, visual-spatial, or neutral content and was administered to right brain-damaged (RBD), left brain-damaged (LBD), and normal control (NC) right-handed adults. Subjects were matched for gender, age, education, and occupational status. The brain-damaged groups were matched for months post-CVA onset and were similar with respect to intrahemispheric site of lesion. While the number of words produced was equivalent for each of the subject groups, the RBDs and LBDs expressed quantitatively less content than did the NCs. When content differences were examined within each subject group, there were no differences for LBDs and NCs, but the RBDs showed a selective deficit when producing emotional content. This finding suggests a special role for the right hemisphere in the production of emotional content in verbal discourse.

Adult↗

PubMed1990

A preliminary characterization of lexical emotional expression in right and left brain-damaged patients.

Disorders in nonverbal communication of emotion have been documented in patients with right hemisphere pathology; lexical expression of emotion is virtually unstudied. In this preliminary investigation, emotionally laden slides were used to elicit discourse from right brain-damaged (RBD), left brain-damaged (LBD), and normal control (NC) subjects. New techniques were developed to examine the ability of these subjects to express emotion in words; formalistic and pragmatic analyses of the discourse were conducted. RBDs, relative to NCs and LBDs, were less successful in using words to convey emotion and produced words of lower emotional intensity. LBD aphasics, despite their linguistic deficits, were comparable to NCs in conveying emotional valence. The data tend to support the speculation that the right hemisphere is dominant for lexical expression of emotion. This study has implications for the neuropsychological investigation of language, emotion, and the brain.

Brain Damage, Chronic↗

PubMed1987

Naming errors in healthy aging and dementia of the Alzheimer type.

Naming errors were analyzed for healthy younger and older adults and patients with a diagnosis of senile dementia of the Alzheimer type (SDAT). Three types of errors were identified, varying in relatedness to the target word: near synonyms; semantically related naming errors; and unrelated naming errors. Older adults made relatively more related errors than did younger adults. SDAT patients were distinguished by the number of unrelated responses given. In addition, SDAT patients who scored within the normal range were identified by the high number of response attempts relative to the number of initial errors. We suggest that error patterns on naming tasks may potentially serve as clinical markers to distinguish healthy older persons with mild naming disorders from patients with SDAT.

Adult↗

PubMed1985

Historical note: Jules Séglas on language in dementia.

In his book Des troubles du language chez les aliénés (1892) Séglas applied the model of language processing of his teacher, Charcot, to analyze the language disorders of various groups of mentally ill, including patients considered to suffer from dementia. Among the language phenomena he described from dementia are logorrhea, neologisms, embolalia, near-mutism, angophrasia, automatic speech, alexia, and agraphia. Séglas must be credited for his early descriptions of how language behaviors cluster in various psychiatric and dementing diseases.

Dementia↗

PubMed1985

On comprehension across the adult lifespan.

To test whether healthy elderly subjects develop language comprehension strategies to compensate for decreases in pure-tone audition, we tested 128 healthy subjects aged 30-79 on two tasks: (1) Comprehension materials from the Boston Diagnostic Aphasia Examination (Goodglass and Kaplan, 1972) presented over babble noise with and without the speaker's face visible; and (2) the Kalikow et al. (1977) Speech Perception in Noise test, which assesses the effect of semantic predictability on sentence-final word intelligibility. Whereas, as predicted, overall performance decreased with advancing age, it appeared, unexpectedly, that older and younger adults were equally affected by the absence of visual input and the absence of semantic predictability.

Adult↗

PubMed1985

Empty speech in Alzheimer's disease and fluent aphasia.

Fourteen measures of empty speech during a picture description task were examined in four subject groups--patients with Alzheimer's dementia, Wernicke's aphasias, anomic aphasias, and normal controls--to discover if these groups could be distinguished on the basis of their discourse. Patients with Alzheimer's dementia were distinguished from patients with Wernicke's aphasia by producing more empty phrases and conjunctions, whereas patients with Wernicke's aphasia produced more neologisms, and verbal and literal paraphasias. The demented patients shared many empty speech characteristics with patients with anomic aphasia. Naming deficits, as measured by confrontation naming tasks, did not correlate with empty discourse production. Our findings may be useful clinically for distinguishing these different patient groups.

Adult↗

PubMed1984

Changes in cerebral lateralization in aging.

To determine whether there is increasing left hemispheric lateralization for language with age and whether the right hemisphere is selectively impaired with advanced age, we tested 96 right-handed people aged 25-80 yr on verbal and non-verbal matching tasks presented tachistoscopically. Task difficulties was equalized by adjusting exposure durations. Exposure duration, error laterality and response latency laterality were analyzed. Typical field effects as well as age-related slowing and sex by task interactions were observed. However, no systematic age-related changes in lateralization were apparent.

Adult↗

PubMed1982