Psychometric and CT scan measurements in a case of crossed aphasia in a dextral

A case of crossed aphasia with lesion deep to the right supramarginal gyrus was studied to determine (1) if this patient behaved similar to patients with the same lesion site in the left hemisphere, (2) if visuospatial deficits were present, and (3) if the CT scan asymmetries were similar to those of other right-handers. Speech and language skills were similar to those patients with similar lesions in the left hemisphere. Visuospatial and arithmetic deficits were similar to those described after right-hemisphere and left-hemisphere damage. CT scan asymmetries were atypical. These results provide behavioral and neuroradiological confirmation of atypical hemispheric dominance.     

Speech prosody in Broca's aphasia

Because speech prosody is thought to be impaired in Broca's aphasia, we conducted three experiments using Broca's aphasics and nonneurological control subjects in order to determine to what extent this statement is accurate. Using three acoustic measures of speech prosody—sentence-final fundamental frequency (F₀) fall, F₀ declination, and sentence-final lengthening—we found that some aspects of prosody were spared while others were abnormal. All Broca's aphasics, regardless of degree of impairment, exhibited sentence-final F₀ fall. F₀ declination was present in simple sentences but was absent over longer domains; moreover, the amount of declination was correlated with the degree of linguistic impairment. Sentence-final lengthening was clearly absent in Broca's aphasia; in fact, sentence-terminal words were actually shorter than their sentence-initial and medial counterparts.     

A comparative study of later work experience among full-time,part-time,and unemployed male youth

This paper considers the unique contribution of prior labor market status, defined in terms of working time, on later work experience controlling for a number of demographic and work pattern variables. The labor market status variables are established on the basis of trends in a young man's early career experience. Part-time employment is found to be a viable early labor market alternative to the extent of later economic and occupational success. Early career unemployment is not a critical factor in retarding personal economic advancement, relative to educational background and first job experience, but does have negative job attitudinal consequences.     

Combined stimulus control over time allocation in response-independent schedules

Rats were exposed to concurrent schedules in which reinforcers occurred independently of behavior. In Experiment 1, rats could control time spent in the following conditions: (1) a light, (2) white noise, and (3) the absence of both light and noise. Response-independent reinforcers occurred at the same rate during the light and the noise and at either a higher rate or not at all in the absence of both stimuli. In subsequent tests, the rats spent more time in a light and noise compound than in either light or noise alone after the absence of both stimuli had signaled no reinforcers. When the absence of both stimuli had signaled a higher rate of reinforcement, however, the rats typically spent less time in the compound than in light or noise alone. In Experiment 2, rats could control time spent in the presence of a light and of a buzzer. The reinforcement rate in the light was twice that in the buzzer. In a later test, the rats spent more time in a light and buzzer compound than in the buzzer, but less time in the compound than in the light. The results show that additive summation, suppressive summation, and stimulus averaging of time allocation occur and that response rate differences between training stimuli are not necessary for these phenomena.     

Mechanisms underlying writing and speech in aphasia

As a parallel to the dual decoding concept for processing of written language we proposed that phonological encoding does not necessarily occur in writing and that the phonemic and graphemic subsystems can be independent on the one-word level. This hypothesis was tested by comparing oral and written performance in a picture-naming task in Broca's and Wernicke's aphasics. In addition, the residual tacit knowledge of the orthographic properties of the names of the pictures was examined with a multiple-choice recognition task. The principal finding is that Broca's aphasics who were better in written than in oral naming showed more graphemically and semantically motivated errors than aphasics who were better in oral than in written naming, the latter producing more phonemically motivated errors. This result supports the dual encoding concept for writing on the singleword level, implying a direct route from the mental lexicon to the graphemic system in parallel with a route mediated by the phonemic system. Multiple-choice recognition was found to be superior to both oral and written performance in both Broca's and Wernicke's aphasics.     

The role of the right hemisphere in the apprehension of complex linguistic materials

To secure information on which aspects of linguistic functioning might be mediated by the nondominant hemisphere, a test battery assessing sensitivity to narrational and humorous materials was administered to a population of right-hemisphere-damaged patients, as well as relevant control groups of normal, aging, and aphasic individuals. While elementary linguistic functioning was adequate, the right-hemisphere-injured groups exhibited consistent difficulties in respecting the boundaries of a fictive entity, assessing the plausibility of elements within a story or joke, selecting the appropriate punch line for a joke, and integrating elements of a story into a coherent narrative. Certain elements—specifically emotional content and noncanonical facts injected into a narrative—also posed characteristic difficulties for these patients. The results suggest that, in contrast to the other populations, right-hemisphere patients exhibit special difficulties in processing complex linguistic entities and in utilizing the surrounding context as they assess linguistic messages.     

Processing of locatives “in,” “on,” and “under” by aphasic patients: An analysis of the regression hypothesis

The present study investigated the comprehension of aphasic subjects as to locative prepositions “in,” “on,” and “under.” Patients had to locate a movable object with reference to a stationary referential object in order to achieve the spatial relations requested under oral instructions. The influence of two types of contextual relations between the objects in each stimulus pair on the subjects' performances was examined. Spatial relations were biased by the conventional knowledge of the most normal relationship between the two elements in everyday life in Experiment 1; in Experiment 2, perceptivomotor constraints constituted the contextual bias. Analyzing the patients' responses in the light of developmental strategies did not lend support to the regression hypothesis. Broca's aphasics were sensitive to the two contextual factors investigated; Wernickes' performances were affected only by the perceptivomotor contextual bias. The results are discussed with reference to earlier studies on the differential syntactical comprehension skills of Broca's and Wernicke's aphasics in sentence-picture matching tasks and production tasks.