Guila Glosser

Disorders in executive control functions among aphasic and other brain-damaged patients

Four experimental procedures for assessing disorders of executive control (Nonverbal Continuous Performance, Graphic Pattern Generation, Sequence Generation Test, and Tower of Hanoi) were administered to 22 left-brain-damaged aphasic patients, 19 right-brain-damaged nonaphasic patients, and 49 healthy controls. Aphasic patients with frontal-lobe lesions were significantly more impaired on these tasks than aphasics with retrorolandic or mixed lesions in the left hemisphere. Patients with right-hemisphere lesions, especially those with frontal-lobe lesions, showed even greater impairments on these visual/spatial tasks. The results suggest that aphasics impairments in executive control are independent of their linguistic and visuospatial deficits and are specific to lesions in left frontal and prefrontal regions. The clinical utility of the experimental procedures is discussed.

Patterns of discourse production among neurological patients with fluent language disorders.

Dissociations between impairments in microlinguistic and macrolinguistic abilities were examined in brain-damaged patients to assess whether these abilities are psychologically and neurologically distinct. The discourse productions of three groups of patients with equally severe fluent language disorders, but varying neuropathology and varying profiles of associated nonlinguistic cognitive impairments, were analyzed. Patients with fluent aphasia secondary to a single left-hemisphere CVA showed the greatest impairment on syntactic and lexical error measures taken to reflect microlinguistic abilities, but normal performance on measures of macrolinguistic organization (i.e., thematic coherence). Patients with probable Alzheimers Disease were impaired on thematic coherence measures, but not on measures reflecting microlinguistic syntactic and phonological processes. Closed head injury patients whose primary clinical symptom was a fluent language disorder were impaired on both microlinguistic and macrolinguistic measures, which appears to parallel their deficits both in language-specific and in nonspecific, higher-order, diffusely organized cognitive processes.

The Continuum of Deep/Phonological Alexia *

Two patients exhibited all the characteristics of deep alexia shortly following brain injury. Both subsequently recovered some reading abilities and evolved to show a pattern of oral reading consistent with phonological alexia. These findings suggest that deep alexia and phonological alexia share common underlying deficits that are mediated by common neurological systems. A two-deficit psycholinguistic model is presented to account for the apparent continuity between deep alexia and phonological alexia.

Cross-Cultural Cognitive Examination: Validation of a Dementia Screening Instrument for Neuroepidemiological Research

Objective: Validation of a new instrument for screening dementia, the Cross Cultural Cognitive Examination (CCCE), is described.

Psychophysical scaling of olfactory, visual, and auditory stimuli by alchoholic Korsakoff patients.

Abstract Ten alcoholic Korsakoff patients, ten alcoholic control subjects, and ten non-alcoholic control subjects performed psychophysical scaling of the intensity of stimuli in the visual, auditory, and olfactory modalities. Whereas the Korsakoff patients displayed normal scaling judgments in all three visual tasks and in two out of three auditory tasks, they evidenced a severe deficit in their scaling of olfactory stimuli. Korsakoffs were shown to have elevated thresholds for the perception of olfactory stimuli. These results are consistent with previous findings of an olfactory sensory impairment in alcoholic Korsakoff patients and may be attributable to damage to diencephalic and limbic brain structures in this disease.

Linguistic and nonlinguistic impairments in writing: a comparison of patients with focal and multifocal CNS disorders.

The hypothesis that the language disorder in Alzheimers disease (AD) depends on degenerative brain changes in classical left-hemisphere language zones was tested by comparing the written language performances of a group of AD patients with mild-moderate dementia and left-hemisphere stroke patients with equally severe naming and auditory comprehension deficits who were in varying stages of recovery from Wernickes aphasia. The results indicated significant qualitative group differences in performances between tasks and in errors within tasks. The findings are consistent with hypothesized disruption of more diffusely organized neurolinguistic systems in AD. The hypothesis that the language disorder in AD represents an exaggeration of the pattern of language change in normal aging was also examined by comparing the performances of AD patients to the changes that occur with very advanced normal aging. The data indicate convergence between AD and very elderly healthy subjects in some aspects of written language production.

Emotional-Behavioral Patterns in Children with Learning Disabilities Lateralized Hemispheric Differences

The relationships between lateralized left and right hemisphere cognitive impairments and various emotional/behavioral characteristics were examined retrospectively in 67 learning disabled children ages 7 to 10. Children with left hemisphere impaired cognitive profiles presented with dysphoria, anxiety, and social withdrawal, while children with right hemisphere impaired cognitive profiles showed low rates of dysphoria/anxiety and increased somatic complaints. Children with nonlateralized cognitive impairments evidenced characteristics of attention deficit disorder and more pervasive emotional disturbances. These relationships between lateralized cognitive impairments and emotional/behavioral patterns in non-neurologically involved learning disabled children parallel findings of emotional disturbance in adults with lateralized hemispheric lesions.

Idiosyncratic word associations following right hemisphere damage

Single oral word associations produced by right-hemisphere-damaged (RHD) stroke patients and age-matched healthy controls were analyzed to assess the right-hemisphere contribution to lexical-semantic processes. RHD patients did not differ from normals in terms of response times, in syntactic class of the response word, or in numbers of errors in response to words drawn from different grammatical categories and words differing in imageability/concreteness. Groups also did not differ in the number of high frequency, popular, associations produced. Despite their apparently intact ability to access high-frequency lexical associates, RHD patients, particularly those with frontal-lobe lesions, also sporadically produced lexical responses that were idiosyncratically related or that were totally unrelated to the stimulus word. An attentional disorder is suggested to explain these pragmatically deviant lexical associations.

Cross-cultural cognitive examination performance in patients with Parkinson's disease and Alzheimer's disease

Performance profiles of patients with different dementia syndromes (Alzheimers disease and Parkinsons disease) were compared with each other and with those of neurologically impaired and healthy individuals without dementia on a new instrument for screening dementia, the Cross-Cultural Cognitive Examination (CCCE). The CCCE measures discriminated reliably between nondemented and demented patients, regardless of etiology. Comparisons between dementia groups found that dementia patients with Parkinsons disease (PD) showed more severe psychomotor slowing and depression, compared with patients with Alzheimers disease, who showed more impaired recall of recently learned verbal information and verbal abstract reasoning. The CCCE also distinguished between the motor and affective symptoms that are common to all PD patients and the dementia symptoms that occur in some PD patients. These results provide further support for the clinical utility of the CCCE for discriminating dementia from normal cognitive functioning and for initial identification of different dementia syndromes.

Some Analyses of the Information Processing and Sensory Capacities of Alcoholic Korsakoff Patients

For the past five years our laboratory has focused upon the factors underlying the amnesic symptoms (i.e., anterograde and retrograde amnesia) displayed by alcoholic Korsakoff patients. Since two comprehensive reviews of these studies have now been published (Cermak and Butters, 1973; Butters and Cermak, 1974), we shall only briefly discuss these findings and then turn to the results of two recent sets of investigations. The first set involves the role of information processing disorders in the memory impairments of alcoholic Korsakoffs and chronic alcoholics. These studies indicate that chronic alcoholics have some of the same cognitive impairments that may play an important role in the Korsakoffs’ amnesic symptoms. The second set of investigations deals with the basic sensory capacities of alcoholic Korsakoff patients. Since the neural structures (n. medialis dorsalis and mammillary bodies) damaged in Korsakoff’s disease have been implicated in the olfactory system, we used psychophysical methods to study the discriminative capacities of these patients in the olfactory, visual, and auditory modalities. The findings of these studies demonstrate a very severe olfactory sensory impairment in alcoholic Korsakoff patients.