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Biomedical subjects

O S Marin

Publications and source records attributed to O S Marin.

At least 19 recordsLinked to original sources
PubMed1984

Interruption of phonological coding in conduction aphasia.

A case study of conduction aphasia, investigating single word repetition, phonological coding, and short-term memory, is reported. Evidence from intact adults suggests that repetition can occur through either a lexical route or a direct auditory-articulatory link. For this conduction aphasic, E.A., the direct link was impaired, although the lexical route could be used to produce accurate single word repetition. Several experiments demonstrated a significant impairment in the generation and maintenance of an abstract phonological code. The consequences of a disruption of phonological coding on speech perception and on verbal short-term memory are discussed.

Aphasia↗
PubMed1983

Visual problem solving in the absence of lexical semantics: evidence from dementia.

A case of dissociation between visual and praxic skills and linguistic, referential, and semantic skills is described in a case of dementia. Testing revealed that her visual processing was intact and that she was capable of a wide range of visually based tasks. These included copying geometric figures and block designs; matching items on the basis of number, color, or relative size, matching upper and lower case letters, sequencing numerals, orienting pictures, coins, and letters appropriately, and solving problems based on the identification of geometric patterns or on the identification of logical sequences based on pattern alternation, number, and size increases. In contrast, she was completely incapable of matching pictures on the basis of their semantic or referential meaning; similarly she had lost all comprehension of language. It was argued that this case demonstrates the capacities of a visual system cut off from all symbolic and semantic processes. When examined with other case studies this case provides information about the nature of and interaction between modality-specific perceptual processing and semantic processing, and information about the various cognitive factors involved in visual gnosis. The CT scan indicated frontal atrophy and marked anterior temporal atrophy, a pattern that is consistent with Pick's disease. The case was discussed in terms of the correlation between the pattern of observed strengths and deficits and the neurological pattern of atrophy.

Dementia↗
PubMed1979

Transient global amnesia: an extensive case report.

A case of transient global amnesia was studied in detail. Of note was a temporally extensive, although quite patchy, retrograde amnesia during the event for information recallable at other times. While a consolidation block can explain the anterograde amnesia in transient global amnesia, the profound retrograde amnesia requires an additional block in the retrieval of old, established memories.

Amnesia↗
PubMed1977

[Nature of repetition disorders in conduction aphasia].

The skeptic over the existence of this important clinical entity, are now very few. Anatomo-clinical studies and the analysis of altered cognitive procedures suggest, however, that we are dealing with a heterogeneous group. Two models of conduction apahasias are presented, in which the mechanism of the altered repetition, as well as the probable localization of the lesion, differ considerably. One has a lesion in the posterior parietal region of the left hemisphere and it exemplifies an acoustic verbal memory deficit (short term memory). The other points at a functional disconnection between the decodification and verbal processes and those of expression. In this case, we are dealing with a left temporal lesion in a left-handed individual. The analysis of our material and of the clinical literature upholds the idea of a plurality of the altered mechanisms in the verbal repetition and suggest that the conduction aphasia is a syndrome.

Adolescent↗
PubMed1976

Mechanism of the inverted supinator reflex. A clinical and neurophysiological study.

The inverted supinator reflex sign was analysed in two patients by recording the response of the finger flexor muscles of the forearm to tapping of the styloid process of the radius before and after procain infiltration of these muscles. It was found that the response persisted despite the block. The findings support the concept that the underlying mechanism is increased alpha motoneurone excitability below the level of the lesion; however, a possible contribution of the dynamic muscle spindles could not be excluded.

Evoked Potentials↗
PubMed1975

Agnosic behavior in anomia: a case of pathological verbal dominance.

The interrelation of perceptual and verbral process was explored in a fluent aphasic with a naming disorder. This patient performed extremely well on complex perceptual tasks as long as he was instructed to remain silent or to count aloud. Whe he began to talk about what he was doing, he misnamed many test items and behaved as if they were what he had called them. The verbal interference effect is explained in terms of cerebral dominance and interhemispheric interaction and it is suggested that a similar mechanism may apply in classical cases of agnosia.

Agnosia↗
PubMedDate not supplied

Cardiac arrhythmias and sudden death in subarachnoid hemorrhage.

Life-threatening cardiac arrhythmias can occur in patients with subarachnoid hemorrhage secondary to rupture of intracranial aneurysms. The arrhythmias are secondary to acute dysfunction of the central nervous system and possibly to sudden increase in intracranial pressure. The autonomic nervous system is the mediator in the production of these disorders. The clinical significance of these rhythm disorders is discussed, particularly in regard to the sudden, unexpected death seen in this type of patient. The possible mechanisms of production are analyzed and their therapeutic implications are stressed.

Adult↗