Biomedical subjects

P S Bisiacchi

Publications and source records attributed to P S Bisiacchi.

7 recordsLinked to original sources

PubMed1992

Naming disorders and semantic representations.

The status of semantic conceptual structures in aphasia was investigated with relation to naming disorders in spontaneous and constrained speech production. A battery of six tasks was administered to 25 control subjects and 25 aphasics: spontaneous speech production (from which the percentage of nouns was calculated), confrontation naming, understanding class relationships (verbal and pictorial), and understanding thematic relationships (verbal and pictorial). Results indicated the important role of taxonomic abilities for naming, while other conceptual structures (i.e., thematic relations) do not seem to play any important role in the process of naming. These results are discussed in terms of the internal organization of semantic information.

Adolescent↗

PubMed1991

Spatial sustained attention: better focused than divided?

Visuospatial attention was studied using three different reaction time tasks in a sustained attention paradigm (N = 35). Contrasting with findings from a phasic attention paradigm, our results suggest an equal ability to divide or focus sustained attention in the left and right fields in simple RT, a Go/No go-task, and choice RT.

Adult↗

PubMed1989

Impairment in processing meaningless verbal material in several modalities: the relationship between short-term memory and phonological skills.

Phonological processing abilities were studied in a patient who, following focal brain damage, showed selective impairment in non-word reading, writing, and repetition and also a severe short-term memory (STM) deficit specific for auditorily presented verbal material. The patient could execute tasks involving phonemic manipulation and awareness perfectly. Our data, in contrast with earlier observations in a case of developmental phonological dyslexia, show that acquired impairment in non-word reading, writing, repetition, and immediate memory may occur despite good phonological processing abilities. The role of STM in processing meaningless verbal material is discussed.

Adult↗

PubMed1988

Left hemisphere superiority for visuospatial functions in left-handers.

Male and female left- and right-handers have been tested with a divided visual field technique on a visuospatial (discrimination of angle width) and on a verbal task (vowel-consonant discrimination) using either a choice or a Go-No-go manual reaction time paradigm. Right-handers showed the expected pattern of hemispheric asymmetries with an advantage of the right hemisphere in the visuospatial task and an advantage of the left hemisphere in the verbal task. Such effects were statistically reliable only in male subjects. Left-handers, on the contrary, showed a different pattern of asymmetries. In the visuospatial task there was an overall superiority of the left hemisphere, while no hemispheric asymmetry was found in the verbal task.

Adult↗

PubMed1988

Acquired stuttering: a motor programming disorder?

Acquired stuttering (AS) can follow unilateral right, left or bilateral hemispheric lesion, and can, but not necessarily, coexist with aphasia. In this paper we experimentally tested motor programming skills in a patient with AS of vascular origin. Motor programming consists in the structuration of the whole sequence of response prior to the onset of the first response element of a sequence of responses. Chronometric studies have shown that the time to initiate a sequence of manual responses is a function of the characteristics of the forthcoming sequence of responses. In our patient, reaction times involving single motor responses performed by right hand were within normal limit. On the contrary, when the task required a sequence of motor responses, there was a consistent difficulty in following the sequence: moreover, in the few correct sequences, reaction time analysis showed a lack of motor programming. It is suggested that AS could be the speech epiphenomenon of a more generalized disturbance of motor programming.

Cognition Disorders↗

PubMedDate not supplied

Planning times during traveling salesman's problem: differences between closed head injury and normal subjects.

We studied planning behavior in a group of normal subjects and a group of closed head injury patients (CHI). A computerized version of the traveling salesman's problem was used as a visuospatial planning ability task. The program collected measurements of partial times, number of moves, and number of skipped subgoals. These measures allow us to calculate a "planning index" of subjects' planning ability. Results show that CHI patients present limitations in the planning process due to the lack of ongoing planning.

Adult↗

PubMedDate not supplied

Neuropsychological evaluation of neurologically asymptomatic HIV-infected children.

Forty-two children born to HIV positive mothers (29 infected at different stages of the disease, according to the Disease Control Classification Centers, and 13 noninfected) underwent evaluation using a battery of neuropsychological tests. Executive function impairments were present in all infected children, whereas memory and visuo-prassic deficits were evident only in those with full-blown AIDS. Language abilities and overall intelligence were spared. Performance of seroreverters was in the normal range. These findings suggest that even in neurologically asymptomatic children, neuropsychological evaluation can identify early impairment of specific cognitive functions. The findings are discussed in the light of the prognostic power of neuropsychological assessment for early signs of HIV neurological involvement.

Adolescent↗