Biomedical subjects

N Allamano

Publications and source records attributed to N Allamano.

3 recordsLinked to original sources

PubMed1999

Pattern span: a tool for unwelding visuo-spatial memory.

Evidence showing that non-verbal short-term memory has distinct visual and spatial/sequential components is reviewed. A new test, The Visual Patterns Test (VPT), which was designed to measure short-term visual memory largely shorn of its spatio-sequential component, is described. Correlational studies of the VPT and the Corsi Blocks Test with healthy subjects and brain-damaged patients indicate a separation between visual and sequential abilities. This separation of function is supported by double dissociations shown by patients. Moreover, in a selective interference experiment, the VPT and the Corsi tests were found to show a double dissociation pattern of interference from visual and spatio sequential subsidiary tasks, respectively. The present results are discussed in relation to other findings in the literature, and it is concluded that non-verbal short-term memory can indeed be viewed as comprising distinct visual and spatio-sequential components. The VPT will be a useful neuropsychological instrument for measuring the visual component.

Adolescent↗

PubMed1998

Writing disorders in Italian aphasic patients. A multiple single-case study of dysgraphia in a language with shallow orthography.

We report results of a writing task given to 53 mildly to moderately aphasic Italian subjects. The task was designed to test the writing performance along the subword-level routine for the spelling of regular words and non-words, and along the lexical routine for the spelling of irregular words. The aim of the study was to identify the incidence of different dysgraphic subtypes in Italian, a language that is considered to have shallow orthography. Its spelling, however, is not completely free of ambiguity. A five-part writing task was used: (i) words with regular one-sound-to-one-grapheme conversion; (ii) words with regular syllabic conversion; (iii) words with ambiguous transcription; (iv) loan-words; and (v) non-words. For regular words, the effects of word length and word frequency, and of the variables determining the complexity of the acoustic-to-phonological conversion (continuant versus plosive phones; consonant-vowel sequence versus doubled consonants or consonant clusters) were also considered. Patients' performances were classified according to the presence of a dissociation between (i) regular words and non-words, (ii) regular words and words with unpredictable spellings, and (iii) one-to-one and syllabic conversions. The 53 aphasic patients span the whole spectrum of dysgraphic taxonomy. Thirty-nine patients, in particular, manifested a dissociated pattern of performance. Eighteen patients showed a prevalent surface dysgraphic pattern and seven a phonological one, while 11 patients showed a mixed pattern (i.e. a better performance for regular words than for ambiguous words or regular non-words). Three patients showed a specific deficit for regular syllabic conversion rules only. A high rate of 'mixed dysgraphia' suggests either a mutual interaction of the two impaired routines when regular words are written, or two separate functional lesions: one at the level of the auditory-to-phonological conversion procedure, the other at the level of the orthographic output lexicon.

Adult↗

PubMed1996

Performance consistency in picture naming: a study of the rehabilitation effect on two aphasic patients.

We describe the effect of language rehabilitation on the naming deficits of 2 patients affected by longstanding amnestic aphasia. In particular, our aim was to study the evolution of the rate of inconsistent naming (i.e., performance with stimuli that were named sometimes correctly and sometimes incorrectly when the test was repeated at close intervals) by means of a stochastic model based on Markov chains (Faglioni & Botti, 1993). From a quantitative point of view, both patients showed a significant improvement that was still present several months after treatment. However, at baseline these patients showed different degrees of consistency which revealed a basic difference in the way their language functions. One case presented with low consistency, delayed responses, and self-corrections: A clear effect of rehabilitation was improvement in consistency and reduction of delays. In the other case, at baseline consistency was greater, but naming of pictures did not improve even after delay or self-correction; after rehabilitation more stimuli were named correctly, but only after delay and self-correction. The relevance of consistency and its relationship with delayed naming and self-corrections is discussed. It is suggested that consistency analysis based on stochastic models would make a useful contribution to the description and interpretation of naming deficits in aphasic patients.

Adult↗