Biomedical subjects

M Laiacona

Publications and source records attributed to M Laiacona.

At least 19 recordsLinked to original sources

PubMed2005

Interpretation of a complex picture and its sensitivity to frontal damage: a reappraisal.

A. R. Luria introduced the interpretation of a meaningful picture as a tool for assessing pre-frontal impairment. We gave this test to 196 normal adults, who were asked to communicate what was happening in the portrayed scene (a boy chases a mouse hidden under a cupboard, while three frightened girls assist). The same subjects were given two other frontal tests (verbal fluency on phonemic cue and Trail Making Test (TMT)) and Raven's Matrices. Twenty-three normal subjects (12%) failed to correctly interpret the picture. We also examined 20 patients whose brain lesion encroached upon pre-frontal areas, in order to check if this version of the test could be easily administered to this type of patient, and if its difficulty level was appropriate for avoiding ceiling and floor effects. Twelve patients were unable to interpret the picture (60%). A similar failure rate was observed with the same subjects on verbal fluency and TMT, while Raven's Matrices were less impaired (35%). Some dissociation was found between Picture Interpretation and the TMT. The Italian version of the Picture Interpretation Test is suitable for the examination of pre-frontal patients.

Adult↗

PubMed2001

Living musical instruments and inanimate body parts?

In the literature about category effects in semantic memory, body parts and musical instruments are often considered atypical, because in cases with a disproportionate impairment of living categories body parts are relatively spared, while musical instruments are often severely defective. In this study the performance of 57 subjects affected by diseases generally associated with lexical-semantic impairment, for the most part Alzheimer's disease and other forms of cortical degeneration, but also herpetic encephalitis and traumatic brain damage are analyzed. The subjects were given a picture naming task tapping eight categories: three living categories (animals, fruits and vegetables) and three non-living categories (tools, furniture and vehicles), plus body parts and musical instruments. On a preliminary analysis at the group level, body parts were the least impaired category and musical instruments the most severely impaired, the six living and non-living categories being intermediate. However, these differences disappeared after covariance for lexical frequency, name agreement and age of acquisition. The relationship between living categories, non-living categories, musical instruments and body parts was investigated by means of a Lisrel model of Confirmatory Factor Analysis. Two latent variables related to living and non-living categories respectively were defined, and it was found that both body parts and musical instruments were significantly related only with non-living categories. The results showed that the definition of the latent variable expressing the substrate of non-living categories was less satisfactory than that expressing the living categories. On this basis, the conclusions of this study appear statistically definite but their psychological interpretation is less straightforward.

Adolescent↗

PubMed2000

Wisconsin card sorting test: a new global score, with Italian norms, and its relationship with the Weigl sorting test.

The Wisconsin card sorting test and the Weigl test are two neuropsychological tools widely used in clinical practice to assess frontal lobe functions. In this study we present norms useful for Italian subjects aged from 15 to 85 years, with 5-17 years of education. Concerning the Wisconsin card sorting test, a new measure of global efficiency (global score) is proposed as well as norms for some well known qualitative aspects of the performance, i.e. perseverative responses, failure to maintain the set and non-perseverative errors. In setting normative values, we followed a statistical methodology (equivalent scores) employed in Italy for other neuropsychological tests, in order to favour the possibility of comparison among these tests. A correlation study between the global score of the Wisconsin card sorting test and the score on the Weigl test was carried out and it emerges that some cognitive aspects are not overlapping in these two measures.

Adolescent↗

PubMed2000

Semantic category dissociations, familiarity and gender.

We carried out four experiments to assess the extent to which familiarity with certain objects in everyday life is related to gender and can account, at least partially, for the semantic category dissociation observed in a few brain-damaged patients. In the first experiment, 210 normal subjects, half males and half females, were given the names of 60 stimuli from the Snodgrass and Vanderwart's set, 30 belonging to living categories and 30 to non-living categories. The task was to rate their familiarity, based on the frequency with which one (i) thinks or speaks of a given item, (ii) sees it represented in the media, and (iii) is confronted with real exemplars. The three indices were highly correlated and their average value was, therefore, used. Females gave higher familiarity ratings to fruit, vegetables and furniture and males to tools. The second experiment was aimed to verify whether the gender difference was responsible for the category dissociation found following brain damage. A male patient with greater impairment for living categories and a female patient with greater impairment for non-living categories were requested to name the same 60 stimuli and their scores were analysed, partialling out the familiarity effect, measured both with the non-gender specific index of Snodgrass and Vanderwart and with the new gender-specific index. In either case, the category dissociation remained significant. To determine if the mean general population familiarity index was valid for the single subject, we studied whether a cohabitant first degree relative was able to predict a normal subject's familiarity better than the population index. Contrary to expectations, the better predictor was the population index. The test-retest reliability of each subject's familiarity ratings was satisfactory, but not higher than the correlation between the personal judgement of each subject and the population index.

Adult↗

PubMed1999

Gender affects word retrieval of certain categories in semantic fluency tasks.

Recent studies suggest that gender influences phonetically-cued fluency and some semantic memory tasks. In this study we analysed the effect of demographic variables on semantic fluency tasks. The semantic categories considered were: animals, fruits, tools and vehicles. The influence of age and education was common to all the categories considered and seems a general characteristic of the semantic fluency task. Gender had a significant effect only with fruits and tools, but a diverging role: females fared better with fruits and males with tools. We discuss whether the source of the gender effect should be located at the level of the semantic representation of each category or at the level of item recall in the short time (one minute) granted for the task.

Adolescent↗

PubMed1999

The 'preliminary neuropsychological battery'. An instrument to grade the cognitive level of minimally responsive patients.

An early, formalized cognitive evaluation of'minimally responsive' patients could be important in the planning of their care and rehabilitation as well as in providing a realistic prognosis and studying the modality of the cognitive recovery. A short, bedside, neuropsychologically-oriented test-battery, the Preliminary Neuropsychological Battery, a psychometric tool which enables the cognitive evaluation of these patients and of patients unable to give verbal or complex motor answers, has been devised. The BNP was administered to a sample of 40 head-injured patients and to a sample of 34 healthy subjects. The aim was (i) to evaluate its usefulness, and (ii) to study its correlation with cortical functions as assessed by a more extensive battery. The findings suggest that the BNP is useful for assessing the general cognitive level of head-injured post-comatose patients. It was able to detect patients deserving a wider, analytic, neuropsychological assessment. Attentional defects emerged as an important variable determining the BNP score.

Adolescent↗

PubMed1998

A normative study on visual reaction times and two Stroop colour-word tests.

Two-hundred and nine normal subjects underwent a study aimed at providing norms for some attention tests currently used in neuropsychological examination. Norms were calculated taking into account the demographic variables. Our battery included single visuo-manual and go/no-go reaction times, and two versions of the Stroop Colour-Word Test. For the latter test, we employed a traditional version based on card presentation and a new version based on computer-assisted presentation. We evaluated the intercorrelation of the different tests, and studied the statistical regression models in order to adjust the original scores according to age, education and gender. Normative values were calculated following the Equivalent Scores method. The pattern of intercorrelation of our battery and the regression models of the scores are discussed with reference to the literature. The newly developed computer-assisted presentation of the Stroop test offers some advantages over the traditional version, especially with patients affected by spatial disorders.

Adolescent↗

PubMed1998

Phonetically cued word-fluency, gender differences and aging: a reappraisal.

Five-hundred and three normal subjects were given a phonetically cued word-fluency task in order to investigate the controversial issue of the influence of gender and aging on this task. Subjects were requested to say in one minute all the words that occurred to them, beginning with a given letter (F, P and L). Besides the expected significance of education, we observed a female advantage, but not a significant decline in the performance with aging. However, the slope of the line expressing word fluency as a function of age was different between females and males, indicating a greater sensitivity to aging for males. We provide inner and outer tolerance limits for this test in the normal population and give a formula useful for adjusting the raw scores on the basis of gender and education. The results are discussed with reference to previous findings and some hypotheses about the origins of the female advantage in PWF.

Adolescent↗

PubMed1998

Picture naming and progression of Alzheimer's disease: an analysis of error types.

Seven patients affected by Dementia of the Alzheimer Type (DAT) took part in a longitudinal study aimed at assessing the qualitative and quantitative evolution of picture naming impairment. The follow-up lasted 6-36 months and the patients were examined at intervals of 6 months or longer. We found that the absolute number of lexical-semantic errors tended to be constant or to rise slightly until an advanced stage of DAT severity was reached. However, the proportion of errors of the lexical-semantic type in relation to the overall number of errors showed a decline as the disease progressed, with empty and unrelated responses being increasingly observed. Visual errors were generally a minority; they were produced in different proportions for each patient but did not vary greatly over time. For the observed patients, the proportion of lexical and semantic errors was inversely related to the overall naming performance, following a negative logarithmic function. This finding was replicated analysing cross-sectional data from another 24 DAT patients who were given the same naming task.

Aged↗

PubMed1998

Semantic category dissociations in naming: is there a gender effect in Alzheimer's disease?

Several studies on picture naming in Alzheimer's disease have reported inconsistent findings regarding semantic category dissociation. To clarify this point, 26 patients suffering from dementia of the Alzheimer's type (DAT) were given a naming task, based on 60 black and white drawings, which allowed us to take into account several variables that might influence performance, notably word frequency, stimulus familiarity and prototypicality, name and image agreement and visual complexity. On a raw analysis, DAT patients as a group gave a lower performance with stimuli of Living Categories (LC) than with stimuli of Non-Living Categories (NLC), but when all the confounding factors were taken into account the category effect disappeared. Nevertheless, with a multiple single case approach, some patients presented a true dissociation: 11 were significantly better with Non-Living stimuli, and 3 with Living stimuli. In order to find what factors were involved in determining this distribution, we took the distribution of asymmetry indices of each patient, and plotted the individual category effect against the level of the general performance. In our sample, the distribution of asymmetry indices was skewed, and included a definite cluster of male subjects who were better at performing with Non-Living stimuli. Multivariate analysis suggested that the greater discrepancy shown by male patients was due to a protection acting on Non-Living stimuli rather than to a selective hampering of Living stimuli. The greater personal experience of males with Non-Living things could explain the relative preservation of these in male DAT subjects.

Aged↗

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↗

PubMed1998

Neuropsychological outcome of operated cerebral aneurysms: prognostic factors on 148 patients.

OBJECTIVES: To analyse prognostic factors in patients operated upon for cerebral aneurysms. A previous investigation by our group showed that patients operated later than 10 days after bleeding have a worse neuropsychological prognosis, but the number of patients operated upon within 3 days was not sufficient. Here, a new sample of patients with early surgery is included in the analyses. MATERIAL AND METHODS: Patients numbered 148 (65 with ACoA, 39 with MCA, and 44 with PCoA aneurysms): 56 were operated within 3 days, 44 within 4-10 days, and 48 after at least 10 days from bleeding. A standardized battery of 13 neuropsychological tests was adopted: we considered both the number of defective scores and the average performance. RESULTS: Patients operated later than 10 days after bleeding had a worse prognosis than the 2 groups with early and intermediate surgery, which were not different. Aneurysm site was not relevant. Old age and low education were associated with a worse prognosis. Hunt and Hess scores at operation and post operation were also predictive of the outcome. CONCLUSION: On the whole, patients operated upon later than 10 days after bleeding have a less favourable prognosis than those with earlier operation timing.

Adolescent↗

PubMed1997

Semantic category dissociations: a longitudinal study of two cases.

We report the neuropsychological findings of two patients (LF and EA) with herpes simplex encephalitis. Both patients presented a greater deficit for living than non-living categories in a number of tasks, although EA was much more impaired than LF. We controlled the several stimulus variables that might affect the performance and could demonstrate that the dissociation was not artifactual. Neither LF nor EA revealed a selective or preferential involvement of perceptual semantic knowledge, and both showed a homogeneous impairment of perceptual and associative encyclopaedic notions. At a second examination, carried out from 1 to 2 years later, LF showed a good recovery, whereas EA's improvement was confined to the non-living categories. The lesion of both patients affected the left temporal pole and the basal neocortical regions of the left temporal lobe. The involvement of limbic areas was more marked in LF, while the Wernicke area and the posterior parts of the middle and inferior temporal gyri were only involved in EA. Besides the basal temporal areas, also the posterior temporal regions are likely to play a role in determining the clinical picture of such patients, and their prospect of recovery.

Adult↗

PubMed1997

A case of concomitant impairment of operational signs and punctuation marks.

A patient affected by amnestic aphasia, E.B., presented with a prevailing impairment in the use of operational signs and punctuation marks. His performance on tasks exploring his knowledge of these symbols is compared with that of two other patients suffering from similar aphasic disturbances. This comparison enables us to reject the hypothesis that E.B.'s defects arise from aphasia per se. A possible cognitive link between operational signs and punctuation marks is discussed.

Aged↗

PubMed1997

Composite neuropsychological batteries and demographic correction: standardization based on equivalent scores, with a review of published data. The Italian Group for the Neuropsychological Study of Ageing.

Equivalent Scores (ES; Capitani & Laiacona, 1988) is a 5-point scale that offers a solution to the problem of standardizing neuropsychological scores after adjustment for age and education, given that the common z-standardization is not generally applicable in these cases. ES are discussed, and their properties and limits are compared with those of z-standardization. In a battery of ES-standardized tests, the average ES (AES) for the whole battery can provide a measure of the overall cognitive level, free of the influence of age and education. We report empirical data from a battery composed of 10 ES-standardized tests, in order to discuss general properties of ES standardization. The expected mean of the AES is constant, regardless of the number or type of tests included. The standard deviation of the AES, however, is variable: it decreases in proportion to the number of tests, but increases in proportion to their intercorrelation. We provide general indications concerning the normality threshold, which are applicable to all batteries of ES-standardized tests regardless of the number and type.

Adult↗

PubMed1996

Normative data for two neuropsychological tests sensitive to frontal dysfunction.

Interest in frontal functions has progressively increased over recent years; however, despite this, there are only a few "frontal" tasks for which Italian normative data are available. The objective of this study was to obtain reference values for two frontal tests from a random sample of normal adults: the first (the Test of Classification and Recall of Pictures) has been shown to reveal selective impairment in patients with unilateral frontal excision; the second (the Odd-Man-Out Test) derives from tasks which have been used to evaluate frontal functions in animals and detect frontal impairment in Parkinson patients. We tested 100 normal subjects, aged 22 to 79 years, stratified by education according to the Italian school system. The correction grids for both tests are also presented. The usefulness of these tests is represented not only by their sensitivity to frontal impairment, but also by the possibility of dissociating the various cognitive aspects of frontal lobe dysfunction.

Adult↗

PubMed1996

Trail making test: normative values from 287 normal adult controls.

The Trail Making Test (TMT), which explores visual-conceptual and visual-motor tracking, is a frequently used neuropsychological test because of its ease of administration and sensitivity to brain damage. In this paper, norms are provided for the time scores derived from parts A and B, and for the (B-A) difference. The data were collected from 287 adult Italian subjects stratified by gender, schooling and age (from 20 to 79 years). The test scores were affected by age, education and general intelligence (as expressed by Raven's Coloured Progressive Matrices). Only for part A did females have longer time scores than males. Test-retest reliability was high for each score.

Adolescent↗

PubMed1996

A case of simulated, psychogenic or focal pure retrograde amnesia: did an entire life become unconscious?

A case of pure retrograde amnesia following mild head injury is reported. Neuropsychological, psychodynamic and statistical approaches are employed in an attempt to disentangle the clinical picture presented by the patient. Focal retrograde amnesia, psychogenic retrograde amnesia and simulated amnesia are all taken into account. From a public events questionnaire and an inquiry about famous people, consistency analyses showed that the patient was able implicitly to use information she denied having, but at the same time, made us lower the probability of a simulated amnesia. Moreover, psychodynamic analysis showed that the patient's personality structure was compatible with hysterical patterns and we suggest that the patient's memory defect may be related to her personality. It seems less likely, though still possible, that the case may be explained in terms of deliberate simulation. In this case we conclude that the classification along the conscious/unconscious dimension seems more informative than the contrast between psychogenic and organic genesis.

Adult↗