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.

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.

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.

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.

Living and non-living categories. Is there a "normal" asymmetry?

A picture naming task and a semantic memory verbal questionnaire were given to normal subjects to assess the possible asymmetry between knowledge for non-living and living things. We first examined 60 elderly subjects with low education. Asymmetry between non-living and living things was found in the semantic knowledge questionnaire and living things fared worse. This difference was not explained by discrepancy in item frequency, familiarity or prototypicality. Using the same questionnaire, we analysed difficulty judgements given by younger, better-educated subjects: questions about living things were slightly, but significantly more difficult than questions regarding non-living things. In order to check for a possible sample bias, we submitted another verbal questionnaire with an analogous structure to different judges and replicated the previous results. These findings are discussed with regard to the selective semantic memory deficit for living things observed in patients. We suggest that the cognitive pattern presented by these cases may be linked to, but not fully explained by the greater difficulty living things present for normal subjects.

Generative associative naming in dementia of Alzheimer's type.

Forty-eight patients with mild to moderate dementia of Alzheimer's type (DAT) were tested with a generative associative naming task, a task that combines the aspects of fluency and of word association tests. The variables taken into consideration were the number of adequate and inadequate responses, conventionality, word frequency and lexical-semantic relation to the target. DAT patients' performances were compared to those of a group of control subjects matched for sex, age and educational level. As a group, the patients gave fewer adequate responses, more idiosyncratic responses and perseverations, while there was no difference in the qualitative variables. However, the analyses of the performance profiles suggest that, irrespective of the severity of the disease, two major subgroups of DAT patients may be identified: (1) a first subgroup of subjects produced words with a lower conventionality rate and these were mostly in propositional relationship to the target; they also produced a higher rate of idiosyncratic responses and perseverations. (2) A second subgroup of subjects gave more conventional responses, mostly in the hierarchical-categorical relationship. The disorders of the former subgroup seem to correspond to a disrupted access to some relatively spared semantic abilities, whereas those of the latter to a semantic breakdown.

Autobiographical recollection and frontal damage.

A neuropsychological experiment on autobiographical retrieval of incidental past events, checked by means of a standardized enquiry, was carried out on a series of 16 patients with CT-assessed frontal lobe lesions. Of 16 patients, six were impaired on autobiographical retrieval. Moreover, eight were impaired on supraspan verbal learning. Impairment on both resulted in three patients, whereas in five there was no impairment on either test. Concordance between autobiographical and learning impairment was far from significant. Poor autobiographical retrieval correlated significantly with "executive" test performances and with the CT-verified bilaterality of the frontal damage. Poor learning of new information did not correlate significantly with "executive" performances, nor did it appear to be related to the hemispheric side or to the bilaterality of the frontal lesion. We propose that the relationship between the attentional system of retrieving from remote memory and of learning new information is qualitatively different.

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.

Perceptual and associative knowledge in category specific impairment of semantic memory: a study of two cases.

We report two head-injured patients whose knowledge of living things was selectively disrupted. Their semantic knowledge was tested with naming and verbal comprehension tasks and a verbal questionnaire. In all of them there was consistent evidence that knowledge of living things was impaired and that of non-living things was relatively preserved. The living things deficit emerged irrespective of whether the question tapped associative or perceptual knowledge or required visual or non visual information. In all tasks the category effect was still significant after the influence on the performance of the following variables was partialled out: word frequency, concept familiarity, prototypicality, name agreement, image agreement and visual complexity. In the verbal questionnaire dissociations were still significant even after adjustment for the difficulty of questions for normals, that had proven greater for living things. Besides diffuse brain damage, both patients presented with a left posterior temporo-parietal lesion.

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.

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.

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.

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.

Factors influencing type and severity of aphasia.

The influence of etiology and sex on aphasia type and the relation of age to the severity and type of language disorders have been assessed in 718 right-handed aphasic patients. Both trauma and neoplasia are associated with fluent aphasia significantly more often, while sex proved to have no influence on aphasia type. The frequency distribution of age according to type and severity of aphasia - studied in vascular patients only (N = 566) - demonstrated that fluency and severity are significantly associated with older age.

Age and evolution of language area functions. A study on adult stroke patients.

This study attempted to verify some of the hypotheses advanced to explain the repeatedly reported finding that non-fluent aphasics are younger than fluent aphasics. One hundred and ninety eight vascular patients with cerebral infarcts documented by CT-scan were investigated. Also in this sample fluent patients were older than non-fluent patients. Age was found not to differ according to lesion site (anterior versus posterior). Patients with extensive lesions were, on average, younger than those with more restricted damage. The most interesting finding was that more than half patients with anterior lesion had fluent aphasia and that were remarkably older than anterior patients presenting with the classical non-fluent picture. It is inferred that anterior language areas undergo some kind of progressive functional evolution with age, though not in the sense postulated by Brown and Jaffe.

Crossed aphasia: one or more syndromes?

Seven strongly right-handed patients developed aphasia following a right hemisphere vascular lesion documented by computerized tomography. One patient had a severe unilateral neglect, indication of its presence were evident in three and absent in three patients. The Token Test scores were significantly higher than in matched controls. Two patients had Broca aphasia, four had Wernicke aphasia and one had agraphia. The correlation between type of aphasia and locus of lesion was not much different from that normally found in standard left hemisphere brain damaged aphasics.

Neuropsychological follow-up of patients operated for aneurysms of anterior communicating artery.

The neuropsychological outcome of 43 patients operated for ACoA aneurysms was assessed with a battery of 15 tests, tapping a wide spectrum of cognitive abilities. As a group ACoA aneurysms patients were impaired on 8 tests, including the three assessing memory. When however, patients falling below the cut-off point determined in normal controls were considered, 42% of the sample was unimpaired and only 35% fell on two or more tests. The analysis of single cases showed that memory was often affected, but short-term memory even more than long-term memory. In addition to the well known memory disorder, the patients showed a wide range of neuropsychological defects, including language and space functions. The hypotheses that could account for this broad-based neuropsychological impairment are discussed.

Neuropsychological follow-up of patients operated for aneurysms of the middle cerebral artery and posterior communicating artery.

This study assessed with a neuropsychological battery the outcome of 27 patients operated on for an aneurysm of the Middle Cerebral Artery a mean of 35 months before, and of 27 patients operated for aneurysms of the Posterior Communicating Artery, a mean of 47 months before. Both groups showed a defective pattern of performance that was related to the hemispheric side of the aneurysm with left-sided patients impaired on naming, verbal fluency and verbal short-term memory and right sided patients on both short-term and long-term spatial memory and discrimination of line orientation. In single cases, the scope of neuropsychological impairment was sometimes wider than that expected only on the basis of the competence of the affected hemisphere.

Poppelreuter-Ghent's Overlapping Figures Test: its sensitivity to age, and its clinical use.

This study aims to identify the cognitive variables involved in a task of visual recognition of meaningful and meaningless two-dimensional line-drawings of shapes; the Poppelreuter-Ghent Overlapping Figures Test. It was found that the performance of healthy controls was influenced by age and education, but not sex. Age and education adjusted norms are set forth. Meaningful patterns were better recognised than meaningless ones. Number of overlapping patterns, direction, and degree of rotation were among the other variables considered. Only the latter variable significantly influenced the difficulty of the task. The clinical use of this test was verified on clinical populations of patients affected by Alzheimer's disease and right or left hemisphere damage. Left hemisphere damaged patients did not show deficits. Alzheimer and right hemisphere damaged patients were impaired and the degree of rotation significantly influenced their performance. In conclusion, the Poppelreuter-Ghent's Test is a multicomponential task, the visuo-spatial components of which were shown to be the most important.

Aphasia in left-handers. Comparison of aphasia profiles and language recovery in non-right-handed and matched right-handed patients.

The present retrospective analysis reports two studies. In Study 1, clinical aspects of aphasia are compared in right-handed (RH) and non-right-handed (NRH) patients; in Study 2, recovery from aphasia is compared in RH and NRH aphasic patients with a minimum of 5 months of daily language rehabilitation. From a continuous series of 1200 brain-damaged subjects, 24 NRH patients with a vascular lesion documented by computerized tomography were selected. In 19 cases the lesion was in the left hemisphere and in 5 cases in the right hemisphere. For 14 NRH patients, a RH subject with similar lesion, matched for age, education, length of illness, etiology (ischemic vs. hemorrhagic), and, when possible, sex was found. Presence and type of aphasia were compared in the two patients of the same pair and were found similar except for Pair 14; the RH subject had global aphasia and the NRH had conduction-like aphasia. Fifteen NRH patients were rehabilitated and reexamined at least 5 months after the first examination. Recovery of the 12 patients with a left-hemisphere lesion was compared with recovery of a group of RH subjects and no significant differences were found. Recovery of the three patients with right-hemisphere lesions is described. It is concluded that differences in type of aphasia and recovery between RHs and NRHs have been overemphasized in the past and must be reconsidered.