Absence of amusia and preserved naming of musical instruments in an aphasic composer.

M.M., a right-handed, 74 year old professional musician and composer, presented with a progressive aphasia with a severe anomia. His musical competence was apparently totally preserved, and he continued his activity as a composer. There was a striking discrepancy between his impaired naming of nonmusical stimuli and his normal naming of musical instruments' sounds. We suggest that the preservation of skills in the musical domain results from an expanded cortical representation of this function in the left hemisphere, secondary to his lifelong formal training, and to the high level of his professional competence. As for his preserved naming of musical instruments, we argue that the early age-of-acquisition and higher than "normal" frequency/familiarity for names of musical instruments facilitate the access to their lexical representation and/or their retrieval within the lexicon.

The influence of semantic and perceptual encoding on recognition memory in Alzheimer's disease.

Previous results from a population of patients with Alzheimer's disease (Dalla Barba and Goldblum, 1996) demonstrated that the ability of patients to make a semantic association between two items was significantly and positively correlated to their performance on a yes/no recognition task for the same items and that patients who were impaired on the semantic task did significantly worse on the recognition task than patients who were unimpaired on the semantic task. These findings gave support to a hierarchical model of organization of human memory in which episodic memory depends on the integrity of semantic memory. The present study further investigates the relationship between semantic memory deficits and episodic recognition memory in 15 patients with Alzheimer's disease and 15 controls, as a function of their semantic and perceptual encoding abilities and of their cognitive impairment in other domains. The results confirmed the previous findings and showed that, although patients heavily relied on perceptual analysis, this type of encoding did not enhance their recognition memory. Correlations analyses showed that some patients who were not impaired in the semantic association, but with particularly low scores on a verbal fluency task presented with a pattern, in recognition memory tasks, that suggests a possible early involvement of frontal lobes in this subgroup of patients.

The influence of semantic encoding on recognition memory in Alzheimer's disease.

Within the framework of the distinction between episodic and semantic memory, it has been argued that these two memory systems are organised in a hierarchical way. The hierarchical hypothesis assumes that episodic memory is a specific subsystem of semantic memory and therefore implies that episodic memory cannot exist without semantic memory. If this hypothesis is correct, it should be expected that patients with impaired semantic memory also have impaired episodic memory. In the present study, two experiments investigated the influence of semantic encoding on recognition memory performance in a population of 20 patients with Alzheimer's disease and 18 normal controls. Both experiments assessed recognition memory for semantically-related items. In Experiment 2, but not in Experiment 1, subjects were explicitly instructed to make a semantic association between the items. Alzheimer's disease patients were impaired, compared to the normal controls, on the recognition memory performance of both experiments. The ability to make a semantic association between two items was significantly and positively correlated with the subjects' performance on the recognition tasks. A further analysis showed that patients who were impaired on the semantic association task did significantly worse on the recognition task of Experiment 2 than normal controls and patients who were unimpaired on the semantic association task. These findings are discussed in the context of memory deficits in Alzheimer's disease, and are interpreted as supporting the view that episodic memory for an item is affected by the level of semantic awareness of that same item.

Classification deficits in Alzheimer's disease with special reference to living and nonliving things.

The present study was conducted to assess the hypothesis that visual similarity between exemplars within a semantic category may affect differentially the recognition process of living and nonliving things, according to task demands, in patients with semantic memory disorders. Thirty-nine Alzheimer's patients and 39 normal elderly subjects were presented with a task in which they had to classify pictures and words, depicting either living or nonliving things, at two levels of classification: subordinate (e.g., mammals versus birds or tools versus vehicles) and attribute (e.g., wild versus domestic animals or fast versus slow vehicles). Contrary to previous results (Montañes, Goldblum, & Boller, 1995) in a naming task, but as expected, living things were better classified than nonliving ones by both controls and patients. As expected, classifications at the subordinate level also gave rise to better performance than classifications at the attribute level. Although (and somewhat unexpectedly) no advantage of picture over word classification emerged, some effects consistent with the hypothesis that visual similarity affects picture classification emerged, in particular within a subgroup of patients with predominant verbal deficits and the most severe semantic memory disorders. This subgroup obtained a better score on classification of pictures than of words depicting living items (that share many visual features) when classification is at the subordinate level (for which visual similarity is a reliable clue to classification), but met with major difficulties when classifying those pictures at the attribute level (for which shared visual features are not reliable clues to classification). These results emphasize the fact that some "normal" effects specific to items in living and nonliving categories have to be considered among the factors causing selective category-specific deficits in patients, as well as their relevance in achieving tasks which require either differentiation between competing exemplars in the same semantic category (naming) or detection of resemblance between those exemplars (categorization).

Verbal skills in relatives of autistic females.

First-degree relatives of 26 autistic females and 26 Down's syndrome females were tested on a battery of verbal tasks designed to detect subtle anomalies. No differences were found when comparing parents of the two groups, but there was a significant difference between siblings. This result was accounted for by a lower performance of the brothers of autistic subjects. The verbal scores of the relatives, either parents or siblings, were not related to the IQ of the proband. Findings are discussed in relation to the hypothesis of genetic and/or environmental factors in autism.

Processing of number and gender inflections by French-speaking aphasics.

This study investigates French-speaking aphasics' sensitivity to gender (of human nouns) and number marking in a sentential context. Using a forced picture choice task, we tested sentences in which grammatical marking surfaced either on a function word or on a content word, within or outside a noun phrase (NP) whose gender or number was required to be identified. Ten fluent and 10 nonfluent aphasics together with 20 adults without neurological history were tested. Results showed that neither group of aphasics presented an across-the-board deficit. Nonfluent patients were strongly impaired when marking surfaced on a content word outside NP (verbs and adjectives), but their sensitivity to grammatical marking was relatively well preserved in the within NP condition (determiners and nouns) and for function words in the outside NP condition (the copula). Fluent patients showed a specific impairment in dealing with semantic gender (as opposed to number information); and their difficulty was exacerbated when the information conveyed by the suffix of a content word must be integrated into an higher order semantic representation, as in the outside NP condition (adjectives). These results are consistent with the view that for both nonfluent and fluent aphasics, the functional locus of their impairment lies on a reduction in the computational resources available to the language processor, which is more severe in the former than in the latter group.

The naming impairment of living and nonliving items in Alzheimer's disease.

Several studies of semantic abilities in Dementia of the Alzheimer Type (DAT) suggest that their semantic disorders may affect specific categories of knowledge. In particular, the existence of a category-specific semantic impairment affecting, selectively, living things has frequently been reported in association with DAT. We report here results from two naming tasks of 25 DAT patients and two subgroups within this population. The first naming task used 48 black and white line drawings from Snodgrass and Vanderwart (1980) which controlled the visual complexity of stimuli from living and nonliving categories. The second task used 44 colored pictures (to assess the influence of word frequency in living vs. nonliving categories). Within the set of black and white pictures, both DAT patients and controls obtained significantly lower scores on high visual complexity stimuli than on stimuli of low visual complexity. A clear effect of semantic category emerged for DAT patients and controls, with a lower performance on the living category. Within the colored set, pictures corresponding to high frequency words gave rise to significantly higher scores than pictures corresponding to low frequency words. No significant difference emerged between living versus nonliving categories, either in DAT patients or in controls. In the two tasks, the two subgroups of DAT patients presented a different profile of performance and error type. As color constitutes the main difference between the two sets of pictures, our results point to the relevance of this cue in the processing of semantic information, with visual complexity and frequency also being very relevant.

Language impairment and rate of cognitive decline in Alzheimer's disease.

There is growing evidence that AD consists of different subtypes, and that language is a pertinent factor to identify a subgroup with a fast rate of cognitive decline. We report the first results of a longitudinal study in which we compared two groups of patients with probable AD. The main result showed that a subgroup with stable MMSE scores during a 1-year follow-up period had an impairment in language domains which are usually preserved until an advanced stage of the disease. It is proposed that this group may correspond to a variety of AD who, in addition to symptoms of AD, present characteristics of primary progressive aphasia. In other respects, we underscore that the high loading in language-mediated tasks of the MMSE makes it a poor index to accurately measure the rate of cognitive decline.

Principal component analysis of language performances in Alzheimer's disease.

This report analyzes the performances of a group of 104 mildly to moderately impaired probable Alzheimer's disease patients (Mini Mental Examination 10 to 23) on linguistic tasks exploring written and oral language. A principal component analysis showed a two-factor solution including 14 out of the 15 linguistic tasks. Each factor is characterized by a type of operation required to process language material: "operativeness factor," where verbal material receives a transformation; "transcoding factor," where verbal material is processed without any structural modification. Oral verbal repetition remained isolated from the solution.

Selective crossed aphasia in a trilingual aphasic patient followed by reciprocal antagonism.

After surgical removal of a parasitic cyst in the right prerolandic area, an educated 25-year-old male exhibited obvious deficits in one of his three languages (Gujarati), with no measurable deficits in the other two (French and Malagasy). The patient spoke all three languages fluently before the operation. Gujarati and Malagasy had been acquired in infancy. Gujarati was the language of his parents and relatives. Malagasy the language of the local population. All the patient's schooling had been in French, the only language in which he was literate. He used French daily at work. Since the acquisition history for Gujarati and Malagasy was identical, while French had been acquired in a different context, one would have predicted, on the basis of W. Lambert and S. Fillenbaum's (1959, Canadian Journal of Psychology, 13, 28-34) hypothesis, that Gujarati and Malagasy should have been equally affected, with French possibly differently so. However, 8 months postoperatively, the patient had regained control of Gujarati, while Malagasy had deteriorated considerably, and his French remained unimpaired. Two years later, the patient had recovered full use of his three languages.

[Recognition of conventional and emotional facial expressions in patients with cortical lesions (author's transl)]. / La reconnaissance des expressions faciales émotionnelles et conventionnelles au cours des lésions corticales.

Recognition of facial expressions was studied in a group of patients with cortical lesions. The test which was used consists in designating 30 expressions upon verbal command. Fifteen items had an emotional characteristic, and fifteen had a conventional characteristic (with an intentional communicative aspect). Results showed that right hemisphere patients had a elective deficit for emotional expressions. Left hemisphere patients had a elective deficit for conventional expressions. Analysis of correlations with associated clinical deficits showed further, that the deficit was associated, in right hemisphere patients, with lesions giving rise to Unilateral Spatial Agnosia. In left hemisphere patients it was associated with posterior lesions outside of the language area.