Xavier Seron

A Case of Prosopagnosia With Some Preserved Covert Remembrance of Familiar Faces

This paper presents the detailed analysis of a case of prosopagnosia in a 54-year-old male farmer following bioccipital vascular disease. In-depth clinical investigations confirmed the diagnosis of prosopagnosia and revealed the absence of any associated defect, except for a slight aspecific disturbance of the short-term memory. Further study of this case indicated that the trouble was not concerned with the class of complex visual stimuli, was not even concerned with facial expressions or unknown faces, was not a perceptual defect, but was related mainly to the operation of individualization. The memory hypothesis was thus retained and supported. Moreover, exploration of the difficulty indicated that the deficiency was limited to defective access to conscious information concerning faces and information associated with these faces (name, context, etc.), effectively stored in memory.

Memory evaluation with a new cued recall test in patients with mild cognitive impairment and Alzheimer’s disease

Free delayed recall is considered the memory measure with the greatest sensitivity for the early diagnosis of dementia. However, its specificity for dementia could be lower, as deficits other than those of pure memory might account for poor performance in this difficult and effortful task. Cued recall is supposed to allow a better distinction between poor memory due to concurrent factors and impairments related to the neurodegenerative process. The available cued recall tests suffer from a ceiling effect. This is a prospective, longitudinal study aiming to assess the utility of a new memory test based on cued recall that avoids the ceiling effect in the early diagnosis of Alzheimer’s disease (AD). Twenty-five patients with mild cognitive impairment (MCI), 22 probable AD patients (NINCDS-ADRDA) at a mild stage, 22 elderly patients with subjective memory complaints (SMC) and 38 normal age-matched controls took part in the study. The patients underwent a thorough cognitive evaluation and the recommended screening procedure for the diagnosis of dementia. All patients were re-examined 12–18 months later. A newly devised delayed cued recall test using semantic cues (The RI48 Test) was compared with three established memory tests: the Ten Word-List Recall from CERAD, the “Doors” and the “Shapes” Tests from “The Doors and People Test Battery”. Forty-four % of the MCI patients fulfilled criteria for probable AD at follow-up. The RI48 Test classified correctly 88% of the MCI and SMC participants and was the best predictor of the status of MCI and mild AD as well as the outcome of the MCI patients. Poor visual memory was the second best predictor of those MCI patients who evolved to AD. A cued recall test which avoids the ceiling effect is at least as good as the delayed free recall tests in the early detection of AD.

Cognitive approaches in neuropsychological rehabilitation

Presenting a new perspective on cognitive therapy in neuropsychology, these papers examine a cognitively-oriented, single-case methodology in neuropsychological rehabilitation. The recommended strategy is in-depth analysis of the precise nature of the impaired as well as the preserved processing components in the individual patient. The objective is to design a therapeutic course based on individual patient needs that is justified by the theoretical interpretation of the location of the deficit in his or her cognitive architecture.

The operativity effect in naming: a re-analysis.

According to Howard Gardner (1973), operativity, i.e. the extent to which it is possible to act with or upon an object, influences picture naming by aphasic subjects. In the present study, this influence is analysed with three purposes: (1) to replicate the Gardners observation, (2) to avoid methodological biases and to extend the analyses, and (3) to look for alternative explanations. Sixty-four pictures corresponding to high- and low-frequency nouns rated as high or low in operativity were presented to 18 aphasic subjects. Frequency and operativity were found to significantly affect naming performance. More particularly, fewer semantic paraphasias were observed in confrontation with operative items and fewer phonemic paraphasias in the production of frequent nouns. However, the influence of operativity on the reduction of errors disappeared when age-of-acquisition and picture familiarity were introduced as co-variables. These dimensions were found to be better predictors of aphasic performance than operativity.

Re-education of a surface dysgraphia with a visual imagery strategy

We report the re-education of a brain-damaged patient, LP, who presented a surface dysgraphia. This dysgraphia resulted from impairments of the lexical procedure of writing arising from a deficit located in the orthographic output lexicon. Our hypothesis was that LP had lost the relevant orthographic representations of some words. A two-stage therapeutic programme was carried out. In the first stage, we tried to optimise the relatively spared phonological procedure in writing by re-teaching some graphemic contextual rules. Because of residual surface dyslexia and verbal memory deficits associated with this surface dysgraphia, and because of the structure of the French language, we retaught, in the second stage, the spelling of some irregular and ambiguous words by means of a visual imagery technique. In post-therapy, we observed a selective effect of this imagery strategy by comparison with a classic methodology of repetitive presentation of ambiguous and irregular spellings. The results of our therapy support cognitive-oriented therapeutic approaches and are discussed with regard to recent debates on the subject in neuropsychology.

Pantomime interpretation and aphasia

Abstract In this study, 27 aphasic patients and 20 normal individuals took a drawn pantomime interpretation test. The scores made by aphasic patients were significantly lower than those of control subjects. The disorders observed could not be explained by the severity of the aphasic disorder considered at a communicative level, the onset time of the brain lesion or by lexical semantic disturbances. The authors suggest that one determinant is the ‘plausibility between the represented gesture and the object chosen. The plausibility factor is probably not of a linguistic nature. This interpretation is discussed in the light of earlier investigations.

Word-finding difficulties and learning transfer in aphasic patients.

Summary The results of two therapy methods of word-finding difficulties have been compared in aphasic patients. Four patients (experimental group) were trained according to a method using only a very small subset of lexicon but emphasizing the recovery of access strategies of disturbed lexicon. During a similar period (twenty therapy sessions in two months), four other patients (control group) were trained according to traditional methods, especially involving the mixing of many lexical items. At the end of the training, in agreement with the findings of Wiegel-Crump and Koenigsknecht (1973) , a learning transfer from lexical drilled items to lexical non-drilled items was observed in a picture naming test. This result proved significant in three out of four patients of the experimental group. As only one patient of the control group had improved, the results support the hypothesis that disorders responsible for word-finding difficulties would consist, in certain cases at least, much more in the access to lexicon than in the items themselves and they point therefore to the need of modifying traditional therapy methods. The results obtained in a semantic classification test are discussed according to the type of therapy and the relationships between word-finding difficulties and the semantic structure of the lexical store.

Ipsilateral Influences On Contralateral Processing in Neglect Patients

Abstract This article addresses the question of whether visual neglect of objects, as evidenced in a naming task, is influenced by the meaningfulness of the ipsilateral side of the stimuli. In the first experiment, six right-lesioned neglect subjects were asked to name drawings of common objects, the meaning of which could be ascertained by discovering the left part. The results indicate that neglect was indeed influenced by the left part of stimuli. Yet, given that some aspects of the results could be due to a ceiling effect and in order to examine if a similar influence of the left part of the stimuli could be observed in a situation that prevent eye movements, a second experiment with the same material was administered to ten normal and three neglect subjects under tachistoscopic condition. The results of the second experiment were very similar to those obtained in free-viewing condition. The theoretical interpretation stresses contextual aspects of neglect symptoms and suggests the influence of top-do...

Decoding Paralinguistic Signals - Effect of Semantic and Prosodic Cues On Aphasics Comprehension

A matching task between sentences voiced with joyful, angry, or sad intonation and pictures of facial expressions representing the same emotions is proposed to 27 aphasics and 20 normal subjects. Semantic contents are either meaningless, neutral, or affectively loaded. In the affective-meaning condition, content is redundant with prosody or conflicting with it. Results are 1. a greater number of nonprosodic choices in the aphasic group; 2. an identical influence of the congruence/conflict variable on aphasic and control subjects; 3. an identical influence of the semantic content of the conflict sentences on both groups. Aphasic impairment is interpreted as purely quantitative, since affective semantic content influences the decoding of the sentences.

Associative encoding deficits in amnestic mild cognitive impairment : a volumetric and functional MRI study.

BACKGROUND Previous functional MRI studies have shown increased hippocampus activation in response to item encoding in amnestic mild cognitive impairment (aMCI). Recent behavioral studies suggested that associative memory could be more impaired than item memory in aMCI. So far, associative encoding has not been evaluated separately from item encoding in functional MRI studies. METHODS We conducted a volumetric and functional MRI study investigating associative encoding in 16 aMCI and 16 elderly controls while controlling for item encoding. RESULTS We confirmed the presence of associative memory impairment in aMCI even after controlling for item memory differences between groups. Associative memory but not item memory correlated with hippocampus volume in aMCI. Such a correlation was not observed in elderly controls. The left anterior hippocampus activation in response to successful associative encoding was decreased in aMCI, even after correction for hippocampus atrophy. CONCLUSION Associative memory impairment in aMCI appears to be related to hippocampus atrophy and left anterior hippocampus hypoactivation.