Patrick Fery

Interaction of attentional and lexical processes in neglect dyslexia

Abstract Two cases of “left” neglect dyslexia are examined. The two patients show qualitatively similar problems of reading behaviour, although they differ quantitatively in terms of the exposure durations under which neglect dyslexia is manifest. Like other neglect patients documented in the literature, the two patients made mainly substitution errors to the left-hand letter in words, tending to misname the word as a neighbour of similar length. Unlike some patients, the two patients here showed lexical effects (i.e. they performed better with words than with nonwords, and they found words with many orthographic neighbours more difficult to identify than those with few orthographic neighbours). In addition, the patients were susceptible to attempts to manipulate the locus of attention, they were induced into producing addition errors by placing a hash at the left-hand end of letter strings, and their neglect reflected the position of the letter in the string rather than in the visual field. The argument ...

Personal name anomia: A single case study

A case presenting an anomia specific for person proper names but no naming impairment either for other types of proper names or for common names is reported. The deficit was equally present both in face-naming and in naming upon definition and was not affected by the descriptiveness of the labels borne by the individuals. The patient had no semantic processing impairment either for faces or names. The results are discussed in terms of impaired access to intact phonological representations.

Is the Addenbrooke's cognitive examination effective to detect frontotemporal dementia?

Abstract.We evaluated the Addenbrooke’s cognitive examination (ACE), a simple instrument to differentiate frontotemporal dementia (FTD) from Alzheimer’s disease (AD), in our dementia patients clinic population. The Verbal-Language/Orientation-Memory (VLOM) ratio, which compares its language and memory scores, determines whether FTD or AD is more likely. The ACE was translated into French with adaptation maintaining the number of words in the name and address learning and delayed recall test, and with cultural adaptation for the semantic memory. The 85 included subjects had no evidence of two or more organic pathologies, after at least six months of follow-up, and an MMSE score ≥ 20/30. Patients with cognitive impairment due to alcohol intake were excluded. The diagnosis of a specific dementing illness was based on the consensus of the neurologist and neuropsychologists in the team. Thereafter, another neurologist expert in dementia, blinded to the ACE result and to the diagnosis and treatment, reviewed all cases files and proposed a diagnosis. A diagnostic agreement was reached for 79 cases (92.9%) with 40 (50.6%) dementia: 25 AD (62.5 %), 9 FTD (22.5 %).We estimated that the sensitivity for detecting dementia of an ACE score ≤ 83/100 was 90% with a specificity of 64.1%. When the ACE score was ≤ 88/100, the sensitivity for diagnosing FTD of a VLOM ratio < 2.2 was 11.1% with a specificity of 88 % and the sensitivity for diagnosing AD of a VLOM ratio > 3.2 was 72%,with a specificity of 69.4%. We conclude that, when used as originally proposed, ACE is very accurate for the detection of dementia, but much less effective in discriminating the most common frontal variant of FTD.

The French Addenbrooke’s Cognitive Examination Is Effective in Detecting Dementia in a French-Speaking Population

We evaluated the sensitivity and specificity of our French version of Addenbrooke’s cognitive examination (ACE) to detect dementia in our patient population. One hundred and fifty-eight cases were included in the study. In our patient series, the sensitivity for diagnosing dementia with a Mini-Mental State Examination (MMSE) score of ≤24/30 was 48.5%, the sensitivity of an MMSE score of ≤27/30 was 82.5% with a specificity of 72.1%, the sensitivity of an ACE score of ≤83/100 was 86.6% with a specificity of 70.5% and the sensitivity of an ACE score of ≤88/100 was 97.9% with a specificity of 59%. We conclude that the French version of the ACE is a very accurate test for the detection of dementia, and should be widely used in clinical practice.

Can amnesic patients learn without awareness? New evidence comparing deterministic and probabilistic sequence learning.

Can associative learning take place without awareness? We explore this issue in a sequence learning paradigm with amnesic and control participants, who were simply asked to react to one of four possible stimuli on each trial. Unknown to them, successive stimuli occurred in a sequence. We manipulated the extent to which stimuli followed the sequence in a deterministic manner (noiseless condition) or only probabilistically so (noisy condition). Through this paradigm, we aimed at addressing two central issues: first, we asked whether sequence learning takes place in either condition with amnesic patients. Second, we asked whether this learning takes place without awareness. To answer this second question, participants were asked to perform a subsequent sequence generation task under inclusion and exclusion conditions, as well as a recognition task. Reaction times results show that amnesic patients learned the sequence only in the deterministic condition. However, they failed to be able to reproduce the sequence in the generation task. In contrast, we found learning for both sequence structures in control participants, but only control participants exposed to a deterministic sequence were successful in performing the generation task, thus suggesting that the acquired knowledge can be used consciously in this condition. Neither amnesic nor control participants showed correct old/new judgments in the recognition task. The results strengthen the claim that implicit learning is at least partly spared in amnesia, and the role of contextual information available for learning is discussed.

The fur of the crocodile and the mooing sheep: A study of a patient with a category-specific impairment for biological things.

We report a single case study of a brain-damaged patient, ER, who showed a remarkably consistent category-specific deficit for living things. His impairment was observed across tasks (naming, definition, matching, drawing from memory, questionnaires), input modalities (visual, verbal, nonverbal auditory), and output modalities (verbal vs. pointing or visual matching responses) as well as for different types of knowledge. Although visual knowledge of living things was severely affected, his category-specific impairment in nonverbal sound recognition is inconsistent with models of category-specific deficits based on pre-semantic visual descriptions. ERs deficit cannot fully be explained by item typicality, word frequency, visual complexity, homomorphy, age of acquisition, value to perceiver, or modality of transaction. Furthermore, in ER, contextual cues were even slightly detrimental for the recognition of animals. ERs naming and recognition errors were constrained by the categorical structure of the knowledge base: In most cases they respected both the second- and first-order superordinates. In particular, ERs knowledge of shared categorical properties related to biological function was almost spared. This result is compatible with the idea that, for living things, shared functional properties and shared perceptual properties are strongly correlated. Feature-based models assuming perceptual vs. functional semantic components cannot account for ERs deficit, since for living things he was impaired on both kinds of features to a similar extent. ERs behaviour is quite consistent with the notion that conceptual knowledge is organised categorically in the brain, with one or several specialised subsystems for biologically related entities.

A Case Study of Visual Agnosia without Perceptual Processing or Structural Descriptions Impairment

We report a new case of visual associative agnosia. Our patient (DJ) was impaired in several tasks assessing visual processing of real objects, colour pictures, and line drawings. The deficit was present both with naming and gesturing responses. Object processing in other modalities (verbal, auditory nonverbal, and tactile) was intact. Semantic processing was impaired in the visual but not in the verbal modality. Picture-word matching was better than single picture identification. DJs visual perceptual processing, was intact in several tasks such as visual attributes discrimination, shape discrimination, illusory contours perception, segmentation, embedded figures processing and matching objects under different viewpoints. Most importantly, we show that there was no impairment of stored structural descriptions and that the patient was able to build new visual representations. These results are considered in the context of Farahs (1990, 1991) proposals about visual associative agnosia.

The Addenbrooke’s Cognitive Examination Revised Is as Effective as the Original to Detect Dementia in a French-Speaking Population

Introduction: This paper presents the validation of the French version of the Addenbrooke’s Cognitive Examination Revised (ACE-R). Methods: The variability of the 3 versions of the ACE-R (A, B and C), performed by the same observer, hence mainly 2 or 3 times on 119 patients showing no progression, was first calculated by Cronbach’s alpha coefficient, t test and linear regression. The alpha coefficients of the 3 versions were obtained showing that the ACE-R versions can be considered as one, and an analysis of the interobserver variability was performed by Cohen’s kappa coefficient, t test and linear regression on 12 patients. Eventually, we performed a receiver operating characteristic (ROC) analysis to compare the sensitivities and specificities to detect dementia of the ACE, the ACE-R and Mini Mental State Examination on 319 consecutive patients. Results: The ROC areas of sensitivities and specificities of the ACE and ACE-R were very similar. Two cutoffs were identified at 83/100 and 89/100 with a specificity to normality of 98.6% if the ACE-R score was ≥83 and a sensitivity to dementia of 98.4% if the ACE-R score was ≤89. Conclusion: ACE-R in French is as reliable and valid as the original version to detect dementia.

Cognitive Improvement of Attention and Inhibition in the Late Afternoon in Children With Attention-Deficit Hyperactivity Disorder (ADHD) Treated With Osmotic-Release Oral System Methylphenidate

Long-acting medications have been developed and approved for use in the treatment of attention-deficit hyperactivity disorder (ADHD). These compounds are intended to optimize and maintain symptoms control throughout the day. We tested prolonged effects of osmotic-release oral system methylphenidate on both attention and inhibition, in the late afternoon. A double-blind, randomized, placebo-controlled study was conducted in 36 boys (7-12 years) with ADHD and 40 typically developing children. The ADHD children received an individualized dose of placebo or osmotic-release oral system methylphenidate. They were tested about 8 hours after taking with 2 continuous performance tests (continuous performance test–X [CPT-X] and continuous performance test–AX [CPT-AX]) and a counting Stroop. A positive effect of osmotic-release oral system methylphenidate was present in CPT-AX with faster and less variable reaction times under osmotic-release oral system methylphenidate than under placebo, and no difference with typically developing children. In the counting Stroop, we found a decreased interference with osmotic-release oral system methylphenidate but no difference between children with ADHD under placebo and typically developing children.

Is the attentional blink effect located in short-term memory?

The attentional blink (AB) effect is characterized by a failure to detect a second target following the identification of a previous target in a RSVP stream. This effect has been attributed to capacity limitations at a central level of visual information processes. Postperceptual models suppose that the AB locus is located in short-term memory. To test this hypothesis, we investigated the influence of a short-term memory deficit on the AB effect in a patient with such a deficit. The three main results of this study are (1) the persistence of an AB effect, (2) a large number of T1 missed identifications and (3) a T2 detection deficit for a specific delay (367 ms). These results indicate that a short-term memory deficit disrupts the processing of each target (T1 and T2) but does not product an abolition of the AB effect.