Josselin Baumard

Apraxia and Alzheimer’s Disease: Review and Perspectives

Apraxia is one of the cognitive deficits that characterizes Alzheimer’s disease. Despite its prevalence and relevance to diagnosing Alzheimer’s disease, this topic has received little attention and is without comprehensive review. The review herein is aimed to fill this gap by first presenting an overview of the impairment caused in different clinical situations: pantomime of tool use, single tool use, real tool use, mechanical problem solving, function and manipulation knowledge tasks, and symbolic/meaningless gestures. On the basis of these results, we then propose alternative interpretations regarding the nature of the underlying mechanisms impaired by the disease. Also presented are principal methodological issues precluding firm conclusions from being drawn.

Tool use disorders after left brain damage

In this paper we review studies that investigated tool use disorders in left-brain damaged (LBD) patients over the last 30 years. Four tasks are classically used in the field of apraxia: Pantomime of tool use, single tool use, real tool use and mechanical problem solving. Our aim was to address two issues, namely, (1) the role of mechanical knowledge in real tool use and (2) the cognitive mechanisms underlying pantomime of tool use, a task widely employed by clinicians and researchers. To do so, we extracted data from 36 papers and computed the difference between healthy subjects and LBD patients. On the whole, pantomime of tool use is the most difficult task and real tool use is the easiest one. Moreover, associations seem to appear between pantomime of tool use, real tool use and mechanical problem solving. These results suggest that the loss of mechanical knowledge is critical in LBD patients, even if all of those tasks (and particularly pantomime of tool use) might put differential demands on semantic memory and working memory.

Mechanical problem-solving strategies in Alzheimer's disease and semantic dementia.

OBJECTIVE The goal of this study was to explore whether the tool-use disorders observed in Alzheimers disease (AD) and semantic dementia (SD) are of the same nature as those observed in left brain-damaged (LBD) patients. Recent evidence indicates that LBD patients with apraxia of tool use encounter difficulties in solving mechanical problems, characterized by the absence of specific strategies. This pattern may show the presence of impaired mechanical knowledge, critical for both familiar and novel tool use. So, we explored the strategies followed by AD and SD patients in mechanical problem-solving tasks in order to determine whether mechanical knowledge is also impaired in these patients. METHOD We used a mechanical problem-solving task in both choice (i.e., several tools were proposed) and no-choice (i.e., only 1 tool was proposed) conditions. We analyzed quantitative data and strategy profiles. RESULTS AD patients but not SD patients met difficulties in solving mechanical problem-solving tasks. However, the key finding is that AD patients, despite their difficulties, showed strategy profiles that are similar to that of SD patients or controls. Moreover, AD patients exhibited a strategy profile distinct from the one previously observed in LBD patients. CONCLUSIONS Those observations lead us to consider that difficulties met by AD patients to solve mechanical problems or even to use familiar tools may not be caused by mechanical knowledge impairment per se. In broad terms, what we call apraxia of tool use in AD is certainly not the same as apraxia of tool use observed in LBD patients. (PsycINFO Database Record

A cognitive-based model of tool use in normal aging

ABSTRACT While several cognitive domains have been widely investigated in the field of aging, the age-related effects on tool use are still an open issue and hardly any studies on tool use and aging is available. A significant body of literature has indicated that tool use skills might be supported by at least two different types of knowledge, namely, mechanical knowledge and semantic knowledge. However, neither the contribution of these kinds of knowledge to familiar tool use, nor the effects of aging on mechanical and semantic knowledge have been explored in normal aging. The aim of the present study was to fill this gap. To do so, 98 healthy elderly adults were presented with three tasks: a classical, familiar tool use task, a novel tool use task assessing mechanical knowledge, and a picture matching task assessing semantic knowledge. The results showed that aging has a negative impact on tool use tasks and on knowledge supporting tool use skills. We also found that aging did not impact mechanical and semantic knowledge in the same way, confirming the distinct nature of those forms of knowledge. Finally, our results stressed that mechanical and semantic knowledge are both involved in the ability to use familiar tools.

Rethinking the Cognitive Mechanisms Underlying Pantomime of Tool Use: Evidence from Alzheimer's Disease and Semantic Dementia.

OBJECTIVES Pantomiming the use of familiar tools is a central test in the assessment of apraxia. However, surprisingly, the nature of the underlying cognitive mechanisms remains an unresolved issue. The aim of this study is to shed a new light on this issue by exploring the role of functional, mechanical, and manipulation knowledge in patients with Alzheimers disease and semantic dementia and apraxia of tool use. METHODS We performed multiple regression analyses with the global performance and the nature of errors (i.e., production and conception) made during a pantomime of tool use task in patients and control participants as dependent variables and tasks investigating functional, mechanical, and manipulation knowledge as predictors. RESULTS We found that mechanical problem solving, assessing mechanical knowledge, was a good predictor of the global performance of pantomime of tool use. We also found that occurrence of conception errors was robustly predicted by the task assessing functional knowledge whereas that of production errors was not explained by only one predictor. CONCLUSIONS Our results suggest that both functional and mechanical knowledge are important to pantomime the use of tools. To our knowledge, this is the first demonstration that mechanical knowledge plays a role in pantomime of tool use. Although impairment in pantomime of tool use tasks (i.e., apraxia) is widely explained by the disruption of manipulation knowledge, we propose that pantomime of tool use is a complex problem-solving task. (JINS, 2017, 23, 128-138).

Mechanical problem-solving and imitation of meaningless postures in left brain damaged patients: two sides of the same coin?

Christophe Jarry , François Osiurak , Josselin Baumard , Mathieu Lesourd , Fr ed erique Etcharry-Bouyx , Val erie Chauvir e d and Didier Le Gall a,b,* a Laboratory of Psychology LPPL (EA 4638), University of Angers, France b Neuropsychological Unit, Department of Neurology, University Hospital of Angers, France c Laboratory for the Study of Cognitive Mechanisms (EA 3082), University of Lyon, France d Department of Neurology, University Hospital of Angers, France

Imitation and matching of meaningless gestures: distinct involvement from motor and visual imagery

AbstractThe aim of the present study was to understand the underlying cognitive processes of imitation and matching of meaningless gestures. Neuropsychological evidence obtained in brain damaged patients, has shown that distinct cognitive processes supported imitation and matching of meaningless gestures. Left-brain damaged (LBD) patients failed to imitate while right-brain damaged (RBD) patients failed to match meaningless gestures. Moreover, other studies with brain damaged patients showed that LBD patients were impaired in motor imagery while RBD patients were impaired in visual imagery. Thus, we hypothesize that imitation of meaningless gestures might rely on motor imagery, whereas matching of meaningless gestures might be based on visual imagery. In a first experiment, using a correlational design, we demonstrated that posture imitation relies on motor imagery but not on visual imagery (Experiment 1a) and that posture matching relies on visual imagery but not on motor imagery (Experiment 1b). In a second experiment, by manipulating directly the body posture of the participants, we demonstrated that such manipulation evokes a difference only in imitation task but not in matching task. In conclusion, the present study provides direct evidence that the way we imitate or we have to compare postures depends on motor imagery or visual imagery, respectively. Our results are discussed in the light of recent findings about underlying mechanisms of meaningful and meaningless gestures.

Tool use in left brain damage and Alzheimer's disease: What about function and manipulation knowledge?

Tool use disorders are usually associated with difficulties in retrieving function and manipulation knowledge. Here, we investigate tool use (Real Tool Use, RTU), function (Functional Association, FA) and manipulation knowledge (Gesture Recognition, GR) in 17 left-brain-damaged (LBD) patients and 14 AD patients (Alzheimer disease). LBD group exhibited predicted deficit on RTU but not on FA and GR while AD patients showed deficits on GR and FA with preserved tool use skills. These findings question the role played by function and manipulation knowledge in actual tool use.

Cerebral correlates of imitation of intransitive gestures: An integrative review of neuroimaging data and brain lesion studies

&NA; The aim of the present review is to investigate the cerebral correlates, more particularly the role of the parietal lobe, when imitating intransitive gestures, a task highly sensitive to apraxic errors. By providing an integrative review of functional imaging and brain lesion studies, we focused our attention on the meaning of gestures (meaningful and meaningless) and the body parts (finger and hand). We found that imitation of intransitive gestures is relying upon a bilateral brain network including fronto‐parietal areas irrespective of meaning or body parts. Moreover, we observed that while imitation of meaningful and meaningless gestures is predominantly impacted following left parietal lesions, more brain areas are engaged during meaningless gesture imitation. Concerning body parts, whereas imitation of hand postures is relying upon the left parietal lobe (angular gyrus), imitation of finger postures is more likely to be impaired following lesions in the frontal lobe, insula and basal ganglia. These results question neuropsychological theories on apraxia and open promising avenues for a better understanding of apraxia.

L’utilisation d’outils chez l’enfant : approche épistémologique et sémiologie clinique dans le trouble développemental de la coordination

Les troubles d’utilisation d’outils constituent une plainte frequente en clinique pediatrique, notamment en cas de trouble developpemental de la coordination (TDC), et peuvent limiter la participation de l’enfant aux activites de vie quotidienne. Pourtant, l’absence de theorie explicative consensuelle dans le TDC induit des strategies d’examen peu structurees, voire affranchies de cadrage theorique, qui n’integrent pas automatiquement l’evaluation du retentissement des difficultes dans la vie quotidienne. Cet article propose d’interroger, dans une premiere partie, la nature des troubles gestuels et de coordination motrice chez l’enfant TDC ainsi que leur role eventuel dans l’utilisation d’outils. La pertinence des concepts theoriques et des evaluations cliniques mises en œuvre est egalement questionnee au regard de l’analyse des difficultes d’utilisation. La seconde partie expose les modelisations theoriques formulees dans le developpement typique et en neuropsychologie adulte, susceptibles d’eclairer la comprehension de ces symptomes chez l’enfant TDC. Enfin, les perspectives d’un examen differentiel et theoriquement guide de l’utilisation d’outils chez l’enfant sont abordees a l’issue de cette revue.