Apraxia: a gestural or a cognitive disorder?

François Osiurak1,2 and Didier Le Gall31 Laboratoire d’Etude des Mécanismes Cognitifs (EA 3082), Université de Lyon, France2 Institut Universitaire de France, Paris, France3 Laboratoire de Psychologie des Pays de la Loire (EA 4638), Université d’Angers, FranceCorrespondence to: François Osiurak, Laboratoire d’Etude des Mécanismes Cognitifs (EA 3082), Institut de Psychologie, 5, avenue Pierre Mendès-France, 69676 Bron Cedex, France E-mail: Francois.Osiurak{at}univ-lyon2.frSir,We read with great interest the article by Buxbaum et al. (2014) about the critical brain regions for tool-related and imitative actions. The authors performed voxel-based lesion–symptom mapping with data from 71 left brain-damaged patients. Three types of actions were examined: (i) pantomime to sight of tools (GestTool); (ii) pantomime on imitation (ImTool); and (iii) imitation of meaningless gestures (ImNov). Impairments in all three of the gesture tasks were associated with lesions in left middle and inferior temporal and inferior parietal regions. Moreover, tool-related actions (both GestTool and ImTool) were dependent on left middle and inferior temporal lobe, whereas imitation of meaningless gestures (ImNov) was dependent on left inferior parietal regions. From these findings, the authors drew two conclusions. First, the left inferior parietal lobe might be the basis for the kinematic component of the praxis system, useful for planning movement trajectories in terms of extent, direction and timing. Second, middle and inferior temporal regions might support representational components of the praxis system (e.g. the arm and hand posture associated with the use of a hammer). Note that these conclusions lead to a profound revision of Buxbaum’s initial (2001) model. In this model, the left inferior parietal lobe was viewed

Apraxia of tool use: more evidence for the technical reasoning hypothesis

Various distinct cognitive processes such as semantic memory, executive planning or technical reasoning have been shown to support tool use. The aim of this study is to investigate the relationship between these processes. To do so, a large apraxia battery was submitted to 16 patients with left brain-damage (LBD) and aphasia and 19 healthy controls. The battery included: classical apraxia tests (Pantomime of Tool Use and Single Tool Use), familiar and novel tool use tests (Tool-Object Pairs and Sequential Mechanical Problem-Solving), semantic memory tests (Recognition of tool utilization gestures and Functional and Categorical Associations) as well as the Tower Of London. The Sequential Mechanical Problem-Solving task is a new task which permits the evaluation of pre-planning in unusual tool use situations. In this task as well as in the Tool-Object Pairs task, participants solved a tool use problem in a Choice and a No-Choice condition to examine the effect of tool selection. Globally, left brain damaged patients were impaired as compared to controls. We found high correlations in left brain damaged patients between performances on classical apraxia tests, familiar and novel tool use tests and Functional and Categorical Associations but no significant association between these performances and Tower Of London or Recognition of tool utilization gestures. Furthermore, the two conditions (Choice and No-Choice) of Tool-Object Pairs and Sequential Mechanical Problem-Solving were associated. In sum, all tasks involving tool use are strongly associated in LBD patients. Moreover, the ability to solve sequential mechanical problems does not depend on executive planning. Also, tool use appears to be associated with knowledge about object function but not with knowledge about tool manipulation. Taken together, these findings indicate that technical reasoning and, to a lesser extent, semantic memory may both play an important role in tool use

Les apraxies : synthèse et nouvelles perspectives

L’étude de l’apraxie a été, et est toujours, sujette à un débat intense, notamment en ce qui concerne l’autonomie du trouble par rapport aux déficits sensorimoteurs élémentaires et aux déficits cognitifs de plus haut niveau. Ces controverses conduisent généralement les cliniciens à s’interroger sur la bonne façon d’évaluer et d’interpréter les phénomènes apraxiques. Dans cet article, nous proposons une lecture des troubles qui s’inspire des développements les plus récents effectués dans le domaine. Après quelques rappels historiques utiles à la compréhension des modèles cognitivistes qui ont émergé au début des années quatre-vingt, nous discuterons l’apport d’études conduites ces quinze dernières années. Les résultats de ces travaux nous invitent à réexaminer les interprétations issues des modèles cognitifs. Par souci de clarté, nous traiterons uniquement des phénomènes apraxiques évalués lors de situations d’imitation de postures non significatives, d’utilisation effective d’outils et de production de pantomimes. Nous espérons que la discussion présentée dans cet article sera utile aux cliniciens mais aussi aux étudiants en neuropsychologie

De l’instrument à l’outil. Réflexions sur les concepts d’improvisation et de pérennité

I- Introduction II- De l\u27instrument à l\u27Outil III- Utilisation d\u27objets et usage : une étude de cas IV- Utilisation non-usuelle d\u27objets et atechnie V- Techniques d\u27improvisation VI- L\u27Outil produit l\u27Ouvrage, la Personne conserve l\u27Usage VII- Pénomènes de fusion et acte d\u27improvisation VIII- Empirie et magie, des visées techniques IX- Conclusio

Re-examining the gesture engram hypothesis. New perspectives on apraxia of tool use

In everyday life, we are led to reuse the same tools (e.g., fork, hammer, coffee-maker), raising the question as to whether we have to systematically recreate the idea of the manipulation which is associated with these tools. The gesture engram hypothesis offers a straightforward answer to this issue, by suggesting that activation of gesture engrams provides a processing advantage, avoiding portions of the process from being reconstructed de novo with each experience. At first glance, the gesture engram hypothesis appears very plausible. But, behind this beguiling simplicity lies a set of unresolved difficulties: (1) What is the evidence in favour of the idea that the mere observation of a tool is sufficient to activate the corresponding gesture engram? (2) If tool use can be supported by a direct route between a structural description system and gesture engrams, what is the role of knowledge about tool function? (3) And, more importantly, what does it mean to store knowledge about how to manipulate tools? We begin by outlining some of the main formulations of the gesture engram hypothesis. Then, we address each of these issues in more detail. To anticipate our discussion, the gesture engram hypothesis appears to be clearly unsatisfactory, notably because of its incapacity to offer convincing answers to these different issues. We conclude by arguing that neuropsychology may greatly benefit from adopting the hypothesis that the idea of how to manipulate a tool is recreated de novo with each experience, thus opening interesting perspectives for future research on apraxia

Apraxia and Alzheimer’s Disease: Review and Perspectives

Apraxia is one of the cognitive deficits that characterizes Alzheimer\u27s disease. Despite its prevalence and relevance to diagnosing Alzheimer\u27s 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

Different constraints on grip selection in brain-damaged patients: Object use versus object transport

The present study discusses the presence of different constraints on action selection during object use versus object transport. Sixteen left brain-damaged (LBD) patients, 10 right brain-damaged (RBD) and 35 healthy controls were examined on a grip preference test consisting of a grasping-to-transport and a grasping-to-use condition. Assessment included a general praxis testing (pantomime production, object utilization gesture recognition and object use). We also reported the case of a close-head injury patient (DR) with an atypical behavioural pattern. Our results supported the different constraint hypothesis. While several LBD and RBD patients performed inappropriate grips in the grasping-to-transport condition, only two patients (L2 and DR) used inappropriate grips in the grasping-to-use condition. No correlation was found between the two conditions of the grip preference test and measures of the general praxis testing. The discussion focuses on the nature of constraints on grip selection during object use and object transport

Vous avez dit Homo Faber ?

Dans cet article, nous nous intéressons à la question des équivalences, similarités et irréductibilités entre l’homme et l’animal non-humain du point de vue de l’activité outillée. Pour cela, nous proposons une revue de littérature pluridisciplinaire sur la sensorimotricité, le raisonnement causal ou encore l’usage des objets. Cette revue est également l’occasion d’un échange critique entre ces apports théoriques et la Théorie de la médiation

Gestural apraxia

Gestural apraxia was first described in 1905 by Hugo Karl Liepmann. While his description is still used, the actual terms are often confusing. The cognitive approach using models proposes thinking of the condition in terms of production and conceptual knowledge. The underlying cognitive processes are still being debated, as are also the optimal ways to assess them. Several neuroimaging studies have revealed the involvement of a left-lateralized frontoparietal network, with preferential activation of the superior parietal lobe, intraparietal sulcus and inferior parietal cortex. The presence of apraxia after a stroke is prevalent, and the incidence is sufficient to propose rehabilitation

The conditions of respect of rules in young and elderly drivers: an exploratory study

This study is concerned with the theoretical field of social representations and conditionality of norms. The aim is to study the perception of driving norms by structuring them around individual and group behaviours. We propose to evaluate driving conditionality with the questionnaire based on conditional scenarios. The tool has been proposed to 40 young drivers and 48 elderly drivers. Results show that the driving representation is conditional for the 2 groups, except with the scenario of wearing seat belt. The more conditional scenarios are the same for the 2 groups (scenarios of speed limit and amber light), with higher scores of conditionality for young drivers. The representation of the driving shows that with the system of legal norms (Highway Code), there is a system of social norms related to the actual practices of the users. This study illustrates an important aspect of road safety: the social perception of rules and its impact on driver behaviour