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.     

Age differences in maximization

Studies have shown the existence of inter-individual differences in choice behavior, some people seeking for the best (maximizers) and others for a good enough option (satisficers). Here, we explored whether these inter-individual differences are influenced by aging and common personality traits (i.e., Big Five model). Young (n = 125; 19 years old) and elderly adults (n = 101; 86 years old) completed different scales assessing – among others – maximization and Big Five traits. Our results indicated a greater proportion of maximizers in elderly than in young adults. We also found a minor association between maximization and Big Five traits in both groups. In sum, aging influences choice behavior, but this cannot be explained by changes of common personality traits.     

Visual memory and visual perception: when memory improves visual search

This study examined the relationship between memory and perception in order to identify the influence of a memory dimension in perceptual processing. Our aim was to determine whether the variation of typical size between items (i.e., the size in real life) affects visual search. In two experiments, the congruency between typical size difference and perceptual size difference was manipulated in a visual search task. We observed that congruency between the typical and perceptual size differences decreased reaction times in the visual search (Exp. 1), and noncongruency between these two differences increased reaction times in the visual search (Exp. 2). We argue that these results highlight that memory and perception share some resources and reveal the intervention of typical size difference on the computation of the perceptual size difference.     

Mechanical knowledge does matter to tool use even when assessed with a non-production task: Evidence from left brain-damaged patients

In the literature on apraxia of tool use, it is now accepted that using familiar tools requires semantic and mechanical knowledge. However, mechanical knowledge is nearly always assessed with production tasks, so one may assume that mechanical knowledge and familiar tool use are associated only because of their common motor mechanisms. This notion may be challenged by demonstrating that familiar tool use depends on an alternative tool selection task assessing mechanical knowledge, where alternative uses of tools are assumed according to their physical properties but where actual use of tools is not needed. We tested 21 left brain-damaged patients and 21 matched controls with familiar tool use tasks (pantomime and single tool use), semantic tasks and an alternative tool selection task. The alternative tool selection task accounted for a large amount of variance in the single tool use task and was the best predictor among all the semantic tasks. Concerning the pantomime of tool use task, group and individual results suggested that the integrity of the semantic system and preserved mechanical knowledge are neither necessary nor sufficient to produce pantomimes. These results corroborate the idea that mechanical knowledge is essential when we use tools, even when tasks assessing mechanical knowledge do not require the production of any motor action. Our results also confirm the value of pantomime of tool use, which can be considered as a complex activity involving several cognitive abilities (e.g., communicative skills) rather than the activation of gesture engrams.     

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.     

A cognitive-based model of tool use in normal aging

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.     

Tool use in neurodegenerative diseases: Planning or technical reasoning?

Recent works showed that tool use can be impaired in stroke patients because of either planning or technical reasoning deficits, but these two hypotheses have not yet been compared in the field of neurodegenerative diseases. The aim of this study was to address the relationships between real tool use, mechanical problem‐solving, and planning skills in patients with Alzheimer's disease (AD, n = 32), semantic dementia (SD, n = 16), and corticobasal syndrome (CBS, n = 9). Patients were asked to select and use ten common tools, to solve three mechanical problems, and to complete the Tower of London test. Motor function and episodic memory were controlled using the Purdue Pegboard Test and the BEC96 questionnaire, respectively. A data‐transformation method was applied to avoid ceiling effects, and single‐case analysis was performed based on raw scores and completion time. All groups demonstrated either impaired or slowed tool use. Planning deficits were found only in the AD group. Mechanical problem‐solving deficits were observed only in the AD and CBS groups. Performance in the Tower of London test was the best predictor of tool use skills in the AD group, suggesting these patients had general rather than mechanical problem‐solving deficits. Episodic memory seemed to play little role in performance. Motor dysfunction tended to be associated with tool use skills in CBS patients, while tool use disorders are interpreted as a consequence of the semantic loss in SD in line with previous works. These findings may encourage caregivers to set up disease‐centred interventions.     

To Watch is to Work: a Review of NeuroImaging Data on Tool Use Observation Network

Neuropsychology Review - Since the discovery of mirror neurons in the 1990s, many neuroimaging studies have tackled the issue of action observation with the aim of unravelling a putative homolog...