Tool use disorders in neurodegenerative diseases: Roles of semantic memory and technical reasoning

Abstract

In the field of apraxia, it has been suggested that the ability to use tools and objects in daily life depends not only on semantic knowledge about tool function and context of use but also on technical reasoning about mechanical properties of tools and objects. The aim of the present work was to assess tool use abilities regarding these hypotheses in patients with neurodegenerative diseases and reduced autonomy. Performance of patients with Alzheimer's disease (AD) (n = 31), semantic dementia (SD) (n = 16) and corticobasal syndrome (CBS) (n = 7) was compared to that of healthy control participants (n = 31) in familiar tool use tasks, functional/contextual associations and mechanical problem solving (MPS). A conversion method was applied to data in order to avoid ceiling effects. Tool use disorders were found in all patient groups but the underlying reasons were different. Patients with SD had difficulties in imagining and selecting familiar tools due to the semantic loss but they performed in normal range in MPS tasks. Interestingly, they performed better with only one tool and its corresponding object, which is interpreted as a partial compensation of semantic loss by spared technical reasoning. Patients with CBS exhibited the reverse pattern, that is, MPS deficits without semantic loss. However, additional qualitative research is needed to disentangle the relative contributions of motor and technical reasoning deficits to this pattern. Both of these profiles were found in patients with AD. For all that, these patients did not commit the same errors as stroke patients with left brain-damage documented in previous works. Several hypotheses are proposed to account for the specificity of tool use disorders in neurodegenerative diseases, and recommendations are provided to caregivers.

Tool use in neurodegenerative diseases: Planning or technical reasoning?

“…However, the nature of the disorder is certainly aetiology‐specific (Table ). In semantic dementia, our results are in line with previous works which demonstrated that the semantic loss prevents patients from selecting familiar tools but not from using them thanks to compensations based on analysis of mechanical properties of tools and objects (Baumard et al ., ). Additionally, the present study suggests that in Alzheimer's disease, impairment in both familiar tool use and mechanical problem‐solving tasks is probably due to general problem‐solving deficit and/or space–time perception rather than specific technical reasoning deficit.…”

“…Therefore, neither the planning nor the technical reasoning hypotheses appear satisfying. Interestingly, patients had to select tools in the Real Tool Use task, and previous findings suggested that tool selection deficits are linked to the loss of knowledge in this disease (Baumard et al ., ). Our results are consistent with previous works which found that despite severe loss of knowledge about tool function, patients with semantic dementia can infer function from structure and suggest potential technical actions to be performed with tools for which they have lost knowledge (Hodges et al ., ).…”

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

“…The concept of mechanical knowledge refers to the capacity to infer possible uses of both familiar and novel tools from analysis of their structural properties (Buxbaum, ; Daprati & Sirigu, ; Goldenberg & Hagmann, ; Hartmann, Goldenberg, Daumüller, & Hermsdörfer, ; Heilman, Maher, Greenwald, & Rothi, ; Hodges, Bozeat, Lambon Ralph, Patterson, & Spatt, ; Osiurak, ; Osiurak & Badets, ; Osiurak, Jarry, & Le Gall, , ; Osiurak & Lesourd, ; Osiurak et al ., ). An association between impaired tool use and decreased mechanical knowledge has been observed in left brain‐damaged (LBD) patients and in patients with neurodegenerative disorders (Baumard et al ., ; Goldenberg & Hagmann, ; Jarry et al ., ; Lesourd et al ., ).…”

“…Mechanical knowledge is commonly investigated by asking subjects to solve mechanical problems (Bartolo, Daumüller, Della Sala, & Goldenberg, ; Baumard et al ., ; Goldenberg & Hagmann, ; Jarry et al ., ; Ochipa, Rothi, & Heilman, ). For example, in the choice condition of the mechanical problem‐solving task (e.g., Lesourd, Baumard, Jarry, Le Gall, ), participants are asked to choose the most appropriate of several tools to extract a target that is stuck inside a box.…”

Assistive Technologies to Address Capabilities of People with Dementia: From Research to Practice

“…The perceived ability to use everyday technology may actually predict overall functional level in people with mild cognitive impairment or mild AD (Ryd, Nygård, Malinowsky, Öhman and Kottorp, 2016). More generally, tool use disorders in neurodegenerative diseases involve impairments in semantic memory and technical reasoning, besides motor capacity (Baumard et al, 2016).…”