Semantic memory representations are generally well maintained in aging, whereas semantic control is thought to be more affected. To explain this phenomenon, this study tested the predictions of the Compensation-Related Utilization of Neural Circuits Hypothesis (CRUNCH), focusing on task demands in aging as a possible framework. The CRUNCH effect would manifest itself in semantic tasks through a compensatory increase in neural activation in semantic control network regions but only up to a certain threshold of task demands. This study compares 39 younger (20–35 years old) with 39 older participants (60–75 years old) in a triad-based semantic judgment task performed in an fMRI scanner while manipulating task demand levels (low versus high) through semantic distance. In line with the CRUNCH predictions, differences in neurofunctional activation and behavioral performance (accuracy and response times) were expected in younger versus older participants in the low- versus high-demand conditions, which should be manifested in semantic control Regions of Interest (ROIs). Our older participants had intact behavioral performance, as proposed in the literature for semantic memory tasks (maintained accuracy and slower response times (RTs)). Age-invariant behavioral performance in the older group compared to the younger one is necessary to test the CRUNCH predictions. The older adults were also characterized by high cognitive reserve, as our neuropsychological tests showed. Our behavioral results confirmed that our task successfully manipulated task demands: error rates, RTs and perceived difficulty increased with increasing task demands in both age groups. We did not find an interaction between age group and task demand, or a statistically significant difference in activation between the low- and high-demand conditions for either RTs or accuracy. As for brain activation, we did not find the expected age group by task demand interaction, or a significant main effect of task demand. Overall, our results are compatible with neural activation in the semantic network and the semantic control network, largely in frontotemporoparietal regions. ROI analyses demonstrated significant effects (but no interactions) of task demand in the left and right inferior frontal gyrus, the left posterior middle temporal gyrus, the posterior inferior temporal gyrus and the prefrontal gyrus. Overall, our test did not confirm the CRUNCH predictions.

BACKGROUND People living with dementia experience autonomy loss, and require caregiver support on a daily basis. Dementia is characterized by progressive communication disorders; a decrease in exchanges leading to isolation in both the person living with dementia and the caregiver, who also experiences stress and increasing burden, making caregivers particularly susceptible to burnout. This has negative effects on the dyad’s members’ quality of life. OBJECTIVE This study examines the efficacy of COMPAs, an app designed on principles of person-centred and emotional communication, aimed at improving well-being in persons living with dementia and caregivers, and reducing the caregiver’s burden METHODS In this implementation study of COMPAs in the public care system, caregivers in two long-term care facilities were trained for the use of COMPAs, and strategies to improve communication with persons living with dementia. Measures were taken before and after 8 weeks of using COMPAs. Qualitative and quantitative analyses, including focus groups, semi-structured interviews and questionnaires were completed. RESULTS The use of COMPAs improved the quality of communication within the dyad as well as the quality of life, reduced caregiver burden, and increased their feeling of personal accomplishment CONCLUSIONS COMPAs contributes to the well-being of a person living with dementia and their caregivers and represents an important tool to improve person-centred communication.