Abstract Executive function operations (Formulate a Goal, Plan, Carry out the task and Verify goal attainment) are important for supporting independence, and are often impacted early in dementia, yet are seldom considered in the design of assistive technologies for cognition for older adults with dementia. This article introduces personas, i.e., fictitious, specific, concrete representations of target users, to support the design of assistive technologies for cognition from the perspective of executive dysfunction. We first categorized the assistance most appropriate to provide, based on a quantitative secondary analysis of annotated videos of 16 older adults who received assistance during a functional assessment. The annotations of the videos classified the assistance required for task completion into categories. We then designed the personas based on this quantitative secondary analysis. A persona was designed for each of the first three executive function operations: Formulate a goal, Plan and Carry out the task. No persona was designed for Verify goal attainment because assistance was seldom provided for this operation. Stimulate the thought process and clarification of instructions were the categories of assistance most frequently identified overall. Each persona is illustrated with examples of assistance. Stimulate the thought process was the category of assistance most frequently provided for goal formulation and plan, and motivational assistance for carry out the task. We defined several design recommendations to support the design of assistive technologies for cognition for older adults on the dementia continuum, including 1) stimulate the person to reason and act by themselves first; 2) design context-aware assistive technologies; 3) consider “goal formulation” and “plan” executive operation dysfunctions; 4) personalize assistive technologies to the specific needs of each individual; 5) do not rely only on personas to take individual needs into account. Personas created from real situations can serve as a tool to better understand the assistance this population requires in order to develop assistive technologies for cognition.

In the last decade, advances in the field of ambient assisted living (AAL) have changed the way services can be provided in smart homes. New possibilities are now offered for addressing complex interaction problems between the technology and users with special needs. Within this context, this study addresses human-computer interactions for cognitive assistance to people with Traumatic Brain Injury (TBI). Interdisciplinary research combining computer science and occupational therapy was conducted to model the interaction between an AAL system (AALS) and a person with cognitive impairments due to TBI residing in an AAL environment. Cognitive assistance is modelled as an interactive exchange where an AALS spreads assistance cues that should induce appropriate behaviours from an assisted person as responses. After an assistance cue is delivered, the AALS should evaluate the user reaction and, stop the interaction if the intended reaction is observed or resume by adapting the assistance. To do so, evidence-based cognitive rehabilitation and speech acts are used to model the interaction content i.e., assistive cues and user feedback, while an ontology formalizes the semantics of this knowledge in a computer readable format. A behavioural model based on behaviour trees informed by the ontological model is then used to enable the cognitive assistant to plan the sequence of cues to be delivered adaptively depending on the circumstances, the assistance goal and the user's behaviour. To show that the proposed interaction model can help an AALS to provide adaptive assistance to people with cognitive impairments, it is exemplified on a cooking safety assistant designed for people with TBI.