The implications of this distinction between implicit and explicit memory for AD care have been developed by the neurophysiologist, Soledad Ballesteros. In a recent experiment, Ballesteros demonstrated how HM’s symptoms are also experienced by those living with AD. Ballesteros asked three groups; one made up of undergraduate students, the second of healthy older adults and the final constituted by those with mild-moderate AD, to identify a collection of familiar objects in a sealed box using only the sense of touch
Crucially, the ability to accurately identify the objects varied little across the groups, suggesting that the tactile memory or implicit memory of those with AD remained largely intact, acting as a trigger or ‘priming’ mechanism, enabling them to recall the object’s name and/or function. However, when half of the objects in the box were swapped with a new set of familiar objects and participants were instead asked to identify the old and new objects, those with AD scored significantly lower than the two control groups, highlighting the impairment of their declarative or explicit memory.158 The case study of HM and Ballesteros’s experiment indicate the importance of touch in enabling motor function (playing the piano) and in priming memory recall (recognising an object and its function) with important consequences for future AD design. For example, Sarah Waller CBE argues that taps in contemporary ECH schemes should function in a familiar or intuitive manner in order to align with undamaged motor function, rather than simply perform as needlessly esoteric features of care home bathrooms and kitchens.
With regard to the potential for touch to prime memory recall, ‘tactile walls’ — sections of wall with a variety of tactile vignettes — are increasingly popular in care homes. Although they may enable memory recall to a certain extent, they are often lacking in spatial and temporal links, limiting their usefulness. A more sophisticated and subtle example can be found at the Ditchburn Care Home, in Cambridge, where carers use cutlery as a haptic primer, to both remind residents of a meal time and to indicate a room’s function. Bringing these findings on the use of haptic or implicit memory to bear on the public realm, I suggest the implementation of grab hoops at pedestrian crossings, the site at which, according to Mitchel and Burton, those with AD are most likely to lose their way. Such grab hoops, a unique urban feature found in Stuttgart, Germany, would be adapted to not only provide physical support at points of changing surface (see chapter above) but also to reinforce the purpose of the route through the introduction of a cast haptic texture onto the handles’ surface.
In this way, the proposal also takes inspiration from the Kofuen and Day Service Centre for Dementia in Kawasaki, Japan, which integrates physical and cognitive supports through the use of a seamless three-story circular open-air ramp in the central courtyard of the centre with a supportive grab rail, which provides safe opportunities for the cognitive need to ‘wander’ felt by many people living with AD.