Unsupervised, frequent and remote: A novel platform for personalised digital phenotyping of long-term memory in humans

Long-term memory tests are commonly used to facilitate the diagnosis of hippocampal-related neurological disorders such as Alzheimer’s disease due to their relatively high specificity and sensitivity to damage to the medial temporal lobes compared to standard commonly used clinical tests. Pathological changes in Alzheimer’s disease start years before the formal diagnosis is made, partially due to testing too late. This proof-of-concept exploratory study aimed to assess the feasibility of introducing an unsupervised digital platform for continuous testing of long-term memory over long periods outside the laboratory environment. To address this challenge, we developed a novel digital platform, hAge (‘healthy Age’), which integrates double spatial alternation, image recognition and visuospatial tasks for frequent remote unsupervised assessment of spatial and non-spatial long-term memory carried out continuously over eight week period. To demonstrate the feasibility of our approach, we tested whether we could achieve sufficient levels of adherence and whether the performance on hAge tasks is comparable to the performance observed in the analogous standard tests measured in the controlled laboratory environments.191 healthy adults (67% females, 18-81 years old) participated in the study. We report an estimated 42.4% adherence level with minimal inclusion criteria. In line with findings using standard laboratory tests, we showed that performance on the spatial alternation task negatively correlated with inter-trial periods and the performance levels on image recognition and visuospatial tasks could be controlled by varying image similarity. Importantly, we demonstrated that frequent engagement with the double spatial alternation task leads to a strong practice effect, previously identified as a potential measure of cognitive decline in MCI patients. Finally, we discuss how lifestyle and motivation confounds may present a serious challenge for cognitive assessment in real-world uncontrolled environments.


Phase
Age group  Total number of Outliers  High performers  1  younger  6  2  1  middle  1  0  1  older  3  3  2  younger  2  0  2  middle  4  1  2 older 1 1 S2  I would like to thank you for the possibility of taking part in this study. It has certainly proved an eye-opener for me when it comes to assessing my memory.

Participant No 25
I am really enjoying and find that made me less blaze and focus. Before, I had an attitude that, if was of no importance to me, I did not need to remember. All that changed, thanks to you all giving me this opportunity. I hope from now on, I can carry on helping in whatever way that I can.

Participant No 77
I have downloaded the new app and I am now using it. The revised tasks are an interesting challenge and I can already see traits in my own capability which are quit revealing even if I can't explain them scientifically! I'm happy to continue with the new app for as long as you find it helpful.

Participant No 80
Thanks for inviting me to participate -I really enjoyed it and like the idea of making a difference.
I may continue using the app for a little while

Participant No 86
It has been a pleasure to participate in the study and I am happy to continue to do so if it is of help to you regardless of reward -kind and useful though that has been.

Participant No 90
Many thanks for your email and for the compensation over the last few months. I hope my stumbling through your app has given you some useful data. I have filled in your questionnaire and attached it to this email. I have also completed the online questionnaire. It's been an interesting personal challenge and an eye opener to say the least. I now know why my 5 year old Granddaughter can beat me at memory card games!

S1 File. Motivation follow-up questionnaire
While being a participant in the hAge experiment, did you find the amount of obligations in your life (both professional and/or social) overwhelming? 6) How about the rewards? As you recall in the current version that we released the participants received £10 reward for their participation, which some chose to donate to a charity of their choice and others decline to take altogether. So different individuals get the feeling of reward and positive stimulation differently. We would like to hear from you, going forward what would be a good reward system which would keep you engaged, if the monetary reward was not available.

7)
We would also like to hear your opinion about the sense of community you got while you used this app. None of you were in any way connected which each other or knew about each other. Do you think, this option would be attractive going forward? Just to tell you an example, during the first stages of the development of our App, I asked my mum and a mum of my partner to play the App; and whenever we met as a family our mums shared their experience which gave them a lot of fun. 8) What is your opinion about self-tracking your performance? Would you trust App-based diagnostics or you would prefer the feedback to be managed by your local GP or other relevant qualified health practitioner? 9) And finally, what kind of problems you would envision with such Apps? E.g. are you concerned with the possible security issues related to your personal data? (and if so what you would like to see implemented to elevate your concerns?)