Retrograde amnesia: Would patients accept to go to a new home home if they were falsely told it was their home? Or accept affection from people to whom they were introduced as close relatives but were actors?

Cubelli R, Beschin N, Della Sala S, Retrograde amnesia: A Selective Deficit Of Explicit Autobiographical Memory. CORTEX, https://doi.org/10.1016/j.cortex.2020.10.003

Rolf Degen's take: https://twitter.com/DegenRolf/status/1319526944925487104

In patients with retrograde amnesia (RA), declarative memory is severely impaired for events that occurred prior to onset of the disorder. Implicit memory might be preserved (Kopelman, 2002), but it is usually tested with priming or procedural learning tasks (Kopelman and Kapur, 2001) that reveal sparing of memory for anterograde events. That is, these tasks assess memory for episodes which happened after the onset of RA. As such, they are appropriate to investigate implicit memory in anterograde amnesia (Schacter, 2019), not in RA.

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LZ acknowledged his lack of empathy towards his wife and his lack of paternal feelings towards his children, aged 15, 13 and 9. Yet he eagerly accepted that they were his family and behaved accordingly. This is a common trait of several RA patients. Researchers and clinicians accept this as a fact. Yet, to other observers this is astounding. Would RA patients eagerly accept to go home, if shown a completely different house, and were falsely told it was their home? Would they accept affection from people to whom they were introduced as close relatives but who were played by actors? Obviously, these thought experiments would be highly unethical...

RA does not entail loss of previously acquired skills, including syntax, and semantic knowledge, including lexicons, nor it is characterized by overt change in habits or emotions. True RA cases should present not only with preserved procedural memory but also with spared access to the entire gamut of implicit memories, quite independently of their verbal reporting. RA patients should not face overt feelings of estrangement when returning home or when mingling with relatives and friends. Therefore, the lack of access to the vast array of implicit memories, procedural, semantic or behavioural, would suggest malingering (e.g., Kurth, 1983; Zago et al. 2004).

In non-scientific parlance, RA is often depicted as sparing procedural memories (Della Sala and Brazzelli, 1998; Baxendale S. BMJ. 2004 Dec 18; 329(7480): 1480–1483). Rarely though other aspects of implicit memory, as above defined, are contemplated. A telling exception is portrayed in Figure 2 taken from a comic crime story of a RA patient who does not recognize his fiancée, yet feels for her and finds solace in her company (see Fig.2).