One extraordinary thing snagged my attention. Calder recalls a series of macabre experiments in Paris after the war in which the severed heads of condemned criminals, following execution by guillotine, responded to questions by flickering their eyelids. This could go on for several seconds. Calder claims that Beckett was deeply impressed by the thought and that this may have led to (for instance) the stage presence of the isolated mouth of Not I and the three babbling heads in pots in Play.
What an idea!
It seemed a peculiarly modern setting for what one imagines was an 18th century line of enquiry. Think of Mary Shelley's Frankenstein (and I'm sure you already know the reason that the Creature had to be assembled from miscellaneous cadavers was to avoid any charge of blasphemy by suggesting the revival of a single dead body, which would technically have been a resurrection, which could only be attributed to that episode with Christ and Lazarus, 'the one occasion,' according to Beckett's character Murphy, 'on which the Messiah had overstepped the mark'.)
I looked up the subject of communicating with recently-severed heads, using the internet they have these days. Needless to say I found no end of horrible stuff. But I also found this absorbing and scholarly piece by Mike Dash on his excellent blog A Blast from the Past which I'd like to share with you (A few 18th century paintings aside, there's no graphic content, but some haunting accounts of (mostly) French investigations into a weirdly compelling aspect of consciousness).