Jonathan Phillips, Adam Morris, and Fiery Cushman, ‘How We Know What Not To Think’, Trends in Cognitive Sciences, 23 (2019), 1026-40: https://doi.org/10.1016/j.tics.2019.09.007
This is another post picking up on an article where the question is not so much ‘why?’ as ‘why not?’. I’ve been swept along with wondering why we aren’t flooded with involuntary memories, and now I am enjoying asking in the negative why we don’t make certain choices, rather than we do make other ones. There is a pattern here: the brain is not a simple input-output machine, and one way that modern science can engage with its complexity, when so many things could happen, is to work out why most of them don’t.
Phillips et al. are interested in the human capacity to plan and communicate countless unrealized things. They wonder how possible and appropriate actions are selected from such a plethora. The bare bones of the conclusion aren’t that arresting — it’s about what is probable and what is valuable — but the finesse is neat: ‘we suggest that the shared sampling mechanism essential for modal cognition — one biased towards valuable and probable actions — was principally designed for decision making. In short, our most basic sense of which actions are possible reflects a first draft of what we would choose.’
They make a nice turn towards language, by recognising that in English a great deal of hard work is done by modal auxiliary verbs: ‘must’, ‘can’, ‘may’, ‘ought’, etc. These are aimed at ‘non-actual possibilities’, and they do a lot to explore the area of the probable and the valuable as noted above. They deal with necessity, possibility, things that should be, things that could be, and so on. So Phillips et al. take modal verbs as an analogy for the way the mind works, again with a finesse: ‘a core component of ordinary modal cognition may not be possible worlds, but practical worlds – those involving actions that are typically worth considering’. It’s important to note that lots of languages do their modal work in very different ways, though (as far as I know, which isn’t that far) they all do it in some way.
Natalie Biderman, Akram Bakkour, and Daphna Shohamy, ‘What Are Memories For? The Hippocampus Bridges Past Experience with Future Decisions’, Trends in Cognitive Sciences, 24 (2020), 542-56: https://doi.org/10.1016/j.tics.2020.12.002
This paper is based on experimental findings suggesting a significant role, indeed a ‘pervasive role’, for the hippocampus, a brain region associated with long-term memory, in decision-making. They go further: this ‘challenges the way we define what memory is and what it does, suggesting that memory’s primary purpose may be to guide future behaviour and that storing a record of the past is just one way to do so’. They suggest that some familiar failures of memory are only such if we think of remembering as retaining a record of the past. If we think of it as future-oriented, aimed at improving responses and choices, then its characteristics make more sense. This fits with the more dynamic models of memory that I’ve come across and written about, where in other ways it’s not just a matter of a stored record. Decisions: they are very interesting. Even though the brain isn’t a simple input-output machine, it still really has to come up with output — action — one way or another.