Of fMRI and Similar Tools for Observing and Inferring the Activities of the Brain and the Mind
Suppose that the levels (Level 1, etc.) shown in Figure 1 below are levels of the physical or material structure of the human brain.
Suppose that the small italicized letters below (f, g, etc.) represent events at a particular physical level of the brain; e.g., f may represent an electrical signal at a synapse.
Suppose that events of type f are observed at Level 1 and observations done to date shows that the pattern of f events at Level 1 occurs (or: has occurred, has been observed to occur) when deception occurs (or: has occurred, has been observed to occur, has been thought to occur).
What can one infer from those observations?
Suppose further that events at Level 1 in Figure 1 are determined by events at Level 2.
Does it matter for inferences about deception that events at Level 2 have not been observed in relationship to instances of deception?
Possibly.
It is logically possible that more that one pattern of events at Level 2 can produce the pattern of events at Level 1 but that only one pattern of events at Level 2 is related to observed instances of deception.
But the same relationship may hold between (i) events at any level and events at a lower level and (ii) events at any lower level and instances of deception. Thus, while only some patterns of events at Level 2 are associated with deception, the probative force of those patterns can in their turn fall victim to the (possible) fact that only one pattern of events at Level 3 is associated with instances of deception. These relationships may be repeated down to the "bottom," which in the above table are quantum processes and events. If so, invariant connections between events and instances of deception cannot be established unless and until observations of quantum level events have been observed.
But it is possible -- is it possible? -- that the structure of the workings of the brain is more complicated (and, perhaps, also less bottom-up driven than is the case with Figure 1). It is possible -- is it possible? -- there are interactions between different Levels of the brain, interactions that affect the pattern of events at each Level of the brain. For example:
And then, of course, it is possible (is it possible?) there are interactions among different parts of the brain (which I will assume, for the sake of convenience, have four levels [though it is practically certain that each part of the brain has more than four levels of "existence"]):The interaction hypothesized in Figure 2 assumes that the processes at each level are not "deterministic" within each level. However, the logic of Figure 2 does not preclude the possibility that all the processes in Figure 1, taken together, are "deterministic" (even if only probabilistically so).
If the sort of interaction shown in Figure 3 happens, inferences drawn from any pattern of events at Level 1 of Figure 1 cannot be drawn with certainty or, probably, even with near-certainty. (However, it does not necessarily follow that we learn nothing from observing events at Level 1 in Figure 1. Whether that's the case or not depends -- on many things.)
Coming soon: the law of evidence on Spindle Law
1 comment:
A reader and I had the following exchnage:
if you say that (1) events f at level 1 are associated with deception and that (2) more than one pattern of events at level 2 can produce events f doesn't it necessarily derive that all these latter patterns must be associated with deception?
Why the observation of an association between deception and an event at a lower level should be more reliable?
I think I'm missing some point.
I replied:
Reason why inference from events at level 1 may be wrong: the observation of events at level 1 was not observation of all events at level 1; events at level 1 are just a sample. Extrapolation from sample of events at level 1 may be wrong because, by happenstance, observed events at level 1 may be (A) accompanied by events at level 2 that are known to be associated with deception but (A) not accompanied by events at level 2 known (or believed) to be not associated with deception (but such level 2 events, it is known or believed, still generate the false positives at level 1).
The question about greater reliability of lower level events -- their greater probative or inferential force -- is interesting.
The reason for more reliability is only this: my assumption (in the argument) that physical processes at lower levels determine events at higher levels.
The first part of my argument (the one tied to Figure 1) does not take into consideration what happens if none of the events in the brain at any level are causally connected with mental phenomena such as deception.
My argument does assume that events at the level that has real causal force are more probative, have more inferential force.
However, Figures 2 & 3 are meant to suggest the possibility that causality may in fact reside in various levels of material existence or in the relationships among those levels. Of course, physicists and other such scientists might wonder how this is possible -- how, for example, it could be that anything "external" could affect the outcomes of quantum processes.
...
Deep mysteries.
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