Forward and Backward Inference in Spatial Cognition
Figure 9
Route planning can be implemented using Forward inference, in which sensory goals are instantiated in LEC (or projections to it), and the recurrent circuitry produces state estimates from path integration , and Bayesian estimation
, that are consistent with those goals. Backward inference takes as input the result of the forward sweep. It produces improved estimates of the hidden states, given by the recursion
, and estimates of control signals given by
. We propose that the prediction error
is computed in MEC and propagated to CA3-CA1 for computation of
and to prefrontal regions for computation of
. See equation 34 for more details.