The characteristics of ascending visual projections will become tests of forward projections (i.e. those conveying prediction errors) and the characteristics of descending visual projections will constitute tests of backward projections (i.e. those conveying predictions).
This view holds that connections mediating predictions should be more modulatory than those conveying prediction errors, and they should have a similar laminar organisation, irrespective of the sensory modality being predicted.
This process mirrors perceptual inference in sensory cortex, where descending connections convey predictions, while ascending connections convey prediction errors.
Conversely, all projections of 'descending' direction will have 'backward' characteristics, because their function is to convey predictions.
These findings fit comfortably with predictive coding models [ 3], which predict that top-down corticocortical connections convey prediction signals at slower time scales (e.g. beta) compared to bottom-up connections that convey prediction error signals at faster time scales (e.g. gamma).
This supports our contention that somatomotor system may implement active inference, in which backward connections provide predictions and forward connections convey prediction errors.
If the theory behind active inference is broadly correct, then all projections of 'ascending' direction will have 'forward' characteristics, because their function is to convey prediction errors.
Based on Bayesian and Helmholtzian principles it has been proposed that forward connections convey prediction-errors that optimize representations in higher levels.
In predictive coding, backward projections from one hierarchical level to its subordinate level furnish predictions of the lower level's representations, while reciprocal forward projections convey prediction errors that report the difference between the representation and the prediction (Mumford 1994).
Our study suggests that CRP levels convey prediction information on the risk of CVD that is complementary to that provided by conventional cardiovascular risk factors and that improvement in the predictions is likely similar in people with diabetes and those without but is not affected by sex.
