Hidden Unit Band

A hidden unit band refers to an organization of the jittered density plot of the activities of a hidden unit to a set of training patterns. The jittered density plot of a hidden value unit is often organized into a set of distinct bands, as shown in the figure below (Berkeley et al., 1995). The patterns that fall into a particular band can be identified, and then the features shared by these patterns can be discovered, permitting an interpretation of the internal structure of a network. While it was originally thought that such bands were associated with the nonmonotonic nature of the value unit's activation function, there is some evidence that they can also be found in more traditional networks of integration devices (Berkeley & Gunay, 2004).

References:

1. Berkeley, I. S. N., Dawson, M. R. W., Medler, D. A., Schopflocher, D. P., & Hornsby, L. (1995). Density plots of hidden value unit activations reveal interpretable bands. Connection Science, 7, 167-186.
2. Berkeley, I. S. N., & Gunay, C. (2004). Conducting banding analysis with trained networks of sigmoid units. Connection Science, 16(2), 119-128.

(Added March 2010)