Do neurons process information by relative intervals in spike trains?

We suggest the possibility that neurons process information in terms of the relative duration of clusters of adjacent and successive inter-action potential intervals ("bytes" of intervals). If this concept is plausible, as is supported by research from several laboratories which have specifically addressed this possibility, one should be able to see evidence for such patterning in the published illustrations from studies in which this concept was not considered. We present some of this evidence here, along with some illustrations from the original publications. Byte patterns are evident in these examples, even though they went unrecognized by authors and readers alike. It is true that interval patterns are not obvious in all published illustrations of spike trains, and we suggest that this can be explained by one or more of the following: (1) some neurons may operate with an interval-pattern code while others do not, (2) a given neuron may use an interval-pattern code only under certain conditions, and (3) even when such a code exists, it may be difficult to detect for identifiable technical reasons. Therefore, we believe that the relative-internal-pattern concept is a valid scientific hypothesis which merits specific testing of its validity and range of applicability.