Physiological and behavioral significance of hippocampal rhythmic, slow activity (“theta rhythm”) Academic Article uri icon


  • This review identifies some of the conflicts among currently popular theories on the significance of hippocampal rhythmic, slow activity (RSA). The review develops the rationale for a dualistic hypothesis in which RSA per se is regarded as having a different meaning from its frequency shifts. The hypothesis holds that RSA is part of an over-all adaptive "readiness response" to biologically significant stimuli that trigger responses in the brainstem reticular formation (BSRF). Specific frequency content of RSA, including shifts to low-voltage desynchrony, reflects the input and output processing reactions performed by the hippocampus as it participates in the brain's response to stimulation. Specifically, RSA frequency shifts reflect the underlying chemical and electrical phenomena that are at least partially involved in regulating the different behaviors with which RSA has been correlated. Previous research has been largely devoted to correlating RSA with various functions and behavior. Correlative data alone cannot indicate whether RSA is a necessary or sufficient condition for occurrence of its correlated behavior. A basic merit of the dualistic hypothesis is that it fosters thinking and research strategies along heretofore unexploited directions, which could create the necessary data base for a more precise concept of RSA significance. This analysis includes suggestions of a general approach for testing the validity of the dualistic hypothesis. © 1976.

author list (cited authors)

  • Klemm, W. R.

citation count

  • 65

publication date

  • January 1976