The Brain–Cognitive Behavior Problem: A Retrospective

Time line of hypothesized behavioral correlates of hippocampal θ oscillations. Most correlates can be lumped as “sensory-attention” (input function) or motor output function. Endre Grastyán’s (left) “orienting response” hypothesis was the first, which was derived from observations in behaving animals (cat). The most influential hypothesis in the rat has remained the “voluntary movement” correlate by Cornelius (Case) H. Vanderwolf (right). Note the large variety of the hypotheses and their culmination in the1970s. The behavior (independent variable)–brain mechanism (dependent correlate) approach failed to produce a consensus on the behavioral significance of θ oscillations. Nota bene: This figure was subsequently published in Hippocampus [Buzsáki G (2005) Theta rhythm of navigation: link between path integration and landmark navigation, episodic and semantic memory. Hippocampus 15:827–840].