Orbitofrontal cortex, associative learning, and expectancies

Abstract

Orbitofrontal cortex is characterized by its unique pattern of connections with subcortical areas, such as basolateral amygdala. Here we distinguish between the critical role of these areas in associative learning and the pivotal contribution of OFC to the manipulation of this information to control behavior. This contribution reflects the ability of OFC to signal the desirability of expected outcomes, which requires the integration of associative information with information concerning internal states and goals in representational memory.

Figures

Figure 1. Neural Correlates of Outcome Expectancies in OFC

Single-unit activity is shown in raster format and perievent time histogram, synchronized to odor onset (100 ms bins; dotted line is 99% CI; top panels, Odor 1+; bottom panels, Odor 2−; odor sampling, gray shading). After odor sampling, the rat had to respond at the fluid well. On odor 1 and 2 trials, the response produced sucrose and quinine, respectively. A delay (pre-sucrose, green; pre-quinine, red) interposed between a response at the well and fluid delivery serves to isolate neural activity signaling the expected outcome.

Figure 2. OFC-ABL Interactions in Establishing Neural Representations

ABL lesions have no effect on outcome-expectant activity in OFC but abolish the activation of these cells during cue sampling. By contrast, OFC lesions disrupt outcome-expectant activity in ABL. C, cue; D, delay before outcome; O, outcome.