Fig. 3. Effects of abdominal surgery on food reinforcement under restricted-access conditions. The mean (SEM) food pellets earned are shown when food was available only for 11 h/day (see Materials and Methods for access conditions). The mean (SEM) food pellets earned in the immediate postoperative period ( upper ) or at later time points ( lower ) are shown after sham surgery ( open bars and circles ) or abdominal surgery with gut manipulation ( dark bars and circles ). * Significantly different from sham surgery ( P < 0.05). # Significantly different from baseline ( P < 0.05).