Within-trial dynamics of radial arm maze performance in rats

The behavior of rats while solving a 12-arm radial maze was investigated using measures of response bias, choice latencies, and behavioral organization. Response bias decreased as a function of choice number, while the amount of time spent on the center platform between choices increased substantially during the last few choices. This increase in time between choices was largely accounted for by increases in investigatory behavior in the area of the doors leading to the arms. These data indicate that the processes involved in radial maze performance change over the course of each trial. As the choice sequence progresses, there is an increasing reliance on the use of information in memory, and a corresponding decrease in the use of response algorithms. In addition, the mean time taken to run down the chosen arm was shorter for correct choices than for incorrect choices, suggesting that arms are sometimes chosen despite a lowered expectation of finding food.