Abstract

Background: Age-related decline in cognitive flexibility and learning contributes to poorer quality of life. Thus, it is important to develop procedures that minimize age-related cognitive decline. Previous research has shown that, when young adult rats were trained in an attention-demanding task with a distracter, they learned a new task more quickly compared with rats trained in the same attention- demanding task without a distracter.

Objective: The goal of the present experiment was to test whether this beneficial effect of distracter exposure was observed in aged rats.

Method: Male FBNF hybrid rats (n=20) trained in a two-lever visual sustained attention task that required discrimination of brief illumination of a centrally located panel light compared with trials when the light was not illuminated. At age 20 months, half of the animals received a flashing houselight distracter for the remaining testing sessions and the other animals did not. After 20 sessions, new task trials were interspersed within the sessions, when the rats received water access for pressing the lever under the left or right panel light after that light was illuminated.

Results: When 70% of the trials in a session were the new discrimination task, the distracter-exposed animals had higher accuracy in detecting the shortest signal in the remaining attention task trials compared with rats not exposed to the distracter.

Conclusion: The present results suggest that aged animals’ learning can benefit from overcoming distracter exposure, although not to the same extent as younger animals.

Keywords: Acetylcholine, attention, cognitive flexibility, learning, muscarinic, vigilance.