Dorsal cortex lesions impair habituation in turtles (Chrysemys picta)

Two experiments investigated habituation in painted turtles (Chrysemys picta). In the first, turtles were given lesions of the dorsal cortex or sham lesions and then trained on a restraint. Although the sham-lesioned turtles learned to tolerate the restraint, the lesioned animals continued to struggle against it. Thus dorsal cortex lesions disrupted habituation to restraint. In order to test habituation to a looming stimulus in a second experiment, all animals were habituated to the restraint before surgery. Postoperatively they continued to be habituated to the restraint. The looming stimulus was a circular shadow that enlarged suddenly on a screen in front of the turtle. It was presented 5 times per day for 15 days. Between-day or long-term habituation was impaired by dorsal cortex lesions.