The effects of lesions of nucleus rotundus on visual intensity difference thresholds in turtles (Chrysemys picta).
Intensity difference thresholds were assessed behaviorally in 7 painted turtles (Chrysemys picta) before and after lesions of nucleus rotundus thalami or control lesions. Three subjects with control lesions and two subjects with slight bilateral damage to nucleus rotundus showed no permanent elevation of threshold postoperatively. In contrast, two subjects with severe damage to nucleus rotundus showed threshold elevations postoperatively and did not recover with further training. The impairment shown by these subjects with damage to nucleus rotundus appeared to be only on the more difficult problems; they performed as they had preoperatively on easy discriminations.
D000818:Animals; D007839:Functional Laterality; D012684:Sensory Thresholds; D013788:Thalamus / Q000502:physiology*; D014426:Turtles / Q000502:physiology*; D014792:Visual Acuity