Yet high validity signals cause more of a problem since the animal does not want to make a wrong choice. This is an interesting decision bias which is found even in humans who tend to freeze when confronted with some novel and emotionally intense situation. Compensation Effects Frogs often tilt their head upward as much as 90 degrees during orientation or simply to get a better view. Since turning is a bodily referenced action some sort of remapping from retinal coordinates to body coordinates seems to be taking place. This may be one of the functions of the nucleus isthmus which has a topographic representation of all the space surrounding the frog.
Correct orientation seems to require input from both eyes via the tectums on each side of the brain.
If the frog is forced to use only one eye it will overshoot the target as shown is figure 9. It appears as if the tectums average the visual locations as seen by each eye to arrive at the correct stopping location. Yet these same frogs will still snap at objects located only 20 degrees away. Habituated areas, like the behavioral field, are relative to the head. An example of the rate of habituation is shown at the top of figure 10 while the toads recovery from that habituation is shown at the bottom.