The intrinsic spatial nature of images was tested by Kosslyn and his colleagues via scanning experiments. The answer to this question is yes, according to a number of Kossln's results, the most famous of which involve the scanning of an imagined map. The issue that next arose concerning this research was whether these results were due to demand characteristics of the experiments. If it did, then imagery is cognitively penetrable, and is not part of the functional architecture. Several experiments have attempted to test this directly, with mixed results.
Propositional supporters find that changes in instruction change subject performance.
Depictive supporters find that these changes do not occur. For Kosslyn, the critical information for resolving the imagery debate came from neuroscience. PET studies have been used to confirm this theory. We found that parts of the brain known to be topographically organized in humans are active during visual mental imagery, even when subjects close their eyes. The experiments summarized here illustrate how behaivoral data can be combined with neurological results, allowing us to distinguish among alternative theories of mental representation.