If visual imagery and visual perception shared many of the same processes, then much of what is known so far about perception could be used and adapted to be able to understand aspects more internal and ambiguous process of visual imagination. The question is: how much of mental imagery is actually part of visual perception? The concept of "unitary mechanism" was mentioned repeatedly in the text, although little was said about what it means and what it implies. This is a term coined by Stephen Kosslyn (2005), who provided a model of visual imagery in which a single visual buffer is used “bottom-up” to display visual perceptions and “top-down” to view internally generated images. The main claim is that the brain areas that implement the "visual buffer" are also central during "visual mental imagery". The “attention window” depicted in the model refers to the covert shift of attention to scan entire images without moving the eyes. “Information shunting” refers to the concept that sometimes it is not possible to identify an object when only part of it is seen and one can rely on stored representations to hypothesize the nature of the object. Despite the logic of the model, research has seriously questioned this idea of ​​a single object. mechanism, bouncing back and forth without a definitive conclusion. Several neuroimaging studies have shown overlapping activation in the brain during perception and imagination. O'Craven and Kanwisher (2000) studied brain activations of faces and places during perception and during mental imagery of faces and places. Similarities emerged between the regions activated during imagery and perception for the corresponding task, although they showed differences in magnitude for imagined and perceived faces and places. So, q… half of the paper… information processing: 20 years of research. Psychological Bulletin, 124, 372-422. Schutz, A. C., Braun, D. I., & Gegenfurtner, K. R. (2011). Eye movements and perception: a selective review. Journal of Vision, 5, 1-30.Shallice,T. (1988). From neuropsychology to mental structure. New York: Cambridge University Press. Sima, J. F., Lindner, M., Schultheis, H., & Barkowsky, T. (2010). Eye movements reflect reasoning with mental images but not with mental models in orientation knowledge tasks. Spatial Cognition, 10, 248-261. Spivey, M. J., & Geng, J. J. (2001). Oculomotor mechanisms activated by imagination and memory: eye movements towards absent objects. Psychological Research, 65, 235-241.Ward, J. (2006). The student guide to cognitive neuroscience. New York: Psychology Press. Watson, J. B. (1913). Psychology as the behaviorist sees it. Psychological review, 20, 158-177.