In some cases, automatic top-down processing of stimuli even seems mandatory. JR Stroop (1935) first demonstrated the compulsory nature of reading. In the study, subjects were presented with a list of words in various colors: red, green, blue, brown and purple. The words were presented in color so that each word was not printed in its representative color; that is, the word “red” might appear in blue ink, or the word “brown” in green ink. Subjects were then asked to indicate the color of the ink the word was printed in rather than the word itself. The results indicated that, compared to when the color of the word was matched to the color typed, those who were presented with contrasting stimuli had slower transmission times when naming the colors. This phenomenon is explained by the concept of interference, as correlated and simultaneously presented stimuli interfere with each other. In this case the interference is due to the unconscious processing of words; although attention is focused on determining the color of the word, the unconscious recognition of the word presents itself to consciousness and the relationship between the two stimuli distracts the focus of attention. Therefore, these top-down attention events influence the conscious perception of stimuli. All of the literature cited above focuses on visual stimuli. However, this is not the only important stimulus when studying attention systems. Like memory systems, different sensory stimuli can have separate but interconnected attention systems that influence consciousness. The study proposed below focuses on the attention system of tactile stimulation. The literature on tactile attention is more limited than for visual and auditory stimuli due to ease of manipulation...... half of article...... Journal of Experimental Psychology, 32, 3-25.Posner, MI (1994) . Attention: the mechanisms of consciousness. Proceedings of the National Academy of Sciences, 91, 7398-7403.Spence, C., Pavani, F., & Driver, J. (2000). Crossmodal links between vision and touch in endogenous covert spatial attention. Journal of Experimental Psychology, 24(4), 1298-1319.Stroop, J. R. (1935). Interference studies in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643-662. doi:http://dx.doi.org/10.1037/h0054651Treisman, A., & Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology, 12, 97-136. Treisman, A., & Schmidt, H. (1982). Illusory conjunctions in the perception of objects. Cognitive Psychology, 14, 107-141. Wolfe, J. M., Kluender, K. R., & Levi, D. M. (2012). Sensation and perception. Sunderland, MA: Sinauer Associates, Inc.