This study was designed to investigate the effects of aging on consciousness in recognition memory, using the Remember/Know/Guess procedure . Remembering and Knowing. In E. Tulving & F. I. M. Craik , The Oxford Handbook of Memory. Oxford University Press.). In recognition memory, older participants report fewer occasions on which recognition is accompanied by recollection of the original encoding context. Two main hypotheses were tested: the speed mediation hypothesis . The processing-speed theory of adult age differences in cognition. Psychological Review, (...) 3, 403–428) and the executive-aging hypothesis . An application of prefrontal cortex function theory to cognitive aging. Psychological Bulletin, 120, 272–292). A group of young and a group of older adults took a recognition test in which they classified their responses according to Gardiner, J. M., & Richarson-Klavehn, A. . Remembering and Knowing. In E. Tulving & F. I. M. Craik , The Oxford Handbook of Memory. Oxford University Press. remember-know-guess paradigm. Subsequently, participants completed processing speed and executive function tests. The results showed that among the older participants, R responses decreased, but K responses did not. Moreover, a hierarchical regression analysis supported the view that the effect of age in recollection experience is determined by frontal lobe integrity and not by diminution of processing speed. (shrink)