%A Bekinschtein,Tristan %A Peeters,Moos %A Shalom,Diego %A Sigman,Mariano %D 2011 %J Frontiers in Psychology %C %F %G English %K Aplysia,Consciousness,Learning,subliminal,trace conditioning,vegetative state %Q %R 10.3389/fpsyg.2011.00337 %W %L %M %P %7 %8 2011-December-06 %9 Hypothesis and Theory %+ Dr Tristan Bekinschtein,Medical Research Council,Cognition and Brain Sciences Unit,Cambridge,CB2 7EF,United Kingdom,trisbek@gmail.com %+ Dr Tristan Bekinschtein,Institute of Cognitive Neurology,Cognitive Neuroscience,Buenos Aires,Argentina,trisbek@gmail.com %# %! Boundaries of consciousness in classical conditioning %* %< %T Sea Slugs, Subliminal Pictures, and Vegetative State Patients: Boundaries of Consciousness in Classical Conditioning %U https://www.frontiersin.org/articles/10.3389/fpsyg.2011.00337 %V 2 %0 JOURNAL ARTICLE %@ 1664-1078 %X Classical (trace) conditioning is a specific variant of associative learning in which a neutral stimulus leads to the subsequent prediction of an emotionally charged or noxious stimulus after a temporal gap. When conditioning is concurrent with a distraction task, only participants who can report the relationship (the contingency) between stimuli explicitly show associative learning. This suggests that consciousness is a prerequisite for trace conditioning. We review and question three main controversies concerning this view. Firstly, virtually all animals, even invertebrate sea slugs, show this type of learning; secondly, unconsciously perceived stimuli may elicit trace conditioning; and thirdly, some vegetative state patients show trace learning. We discuss and analyze these seemingly contradictory arguments to find the theoretical boundaries of consciousness in classical conditioning. We conclude that trace conditioning remains one of the best measures to test conscious processing in the absence of explicit reports.