Contingency learning without awareness: Evidence for implicit control

Abstract

The results of four experiments provide evidence for controlled processing in the absence of awareness. Participants identified the colour of a neutral distracter word. Each of four words (e.g., MOVE) was presented in one of four colours 75% of the time (Experiments 1 and 4) or 50% of the time (Experiment 2 and 3). Colour identification was faster when the words appeared in the colour they were most often presented in relative to when they appeared in another colour, even for participants who were subjectively unaware of any contingencies between the words and colours. An analysis of sequence effects showed that participants who were unaware of the relation between distracter words and colours nonetheless controlled the impact of the word on performance depending on the nature of the previous trial. A block analysis of contingencyunaware participants revealed that contingencies were learned rapidly in the first block of trials.Experiment 3 showed that the contingency effect does not depend on level of awareness, thus ruling out explicit strategy accounts. Finally, Experiment 4 showed that the contingency effect results from behavioural control and not from semantic association or stimulus familiarity. These results thus provide evidence for implicit control. Implicit Control 3Contingency Learning without Awareness: Evidence for Implicit Control Cognitive processes that are controlled are conventionally assumed to operate in a slow, effortful, and voluntary manner (Posner & Cohen, 1984;Posner & Snyder, 1975; Shiffrin & Schnieder, 1977). Thus, when researchers discuss the influence of "controlled" processes, it is typically assumed that such processes are explicit (i.e., conscious; cf., Besner & Stolz, 1999). As such, the term "implicit control" would seem to be nonsensical, because "implicit" (i.e., unconscious) seems to preclude the possibility of control. However, etymologically speaking this is not a necessary conclusion. The Oxford English Dictionary (2001) Evidence for cognitive control, which is assumed to be explicit and strategic in nature, has been drawn from the Stroop literature (Stroop, 1935). In the Stroop task, identification of the print colour of colour words is slower when the word and ink colour are incongruent (e.g., the word GREEN in orange; GREEN orange ) than when they are congruent (e.g., ORANGE orange ; see MacLeod, 1991, for a review). Probably the most important demonstration of putatively controlled processes in the Stroop literature is the proportion congruent effect. The proportion congruent effect refers to the finding that the size of the Stroop effect is influenced by the proportion of congruent items in a block of trials (Lindsay & Jacoby, 1994;Logan & Zbrodoff, 1979). Specifically, the Stroop effect is much larger in a high proportion congruent block of trials than in a low proportion congruent block of trials. This effect is commonly attributed to Implicit Control 4 participants explicitly learning to predict the colour from the word. Specifically, because the word us...

Contingency learning and unlearning in the blink of an eye: A resource dependent process

“…It is already known that the colour-word contingency effect appears relatively early on in the course of an experiment. In a block analysis, Schmidt et al (2007) found that the contingency effect was already significant in the very first block of 48 trials. The first goal of Experiment 1 is to increase the resolution of the block analysis by using smaller blocks of 18 trials.…”

“…A full description of the methodology for the experiment used in this reanalysis can be found in the original article (Schmidt et al, 2007, Experiment 2). The study was very similar to Experiment 1 here.…”

“…The earliest experiments I conducted using the colour-word contingency paradigm had constraints on presentation order such that no colour could be repeated from one trial to the next, thus making it impossible for such complete repetitions (e.g., MOVE blue could never directly follow MOVE blue ; Schmidt et al, 2007) and I have also been careful to control for n -1 sequence effects wherever I had enough data per cell to do so (i.e., by deleting trials in which the colour repeats, thus eliminating complete repetitions, which are faster than other trials). Thus, I can already rule out an account that holds that colourword contingency learning results from trial n -1 repetition effects.…”

“…Other paradigms allow one to assess learning without asking participants to explicitly judge the strength of contingencies. One version of this is the colour-word contingency learning paradigm (Schmidt, Crump, Cheesman, & Besner, 2007; see also Schmidt & Besner, 2008;Musen & Squire, 1993). For instance, Schmidt and colleagues presented four arbitrary words in four different display colours in a colour identification task using a key press response.…”

The Parallel Episodic Processing (PEP) model: Dissociating contingency and conflict adaptation in the item-specific proportion congruent paradigm

“…A drastically different interpretation of the ISPC effect (and PC effects in general) was presented by Schmidt and colleagues (Schmidt & Besner, 2008;Schmidt, Crump, Cheesman, & Besner, 2007;see also, Mordkoff, 1996). According to these authors, participants might simply be learning the contingencies between distracting words and responses to the colour.…”