1. On the unconscious context-specific proportion congruency effect:
The role of facilitation and interference
MACLab
Chris Blais Molly E. Benkaim Gene A. Brewer
Arizona State University
The Present Investigation
Results
Cognitive control is widely examined in psychology and cognitive neuroscience, and modulating Stroop interference is considered one of its hallmarks. Although recent work has focused on many of the low-level processes that contribute to these effects, such as feature integration and implicit learning, cognitive control is still highly associated with consciousness and strategic thoughts and actions.
A recent paper1 questions this assumption by reporting the presence of an interaction between the proportion of congruent trials and the magnitude of the Stroop effect—an effect long cited as evidence for strategic control—in the absence of awareness.
We replicated and extended this work by measuring the extent to which this interaction was driven by the modulation of interference or facilitation. Across several behavioral and EEG studies, we find that the interaction primarily results from modulation of facilitation. We conclude that control in the form of suppressing word processing cannot operate in the absence of awareness. 60
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1.0
-1.0
-0.5
0.5
MC – MI:
Stroop Effect
Facilitation
Interference
d95%
Methods and Design
Procedure based on prior work1-2
Behavioral Participants: N=64. Four were excluded from the analysis for <70% accuracy rates leaving N=60 subjects. The task took ~60 minutes to complete.
EEG Participants: N=70. Seven were excluded for <70% accuracy rates leaving N=62 subjects. The EEG task, including prep time, took ~105 minutes to complete.
N=31 identical to the behavioral only
N=31 ran in a slower version. +
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BROWN
500ms
100ms
subjective
threshold
850 or 450ms
variable
500 or 200 ms
up to
1500ms
shorter = -17 ms
longer = +34 ms
until
response
shorter
same
longer
4 consecutive “same”
responses to terminate
Subjective threshold = duration of word
Thresholding procedure
Experimental procedure Cz
Conclusion
We measured the extent to which the unconscious context-specific proportion congruency effect was driven by the modulation of interference or facilitation and showed that the interaction primarily results from modulation of facilitation.
Thus “control” – in the form of suppressing word processing – does not appear capable of operating in the absence of awareness (see also2-4).
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No Word
Incongruent
Congruent
WHITE
BROWN 18 12 6
%%%%%%%
Mostly Incongruent
Mostly Congruent
N=15 Blocks of 72 trials
References: (1) Panadero, Castellanos, & Tudela (2015). Unconscious context-specific proportion congruency effect in a Stroop-like task. Consciousness & Cognition, 31, (2) Cheesman & Merikle (1986). Distinguishing conscious from unconscious perceptual processes. Canadian Journal of Experimental Psychology, 40, (3) Kunde (2003). Sequential modulations of stimulus–response correspondence effects depend on awareness of response conflict. Psychonomic Bulletin & Review, 10, 198–205. (4) Desender & Van den Bussche (2012). Is consciousness necessary for conflict adaptation? A state of the art. Frontiers in Human Neuroscience, 6 (3).
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