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Supra- and subliminal priming. Piotr Jaśkowski Department of Cognitive Psychology University of Finance and Management, Warszawa. RT. What is supraliminal priming?. Prime is fully visible. target. congr. incongr. prime. Task: Respond with the hand the arrow points to.
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Supra- and subliminal priming Piotr Jaśkowski Department of Cognitive Psychology University of Finance and Management, Warszawa
RT What is supraliminal priming? Prime is fully visible target congr incongr prime Task:Respond withthe hand the arrow points to Source: Jaśkowski, Consc.Cogn., 2006
What is subliminal priming? Semantic priming Source: Dehaene et al., Nature 1998
6 6 six six 3 three 3 three V-A A-V V-V V-V What is subliminal priming? Semantic priming prime target Source: Dehaene et al., Nature 1998
PE > 0 PE < 0 What is subliminal priming? Priming effect PE = RT(incomp.) – RT(comp.) Positive compatibility effect (PCE): Negative compatibility effect (NCE): Source: Dehaene et al., Nature 1998
What is subliminal priming? Semantic priming PCE for all conditions Source: Dehaene et al., Nature 1998
Respond to the target’s side RT 50 ms comp. incomp. target What is subliminal priming? Motor priming Source:Neumann & Klotz, Att Perform.1994
What is this talk about? Questions to answer • Is it possible to control subliminal processing? • How neutral is a neutral mask? • Is a double dissociation a proof for subliminal processing?
Subliminal situation red #$&%$ ##### 33 ms 267 ms Supraliminal situation red ##### 300 ms Is it possible to control subliminal processing? Task: call the target’s color Stroop-like task Source: Merikle & Joordans, Consc.Cogn., 1997
supraliminal compatible condition: 25% trials red ##### RT RT incompatible condition: 75% trials comp. incomp. red ##### subliminal comp. incomp. Is it possible to control subliminal processing? Stroop-like task Source: Merikle & Joordans, Consc.Cogn., 1997
Is it possible to control subliminal processing? Stroop-like task • The reversed effect was found under the supraliminal condition, because under this condition participants had the possibility to ‘‘capitalize on the predictive information provided by the primes’’. • Strategical control can be exercised only under supraliminal condition. Source: Merikle & Joordans, Consc.Cogn., 1997
Is it possible to control subliminal processing? Problem • If there is no control over subliminal stimuli: • Itshould be possible to trigger one’s response against one’s will. • It should be possible to trigger one’s response by means of several subsequently presented subliminal primes.
Target Task: respond with left/right key depending on target position. Is it possible to control subliminal processing? Multiple priming Source: Jaśkowski et al., J.Cogn.Neurosci., 2003
prime duration = 11.6 ms target duration = 100 ms 35 ms 35 ms 35 ms 35 ms Is it possible to control subliminal processing? Source: Jaśkowski et al., J.Cogn.Neurosci., 2003
Is it possible to control subliminal processing? Condition 80/20 - 20% compatible - 80% incompatible Condition 20/80 - 80% compatible - 20% incompatible priming sequence Source: Jaśkowski et al., J.Cogn.Neurosci., 2003
Is it possible to control subliminal processing? Reaction time (ms) Source: Jaśkowski et al., J.Cogn.Neurosci., 2003
Is it possible to control subliminal processing? Conclusions: • Even when stimuli are subliminal participants can control their influence on their behavior: • Plausibly, they can augment or damp the subliminal influence off-line. • A need for such a regulation partcipants can infer from observation of their own performance. Source: Jaśkowski et al., J.Cogn.Neurosci., 2003
Is it possible to control subliminal processing? Correction of performance is mediated by frontal cortex Source: Wolbers et al. Cerebral Cortex, 2005
Is it possible to control subliminal processing? Strategical control can be exercised only under supraliminal condition. not true Source: P. Collins, www.philcollins.co.uk
How neutral is a neutral mask? Negative compatibility effect • A mask reduces the participants’ conscious accessibility to the prime information, but it does not affect response to the target provided that the mask is neutral. • A mask is neutral if it induces no response to the target.
RT How neutral is a neutral mask? Negative compatibility effect congr incongr Task:Respond withthe hand the arrow points to Source: Eimer & Schlaghecken, JEP:HPP, 1998
negative RT RT comp. incomp. positive comp. incomp. How neutral is a neutral mask? Negative compatibility effect Source: Verleger et al., JEP:General, 2004
How neutral is a neutral mask? A mask does not affect response to the target provided that it is neutral. not true Source: P. Collins, www.philcollins.co.uk
negative (NCE) RT RT comp. incomp. positive (PCE) comp. incomp. Is a double dissociation an evidence for subliminal processing? NCE vs. PCE Source: eg. Klapp & Hinkley, JEP:Gen, 2002
Is a double dissociation an evidence for subliminal processing? • NCE for masked and PCE for unmasked stimuli is a stronger evidence than for nonconscious influences. This dissociation shows that there are different mechanisms underlying conscious and nonconscious processing. • If there is a qualitative difference in performance under the masking and nonmasking condition, it is a strong evidence for subliminal processing. Source: Klapp & Hinkley., JEP:HPP, 2005
NCE: no masking NCE: efficient masking possible mask temporal positions Is a double dissociation an evidence for subliminal processing? Negative compatibility effect Source: Jaśkowski, JEP:HPP, in press
No masking at all Is a double dissociation an evidence for subliminal processing? Negative compatibility effect Source: Jaśkowski, JEP:HPP, in press
Oh, think twice... Source: P. Collins, www.philcollins.co.uk Is a double dissociation an evidence for subliminal processing? Advice 3 If there is a qualitative difference in performance under the masking and nonmasking condition, it is a strong evidence for subliminal processing. before you conculude like this.
How far can you go with generalization? Arrowness • Have different types of priming (semantic, perceptual, motor etc.) common features (dynamics, persistence etc.)?
mask Is a double dissociation an evidence for subliminal processing? Negative compatibility effect Source: Jaśkowski & Ślósarek, Consc.Cogn., in press
Oh, think twice... Source: P. Collins, www.philcollins.co.uk Is a double dissociation an evidence for subliminal processing? Advice 4 before you try to generalize your finding
Conclusions • We control if our performance is or not consistent with our goals even if the stimuli are subconsciously processed. • A mask is not a neutral stimulus. It is actively processed and our behavior is corrected according to the information the mask brings. • Not every double dissociation is an evidence for subliminality. • Be careful with generalizations!