Interaction between top-down decision-driven congruency effect and bottom-up input-driven congruency effect is...

Area of Science:

• Cognitive Neuroscience
• Psychology
• Neuroscience

Background:

• The Stroop priming paradigm demonstrates that prime-target incongruency delays response time (RT).
• Incongruency between target and subjectively reported prime identity also delays RT, beyond the classic congruency effect.
• When primes are invisible, these effects are categorized as bottom-up (BU) stimulus-driven and top-down (TD) guess-driven congruency effects, respectively.

Purpose of the Study:

• To test the global neuronal workspace theory's postulate on TD-BU network interaction during conscious and unconscious processing.
• To investigate the neural population overlap for TD and BU prime representations under varying visibility conditions.

Main Methods:

• Two behavioral experiments utilizing a modified Stroop priming paradigm.
• Manipulation of prime visibility to distinguish between conscious and unconscious processing.
• Measurement of response times (RT) to assess congruency effects.

Main Results:

• Additive RT effects for TD and BU congruency on prime-invisible trials, indicating independent neuronal activation.
• Underadditive interaction effects as prime visibility increased, suggesting overlapping neuronal populations during conscious perception.
• Behavioral evidence supporting the global neuronal workspace theory's predictions.

Conclusions:

• TD and BU prime representations are processed by independent neuronal populations during unconscious perception.
• TD and BU prime representations recruit overlapping neuronal populations during conscious perception.
• The developed behavioral paradigm offers a cost-effective method for detecting representational overlap in various mental processes.