Automatic Processing of Emotional Words in the Absence of Awareness: The Critical Role of P2

Abstract

It has been long debated to what extent emotional words can be processed in the absence of awareness. Behavioral studies have shown that the meaning of emotional words can be accessed even without any awareness. However, functional magnetic resonance imaging studies have revealed that emotional words that are unconsciously presented do not activate the brain regions involved in semantic or emotional processing. To clarify this point, we used continuous flash suppression (CFS) and event-related potential (ERP) techniques to distinguish between semantic and emotional processing. In CFS, we successively flashed some Mondrian-style images into one participant's eye steadily, which suppressed the images projected to the other eye. Negative, neutral, and scrambled words were presented to 16 healthy participants for 500 ms. Whenever the participants saw the stimuli—in both visible and invisible conditions—they pressed specific keyboard buttons. Behavioral data revealed that there was no difference in reaction time to negative words and to neutral words in the invisible condition, although negative words were processed faster than neutral words in the visible condition. The ERP results showed that negative words elicited a larger P2 amplitude in the invisible condition than in the visible condition. The P2 component was enhanced for the neutral words compared with the scrambled words in the visible condition; however, the scrambled words elicited larger P2 amplitudes than the neutral words in the invisible condition. These results suggest that the emotional processing of words is more sensitive than semantic processing in the conscious condition. Semantic processing was found to be attenuated in the absence of awareness. Our findings indicate that P2 plays an important role in the unconscious processing of emotional words, which highlights the fact that emotional processing may be automatic and prioritized compared with semantic processing in the absence of awareness.

Attention Bias to Pain Words Comes Early and Cognitive Load Matters: Evidence from an ERP Study on Experimental Pain

“…Many studies have examined the differences in the processing of different words on a behavioral level, but not sufficient for pain words for persons with pain. Our findings supported those of previous studies by reporting facilitative processing of special words [ 7 , 22 , 25 ] and added new evidence for a particular group of people.…”

“…After examining the grand-averaged waveforms in our study and referring to those in previous studies [ 7 , 22 ], we set the time windows for the ERP components as follows: N1, 70-170 ms, with a peak at about 120 ms; P2, 150-250 ms, with a peak at about 200 ms; and N3, 250-350 ms, with a peak at about 300 ms. We included nine electrodes in the analysis on the basis of previous findings according to the frontal (F3, Fz, and F4), central (C3, Cz, and C4), and partial (P3, Pz, and P4) sides, as reported elsewhere [ 22 , 23 ].…”

Regression to the Mean Does Not Explain Away Nonconscious Processing

“…Campbell and Kenny (1999, pp. xiii) Examinations of the capacities and capabilities of nonconscious processes have been part of experimental psychology from the late 19th century (e.g., Peirce & Jastrow, 1885;Sidis, 1898) throughout the 20th century (e.g., Bruner, 1957;Dehaene et al, 1998;Greenwald, 1992;Greenwald et al, 1996;Marcel, 1983) and are still flourishing in the second decade of the 21st century (e.g., Abir et al, 2017;Faivre et al, 2014;Lei et al, 2017;Moors et al, 2017;Salomon et al, 2017). In recent decades, the modal view suggests that nonconscious mental processes are an inherent part of human psychology (e.g., Bargh et al, 2012;Breitmeyer & Ögmen, 2006;Capa et al, 2011;Dehaene et al, 2006;Dijksterhuis et al, 2006;Faivre et al, 2014;Goldstein & Hassin, 2017;Hassin, 2013;Hassin & Sklar, 2014;Lamy et al, 2008;Sklar et al, 2018;Van Opstal et al, 2010;Zacks et al, 2007).…”

Neural Correlates of Emotion Processing in Word Detection Task

“…For example, using an emotional Stroop task in which subjects completed color-relevant tasks and word-relevant tasks, in the color-relevant tasks the color of word was identified and in the word-relevant tasks the words were classified as threatening or not, earlier research found that threat words were associated with a larger P2 amplitude across tasks ( Thomas et al, 2007 ). Therefore, Lei et al (2017) showed that P2 play an important role in the unconscious processing of emotional words.…”