Purchase this article with an account.
Simon van Gaal, Lionel Naccache, Julia Meuwese, Laurent Cohen, Stanislas Dehaene; Logical semantic operations in the absence of visual awareness. Journal of Vision 2013;13(9):1143. doi: 10.1167/13.9.1143.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Accumulating evidence suggests that non-conscious cognition is extremely powerful. Brain-imaging studies have revealed extensive subliminal information processing in many different brain areas, from low-level perceptual regions, to regions in the parietal and temporal cortex, even up to "executive" areas at the highest level of the cortical and cognitive hierarchy, in the prefrontal cortex. Although great progress has been made in characterizing the flow of information triggered by unconscious visual stimuli in isolation, if and how multiple sources of unconscious information are integrated and combined is largely unexplored. I will present a series of behavioral and ERP studies in which we probed the possible flexibility and complexity at which multiple unconscious elements can be logically combined. Therefore, we designed a masked priming paradigm in which subjects were presented with a rapid stream of three words: an adverb ("not"/"very"), an adjective (e.g., "good"/"bad") and a target noun (e.g., "peace"/"murder"). The first two words could either be masked, or not masked. Subjects indicated whether the consciously presented target noun had a positive or negative valence. Crucially, the nature of the adverb dictated whether the overall three-word sequence was contextually consistent (e.g., very-bad-murder) or contextually inconsistent (e.g., not-bad-murder). Electrophysiological recordings revealed that such logical negation computations can partly unfold unconsciously, as reflected in similar effects for conscious and unconscious sequences on the N400 ERP component. However, at the same time qualitative neural differences between conscious and unconscious logical negation operations were observed on a the later P600 ERP component. Only conscious sequences elicited P600 effects, which were significantly stronger than the unconscious effects. These results suggest that some aspects of negation can unfold unconsciously, whereas others might not.
Meeting abstract presented at VSS 2013
This PDF is available to Subscribers Only