The importance of awareness for understanding language

Abstract

Is consciousness required for high level cognitive processes, or can the unconscious mind perform tasks that are as complex and difficult as, for example, understanding a sentence? Recent work has argued that, yes, the unconscious mind can: Sklar et al. (2012) found that sentences, masked from consciousness using the technique of continuous flash suppression (CFS), broke into awareness more rapidly when their meanings were more unusual or more emotionally negative, even though processing the sentences’ meaning required unconsciously combining each word’s meaning. This has motivated the important claim that consciousness plays little-to-no functional role in high-level cognitive operations. Here, we aimed to replicate and extend these findings, but instead, across 10 high-powered studies, we found no evidence that the meaning of a phrase or word could be understood without awareness. We did, however, consistently find evidence that low-level perceptual features, such as sentence length and familiarity of alphabet, could be processed unconsciously. Our null findings for sentence processing are corroborated by a meta-analysis that aggregates our studies with the prior literature. We offer a potential explanation for prior positive results through a set of computational simulations, which show how the distributional characteristics of this type of CFS data, in particular its skew and heavy tail, can cause an elevated level of false positive results when common data exclusion criteria are applied. Our findings thus have practical implication for analyzing such data. More importantly, they suggest that consciousness may well be required for high-level cognitive tasks such as understanding language.

Neural capacity limits during unconscious semantic processing

“…In a novel behavioral study with CFS, Sklar et al (2012) recently proposed that multiple word expressions can be processed without conscious awareness. However, the present findings are more consistent with subsequent studies supporting the more conservative view that consciousness is required for complex cognitive tasks such as sentence comprehension and arithmetic (Moors & Hesselmann, 2018;Rabagliati et al, 2018). On unmasked trials, the behavioral effect of subject-verb congruency was associated with a significant negative-going ERP difference between congruent and incongruent trials that appeared 450 ms after target in bilateral centro-posterior regions and thus corresponded to the well-known N400 component evoked by semantic incongruity (Kutas & Hillyard, 1980;Holcomb, 1993;Van Petten & Luka, 2006;Hagoort & van Berkum, 2007).…”

“…() recently proposed that multiple word expressions can be processed without conscious awareness. However, the present findings are more consistent with subsequent studies supporting the more conservative view that consciousness is required for complex cognitive tasks such as sentence comprehension and arithmetic (Moors & Hesselmann, ; Rabagliati et al ., ).…”

No language unification without neural feedback: How awareness affects sentence processing

“…Our results are consistent with previous work, in which no evidence for sentence processing under reduced awareness was found (Rabagliati et al, 2018;Yang et al, 2017). However, our findings contrast with other work, which suggests that sentence processing under reduced awareness may be possible, to some extent and under certain conditions Axelrod et al, 2015;Batterink and Neville, 2013;Nakamura et al, 2018;Sklar et al, 2012).…”

“…As in the previous study, their results could be due to lexical differences between related (drink-coffee) and unrelated (iron-coffee) items, instead of unification mechanisms. Moreover, recently Sklar et al's findings failed to replicate (Rabagliati et al, 2018), and have been criticized based on methodological grounds as well (Shanks, 2017). Batterink and Neville (2013) used a cross-modal attentional blink paradigm to investigate undetected syntactic violations within sentences.…”

“…not good), can be performed under masked processing van Gaal et al, 2014), although only after considerable training of the negation process (van Gaal et al, 2014). Some authors have suggested that masked combinatorial processing occurs for entire sentences Nakamura et al, 2018;Sklar et al, 2012), even though evidence is mixed (Rabagliati et al, 2018;Yang et al, 2017).…”