Abstract
Subjective experience can be influenced by top-down factors, such as expectations and stimulus relevance. Recently, it has been shown that expectations can enhance the likelihood that a stimulus is consciously reported, but the neural mechanisms supporting this enhancement are still unclear. We manipulated stimulus expectations within the attentional blink (AB) paradigm using letters and combined visual psychophysics with magnetoencephalographic (MEG) recordings to investigate whether prior expectations may enhance conscious access by sharpening stimulus-specific neural representations. We further explored how stimulus-specific neural activity patterns are affected by the factors expectation, stimulus relevance and conscious report. First, we show that valid expectations about the identity of an upcoming stimulus increase the likelihood that it is consciously reported. Second, using a series of multivariate decoding analyses, we show that the identity of letters presented in and out of the AB can be reliably decoded from MEG data. Third, we show that early sensory stimulus-specific neural representations are similar for reported and missed target letters in the AB task (active report required) and an oddball task in which the letter was clearly presented but its identity was task-irrelevant. However, later sustained and stable stimulus-specific representations were uniquely observed when target letters were consciously reported (decision-dependent signal). Fourth, we show that global pre-stimulus neural activity biased perceptual decisions for a 'seen' response. Fifth and last, no evidence was obtained for the sharpening of sensory representations by top-down expectations. We discuss these findings in light of emerging models of perception and conscious report highlighting the role of expectations and stimulus relevance.
Original language | English |
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Article number | niz011 |
Pages (from-to) | niz011 |
Journal | Neuroscience of consciousness |
Volume | 2019 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2019 |
Funding
This work was supported by grants from the European Research Council (ERC-2015-STG_679399, awarded to H.A.S.; ERC-2015-STG_678286 awarded to F.P.d.L.) and The Netherlands Organisation for Scientific Research (NWO Vidi grant 452-13-016, awarded to F.P.d.L.).
Funders | Funder number |
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Horizon 2020 Framework Programme | 679399, 678286 |
European Research Council | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 452-13-016 |