Intensity expectation modifies gustatory evoked potentials to sweet taste: Evidence of bidirectional assimilation in early perceptual processing

Wilton, Moon ORCID: 0000-0003-4052-7918, Stancak, Andrej ORCID: 0000-0003-3323-3305, Giesbrecht, Timo, Thomas, Anna and Kirkham, Tim ORCID: 0000-0001-5440-2513 (2019) Intensity expectation modifies gustatory evoked potentials to sweet taste: Evidence of bidirectional assimilation in early perceptual processing. PSYCHOPHYSIOLOGY, 56 (3). e13299-.

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Official URL: http://dx.doi.org/10.1111/psyp.13299

Abstract

Expectations can affect subjective sensory and hedonic ratings of tastes, but it is unclear whether they also shape sensory experience at a perceptual level. The neural correlates of the taste-expectancy relationship were explored through EEG analysis. Using a trial-by-trial cueing paradigm, lingual delivery of 0.05 M or 0.3 M sucrose solutions was preceded by congruent or incongruent visual cues designed to promote anticipation of either a low-sweet or high-sweet solution. When participants were cued to expect low-sweet, but received high-sweet (incongruent cue), intensity ratings for high-sweet decreased. Likewise, expectation of high-sweet increased intensity ratings of low-sweet solutions. Taste-dependent, right central-parietal gustatory ERPs were detected, with greater P1 (associated with greater right insula activation) and P2 peak amplitudes for high-sweet tastes. Valid cue-taste pairings led to specific reduced right-lateralized N400 responses (associated with an attenuation in right insula activation) compared with invalid cue-taste pairings. Finally, P1 amplitudes following invalidly cued low-sweet tastes closely matched those generated by expected high-sweet tastes, and P1 amplitudes for invalidly cued high-sweet tastes resembled those generated by low-sweet tastes. We conclude that, as well as modifying subjective ratings toward the anticipated intensity level, expectations affect cortical activity in a top-down manner to induce bidirectional assimilation in the early perceptual processing of sweet taste and modulate N400 ERP components not previously associated with gustatory stimulation.

Item Type:	Article
Uncontrolled Keywords:	assimilation, EEG, ERPs, expectation, gustation, source localization
Depositing User:	Symplectic Admin
Date Deposited:	05 Apr 2019 14:05
Last Modified:	19 Jan 2023 00:55
DOI:	10.1111/psyp.13299
Open Access URL:	https://doi.org/10.1111/psyp.13299
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3035934