Neurophysiological Effects Associated With Subliminal Conditioning of Appetite Motivations

Abstract

When attempting to encourage eating, explicitly providing statements like “eating is pleasant” may produce little effect. This may be due to subjective, negatively-valenced narratives evoked by perception of the verb “eating” (e.g., eating →fat →lonely), overriding any explicitly provided eating-pleasant valence information. In our study, we presented eating-related verbs under subliminal visual conditions to mitigate the onset of eating-associated deliberation. Verbs were linked with neutral or positively valenced terms across independent blocks. Modulations of event-related magnetoencephalographic (MEG) components and parietal activations in the alpha range (8–12 Hz) illustrated a significant effect of valence during pre-lexical time windows. We found significantly greater saliva production and declarations of increasing hunger after eating-related verbs were linked with positive terms. Orally reported preferences did not vary between conditions.

Valence generalization across nonrecurring structures.

“…Clicking on the fixation with the mouse pointer “forced” participants to orient toward a rapidly updating stimulus sequence in the same location. Orienting toward stimulus sequences can facilitate CS-US acquisition (Amd & Baillet, 2019, 2017; Amd et al, 2018; Ribeiro et al, 2020; Sokolov, 1963). The display sequence contained 22 stimuli in randomized orders—this included 20 happy/20 angry faces, and a pair of English/Phoenician strings from the same grammar for a given participant.…”

Effects of Nodal Distance on Conditioned Stimulus Valences Across Time

“…It may be more fruitful to hypothesize structural/associative and context-sensitive, propositional processes interact to produce CS evaluations (Berlyne, 1965). We already have evidence of bottom-up valence effects during time windows too early to attribute to propositional reasoning processes (Amd et al, 2013; Bayer et al., 2017; Amd and Baillet, 2019). To be fair, advocating for dual processes requires a satisfactory explanation of how propositions arise from, as well as interact with, structures of associative S-S links, for which we have no satisfactory response presently (De Houwer, 2018; although see Gawronski and Bodenhausen, 2018).…”

“…After conditioning, all subjects produced card pairs from a deck containing all CS0 and CS2 stimuli as a test for contingency awareness for an unrelated investigation. As contingency awareness may not be critical for CS valence transformations (Amd and Baillet, 2019) and the present investigation was not concerned with sorting/transitivity performances anyway (but see Amd and Roche, 2017; Amd et al., 2018), no further mention of sorting performances are provided.…”

<strong>Valence generalization across non-recurring structures</strong>

“…For readers who adopt our framework, distinctions between 'associative-propositional' and/or 'functional-cognitive' processes become largely redundant since (we assume) unifying 'cross-sections' hierarchically embody all psychologically relevant relations, regardless of conscious accessibility (cf., Tonneau, 2013). Our position explains how (say) affective relations influence motivational systems in the absence of top-down/symbolic moderation (e.g., Amd & Baillet, 2019;Boag, 2008). Cross sections may also embody organizing relations that operate 'without terms' and therefore without explicit deliberation, as the present work suggests.…”