Subliminally and Supraliminally Acquired Long-Term Memories Jointly Bias Delayed Decisions

Abstract

Common wisdom and scientific evidence suggest that good decisions require conscious deliberation. But growing evidence demonstrates that not only conscious but also unconscious thoughts influence decision-making. Here, we hypothesize that both consciously and unconsciously acquired memories guide decisions. Our experiment measured the influence of subliminally and supraliminally presented information on delayed (30–40 min) decision-making. Participants were presented with subliminal pairs of faces and written occupations for unconscious encoding. Following a delay of 20 min, participants consciously (re-)encoded the same faces now presented supraliminally along with either the same written occupations, occupations congruous to the subliminally presented occupations (same wage-category), or incongruous occupations (opposite wage-category). To measure decision-making, participants viewed the same faces again (with occupations absent) and decided on the putative income of each person: low, low-average, high-average, or high. Participants were encouraged to decide spontaneously and intuitively. Hence, the decision task was an implicit or indirect test of relational memory. If conscious thought alone guided decisions (= H0), supraliminal information should determine decision outcomes independently of the encoded subliminal information. This was, however, not the case. Instead, both unconsciously and consciously encoded memories influenced decisions: identical unconscious and conscious memories exerted the strongest bias on income decisions, while both incongruous and congruous (i.e., non-identical) subliminally and supraliminally formed memories canceled each other out leaving no bias on decisions. Importantly, the increased decision bias following the formation of identical unconscious and conscious memories and the reduced decision bias following to the formation of non-identical memories were determined relative to a control condition, where conscious memory formation alone could influence decisions. In view of the much weaker representational strength of subliminally vs. supraliminally formed memories, their long-lasting impact on decision-making is noteworthy.

Larger capacity for unconscious versus conscious episodic memory

“…[23][24][25][26][27][28] These findings confirm newer theoretical claims 3,4,8 that the sole premise for episodic encoding through hippocampus is not consciousness but a task that calls upon the core computational competence of the hippocampus, namely, the rapid formation of new and flexible associations. When applying such tasks, unconscious episodic encoding and retrieval was revealed using subliminal word pairs, 23,29,30 subliminal face-word pairs, 24,[31][32][33] and subliminal objects in space. 26 Moreover, participants inferred unconsciously that two ordinarily unrelated words A-C are semantically related based on the preceding subliminal encoding of discontinuously flashed subliminal word pairs A-B and B-C. 34,35 Furthermore, subliminal associative encoding encompassed the encoding of complex visuospatial second-order sequences, 36 the understanding of causal events, 37 and narratives from spatial-temporal movement patterns.…”

“…[42][43][44][45] Because visual input is stronger during supraliminal versus subliminal encoding, we expected steeper local maxima in brain activation and broader activation clusters during conscious versus unconscious processing. 23,35,[46][47][48][49][50] We also hypothesized that unconscious retrieval performance would remain stable with increasing information load, 23,24,26,[29][30][31][32][33][34][35] while conscious retrieval performance would drop. Finally, we measured the participants' habitual decision style-intuitive versus deliberative-to account for the possibility that habitually intuitive decision makers would outperform deliberative decision makers in the unconscious condition that required intuitive decisions at test.…”

Electrophysiological indexes of option characteristic processing

“…In our opinion, the sensitivity of the P1 amplitude stems from unconscious attentional capture of reward‐related stimuli during the option assessment stage, which is supported by previous findings that attention, but not awareness, is essential to control motivated behavior (Mastropasqua & Turatto, ). Additionally, previous studies have revealed that subconscious contextual reward cues produce biases in decision making (Pessiglione et al, ; Ruch, Herbert, & Henke, ). Furthermore, this finding implies that value‐based decision preference might have been developed before human species consciously attended to the options.…”

Unconscious integration: Current evidence for integrative processing under subliminal conditions

“…For example, after subliminal exposure to ‘winter‐red’ and ‘red‐computer’ pairs, response to the target ‘winter‐computer’ was facilitated. Meanwhile, subliminal pairings of a face with an occupation label, also influenced occupation‐related judgement towards the face when it was later presented as a visible target (Degonda et al, 2005; Duss et al, 2011; Henke, Mondadori, et al, 2003; Henke, Treyer, et al, 2003; Ruch et al, 2016, 2017; Züst et al, 2015). Furthermore, the authors also remarkably proposed the integration of complex relational/visuospatial information between various subliminal visual scenes/items (Nickel et al, 2015; Schneider et al, 2021; Wuethrich et al, 2018).…”