Optimistic Amnesia: How Online and Offline Processing Shape Belief Updating and Memory Biases in Immediate and Long-Term Optimism Biases. Ziqing Yao, Xuanyi Lin, Xiaoqing Hu. Social Cognitive and Affective Neuroscience, nsab011, January 27 2021. https://doi.org/10.1093/scan/nsab011
Rolf Degen's take: Our memory helps preserve a rosy view, wiping out inconvenient truths about ourselves. https://t.co/Xn0TYMNLZs https://t.co/OqSl8sKCdP
Abstract: When people are confronted with feedback that counters their prior beliefs, they preferentially rely on desirable rather than undesirable feedback in belief updating, i.e., an optimism bias. In two pre-registered EEG studies employing an adverse life event probability estimation task, we investigated the neurocognitive processes that support the formation and the change of optimism biases in immediate and 24-hour delayed tests. We found that optimistic belief updating biases not only emerged immediately, but also became significantly larger after 24 hours, suggesting an active role of valence-dependent offline consolidation processes in the change of optimism biases. Participants also showed optimistic memory biases: they were less accurate in remembering undesirable than desirable feedback probabilities, with inferior memories of undesirable feedback associated with lower belief updating in the delayed test. Examining event-related brain potentials (ERPs) revealed that desirability of feedback biased initial encoding: desirable feedback elicited larger P300s than undesirable feedback, with larger P300 amplitudes predicting both higher belief updating and memory accuracies. These results suggest that desirability of feedback could bias both online and offline memory-related processes such as encoding and consolidation, with both processes contributing to the formation and change of optimism biases.
Keywords: optimism bias, belief updating, offline processing, P300, motivated cognition
Discussion
Encountering feedback that challenges one’s prior beliefs, people preferentially rely on desirable
than undesirable feedback to guide belief updating, i.e., the optimism bias (Dricu et al., 2020;
Sharot & Garrett, 2016; Sharot et al., 2011). Here, we provide novel evidence that optimism
biases are partially driven by shallower encoding and inferior memories of undesirable versus
desirable feedback, i.e., an optimistic amnesia effect. Moreover, we observed that optimistic
updating biases became larger over time, with preferential retention of updating in the desirable
condition and declined updating in the undesirable condition. Desirability of feedback
consistently modulated parietal P300 brain activities that may indicate encoding depth, with
larger P300s for desirable than undesirable probability feedback.
The present research provides the first evidence that optimism biases become larger over
24 hours. This finding is noteworthy because it suggests that the desirability of feedback not only
influences online attention/encoding-related processes but also biases offline consolidation
processes. A closer inspection of our data suggested that over time, belief updating, and
memories of desirable feedback were largely preserved, whereas updating and memories
significantly declined for undesirable feedback. These findings contribute to a growing literature
suggesting that motivation (e.g., valence, reward) could bias offline consolidation processes and
then influence long-term judgments (Payne & Kensinger, 2018; Rasch & Born, 2013; Stickgold
& Walker, 2013).
Our findings that belief updating and memories changed more significantly in the
undesirable but not in the desirable condition provide additional evidence that optimism bias is
primarily driven by insufficient updating when receiving undesirable feedback (Eil & Rao, 2011;
Sharot et al., 2011). Prior research found that self-related undesirable updating was not only
lower than self-related desirable updating but also lower than other-related updating in general
(Kuzmanovic et al., 2016). Moreover, aging participants showed reduced belief updating
following undesirable feedback compared to young adults, leading to larger optimism biases
(Chowdhury et al., 2014). In contrast, patients with major depressive disorder or individuals with
high functioning autism showed enhanced belief updating toward undesirable feedback relative to
healthy controls, leading to smaller optimism biases (Garrett et al., 2014; Korn et al., 2014;
Kuzmanovic et al., 2019). These findings, together with our novel results on delayed belief
updating and memory biases, consistently suggest that insufficient updating in response to
undesirable feedback is a fundamental mechanism that drives immediate and long-term optimism
biases.
Tracking ERPs allows us to investigate how the desirability of feedback biases
information processing along millisecond temporal scale. We found that the desirability of
feedback significantly modulated P300, and to a less extent, the LPP, but not the FRN. As one of
the most investigated ERP components, P300 has been associated with a range of cognitive
processes, including context updating, motivational salience, evaluation and categorization,
encoding depth, etc. (Azizian & Polich, 2007; Polich, 2007, 2012). In the present study, enhanced
parietal P300s to desirable versus undesirable feedback suggested that participants preferentially
encoded desirable feedback, which then exerted a greater impact on subsequent belief updating
and memory performance. Regarding the LPP effect, prior research suggested that LPP may
reflect in-depth elaboration of motivationally salient stimuli (Hajcak & Foti, 2020). Indeed,
multilevel analyses with trial-level data showed that enhanced P300 and LPPs to feedback
predicted larger belief updating and more accurate memories of feedback probabilities,
substantiating the putative role of the P300/LPP in encoding and elaboration processes (Kamp et
al., 2015; Otten & Donchin, 2000; Otten & Rugg, 2001; Rigney et al., 2020). These ERPs results
also suggest that differential processing of desirable and undesirable feedback can occur rapidly
after the initial valence processing.
We hypothesized that the frontocentral FRN would encode the desirability of feedback,
with larger FRNs elicited by undesirable versus desirable feedback (Heydari & Holroyd, 2016;
Yeung & Sanfey, 2004). However, the desirability of feedback was not observed to modulate
FRN. The insensitivity of FRN to feedback valence in the belief updating task raises the
possibility that estimation errors and reward prediction errors could reflect distinctive
computational processes of error tracking (Sharot & Garrett, 2016). Specifically, FRNs are
typically observed in reward processing tasks during which feedback conveys monetary gains and
losses (Hajcak et al., 2006; Heydari & Holroyd, 2016; Proudfit, 2015), whereas feedback in our
task indicated numerical discrepancies between estimations of probabilities. Specifically,
participants in the belief updating task needed to calculate the discrepancies between feedback
probabilities and their initial estimations to guide belief updating. Such high-level inferential and
calculation processes might make FRNs insensitive to the desirability of feedback in the present
context. Moreover, FRNs have been suggested to be involved in both error tracking and
behavioral adjustment. For example, in reward tasks, FRNs elicited by undesirable feedback (e.g.,
a loss) could guide behavioral adjustment to avoid losses (Cohen et al., 2007; Holroyd & Coles,
2002; Hu et al., 2015; Walsh & Anderson, 2012). However, in our belief updating task,
participants preferentially used desirable rather than undesirable feedback to guide belief
updating. The FRNs may reflect complex motivational-cognitive processes including both error
tracking (in response to both desirable and undesirable feedback), and the signaling of behavioral
adjustment (i.e., in response to desirable feedback). A mixture of these motivational-cognitive
processes may thus lead to comparable FRNs in both desirable and undesirable conditions.
Regarding the delayed optimism biases, although our results suggest that time delay and
offline processes contributed to the enhancement of optimism biases, it remains unknown
whether sleep or wakefulness may differentially influence belief updating and memory biases. On
the one hand, enhancement of optimism biases may be time-dependent rather than sleepdependent. Alternatively, given that sleep plays an important role in memory consolidation
(Rasch & Born, 2013), sleep-based consolidation may be necessary for optimism biases to
change. Future studies shall directly link sleep, offline consolidation processes, and optimism
biases to test this novel hypothesis.