First impressions or good endings? Preferences depend on when you ask.

Rewards often unfold over time; we must summarize events in memory to guide future choices. Do first impressions matter most, or is it better to end on a good note? Across nine studies (N = 569), we tested these competing intuitions and found that preferences depend on when rewards occur and when we are asked to evaluate an experience. In our "garage sale" task, participants opened boxes containing sequences of objects with values. All boxes were equally valuable, but rewards were either evenly distributed or clustered at the beginning, middle, or end of the sequence. First, we tested preferences and valuation shortly after learning; we consistently found that boxes with rewards at the beginning were strongly preferred and overvalued. Object-value associative memory was impaired in boxes with early rewards, suggesting that value information was linked to the box rather than the objects. However, when tested after an overnight delay, participants equally preferred boxes with any cluster of rewards, whether at the beginning, middle, or end of the experience. Finally, we demonstrated that evaluating shortly after an experience led to lasting preferences for early rewards. Overall, we show that people summarize rewarding experiences in a nonlinear and time-dependent way, unifying prior work on affect, memory, and decision making. We propose that short-term preferences are biased by first impressions. However, when we wait and evaluate an experience after a delay, we summarize rewarding events in memory to inform adaptive longer term preferences. Preferences depend on when rewards occur and when we first evaluate an experience. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Instructed motivational states bias reinforcement learning and memory formation.

Motivation influences goals, decisions, and memory formation. Imperative motivation links urgent goals to actions, narrowing the focus of attention and memory. Conversely, interrogative motivation integrates goals over time and space, supporting rich memory encoding for flexible future use. We manipulated motivational states via cover stories for a reinforcement learning task: The imperative group imagined executing a museum heist, whereas the interrogative group imagined planning a future heist. Participants repeatedly chose among four doors, representing different museum rooms, to sample trial-unique paintings with variable rewards (later converted to bonus payments). The next day, participants performed a surprise memory test. Crucially, only the cover stories differed between the imperative and interrogative groups; the reinforcement learning task was identical, and all participants had the same expectations about how and when bonus payments would be awarded. In an initial sample and a preregistered replication, we demonstrated that imperative motivation increased exploitation during reinforcement learning. Conversely, interrogative motivation increased directed (but not random) exploration, despite the cost to participants' earnings. At test, the interrogative group was more accurate at recognizing paintings and recalling associated values. In the interrogative group, higher value paintings were more likely to be remembered; imperative motivation disrupted this effect of reward modulating memory. Overall, we demonstrate that a prelearning motivational manipulation can bias learning and memory, bearing implications for education, behavior change, clinical interventions, and communication.

Ultra High Field fMRI of Human Superior Colliculi Activity during Affective Visual Processing.

Research on rodents and non-human primates has established the involvement of the superior colliculus in defensive behaviours and visual threat detection. The superior colliculus has been well-studied in humans for its functional roles in saccade and visual processing, but less is known about its involvement in affect. In standard functional MRI studies of the human superior colliculus, it is challenging to discern activity in the superior colliculus from activity in surrounding nuclei such as the periaqueductal gray due to technological and methodological limitations. Employing high-field strength (7 Tesla) fMRI techniques, this study imaged the superior colliculus at high (0.75 mm isotropic) resolution, which enabled isolation of the superior colliculus from other brainstem nuclei. Superior colliculus activation during emotionally aversive image viewing blocks was greater than that during neutral image viewing blocks. These findings suggest that the superior colliculus may play a role in shaping subjective emotional experiences in addition to its visuomotor functions, bridging the gap between affective research on humans and non-human animals.