Episodic Memory Integration and Interference

After being informed about the study, all participants giving written informed consent will complete three experimental sessions. On Day 1, participants will encode AB neutral word pairs (e.g., Pencil - Car) shown alongside positive, negative, or neutral images. Participants will also rate the images on valence and arousal. After encoding all stimuli, participants will immediately complete a retrieval task, during which they will be presented with the cue word (A; e.g., Pencil) and asked to recall the corresponding associate (B, e.g., Car). If incorrect, the correct word pair will be shown before the next trial. The complete list of word pairs will be shown until at least 90% of the word associates are recalled. On Day 2 (~24 h later), participants will return to encode new AC word pairs, where one of the words is the same from the first encoding session and one is different (e.g., Pencil - Book). These AC words pairs will be encoded alongside new images that either match the valence of the first session or shift to a different valence. Again, participants will rate the valence and arousal of each image and complete a subsequent memory test until they reach 90% accuracy on all word pairs. On Day 3, participants will complete the final session of the study, during which they will be shown a cue word (e.g., Pencil) and asked to freely recall the corresponding associates from days 1 and 2 (e.g., Car and Book). Participants will also be asked to remember the day each word associate was originally shown and the valence of the paired image from that day. 100 participants will complete these sessions and their corresponding behavioral tasks online (e.g., via Prolific). An additional 50 participants will complete these sessions in-person, and functional magnetic resonance imaging will be collected during Day 1 and Day 2 to examine how the blood oxygen-level dependent (BOLD) signal is modulated by task conditions. Psychophysiological data such as respiration and heart rate may also be collected. All participants (online and fMRI) will provide individual difference metrics on mood and well-being, including the Beck Depression Inventory, State-Trait Anxiety Inventory, NEO Personality Inventory, and Ruminative Responses Scale. On each day prior to the start of the experimental task, participants will also complete the Profile of Mood States, Positive and Negative Affect Scale, the Pittsburgh Sleep Quality Index, and sleep logs for the night before to index the amount and quality of sleep.

Inclusion criteria

• All participants: willing and able to follow the protocol
• All participants: fluent in English
• Online participants: online account in the crowdsourcing platform that will be used (e.g., Prolific)

Exclusion criteria

• All participants: history of a psychiatric or neurological condition, and/or current psychotropic drug use (indicated by the participant)
• fMRI participants: pregnant, metal in body (incl piercings or metallic makeup if unwilling to remove), unable to lie still for duration of scan (e.g., due to pain), Meniere's disease, claustrophobic, or other contraindication for MRI as determined my MRI technician, left-handed