Optimizing the mnemonic similarity task for efficient, widespread use

Introduction: The Mnemonic Similarity Task (MST) has become a popular test of memory and, in particular, of hippocampal function. It has been heavily used in research settings and is currently included as an alternate outcome measure in a number of clinical trials. However, as it typically requires ~15 min to administer and benefits substantially from an experienced test administrator to ensure the instructions are well-understood, its use in trials and in other settings is somewhat restricted. Several different variants of the MST are in common use that alter the task format (study-test vs. continuous) and the response prompt given to participants (old/similar/new vs. old/new).
Methods: In eight online experiments, we sought to address three main goals: (1) To determine whether a robust version of the task could be created that could be conducted in half the traditional time; (2) To determine whether the test format or response prompt choice significantly impacted the MST’s results; an..., Overview:
Briefly, each sheet contains data from one of the experiments. Each experiment consisted of giving participants both the classic MST and a variant of the MST (order was counter-balanced). 
Published Methods
The MST has been extensively described elsewhere (Stark et al., 2013, 2019). Briefly, when used in the study-test format, pictures of color objects appear on the screen (2.0s, ≥0.5s ISI) initially during an incidental encoding phase in which participants were asked to classify each object as belonging indoors or outdoors. For example, one might judge a picnic basket as an outdoor item and a rubber duck as an indoor item. The traditional full-length version uses 128 study items and is partially self-paced (the image disappears after the 2s duration, but the prompts remain on screen until the participant makes a response with a minimum total trial length of 2.5s). Immediately following the encoding phase, a test phase is given with an equal number of novel foils that are unre..., , # Optimizing the mnemonic similarity task for efficient, widespread use

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The Mnemonic Similarity Task (MST) has become a popular test of memory and, in particular, of hippocampal function. It has been heavily used in research settings and is currently included as an alternate outcome measure on a number of clinical trials. However, as it typically requires \~15 minutes to administer and benefits substantially from an experienced test administrator to ensure the instructions are well-understood, its use in trials and in other settings is somewhat restricted. Several different variants of the MST are in common use that alter the task format (study-test vs. continuous) and the response prompt given to participants (old / similar / new vs. old / new). Here, we sought to address three main goals: 1) To determine whether a robust version of the task could be created that could be conducted in half the trad...