EXPRESS: Remembering spatial words: Sensorimotor simulation affects verbal recognition memory

Previous evidence shows that words with implicit spatial meaning or metaphorical spatial associations are perceptually simulated and can guide attention to associated locations (e.g., bird – upward location). In turn, simulated representations interfere with visual perception at an associated location. The present study investigates the effect of spatial associations on short-term verbal recognition memory to disambiguate between modal and amodal accounts of spatial interference effects across two experiments. Participants in both experiments encoded words presented in congruent and incongruent locations. Congruent and incongruent locations were based on an independent norming task. In Experiment 1, an auditorily presented word probed participants’ memory as they were visually cued to either the original location of the probe word or a diagonal location at retrieval. In Experiment 2, there was no cue at retrieval but a neutral encoding condition in which words normed to central locations were shown. Results show that spatial associations affected memory performance although spatial information was neither relevant nor necessary for successful retrieval: Words in Experiment 1 were retrieved more accurately when there was a visual cue in the congruent location at retrieval but only if they were encoded in a non-canonical position. A visual cue in the congruent location slowed down memory performance when retrieving highly imageable words. With no cue at retrieval (Experiment 2), participants were better at remembering spatially congruent words as opposed to neutral words. Results provide evidence in support of sensorimotor simulation in verbal memory and a perceptual competition account of spatial interference effect.

Acute effects of naturalistic THC vs. CBD use on recognition memory: a preliminary study

The ratio of ∆9-tetrahydrocannabinol (THC) to cannabidiol (CBD) varies widely across cannabis strains. CBD has opposite effects to THC on a variety of cognitive functions, including acute THC-induced memory impairments. However, additional data are needed, especially under naturalistic conditions with higher potency forms of cannabis, commonly available in legal markets. The goal of this study was to collect preliminary data on the acute effects of different THC:CBD ratios on memory testing in a brief verbal recognition task under naturalistic conditions, using legal-market Colorado dispensary products. Thirty-two regular cannabis users consumed cannabis of differing THC and CBD levels purchased from a dispensary and were assessed via blood draw and a verbal recognition memory test both before (pretest) and after (posttest) ad libitum home administration in a mobile laboratory. Memory accuracy decreased as post-use THC blood levels increased (n = 29), whereas performance showed no relationship to CBD blood levels. When controlling for post-use THC blood levels as a covariate, participants using primarily THC-based strains showed significantly worse memory accuracy post-use, whereas subjects using strains containing both THC and CBD showed no differences between pre- and post-use memory performance. Using a brief and sensitive verbal recognition task, our study demonstrated that naturalistic, acute THC use impairs memory in a dose dependent manner, whereas the combination of CBD and THC was not associated with impairment.