Cortis Mack, C., Harding, M., Davies, N., & Ward, G. (2019). RECAPP-XPR: A smartphone application for presenting and recalling experimentally controlled stimuli over longer timescales. Behavior research methods, 51(4), 1804-1823.

Members from the PACTMAN team at University of Essex (Cathleen Cortis Mack and Geoff Ward) and Lancaster University (Mike Harding and Nigel Davies) have published a detailed account of the RECAPP-XPR application in the international journal, Behaviour research methods. This iPhone application can be used for presenting and recalling experimentally controlled stimuli over extended timescales.

Historically, many psychology experiments examine human memory by testing memory for lists of carefully-controlled stimuli in the laboratory under specified schedules. Although great progress has occurred using these methods, they are most effective at understanding memory for events that are separated and recalled after intervals of seconds or at most minutes. By contrast, it would be unfeasible to invite participants back to the laboratory in order to present sequences of items separated by hours, days, or weeks.

We follow up on our recent work (Cortis Mack, Davies, Harding & Ward, 2017) and we report two experiments that used smartphone applications for presenting and recalling verbal stimuli over extended timescales. In Experiment 1, we used an iPhone application that we had developed, called RECAPP-XPR, to present 76 participants with a single list of eight words presented at a rate of one word every hour, followed by a test of free recall an hour later. The experiment was exceptionally easy to schedule, taking only between 5 and 10 min to set up using a web-based interface. RECAPP-XPR randomly samples the stimuli, presents the stimuli, and collects the free recall data. The stimuli disappear shortly after they have been presented, and RECAPP-XPR collects data on when each stimulus was viewed.

In Experiment 2, the study was replicated using the widely used image-sharing application Snapchat. A total of 197 participants were tested by 38 student experimenters, who manually presented the stimuli as “snaps” of experimentally controlled stimuli using the same experimental rates that had been used in Experiment 1. Like all snaps, these stimuli disappeared from view after a very short interval. In both experiments, we observed significant recall advantages for the first and last list items (primacy and recency effects, respectively), and there were clear tendencies to make more transitions at output between near-neighbouring items, with a forward-ordered bias, consistent with temporal contiguity effects. The respective advantages and disadvantages of RECAPP-XPR and Snapchat as experimental software packages are discussed, as is the relationship between single-study-list smartphone experiments and long-term recency studies of real-world events.

Cortis Mack, C., Cinel, C., Davies, N., Harding, M., & Ward, G. (2017). Serial position, output order, and list length effects for words presented on smartphones over very long intervals. Journal of memory and language, 97, 61-80.