When repeated presentation of visual feature bindings does and does not result in learning: Visual short-term and long-term memory are distinct but work in tandem

Two experiments explored a finding that multiple, repeated presentations of the same, six-item colour-shape-location array results in no, or very slow improvements in change detection performance. This contrasts with studies showing clear learning from small numbers of repetitions of verbal and visual stimuli with memory tested by recall or reconstruction. Experiment 1 presented the same six-item visual array repeated across 120 trials for change detection between a study presentation and a test presentation that was identical or depicted a feature swap on 50% of trials. Longer (5000 ms) versus shorter (2000 ms and 500 ms) intervals between the study array and the test array resulted in more participants improving their performance, but only after at least 30 repetitions of the array. A study-test interval of 500 ms resulted in no improvement in performance across 180 repetitions of the same array. Experiment 2 showed that, regardless of the stimulus duration, presenting different arrays on each trial resulted in a lack of learning that was similar to that in Experiment 1 for a 500 ms study-test interval. Results appear consistent with reliance on a limited capacity temporary visual memory for change detection that retains the array only for the current trial and does not support learning across repetitions. With a sufficiently long study-test interval, it is proposed that on each trial there is, in addition, a weak long-term episodic trace of the array that gradually strengthens across repetitions until it is sufficiently strong to be useful for supplementing performance.