Accuracy-based measures provide a better measure of sequence learning than reaction time-based measures

Abstract

The Serial Reaction Time Task (SRTT) was designed to measure motor sequence learning and is widely used in many fields in cognitive science and neuroscience. However, the common performance measures derived from SRTT—reaction time (RT) difference scores—may not provide valid measures of sequence learning. This is because RT-difference scores may be subject to floor effects and otherwise not sufficiently reflective of learning. A ratio RT measure might minimize floor effects. Furthermore, measures derived from predictive accuracy may provide a better assessment of sequence learning. Accordingly, we developed a Predictive Sequence Learning Task (PSLT) in which performance can be assessed via both RT and predictive accuracy. We compared performance of N = 99 adults on SRTT and PSLT in a within-subjects design and also measured fluid abilities. The RT-difference scores on both tasks were generally not related to fluid abilities, replicating previous findings. In contrast, a ratio RT measure on SRTT and PSLT and accuracy measures on PSLT were related to fluid abilities. The accuracy measures also indicated an age-related decline in performance on PSLT. The current patterns of results were thus inconsistent across different measures on the same tasks, and we demonstrate that this discrepancy is potentially due to floor effects on the RT difference scores. This may limit the potential of SRTT to measure sequence learning and we argue that PSLT accuracy measures could provide a more accurate reflection of learning ability.

Time course of colour-word contingency learning: Practice curves, pre-exposure benefits, unlearning, and relearning

“…Though obviously still a genuine learning effect regardless of how the effect is scaled, this does make it difficult to directly relate the magnitude of a contingency effect to the amount of underlying contingency knowledge. Similar points have been raised outside the acquisition domain (Kaufman et al, 2010;Stevens et al, 2002;Urry et al, 2015).…”

“…That is, overall learning effects might be larger when overall responding is slower (Stevens et al, 2002;Urry, Burns, & Baetu, 2015). In the initial blocks of learning, the contingency effect might be inflated simply because overall responding is slower early in the experiment.…”

Age‐related differences in sequence learning: Findings from two visuo‐motor sequence learning tasks

“…The sequence learning tasks were similar to the ones we previously used (see Baetu, Burns, Urry, Barbante, & Pitcher, ; Urry et al ., ). The SRTT and PSLT were matched in appearance and sequences.…”

“…We have previously investigated the possibility that traditional RT‐difference scores might mask associations between motor sequence learning and individual differences using a Predictive Sequence Learning Task (PSLT Urry et al ., ). PSLT is a modified version of SRTT that is very similar to it but requires participants to predict, rather than react to, the location of the next stimulus.…”

“…So the measure reliability confound could cast doubt on the empirical evidence that is consistent with a dual‐systems theory. The results of previous studies do suggest that implicit‐like (RT‐based) measures are less reliable than explicit‐like (accuracy‐based) measures in memory (Ward et al ., ,b) and sequence learning (Urry, Burns, & Baetu, ) tasks and are therefore less sensitive to individual differences. We provide here further evidence that this is the case, focusing on age effects in sequence learning.…”