Implicit Learning of Sound Localisation

Humans can implicitly learn patterns in visual stimuli which may facilitate doing other tasks in parallel. Given that we are constantly surrounded by sounds, we wanted to exploratory investigate whether humans implicitly can learn sequences in sounds emitted from different positions. We developed a new experimental paradigm based on the Serial Reaction Time Task and collected three independent data samples, altogether data from 75 healthy participants aged 18-40. Our group-level results show a smaller implicit learning effect than many previous studies using the conventional tests of implicit learning of visual stimuli. However, observed individual differences were large with 33-67% participants showing indications of implicit learning. No robust differences in attentional ability or sleepiness between learners and non-learners were found. However, in general participants reported high and increasing levels of sleepiness during the testing as well as high-levels of mind-wandering. We conclude that there could be important individual differences in implicit learning but that future tests of implicit learning probably need to be more motivating and engaging to achieve cleaner, more reliable assessments of implicit learning.