Finding pattern in the noise: Persistent implicit statistical knowledge impacts the processing of unpredictable stimuli

Abstract

Previous research recognized that humans could extract statistical regularities of the environment to automatically predict upcoming events. However, it has remained unexplored how the brain encodes the distribution of statistical regularities if it continuously changes. To investigate this question, we devised an fMRI paradigm where participants (N = 32) completed a visual four-choice reaction time (RT) task consisting of statistical regularities. Two types of blocks involving the same perceptual elements alternated with one another throughout the task: While the distribution of statistical regularities was predictable in one block type, it was unpredictable in the other. Participants were unaware of the presence of statistical regularities and of their changing distribution across the subsequent task blocks. Based on the RT results, although statistical regularities were processed similarly in both the predictable and unpredictable blocks, participants acquired less statistical knowledge in the unpredictable as compared with the predictable blocks. Whole-brain random-effects analyses showed increased activity in the early visual cortex and decreased activity in the precuneus for the predictable as compared with the unpredictable blocks. Therefore, the actual predictability of statistical regularities is likely to be represented already at the early stages of visual cortical processing. However, decreased precuneus activity suggests that these representations are imperfectly updated to track the multiple shifts in predictability throughout the task. The results also highlight that the processing of statistical regularities in a changing environment could be habitual.

Modulating Visuomotor Sequence Learning by Repetitive Transcranial Magnetic Stimulation: What Do We Know So Far?

“…The role of the cerebellum in sequence learning is highly uncertain in the literature (Baetens et al 2020;Janacsek et al 2020). While the detrimental effect of cerebellar damage on sequence learning assumes its essential role (Dirnberger et al 2013;Doyon et al 1997;Gomez-Beldarrain et al 1998;Shin and Ivry 2003), neuroimaging studies do not always support this hypothesis (Janacsek et al 2020;Kóbor et al 2022;Seidler et al 2002;van der Graaf et al 2006). However, a recent fMRI study revealed that the cerebellum is involved in the early phase of task performance and coordination since its activity diminishes as the task becomes well practiced (Hermsdorf et al 2020).…”

The complexity of measuring reliability in learning tasks: An illustration using the Alternating Serial Reaction Time Task

“…The task has been employed to study a wide array of questions, ranging from the developmental trajectory of implicit and explicit learning (Nemeth, Janacsek, & Fiser, 2013a) to the effect of instruction on automatization and rewiring (Szegedi-Hallgató et al, 2017). It has been used with EEG (Horváth et al, 2021;Kóbor et al, 2019Kóbor et al, , 2021Takács et al, 2021), non-invasive brain stimulation (Ambrus et al, 2020;Janacsek et al, 2015;Zavecz, Horváth, et al, 2020a), and both structural (Bennett et al, 2011) and functional MRI (Kóbor et al, 2022). It has also been employed to gain insight into both atypical neurocognitive development (Csábi et al, 2016;Nemeth, Janacsek, Balogh, et al, 2010a;Simor et al, 2017;Takács et al, 2018;Tóth-Fáber, Tárnok, Janacsek, et al, 2021a;Tóth-Fáber, Tárnok, Takács, et al, 2021b) and neurological or psychiatric disorders (Janacsek et al, 2018;Nemeth, Janacsek, Király, et al, 2013b;Unoka et al, 2017).…”