Tracking the implicit acquisition of nonadjacent transitional probabilities by ERPs

Andrea Kóbor,Kata Horváth,Karolina Janacsek,Zsófia Kardos,Ádám Takács,Valéria Csépe,Dezso Nemeth

doi:10.3758/s13421-019-00949-x

Abstract

The implicit acquisition of complex probabilistic regularities has been found to be crucial in numerous automatized cognitive abilities, including language processing and associative learning. However, it has not been completely elucidated how the implicit extraction of second-order nonadjacent transitional probabilities is reflected by neurophysiological processes. Therefore, this study investigated the sensitivity of event-related brain potentials (ERPs) to these probabilistic regularities embedded in a sequence of visual stimuli without providing explicit information on the structure of the stimulus stream. Healthy young adults (N = 32) performed a four-choice RT task that included a sequential regularity between nonadjacent trials yielding a complex transitional probability structure. ERPs were measured relative to both stimulus and response onset. RTs indicated the rapid acquisition of the sequential regularity and the transitional probabilities. The acquisition process was also tracked by the stimulus-locked and response-locked P3 component: The P3 peak was larger for the sequence than for the random stimuli, while the late P3 was larger for less probable than for more probable short-range relations among the random stimuli. According to the RT and P3 effects, sensitivity to the sequential regularity is assumed to be supported by the initial sensitivity to the transitional probabilities. These results suggest that stimulus–response contingencies on the probabilistic regularities of the ongoing stimulus context are implicitly mapped and constantly revised. Overall, this study (1) highlights the role of predictive processes during implicit memory formation, and (2) delineates a potential to gain further insight into the dynamics of implicit acquisition processes.

Highlights

The implicit acquisition of complex probabilistic regularities has been found to be crucial in numerous automatized cognitive abilities, including language processing and associative learning
Our previous findings indicate that acquisition processes related to certain types of probabilistic regularities can be distinguished at the level of event-related brain potentials (ERPs), when the repeating regularity determining stimulus presentation is explicitly cued (Kóbor et al, 2018)
Assumptions formulated in prior ERP research have been unspecific about which phase of, which parameter of, and how the P3 component should be modulated by the acquisition of predictive relations

Summary

Introduction

The implicit acquisition of complex probabilistic regularities has been found to be crucial in numerous automatized cognitive abilities, including language processing and associative learning. In a handful of studies, larger P3 amplitudes were found for the more predictable events than for the less predictable ones in the explicit condition (Batterink, Reber, & Paller, 2015; Fogelson, Shah, Scabini, & Knight, 2009), in the implicit condition (Baldwin & Kutas, 1997; Daltrozzo et al, 2017; Jost et al, 2015; Rose et al, 2001; Rüsseler et al, 2018; Stadler et al, 2006), or both (Fogelson & Fernandezdel-Olmo, 2013) It seems that the P3 amplitude enhancement for the more rather than the less predictable events has usually been observed in highly structured tasks including short, repeating predictor–target sequences, in which the transitional probabilities between the predictors and the target have had to be extracted. The question has remained whether amplitude modulations of the P3 could track the temporal trajectory of implicitly acquiring complex second-order nonadjacent transitional probabilities and it has yet to be clarified which phase of the component in what direction would change as a reflection of this perceptualcognitive process

Methods

Results

Discussion

Conclusion