Disruption to left inferior frontal cortex modulates semantic prediction effects in reading and subsequent memory: Evidence from simultaneous TMS-EEG

Abstract

Readers use prior context to predict features of upcoming words. When predictions are accurate, this increases the efficiency of comprehension. However, little is known about the fate of predictable and unpredictable words in memory or the neural systems governing these processes. Several theories suggest that the speech production system, including the left inferior frontal cortex (LIFC), is recruited for prediction but evidence that LIFC plays a causal role is lacking. We first examined the effects of predictability on memory and then tested the role of posterior LIFC using transcranial magnetic stimulation (TMS). In Experiment 1, participants read category cues, followed by a predictable, unpredictable, or incongruent target word for later recall. We observed a predictability benefit to memory, with predictable words remembered better than unpredictable words. In Experiment 2, participants performed the same task with electroencephalography (EEG) while undergoing event-related TMS over posterior LIFC using a protocol known to disrupt speech production, or over the right hemisphere homologue as an active control site. Under control stimulation, predictable words were better recalled than unpredictable words, replicating Experiment 1. This predictability benefit to memory was eliminated under LIFC stimulation. Moreover, while an a priori ROI-based analysis did not yield evidence for a reduction in the N400 predictability effect, mass-univariate analyses did suggest that the N400 predictability effect was reduced in spatial and temporal extent under LIFC stimulation. Collectively, these results provide causal evidence that the LIFC is recruited for prediction during silent reading, consistent with prediction-through-production accounts.

The costs (and benefits?) of effortful listening for older adults: Insights from simultaneous electrophysiology, pupillometry, and memory

“…We found that high-constraint sentences were generally remembered better than low-constraint sentences and that expected sentence-final words were recalled better than unexpected sentence-final words. In general, this adds to the growing literature that engaging in predictive processes can benefit memory (e.g., Silcox, Mickey, & Payne, 2023;Silcox & Payne, 2021;Gordon-Salant & Fitzgibbons, 1997;Kutas, 1993). The results from the current study also showed that prediction is not just helpful when a prediction turns out to be correct but also when it is incorrect.…”

“…Indeed, over the last 70 years (Black, 1952;Howes & Osgood, 1954;Miller, 1951;Taylor, 1953), studies have explored the effects of prior linguistic context on perception and comprehension and have reliably shown that words congruent with (and more predictable from) prior context are facilitated in processing relative to less expected input. Predictable words show faster visual and auditory word recognition in lexical decision tasks (Schwanenflugel & Shoben, 1985;Fischler and Bloom, 1979), shorter fixation durations during natural reading (Staub, 2015), improved word recognition in noise (Pichora-Fuller et al, 1995), improved memory (Gordon-Salant & Fitzgibbons, 1997;Kutas, 1993;Silcox, Mickey, & Payne, 2023;Silcox & Payne, 2021), and facilitated semantic processing as revealed by recordings of event-related brain potentials (ERPs) (Kutas & Federmeier, 2011;Federmeier, 2022).…”

“…Late frontal ERP responses, typically occurring after the onset of the N400 have been consistently observed across multiple studies (e.g., Wlotko & Federmeier, 2012;Payne & Federmeier, 2017;Hubbard & Federmeier, 2021;Federmeier et al, 2007Federmeier et al, , 2010DeLong et al, 2014;Kuperberg et al, 2020). However, these later frontal responses are not always observed (e.g., Stone et al, 2022;Stites et al, 2017;Silcox & Payne, 2021;Silcox et al, 2023). Moreover, even when observed, features of the study design and stimuli can make it difficult to differentiate between two distinct but spatiotemporally overlapping late frontal responses.…”