Despite strong evidence for prediction during language comprehension, the underlying mechanisms, and the extent to which they are specific to language, remain unclear. Re-analysing an event-related potentials study, we examined responses in the time-frequency domain to expected and unexpected (but plausible) words in strongly and weakly constraining sentences, and found results similar to those reported in nonverbal domains. Relative to expected words, unexpected words elicited an increase in the theta band (4–7 Hz) in strongly constraining contexts, suggesting the involvement of control processes to deal with the consequences of having a prediction disconfirmed. Prior to critical word onset, strongly constraining sentences exhibited a decrease in the alpha band (8–12 Hz) relative to weakly constraining sentences, suggesting that comprehenders can take advantage of predictive sentence contexts to prepare for the input. The results suggest that the brain recruits domain-general preparation and control mechanisms when making and assessing predictions during sentence comprehension.
2 June 2014 in Language, Cognition and Neuroscience
Many theories of visual word processing assume obligatory semantic access and phonological recoding whenever a written word is encountered. However, the relative importance of different reading processes depends on task. The current study uses event-related potentials (ERPs) to investigate whether – and, if so, when and how – effects of task modulate how visually presented words are processed. Participants were presented written words in the context of two tasks, delayed reading aloud and proper name detection. Stimuli varied factorially on lexical frequency and on spelling-to-sound regularity, while controlling for other lexical variables. Effects of both lexical frequency and regularity were modulated by task. Lexical frequency modulated N400 amplitude, but only in the reading aloud task, whereas spelling-to-sound regularity interacted with frequency to modulate the late positive complex, again only in the reading aloud task. Taken together, these results demonstrate that task demands affect how meaning and sound are generated from written words.
• ERPs were used to compare multiplication fact processing in children and adults. • Different brain responses were elicited by children (N400) and adults (P300). • Results were directly compared to a language task (word-picture verification). • Access to arithmetic facts resembles language processing in children. • Adults interpret solutions as targets and categorize them efficiently.