Context-specific effects of violated expectations: ERP evidence.

A complete understanding of the predictive processing effect in sentence comprehension needs to understand both the facilitation effect of successful prediction and the cost associated with disconfirmed predictions. The current study compares the predictive processing effect across two types of contexts in Mandarin Chinese: the classifier-noun vs. verb-noun phrases, when controlling for the degree of contextual constraints and cloze probability of the target nouns across the two contexts. The two contexts showed similar N400 patterns for expected target nouns, indicative of an identical facilitation effect of confirmed contextual expectation. But in the post-N400 time window, the processing cost associated with the unexpected words differed between the two contexts. Additional differences between the two contexts were also revealed by the neural oscillation patterns obtained prior to the target noun. The differences between the classifier vs. verb contexts shed new light on the revision mechanism that deals with disconfirmed expectations.

The default-interventionist model underlies premise typicality weakening the premise diversity effect during category-based induction: Event-related potentials evidence.

The diversity effect during category-based induction (CBI) means that the more diverse the evidence, the higher will be the conclusion's inductive strength. However, it is influenced by the premise typicality. Three competitive cognitive processing models account for this influence: (1) The pre-emptive conflict resolution model assumes that only premise typicality activates; (2) the parallel-competitive model assumes that premise typicality and diversity activate in parallel; and (3) the default-interventionist model assumes that a default response of premise diversity first activates and is subsequently followed by premise typicality, or premise typicality activates first, followed by premise diversity. The timing of premise typicality affecting the diversity effect during CBI was measured using event-related potentials to determine which cognitive model best explains this influence. Similar to previous studies, non-diverse premise inductive tasks involving two typical premise categories were compared with diverse premise inductive tasks involving a typical and an atypical category. The results showed that non-diverse conditions had higher "correct" response proportions, greater inductive strength, higher "definitely" response proportions, and shorter reaction times than diverse conditions, showing that premise typicality weakens the diversity effect. Moreover, the diverse premises elicited larger P2, smaller FN400, and greater frontal post-N400-positivity amplitudes than non-diverse premises, suggesting that premise diversity was facilitated during a relatively early time window and revised by premise typicality in a later window. These results support the default-interventionist in nature during thinking and reasoning.

Semantic P600-but not N400-effects index crosslinguistic variability in speakers' expectancies for expression of motion.

The expression of motion shows strong crosslinguistic variability; however, less is known about speakers' expectancies for lexicalizations of motion at the neural level. We examined event-related brain potentials (ERPs) in native English or Spanish speakers while they read grammatical sentences describing animations involving manner and path components of motion that did or did not violate language-specific patterns of expression. ERPs demonstrated different expectancies between speakers: Spanish speakers showed higher expectancies for motion verbs to encode path and English speakers showed higher expectancies for motion verbs to encode manner followed by a secondary path expression. Interestingly, grammatical but infrequent motion expressions (manner verbs in Spanish, path verbs and secondary manner expressions in English) elicited semantic P600 rather than the expected N400 effects-with or without post-N400 positivities-that are typically associated with semantic processing. Overall, our findings provide the first empirical evidence for the effect of crosslinguistic variation in processing motion event descriptions at the neural level.

Electrophysiological evidence for preserved primacy of lexical prediction in aging.

Young adults show consistent neural benefits of predictable contexts when processing upcoming words, but these benefits are less clear-cut in older adults. Here we disentangle the neural correlates of prediction accuracy and contextual support during word processing, in order to test current theories that suggest that neural mechanisms underlying predictive processing are specifically impaired in older adults. During a sentence comprehension task, older and younger readers were asked to predict passage-final words and report the accuracy of these predictions. Age-related reductions were observed for N250 and N400 effects of prediction accuracy, as well as for N400 effects of contextual support independent of prediction accuracy. Furthermore, temporal primacy of predictive processing (i.e., earlier facilitation for successful predictions) was preserved across the lifespan, suggesting that predictive mechanisms are unlikely to be uniquely impaired in older adults. In addition, older adults showed prediction effects on frontal post-N400 positivities (PNPs) that were similar in amplitude to PNPs in young adults. Previous research has shown correlations between verbal fluency and lexical prediction in older adult readers, suggesting that the production system may be linked to capacity for lexical prediction, especially in aging. The current study suggests that verbal fluency modulates PNP effects of contextual support, but not prediction accuracy. Taken together, our findings suggest that aging does not result in specific declines in lexical prediction.