Previous studies find that the feedback-related negativity in brain potentials is sensitive to the negative outcome of one’s own performance. The feedback-related negativity is suggested to reflect the learning processes using feedback about the consequences of recent actions. Learning can also take placewhen one observes other people’s actions and the associated outcomes. We recorded brain potentials while the participant received outcome feedback for their own or for another person’s performance in a gambling task. The feedback-related negativity or the feedback-related negativity-like effects were obtained in both situations, suggesting that similar neural mechanisms are involved in evaluating the outcomes of one’s own and the other’s actions. Thus, the neural processes in learning-by-observation resemble those in learning-by-doing. NeuroReport 17: 1747-1751 © 2006 LippincottWilliams &Wilkins.

The event-related potential (ERP) technique was used to investigate the neural dynamics in processing different levels of the hierarchical syntactic structure during comprehension of Chinese sentences with the ba construction. In these sentences, the structural auxiliaries, which mark either the adjective (-de) or the adverb (-di) category, were embedded in a hierarchical structure at the lower level, i.e., BA-adjective (-de)-noun-verb, or at the higher level, i.e., BA-noun-adverb (-di)-verb. Violations of the lower-and the higher-level structural constraints were constructed by misapplication of these structural auxiliaries. Participants were required to read all the sentences for comprehension and to complete a sentence recognition test at the end of the experiment. Violation of the lower-level constraints elicited a left-lateralized, anteriorly maximized negativity, whereas violation of the higher-level constraints elicited a right anterior negativity (RAN) and a right centro-parietal negativity (N400) from 300 to 500ms postonset of the auxiliary phrase. Neither type of violation led to a late positivity effect on the critical auxiliary phrases. These findings suggest that processing different levels of syntactic hierarchy during natural language comprehension may involve different neural mechanisms.

The issue of how phonological information becomes available in reading Chinese and the role that it plays in lexical access was investigated for Chinese compound words, using pseudohomophone effects in lexical and phonological decision as a diagnostic tool. Pseudohomophones were created by replacing one or both constituents of two-character compound words with orthographically dissimilar homophonic characters. Experiment 1 found that mixed pseudohomophones sharing one constituent with their base words were more difficult to reject than control nonwords in lexical decision. Pure pseudohomophones sharing no constituents with their base words did not show this effect. Experiment 2 used mixed pseudohomophones and found an interaction between base word frequency and the frequency of constituent characters in determining pseudohomophone effects. Experiment 3 used a phonological decision task and found exceptionally poor performance for pure pseudohomophones. These results are interpreted in an interactive framework where the direct mapping from orthography to semantics is dominant and phonology plays a subsidiary role.

Two experiments were conducted to examine the Simon effect (i.e., faster responding when irrelevant stimulus location corresponds with response location than when it does not) in visual search tasks. The search items were arranged in a 4 × 4 grid, and grid locations were coded into sets of four, two involving inner columns and two involving outer columns. In experiment 1, three different types of inefficient search tasks were used. The Simon effects were shown to be larger when the target appeared in one of the outer columns than in one of the inner columns (“laterality effect”). This pattern of results was not observed when distractors were absent, suggesting that the laterality effect depends on the operation of selective attention. In experiment 2, a pop-out search task was used, and no significant effect of target location on the Simon effect was found. Interpretations of the results based on the attention-shift account and referential-coding account were discussed.

This study investigated whether individuals with a high trait anxiety (HTA) rating retain attentional bias towards threatening pictures when such pictures are repeatedly presented. Subjects rated high (n = 20) and low (n = 20) on an anxiety scale participated in a forced-choice reaction time version of a modified dotprobe task. Picture pairs were presented in four exposure blocks. On each exposure, the attentional bias to the threatening pictures was measured. HTA individuals showed more selective attention to the high threatening pictures than individuals with low trait anxiety (LTA). However, HTA individuals did not maintain attentional bias. On the fourth block, the attentional bias to threatening pictures disappeared. Theoretical and methodological implications of these findings are discussed.