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.

The role of perceptual load in selective attention to multidimensional objects was investigated by independently manipulating the load along the task-relevant and the task-irrelevant dimensions in the central search array, which was flanked by congruent, incongruent, or neutral peripheral distractors. The relative bottom-up perceptual saliency of these dimensions in capturing attention was manipulated between experiments. When the task-relevant dimension was the color of the letter and the task-irrelevant dimension was the visual shape of the letter (Experiment 1), manipulation of the letter shape perceptual load had no impact upon the pattern of congruency effects in responding to the color, i.e., smaller congruency effects under higher color perceptual loads and larger congruency effects under lower color perceptual loads. When the task-relevant dimension was the shape of the letter and the task-irrelevant dimension was the color of the letter (Experiment 2), there were no congruency effects in responding to the letter shape under high color perceptual loads irrespective of the letter shape loads. When only the target and the flanker were colored whereas the distractors in the central array were not (Experiment 3), the taskirrelevant color information reduced or eliminated the impact of letter shape perceptual load on the congruency effects in responding to the letter shape. These findings suggested that selective attention to multidimensional objects follows the general principles suggested by the perceptual load theory, but the bottom-up perceptual saliency plays a primary role in the distribution of attentional resources over objects and dimensions.

Feedback-related negativity is a negative deflection in brain potentials associated with feedback indicating monetary losses or response errors. Feedback-related negativity is studied primarily in paradigms in which participants experience negative outcomes that appear to be contingent upon their previous choices. This study investigated whether feedback-related negativity can be elicited by a randomly assigned cue indicating potential monetary loss. The expected loss or win can be materialized or averted depending on participants’ performance in a subsequent game. Compared with the win cue, the loss cue elicited a weak but significant feedback-related negativity-like effect. It is suggested that the anterior cingulate cortex, which generates feedback-related negativity, may function as a pre-warning system that alerts the brain to get ready for future events. NeuroReport 17: 1649-1653 © 2006 Lippincott Williams &Wilkins.

This study explored the interaction between the spatial distribution of attention during inhibition of return (IOR) and different levels of flanker interference in congenitally deaf subjects as compared with hearing subjects. Color (Experiment 1) and alphanumeric (Experiment 2) flanker interference effects were differentiated into the pre-response and the response levels. The spatial distribution of attention was manipulated through IOR. Subjects were asked to either make color or letter/digit discriminations to the central targets or detect the abrupt-onset peripheral targets. Deaf subjects were significantly faster than hearing subjects at detecting peripheral targets irrespective of the cue validity, while the two groups had comparable sizes of IOR. In the central discrimination tasks, deaf subjects showed significant response level, but not pre-response level, flanker effects irrespective of the type of stimuli and the spatial location of the flanker. For hearing subjects, however, spatial attention interacted with the pre-response and response flanker effects in different ways. While flankers at the cued location caused interference effects at the response level and facilitatory effects at the pre-response level, those at the uncued location caused different effects depending on the type of stimuli. Moreover, increasing the peripheral attention for hearing subjects, by increasing the proportion of peripheral detection trials, made hearing subjects behave like deaf subjects. These results demonstrate that deaf people possess enhanced peripheral attentional resources as compared with hearing people. The spatial distribution of attention modulates mainly the resolution of the pre-response flanker interference in hearing people, but affects neither the pre-response nor the response level interference in deaf people.

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.