Biomedical subjects

Yue-Jia Luo

Publications and source records attributed to Yue-Jia Luo.

9 recordsLinked to original sources

PubMed2006

Attention shortage resistance of negative stimuli in an implicit emotional task.

Considerable evidence from behavioral studies has indicated that people tend to pay attention to negative stimuli preferentially. The attentional bias can occur rapidly and automatically. In the current study, a 'cue-target' paradigm was utilized to manipulate the attention allocation. Seventeen healthy undergraduates participated in the experiment. The stimuli were emotional pictures (positive, neutral and negative), which were upper and lower adjacent patchworks of a normal scene and its inverted copy. The subjects should judge whether the normal scene (compared with the inverted scene) was located in the upper or lower part of the whole patchwork. We used this implicit emotional task to avoid the task relevance effect. It was found that the amplitude of P2 waves was enlarged by the negative pictures and there was a significant interaction between the cue effect and the emotional valence. We can conclude that the negative information exerts an attentional bias effect in the emotional perception, and that the negative contents suffer less in the insufficient attention condition compared with the positive and the neutral conditions.

Adult↗

PubMed2006

Brain dynamic mechanisms of scale effect in visual spatial attention.

The dynamic mechanisms of the early event-related potential scale effect of different attentive regions in the brain was studied. The paradigm of this experiment is the precue-target visual search paradigm by event-related potential technique. The results showed that the reaction time was shortened with the reduction of cue scale, a cue to how big the search area would be, and fixed target stimulus, while the amplitudes of P1 and N1 components of event-related potentials increased. These results not only provided the electrophysiological evidences that supported the zoom-lens theory, but also indicated that the zoom-lens effect happened at the early selected attention period. The results also showed that there existed two kinds of separation in the P2 effect.

Adult↗

PubMed2006

Differential influences of negative emotion on spatial and verbal working memory: Evidence from event-related potential and source current density analysis.

We used the event-related potential technique to assess the influences of negative emotion on spatial and verbal working memory with a modified n-back task. In both spatial and verbal tasks, the anterior late positive component and the posterior P300 were affected by negative emotion. These effects were, however, greater in spatial tasks than in verbal ones. Especially, the parietal P300 was reduced by negative emotion in spatial tasks, but not in verbal tasks. Current density analysis revealed high current density in the frontal-parietal cortex, but only in the spatial tasks. The results suggest differential effects of negative emotion on spatial and verbal working memory and that the frontal-parietal cortex may be the area where negative emotion and spatial working memory interact.

Adult↗

PubMed2006

Temporal course of emotional negativity bias: an ERP study.

There is considerable evidence that people are especially sensitive to emotionally negative materials. However, the temporal course of the negativity bias is still unclear. To address this issue, we observed the changes of P2, late positive components (LPC) and lateralized readiness potential (LRP) under positive, negative and neutral conditions, with International Affective Picture System (IAPS) pictures as emotional stimuli. We found that the amplitude of P2 in the negative block was significantly larger than that in the positive block, indicating that the attentional negativity bias occured very early in emotion perception. The LPC amplitude evoked by negative pictures was larger than that by positive and neutral pictures, suggesting that the negativity bias also occurred in a later evaluation stage of emotion processing. The response-locked LRP interval was shortest in the block of negative pictures, indicating that the negative contents elicited a reaction priming effect. Above all, this research showed that emotional negativity bias could occur in several temporal stages distinguished by attention, evaluation and reaction readiness periods.

Adult↗

PubMed2005

Counting in everyday life: discrimination and enumeration.

Enumerating the number of items in a set accurately and quickly is a basic mathematical skill. This ability is especially crucial in the more real-life situations, where relevant items have to be discriminated from irrelevant distracters. Although much work has been done on the brain mechanisms and neural correlates of the enumeration and/or discrimination process, no agreement has been reached yet. We used event-related potentials (ERPs) to show the time course of brain activity elicited by a task that involved both enumeration and discrimination at the same time. We found that even though the two processes run to some extent in parallel, discrimination seems to take place mainly in an earlier time window (from 100 ms after the stimulus onset) than enumeration (beyond 200 ms after the stimulus onset). Moreover, electrophysiological evidence based on the N2 and P3 components make it reasonable to argue for the existence of a dichotomy between subitizing (for sets of less than four items) and counting (for sets of four and more items). Source estimation suggests that subitizing and counting, though being distinct brain processes, do recruit similar brain areas.

Activities of Daily Living↗

PubMed2005

Anxiety and attentional bias for threat: an event-related potential study.

We investigated the attentional bias for threat in selected high and low trait-anxious participants using an event-related potential technique. A modified cue-target paradigm was adopted with threatening and nonthreatening pictures as uninformative location cues. In high anxious individuals, reactions were speeded up and the occipitoparietal P1 amplitude was enhanced when targets appeared at the same location as threatening pictures relative to nonthreatening ones, whereas in low anxious individuals, the P1 amplitude tended to be enhanced when the targets appeared at the opposite location to threatening pictures. These results suggest that the attentional bias caused by peripheral threatening stimuli is able to modulate the visual inputs in early processing stages, and this mechanism is markedly influenced by an individual's anxiety level.

Adult↗

PubMed2004

"Aha!" effects in a guessing riddle task: an event-related potential study.

Insight problem solving has been the topic of much investigation. It is believed widely that insight critically contains the process of breaking one's mental set. Recent functional magnetic resonance imaging (fMRI) research on puzzle solving showed that insight was associated with activities in anterior cingulate cortex (ACC) and other areas (Luo and Niki [2003]: Hippocampus 13:274-281). We proposed ACC might mediate processes of breaking one's mental set, given its well-known role in cognitive conflict. In the present research, high-density event-related potentials (ERPs) were recorded to examine the electrophysiologic correlates of insight problem solving. One hundred twenty interesting Chinese riddles (half difficult and half easy) were adopted as materials. For each trial, subjects were either given an easy puzzle followed by a keyword that was consistent with the subject's initial thinking ("No-aha answer"), or a difficult puzzle followed by a keyword that was consistent with an unusual interpretation, so that it broke the subject's initial mental set ("Aha answer"). Results from 14 subjects showed that Aha answers elicited a more negative ERP deflection than did No-aha answers in the time window from 250-500 msec after onset of the answer. The ERP difference wave (Aha minus No-aha answer) showed the maximum amplitude over the central site (Cz) with a peak latency of 380 msec (N380). Voltage and current density maps of the difference wave showed strong activity and current density in the frontocentral region. Dipole analysis localized the generator of the N380 in the ACC. N380 therefore probably reflects an "Aha!" effect, and the ACC generator may be involved in the breaking of mental set.

Adult↗

PubMed2002

A modified oddball paradigm "cross-modal delayed response" and the research on mismatch negativity.

A modified oddball paradigm was developed to facilitate the focus of attention and to minimize target effects on deviant-related components of auditory and visual event-related potentials (ERPs) elicited with long interstimulus intervals. Subjects were required to focus on either the visual or auditory stimulus in each stimulus block. Deviant-related components were obtained by subtracting ERPs of the standard stimulus from that of the deviant stimulus for each modality with each stimulus condition. Results showed that auditory mismatch negativity (MMN) and a visual early deviant related negativity (DRN1) were elicited both when stimuli were attended and unattended. In contrast, N2b and P3 were produced only under the attended condition. In comparison of attended MMN and unattended MMN at three time windows (100-150 ms, 150-200 ms, and 200-250 ms) of MMN zone, different scalp distributions were shown, depending on the time windows. This result suggests that the attended auditory MMN is a mixed wave, consisting of genuine MMN, N2b, and possible P165. The effect of attention on MMN may stem from the contamination of these overlapping components. With the present paradigm, at least three sensory memory traces have to be maintained simultaneously in multiple sensory modalities to support automatic processing.

Adult↗

PubMed2002

Priming of two-dimensional visual motion is reduced in older adults.

Previously, Y. Jiang, P. Greenwood, and R. Parasuraman (1999) reported that priming of rotating three-dimensional visual objects is age sensitive. The current study investigated whether there is also an age-related difference in priming with simple two-dimensional (2-D) moving stimuli (i.e., whether a prime stimulus moving in a particular direction causes a subsequent ambiguous target stimulus to be seen moving in the same direction as the prime). In 2 experiments, younger and older adults judged the directions of moving sine-wave gratings. Groups differed neither in determining the direction of a single 2-D movement nor in detecting motion reversals in successively moving gratings. However, the older group showed a significant reduction in the extent of 2-D motion priming. The decrement in older adults for visual motion priming may reflect age-related changes in temporal processing in human visual cortex.

Adult↗