Biomedical subjects

Jinghan Wei

Publications and source records attributed to Jinghan Wei.

3 recordsLinked to original sources

PubMed2005

Spoken word recognition in context: evidence from Chinese ERP analyses.

Two event-related potential (ERP) experiments were conducted to investigate spoken word recognition in Chinese and the effect of contextual constraints on this process. In Experiment 1, three kinds of incongruous words were formed by altering the first, second or both syllables of the congruous disyllabic terminal words in high constraint spoken sentences. Results showed an increase of N400 amplitude in all three incongruous word conditions and a delayed N400 effect in the cohort incongruous condition as compared with the rhyme incongruous and plain incongruous condition. In addition, unlike results in English, we found that the N400 effect in the rhyme incongruous condition disappeared earlier than in the plain incongruous condition. In Experiment 2, three kinds of nonwords derived from sentence congruous words were constructed by altering few or many phonetic features of the onset or the whole of the first syllable, and the resulting nonwords appeared as disyllabic terminal forms in either high or low constraint sentences. All three nonword conditions elicited the N400 component. In addition, in high constraint sentences but not in low, the amplitude and duration of the N400 varied as a function of the degree of phonetic mismatch between the terminal nonword and the expected congruous word.

Adult↗

PubMed2005

The recognition potential: semantic processing or the detection of differences between stimuli?

The recognition potential is traditionally described as an electrical index elicited when subjects view a recognizable stimulus. Recent studies further show that it may be influenced by semantic processing. In this study, we investigated whether this observed influence is really produced by differences in semantic processing or whether it might be caused by the detection of differences between sequentially presented stimuli. In two different experiments, we systematically altered the type of background images presented while keeping the recognizable word constant. Analyses revealed that the same recognizable words elicited an RP with different amplitudes and latencies when viewed under different background conditions. Control stimuli, which were identical to background stimuli, did not elicit the RP. Hence, we postulate that when using the rapid stream stimulation paradigm, RP might also be influenced by the detection of differences between sequentially input stimuli. It is necessary to clarify whether RP changes are caused by the processing of the stimuli or by the detection of difference between successively input stimuli before any conclusion could be made.

Adult↗

PubMed2002

A pilot study of functional magnetic resonance imaging of the brain during manual and electroacupuncture stimulation of acupuncture point (LI-4 Hegu) in normal subjects reveals differential brain activation between methods.

OBJECTIVES: To characterize the brain activation patterns evoked by manual and electroacupuncture on normal human subjects. DESIGN: We used functional magnetic resonance imaging (fMRI) to investigate the brain regions involved in electroacupuncture and manual acupuncture needle stimulation. A block design was adopted for the study. Each functional run consists of 5 minutes, starting with 1-minute baseline and two 1-minute stimulation, the interval between the two stimuli was 1 minute. Four functional runs were performed on each subject, two runs for electroacupuncture and two runs for manual acupuncture. The order of the two modalities was randomized among subjects. During the experiment, acupuncture needle manipulation was performed at Large Intestine 4 (LI4, Hegu) on the left hand. For each subject, before scanning started, the needle was inserted perpendicular to the skin surface to a depth of approximately 1.0 cm. Electroacupuncture stimulation was delivered using a continuous rectangular wave form (pulse width 30 ms) at a frequency of 3 Hz. For manual acupuncture, the needle was rotated manually clockwise and counterclockwise at a rate of about 180 times per minute (3 Hz). SUBJECTS: Eleven right-handed, normal, healthy volunteer adults, 6 male and 5 female, ages 21-64 participated in the experiment. RESULTS: Results showed that electroacupuncture mainly produced fMRI signal increases in precentral gyrus, postcentral gyrus/inferior parietal lobule, and putamen/insula; in contrast, manual needle manipulation produced prominent decreases of fMRI signals in posterior cingulate, superior temporal gyrus, putamen/insula. CONCLUSION: These results indicate that different brain networks are involved during manual and electroacupuncture stimulation. It suggests that different brain mechanisms may be recruited during manual and electroacupuncture.

Acupuncture Points↗