Biomedical subjects

Danling Peng

Publications and source records attributed to Danling Peng.

11 recordsLinked to original sources

PubMed2006

Speaking words in the second language: From semantics to phonology in 170 ms.

The temporal course of semantic and phonological retrieval when producing words in the second language was investigated using ERP technique. In the experiment, less proficient Chinese-English bilinguals were required to name pictures in their second language. Before performing this task, they carried out a dual choice go/nogo task on the basis of a picture's semantic information (i.e., whether the picture was of an object or an animal) and phonological information (e.g., whether the picture's English name starts with the letter C or F). During the time window of 200-600ms after stimulus onset, nogo trials generated a more negative ERP profile relative to go trials. A clear-cut N200 was obtained from their difference waves. Overall, the peak latency of N200 elicited by semantic information is earlier than that by phonological information. It takes unbalanced bilinguals approximate 170ms to retrieve phonological information after semantic information becomes available in the second language production. These findings suggest that the semantic information is encoded earlier than the phonological information during the second language production.

Adolescent↗

PubMed2006

Event-related potential evidence for parallel activation of two languages in bilingual speech production.

The cross-language identity effect refers to the benefit of processing a translation distractor in the cross-language picture-word interference task. The first event-related-potential evidence for this effect was obtained in a picture-naming priming task using Chinese-English bilinguals of languages with distinct scripts. The results indicated that parallel activation of both languages is a universal phenomenon in bilingual speech production. Furthermore, the present study revealed that the temporal course and magnitude of activation of the nontarget language during target language production was modulated by the relative proficiency in the two languages.

Adult↗

PubMed2005

Dissociation in the neural basis underlying Chinese tone and vowel production.

Neuropsychologists have debated over whether the processing of segmental and suprasegmental units involves different neural mechanisms. Focusing on the production of Chinese lexical tones (suprasegmental units) and vowels (segmental units), this study used the adaptation paradigm to investigate a possible neural dissociation for tone and vowel production. Ten native Chinese speakers were asked to name Chinese characters and pinyin (Romanized phonetic system for Chinese language) that varied in terms of tones and vowels. fMRI results showed significant differences in the right inferior frontal gyrus between tone and vowel production (more activation for tones than for vowels). Brain asymmetry analysis further showed that tone production was less left-lateralized than vowel production, although both showed left-hemisphere dominance.

Adult↗

PubMed2005

The role of phonological activation in the visual semantic retrieval of Chinese characters.

The Stroop paradigm was used to examine the role of phonological activation in semantic access and its development in reading Chinese characters. Subjects (age 7-23 years) of different reading ability were asked to name the display color of Chinese characters. The characters were displayed in four different colors: red, yellow, blue and green. There were five types of relationships between a character and its display color: semantically congruent, phonologically congruent, semantically incongruent, phonologically incongruent and neutral. In addition to the classical Stroop effects, interference and facilitation effects from the homophones of color characters were also observed. The younger children and those with lower reading ability exhibited stronger Stroop effects. These findings suggest that phonological codes are activated automatically in Chinese character recognition. Furthermore, there is more phonological activation in the semantic retrieval of children in lower grades and those with lower reading ability.

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↗

PubMed2004

Neural substrates of visual perceptual learning of simple and complex stimuli.

OBJECTIVE: The two experiments described here used event-related potentials (ERPs) to investigate whether perceptual learning of different complexities of stimuli involves different levels of visual cortical processing in human adults. METHODS: Reaction times and ERPs were recorded during 3 consecutive training sessions in which subjects discriminated between simple stimuli made of line segments or complex stimuli made of compound shapes. RESULTS: Reaction times in both experiments were shortened across training sessions. For simple stimuli, training resulted in a decreased N1 (125-155ms) and an increased P2 (180-240ms) over the occipital area. For complex stimuli, however, training resulted in a decreased N1 (125-155ms) and N2 (290-340ms) and an increased P3 (350-550ms) over the central/parietal areas. CONCLUSIONS: These findings suggest that perceptual learning modifies the response at different levels of visual cortical processing related to the complexity of the stimulus. SIGNIFICANCE: The neuronal mechanisms involved in perceptual learning may depend on the nature (e.g. the complexity) of the stimuli used in the discrimination task.

Adult↗

PubMed2004

Emotional valence of words modulates the subliminal repetition priming effect in the left fusiform gyrus: an event-related fMRI study.

The present study investigated if the emotional valence of words modulates the subliminal repetition priming effect in the brain, in particular, the occipitotemporal visual cortex, by adopting a rapid presentation event-related fMRI design. A masked repetition priming paradigm was adopted, in which, before the presentation of the target (either positive or negative or neutral in meaning), a masked prime word that was either a repetition or an unrelated word of the target was presented. The subject made a perceptual judgment on the target. The results revealed that the left mid-fusiform gyrus was sensitive to the emotional manipulation of the repetition priming effect and that the priming effect in the region was greater in the positive than in the negative word condition. The priming effect in the fusiform gyrus in neutral words was not significant, which might be a result of suppression caused by the emotional context. No effect of valence or repetition was found in the amygdala.

Adolescent↗

PubMed2004

Semantic processing of Chinese in left inferior prefrontal cortex studied with reversible words.

This study utilized fast event-related fMRI with reversible words to examine the role of left inferior prefrontal cortex (PFC) in semantic processing of Chinese. As a special linguistic phenomenon in Chinese, a reversible word is a two-character word (AB) that, when read from right to left (BA), opposite to the normal left to right reading direction, is also a real word. The two words, AB and BA, can have very different meanings. Fourteen native Chinese saw a reversible word (BA) and were asked to read it backward silently to obtain the meaning of AB, defined as the target meaning. They then saw two test words and decided which of the two was semantically related to the target meaning. Activity in a subregion of BA47 was found to be modulated by the extent to which irrelevant semantic activation of the distractor word BA interfered with semantic retrieval of the target word AB. This finding demonstrated the involvement of the left inferior PFC in the control processes of semantic retrieval in Chinese. In addition, comparing conditions using reversible with that using nonreversible words, we found evidence suggesting a semantic/phonological functional subdivision in left inferior PFC, consistent with that in English.

Adult↗

PubMed2004

The nature of the mental representation of radicals in Chinese: a priming study.

Using a priming procedure, 4 experiments were carried out to investigate the effects of a short preexposure of a prime that was a radical or contained radicals identical to the target. Significant facilitation was found when the target contained the prime as a radical, although only for low-frequency targets which did not arise merely as a result of graphical similarity. Facilitation also occurred when the prime and target shared a radical in the same position but not when in different positions. When the prime and target had exactly the same radicals but in different positions, however, the priming effect was inhibitory. This set of results suggests that simple characters (radicals) and complex characters are represented at a different level.

Comprehension↗

PubMed2003

Neural mechanisms underlying semantic and orthographic processing in Chinese-English bilinguals.

Brain activation underlying language processing in Chinese-English bilinguals was examined using fMRI in an orthographic search and a semantic classification task. In both tasks, brain areas activated by Chinese characters and English words were very similar to tasks examining Chinese reading using Chinese pinyin (an alphabetic Chinese script) and Chinese characters. However, the degree of later-alization was different, with English words (second language) causing much more right hemisphere activation than Chinese characters (native language). These differences support the hypothesis that second language usage causes more right hemisphere activation than native language usage.

Adult↗

PubMed2003

The neural substrate of analogical reasoning: an fMRI study.

This study investigated the anatomical substrate of analogical reasoning using functional magnetic resonance imaging. In the study, subjects performed a verbal analogy task (e.g., soldier is to army as drummer is to band) and, to control for activation caused by purely semantic access, a semantic judgment task. Significant activation differences between the verbal analogy and the semantic judgment task were found bilaterally in the prefrontal cortex (right BA 11/BA 47 and left BA45), the fusiform gyrus, and the basal ganglia; left lateralized in the postero-superior temporal gyrus (BA 22) and the (para) hippocampal region; and right lateralized in the anterior cingulate. The role of these areas in analogical reasoning is discussed.

Adult↗