Hongchuan Zhang

Adolescent Problem Behavior in China and the United States: A Cross-National Study of Psychosocial Protective Factors

An explanatory model of adolescent problem behavior (problem drinking, cigarette smoking, and general delinquency) based on protective and risk factors in the individual and in 4 social contexts (family, peer group, school, and neighborhood) is employed in school-based samples from the People’s Republic of China (N 51,739) and the United States (N 51,596). Despite lower prevalence of the problem behaviors in the Chinese sample, especially for girls, a substantial account of problem behavior is provided by the same protective and risk factors in both countries and for both genders. Protection is generally higher in the Chinese sample than in the U.S. sample, but in both samples protection also moderates the impact of risk. Despite mean differences in psychosocial protective and risk factors, as well as in problem behavior, in the 2 samples—differences that may reflect societal variation— the explanatory model has, to a large extent, cross-national generality.

The Role of Social Contexts in Adolescence: Context Protection and Context Risk in the United States and China

A theoretical framework about protective factors (models protection, controls protection, support protection) and risk factors (models risk, opportunity risk, vulnerability risk) was employed to articulate the content of 4 key contexts of adolescent life—family, peers, school, and neighborhood—in a cross-national study of problem behavior among 7th-, 8th-, and 9th-grade adolescents in the United States (n = 1,596) and the Peoples Republic of China (n = 1,739). Results were very similar in both samples and across genders. Measures of protection and risk in each of the 4 contexts uniquely contributed to the account of problem behavior involvement even when individual-level measures of protection and risk were controlled. Context protection was also shown to moderate individual-level risk and protection in 1 context moderated risk within that context and in other contexts. Controls protection—protection provided by rules, regulations, and expected sanctions for transgression from adults and peers—was the most important measure of context protection in all but 1 context. The family and peer contexts were the most influential in the U.S. sample, and the peer and school contexts were the most influential in the Chinese sample; the neighborhood context was least influential in both samples.

Distinct representations of subtraction and multiplication in the neural systems for numerosity and language.

It has been proposed that recent cultural inventions such as symbolic arithmetic recycle evolutionary older neural mechanisms. A central assumption of this hypothesis is that the degree to which a preexisting mechanism is recycled depends on the degree of similarity between its initial function and the novel task. To test this assumption, we investigated whether the brain region involved in magnitude comparison in the intraparietal sulcus (IPS), localized by a numerosity comparison task, is recruited to a greater degree by arithmetic problems that involve number comparison (single‐digit subtractions) than by problems that involve retrieving number facts from memory (single‐digit multiplications). Our results confirmed that subtractions are associated with greater activity in the IPS than multiplications, whereas multiplications elicit greater activity than subtractions in regions involved in verbal processing including the middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) that were localized by a phonological processing task. Pattern analyses further indicated that the neural mechanisms more active for subtraction than multiplication in the IPS overlap with those involved in numerosity comparison and that the strength of this overlap predicts interindividual performance in the subtraction task. These findings provide novel evidence that elementary arithmetic relies on the cooption of evolutionary older neural circuits. Hum Brain Mapp, 2011.

Protective and risk factors in health-enhancing behavior among adolescents in China and the United States: does social context matter?

An explanatory model of adolescent health-enhancing behavior based on protective and risk factors at the individual level and in 4 social contexts was used in a study of school-based samples from the Peoples Republic of China (n = 1,739) and the United States (n = 1,596). A substantial account of variation in health-enhancing behavior--and of its developmental change over time--was provided by the model for boys and girls, and for the 3 grade cohorts, in both samples. In both samples, social context protective and risk factors accounted for more unique variance than did individual-level protective and risk factors, and context protection moderated both contextual and individual-level risk. Models protection and controls protection were of particular importance in the explanatory account.

Chinese kindergartners' automatic processing of numerical magnitude in Stroop-like tasks

Using Stroop-like tasks, this study examined whether Chinese kindergartners showed automatic processing of numerical magnitude. A total of 36 children (mean age 5 5 years 10 months) were asked to perform physical size comparison (i.e., “Which of two numbers is bigger in physical size?”) and numerical magnitude tasks (i.e., “Which of two numbers is bigger in numerical magnitude?”) on 216 number pairs. These number pairs varied in levels of congruence between numerical magnitude and physical size (for Stroop effect) and numerical distance (for distance effect). On the basis of analyses of response time and error rates, we found that Chinese kindergartners showed automatic processing of numerical magnitude. These results are significantly different from previous studies’ findings about the onset age (ranging from around the end of first grade to third grade) for automatic processing of numerical magnitude.

Detecting faces in pure noise images: a functional MRI study on top-down perception.

To assess the nature of top-down perceptual processes without contamination from bottom-up input, this functional MRI study investigated face detection in pure noise images. Greater activation was revealed for face versus nonface responses in the fusiform face area, but not in the occipital face area. Across participants, positive correlations were found for the degree of greater face-detection activation between the fusiform face area and bilateral inferior frontal gyri, suggesting a top-down pathway generating perceptual expectations. In contrast, the medial frontal, parietal, supplementary motor, parahippocampal, and striatal areas produced negative correlations between degrees of greater face-detection activation and behavioral responses, suggesting a possible role for these areas in selecting and executing appropriate responses that are based on the top-down expectations.

Effective connectivities of cortical regions for top-down face processing: A Dynamic Causal Modeling study

To study top-down face processing, the present study used an experimental paradigm in which participants detected non-existent faces in pure noise images. Conventional BOLD signal analysis identified three regions involved in this illusory face detection. These regions included the left orbitofrontal cortex (OFC) in addition to the right fusiform face area (FFA) and right occipital face area (OFA), both of which were previously known to be involved in both top-down and bottom-up processing of faces. We used Dynamic Causal Modeling (DCM) and Bayesian model selection to further analyze the data, revealing both intrinsic and modulatory effective connectivities among these three cortical regions. Specifically, our results support the claim that the orbitofrontal cortex plays a crucial role in the top-down processing of faces by regulating the activities of the occipital face area, and the occipital face area in turn detects the illusory face features in the visual stimuli and then provides this information to the fusiform face area for further analysis.

Neural substrates for forward and backward recitation of numbers and the alphabet: A close examination of the role of intraparietal sulcus and perisylvian areas

Despite numerous studies on the neural basis of numerical processing, few studies have examined the neural substrates of one of the most basic numerical processing-number sequence recitation. The present study used fMRI to investigate neural substrates of number sequence recitation, focusing on the intraparietal sulcus (IPS) and perisylvian areas. This study used a 2 (number versus alphabet) x 2 (forward versus backward recitation) design. 12 Chinese undergraduates were asked to recite overtly but gently numerical and alphabetical sequences forward and backward. Results showed that, for both numerical and alphabetic sequences, the left IPS was activated when performing backward recitation, but not when performing forward recitation. In terms of perisylvian areas, all four tasks elicited activation in bilateral superior temporal gyrus and inferior frontal gyrus, but forward recitation elicited greater activation in the left posterior superior temporal gyrus than did backward recitation, whereas backward recitation elicited greater activation in the left inferior frontal gyrus than did forward recitation. These results suggest that forward recitation of numbers and the alphabet is typically based on verbal processing of numbers implemented in the perisylvian area, whereas backward recitation would likely require additional neural resources in the IPS.

Neural Correlates of Top-Down Letter Processing.

This fMRI study investigated top-down letter processing with an illusory letter detection task. Participants responded whether one of a number of different possible letters was present in a very noisy image. After initial training that became increasingly difficult, they continued to detect letters even though the images consisted of pure noise, which eliminated contamination from strong bottom-up input. For illusory letter detection, greater fMRI activation was observed in several cortical regions. These regions included the precuneus, an area generally involved in top-down processing of objects, and the left superior parietal lobule, an area previously identified with the processing of valid letter and word stimuli. In addition, top-down letter detection also activated the left inferior frontal gyrus, an area that may be involved in the integration of general top-down processing and letter-specific bottom-up processing. These findings suggest that these regions may play a significant role in top-down as well as bottom-up processing of letters and words, and are likely to have reciprocal functional connections to more posterior regions in the word and letter processing network.

The operand-order effect in single-digit multiplication: An ERP study of Chinese adults

Unlike those used in the West, a typical Chinese multiplication table includes only smaller-operand-first entries (e.g., 3 x 7=21, but not 7 x 3=21). Due to this unique feature, multiplication for Chinese subjects has been found to show an operand-order effect. The present study aims to investigate the neural bases of the operand-order effect. Subjects were 20 Mainland Chinese subjects who learned as children the half multiplication table (i.e., smaller-operand-first entries only) and 20 Hong Kong and Macao Chinese subjects who learned as children the whole multiplication table (i.e., both smaller- and larger-operand-first entries) under the British and Portuguese educational systems, respectively. ERP data showed that, for those who learned the half table (Mainland Chinese), but not for those who learned the whole table (Hong Kong and Macao Chinese), the larger-operand-first problems elicited greater negative potentials across representative electrodes of the whole scalp, emerging at about 120 ms after the onset of the second operand and lasting until around 750 ms. These results suggest that the particular experience of acquiring multiplication facts had pronounced impact on their representations in the brain.