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Brain Potentials to Speech and Acoustic Sound Discrimination Uncover the Origin of Individual Differences in Perceiving the Sounds of A Second Language FAN Ruolin;MO Lei;XU Guiping;ZHONG Weifang;ZHOU Ying;YANG Li 2014, 46 (5):  569-580.  doi: 10.3724/SP.J.1041.2014.00569 Abstract ( 1299 )   PDF (531KB) ( 3376 )   Peer Review Comments As to the origin of individual differences in perceiving the sounds of a second language, the scientific community has been divided. There are two alternative explanations: a general psychoacoustic origin vs. a general speech one. A previous study (Díaz et al., 2008) has shown that such individual variability is linked to the perceivers’ general speech abilities. However, our research casts doubt on the conclusion for two reasons. Firstly, this study exclusively focused on speech sounds in the same language family, rather than explored the languages from different language families. It has only been proved that individual variability in L2 is related to varied sensitivities to the speech sounds within the same language family rather than in the general speech system including different language families. Moreover, the study selected pure tones as acoustic materials, neglecting another important acoustic signals, complex sounds. It is obvious that we can’t draw the conclusion that ability of processing general sounds has no impact on discrimination of speech sounds in L2, without studying complex tones. Here, studying speech sounds from different language families and complex sounds, the main purpose of present study was to explore whether the individual differences in perceiving L2 stem from their ability of processing general phonetic signals or phonetic stimuli within the specific language family, and farther explore whether such individual variability deeply stems from individual sensitivity to complex tones. In the present study, 14 L2 good perceivers (GP) and 14 L2 poor perceivers (PP), in order to participate in the following ERP experiment, were selected from 130 healthy Cantonese (L1)-mandarin (L2) bilinguals according to their performances in a behavior task. To precisely measure the participants’ sound discrimination, MMN elicited by oddball paradigm was recorded in the following experiment. The ERP experiment consists of three sections, including native speech sounds, speech sounds in different language families and complex tones. And every participant took part in all three material sections. The results showed that significant differences between GP and PP were found when the two groups were presented with all 3 stimuli: GP showed larger MMN responses to both phonetic and acoustic stimuli than PP. This result reveals individual differences in discriminating the sounds in L2 not only stem from their sensitivity to phonetic sounds but also ultimately from their sensitivity to acoustic signals. Related Articles | Metrics

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Conflict Adaptation Is Independent of Consciousness: Behavioral and ERP Evidence JIANG Jun;XIANG Ling;ZHANG Qinglin;CHEN Antao 2014, 46 (5):  581-592.  doi: 10.3724/SP.J.1041.2014.00581 Abstract ( 1263 )   PDF (584KB) ( 2959 )   Peer Review Comments Previous studies have suggested that some cognitive control functions such as inhibition control and task switching were independent of consciousness, but it is unclear whether consciousness is necessary for conflict adaptation. Prior studies in consciousness domain showed that conflict adaptation reflected on behavioral measures and ERP components (N2 and P3). The purpose of current study is to test whether consciousness is necessary for conflict control. If conflict control was independent of consciousness, we would observe that the conflict effect indexed on reaction times and N2 and P3 amplitude modulated by previous trial congruency regardless of consciousness. If these hypotheses were verified, it could deepen our understanding of unconscious information processing and give us insight into the function of consciousness. To test our hypotheses, we obtained the behavioral and electroencephalogram (EEG) data from 18 subjects using an arrow version meta-contrast masking task, in which the primes fitted exactly within the inner contour of the target. By manipulating the time interval of prime and target and the presentation time of primes, the prime can be weakly or strongly masked. One subject was excluded from further analysis due to too many artifacts. To exclude the alternative interpretation of conflict adaptation by stimulus/response repetitions, stimulus or (and) response repetitions trials were removed before further analysis. After removing the artifacts included in the EEG segments, the ERPs were obtained according to each condition. The negative peak of N2 was averaged during 240-320 ms across fronto-central ROI electrode sites, while the P3 was averaged during the time 350-500 ms across centro-parietal ROI electrode sites. All analyses were performed separately based on the conditions of consciousness. The results showed that there was reliable conflict effect on reaction times and N2 and P3 amplitudes under conscious and unconscious conditions, and these effects were modulated by the congruency of previous trial type. Specifically, the conflict effect is smaller when the previous trials were incongruent than when they were congruent. Nevertheless, the size of conflict adaptation effect indexed on reaction times and N2 amplitude were larger under conscious condition than under unconscious condition, while the size of conflict adaptation between conscious and unconscious conditions were not significant. To our knowledge, we are the first to use ERP methods to study whether consciousness is necessary for conflict adaptation. These results not only suggest that the unconscious experience has great impact on human information processing system, but also suggest that conflict control is independent of consciousness. The difference in magnitude of conflict adaptation effect may come from the magnitude difference of conflict effect, and conscious conflict is far larger than unconscious conflict. Thus, in further studies we should pay attention to the difference and common aspects on unconscious and conscious conflict control. Moreover, the conflict monitoring theory can be perfectly interpreted the conflict control, but it do not elucidate the function of consciousness in the loop of conflict control. In conclusion, the current findings indicate that conflict adaptation is independent of consciousness. The current study could give some insights to understand and reveal the function of consciousness as well as its effect on conflict control. Related Articles | Metrics

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The Effect of Encoding Effectiveness from the Stimulus on Repetition Blindness LENG Ying;ZOU Yuhui;MO Lei 2014, 46 (5):  593-606.  doi: 10.3724/SP.J.1041.2014.00593 Abstract ( 745 )   PDF (556KB) ( 1587 )   Peer Review Comments Repeating an item in a brief or rapid display usually produces faster or more accurate identifying of the item. However, sometimes the repetition produces the opposite effect that the second occurrence (R2) of a target (R1) in RSVP paradigm often fails to be reported. This phenomenon is called repetition blindness (Kanwisher, 1987). Existing theories of repetition blindness can be classified as activation/inhibition view which holds that the ability to report an item’s occurrence in short time depends on activation of an abstract representation of the item, and construction/attribution view which hold that the variability of repetition blindness when different aspects of the processing episode are changed (Morris, Still, & Caldwell-Harris, 2009). But neither view is able to explain the evidence from studies supporting the other view. Morris et al. (2009) supposed the Competition Hypothesis and challenged those views. According to the hypothesis, inter-item competition in RSVP is the key to initiate repetition blindness. However, the Competition Hypothesis did not explore the effect of encoding effectiveness from the different stimuli in RSVP on the inter-item competition. The present study conducted three experiments with the RSVP paradigm to investigate the occurrence mechanism of repetition blindness. We manipulated the property of target stimuli (English letters or computer symbols) in Experiment 1a and the position of target stimuli (Position 1 and 3 or Position 2 and 4) in Experiment 1b to explore whether the encoding effectiveness of stimuli influenced the processing of repeated items. In Experiment 2, the property of target stimuli (Chinese characters or computer symbols) was manipulated to verify the reliability of the result of Experiment 1 and the rationality of the Competition Hypothesis. Experiment 3 investigated the effect of the encoding effectiveness of non-target stimuli on repetition blindness by manipulating the word frequency of non-target stimuli (high frequency or low frequency). The accuracy rates for reporting R2 were compared using a two-way repeated-measures analysis of variance for each experiment. Results of Experiment 1a showed less repetition blindness on the condition that the target items were symbols. Experiment 1b found that repetition blindness occurred on the condition that the target items were on Position1and Position 3, not on the condition that the target items were on Position2 and Position 4. In Experiment 2, when the non-target stimuli were high frequent Chinese characters, and the target stimuli were high frequent Chinese characters and computer symbols, repetition blindness of the former was larger than that of the latter. In Experiment 3, when the target stimuli were high frequent Chinese characters, repetition blindness occurred on the condition that the non-target items were high frequent Chinese characters, and there was no repetition blindness on the condition that the non-target items were low frequent Chinese characters. Therefore, the results in the three experiments supported the Competition Hypothesis. Further, the present study indicated that either in English letters or in Chinese characters, the encoding effectiveness from the target and non-target stimuli affected the repetition blindness. Related Articles | Metrics

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The Impact of the Perceptual Similarity of Concrete Objects’ Shape in Visual Metaphor Processing HU Xueping;SUN Jimin;CAO Rui;YAO Wenqing;WANG Meizhu 2014, 46 (5):  607-620.  doi: 10.3724/SP.J.1041.2014.00607 Abstract ( 1101 )   PDF (570KB) ( 2608 )   Peer Review Comments Previous studies have shown that the shape effect exists in comparing or recognizing simple black and white line drawing objects in the visual metaphor processing, but not for concrete objects. However, all objects in our world are either natural or artificial, therefore doing research on concrete objects seems to be a great significance in helping us to know the world. In the present study, three experiments were conducted to explore the shape effect in four different experimental conditions: conceptually and perceptually similar, conceptually similar and perceptually dissimilar, conceptually dissimilar and perceptually similar, and conceptually and perceptually dissimilar. In this way, we could explore the role of the perceptual similarity of concrete objects’ shape in visual metaphor processing, especially when common categories were absent. Experiment 1 and 2 demonstrated whether perceptual similarity affects the visual metaphor processing, and we used the production task during the third experiment to explore how perceptual similarity affects visual metaphor processing, and what inner psychological processing is. Based on the masked priming paradigm, we used similarity judgment tasks in the first experiment, matching pictures were presented for a duration of 48 ms only and the participants needed to judge whether the picture pairs could be used for the same purpose. The result showed that no matter the concept was the same or not, similarity in shapes had a “facilitation effect” on individual object recognition, and the functional consistency judgment of shape similarity was significantly faster than that of shape dissimilarity. In the second experiment, the object pairs were simultaneously presented for 2 seconds, during which participants were asked to perform the 9 points Likert scale to rate the functional consistency. The result suggested that in the absence of category, individuals would be experienced uncertainty and had a moderate rating when they made judgments on the function of objects which had similar shapes. A production task was applied in the third experiment, within a time frame of 20 seconds, participants were asked to describe pictures presented with pairs, in order to test whether shape similarity affected the number of correspondences between two objects, then we analyzed the correspondences and speech onset times. The results suggested that when objects were similar in shape, individual speech onset time was shorter than when the shape was dissimilar, and much more consistent descriptions would be produced. When common categories were absent, individuals would try to build an ad hoc category to achieve object classification. In conclusion, according to results of the three experiments, physical shape similarity is more “conducive” for object recognition and visual metaphor processing. Related Articles | Metrics

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The Development of Allocation of Study Time on Part-list Cuing Effect of Pictures TANG Weihai;LIU Tuanli;SHI Ying;FENG Hong;LIU Xiping 2014, 46 (5):  621-638.  doi: 10.3724/SP.J.1041.2014.00621 Abstract ( 999 )   PDF (706KB) ( 2430 )   Peer Review Comments When people are asked to recall words they have studied earlier from a list, those given a subset of these words as cues recall fewer words than people who do not receive any cues. This phenomenon is the so called part-list cuing effect. This phenomenon seems to be alien from the general thought that cues can help to prompt memories. The current research examined the part-list cuing effect of participants of different ages in learning pictures, and also explored their memory monitoring and control. Adopting 3 experiments, we explored the development of part-list cuing effect of pictures, and the allocation of study time of different ages. Experiments 1 explored whether retrieval cues would have detrimental effects on participants’ recall of the remaining items after learning pictures, and Experiments 2 explored the performance of students in Grade 2 and Grade 5 of a primary school, Grade 2 of a junior high school, Grade 2 of a senior high school and Grade 2 of a university. Experiments 3 studied the development of memory control of different ages. The results showed that: (1) After participants learned a list of pictures, the presentation of a subset of learned pictures’ names as retrieval cues didn’t have detrimental effects on their recall of the remaining items significantly; (2) After participants learned a list of pictures, the presentation of a subset of learned pictures as retrieval cues had detrimental effects on their recall of the remaining items, that is to say, part-list cuing effect occurred; (3) The part-list cuing effect occurred in all age selected. And with the increase of age, its amount changed as an inverted U shape; (4) Participants’ allocation of study time was affected by the times they had practiced with part-list cueing, which was different among participants of different ages. Grade 2 of primary school students couldn’t predict the detrimental effect of part-list cues no matter how many times they had practiced. After practicing twice, Grade 5 of primary school students could realize part-list cues’ detrimental effect and effectively allocate their cognitive resources. And only after one practice, Grade 2 of junior high school and senior high school students could realize that the part-list cuing recall was more difficult compared to free recall and allocate their study time appropriately. Moreover, students in Grade 2 of senior high school did even better than those in junior high school. The present findings revealed that in the picture studying, cues presented by way of cross-domain is a boundary condition of part-list cueing effect, while age is not a boundary condition of part-list cueing effect. The development of children’s strategy on allocation of study time had a great change from Grade 2 of primary school to Grade 5 of primary school students, while the learning efficiency had a great change from Grade 2 of junior high school to Grade 2 of senior high school students. Related Articles | Metrics

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A New Animal Model of Depression Induced by Repeated Central Lipopolysaccharide Administration TANG Mingming;PAN Yuqin;LIN Wenjuan 2014, 46 (5):  639-646.  doi: 10.3724/SP.J.1041.2014.00639 Abstract ( 1205 )   PDF (521KB) ( 1423 )   Peer Review Comments The administration of lipopolysaccharide (LPS), a component of the cell wall of gram negative bacteria, is commonly-used method to cause immune activation and the release of cytokines both in the periphery and in the brain in rodents. The cytokine theory of depression indicated that pro-inflammatory cytokines play an important role in the pathological mechanism of depression. Many studies used the peripheral administration of LPS to induce depressive-like behaviors. However, in these studies, the altered behaviors usually last only a few hours, seldom longer than 24h. Such short-term depressive behavior can hardly be regarded as a model of depression.. Thus, the aim of the present study was therefore to develop a new animal model of depression with apparent depressive-like behavior at - and after- 24h post-LPS injection. In this study, single and triple central LPS administration were used to induce depressive-like behavior respectively. Sprague-Dawley rats were randomly divided into LPS group and control group. LPS (100ng/rat, one injection; or once every second day, total three times) or isotonic saline was administered by intracerebroventricular microinjection. The depressive-like behavior was measured by preference to saccharin, locomotor activity and immobility time of tail suspension. The result indicated that single central LPS injection induced partial depressive-like behaviors. There was significant difference in locomotor activity, but not in the preference of saccharin and immobility time of tail suspension. However, repeated central LPS administration induced significant depressive-like behaviors after 24h of the last LPS injection. The animals with triple central LPS administration consumed less saccharin solution, exhibited less locomotor activity in the open field, and maintained immobility time in tail suspension. The changes in locomotor activity and immobility time of tail suspension were even apparent until 72h after the last LPS injection. Our results demonstrate that a new effective model of depression can be established by means of repeated lateral ventricle LPS injections, and the induced depressive-like behavior has longer time duration than by the peripheral injection of LPS. Related Articles | Metrics

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Cortisol Reactivity to Stress and Decision–making in Adolescents: There is Gender Difference LU Qingyun;TAO Fangbiao;HOU Fangli;SUN Ying 2014, 46 (5):  647-655.  doi: 10.3724/SP.J.1041.2014.00647 Abstract ( 1262 )   PDF (412KB) ( 3259 )   Peer Review Comments Acutely elevated levels of cortisol are associated with euphoria and reward-like properties related to sensation-seeking behavior. Moreover, research suggested cortisol response had different effects on risk taking in males and females. The main purpose of this research was to test whether cortisol reactivity to stress was associated with decision-making and there had the gender difference. Healthy junior school students performed the Trier Social Stress Test (TSST), and the objective measure-salivary cortisol at different time points were assessed. Then, participants played a Balloon Analogue Risk Task (BART) to measure decision-making after completing TSST. The results showed that male participants exhibited a significant increase in salivary cortisol reactivity following the TSST compared to female. Furthermore, while males with high responders showed more risk-taking behavior and lower monetary reward in the BART compared to low responders, females with high responders did report higher monetary reward compared to low responders. In conclusion, this study demonstrated that cortisol reactivity to acute stress as induced by the TSST was related to decision-making behavior of males and females differently. Especially, in males, higher cortisol reactivity was associated with risk-taking performance in BART. In females, elevated reactivity of cortisol after the TSST was associated with higher BART scores. Related Articles | Metrics

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The Effect of Cognitive Distraction’s Intensity on the Process of Trauma-related Information: Evidence from ERP DOU Weiwei;ZHENG Xifu;YANG Huifang;WANG Junfang;LI Yue;E Xiaotian;Chen Qianqian 2014, 46 (5):  656-665.  doi: 10.3724/SP.J.1041.2014.00656 Abstract ( 1186 )   PDF (532KB) ( 2473 )   Peer Review Comments The visual-spatial resource competition theory suggests that the frequency of flashback could be reduced, when a visual task competes with trauma-related negative pictures for the limited space resources. However, the cognitive control theory hold the view that the central executive control system, as the core of the working memory system, compete with trauma-related negative images for the cognitive control ability. And this ability can be reflected by intense cognitive distraction tasks, indexed by N2 and the late positive potential (LPP) at the neural level. However, it is unclear how the intensity of cognitive distraction modulates the neural processing of the trauma-related information. The present event-related potentials (ERP) study used the traumatic film paradigm and improved working memory paradigm to investigate the effect of cognitive distraction’s intensity on the process of trauma-related information. Two parts consisted of the experiment: watching the traumatic film and completing working memory task. Before and after watching the traumatic film, 22 Participants completed PANAS, but the STAI scale was used only before the film. During the working memory task, participants were told to perform a task which requiring to memorize letters at the beginning. Each trial began with a two- or six-letter string presented on a black background for 5, 000 ms. Next, a white fixation cross appeared for 500~1, 000 ms, followed by a trauma-related picture or a unrelated neutral picture in random order for 2,000 ms. Then, the words ‘what were the letters?’ were presented on the screen. In the following, participants pressed the key of ‘Enter’ and typed the letters in the black empty screen in the order they had memorized them. Participants could use the backspace key to correct mistakes. The trial ended when participants pressed the enter key again when they finished typing letters. The trial interval varied randomly from 2,000 to 2,500 ms, during which a white fixation cross was presented on a black background. The EEG was recorded while the picture appeared. Participants then completed PANAS again after the working memory task. The results showed that: (1) the amplitudes of N2 to the high-load task were significantly larger than those of low-load task; (2) the amplitudes of LPP for trauma-related negative pictures were larger than trauma-related neutral and unrelated neutral pictures in the low-load task, whereas there were no significant differences among the three kinds of pictures in the high-load task; (3) for the trauma-related negative pictures, LPP activity was significantly greater to the high-load task than the low-load task. The results of the present study indicated that the cognitive distraction of the high-load task had a stronger modulation to trauma-related information. This provided support for the cognitive control theory. Related Articles | Metrics

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Effect of Interpersonal Distance on Neural Basis of Self- and Other Representation: Evidence from the oFRN Component YANG Shuai;HUANG Xiting;CHEN Youguo;FU Yuling;LIU Mengchao 2014, 46 (5):  666-676.  doi: 10.3724/SP.J.1041.2014.00666 Abstract ( 1461 )   PDF (489KB) ( 3001 )   Peer Review Comments Since the concept of inclusion of other in the self (IOS) appeared, the topic of interpersonal distance has become an important research framework in social cognition. Similar to the self-reference effect, the other-reference effect was found when information related to close others (e.g. mother) was processed. These findings suggest that the representations of self and others are similar. Interestingly, studies on overcome evaluation indicated the same phenomenon. When participants monitor errors made by others, a similar ERP waveform could be detected by the observers just as they committed errors themselves. It is so-called observer feedback related negativity (oFRN). Although interpersonal distance is considered to play an important role, it is still unclear that how self- and other representation are modulated by interpersonal distance, since there are no consistent findings in previous studies. Thus, the purpose of this article was to confirm the effect of interpersonal distance on the oFRN, and to reveal the similarity of brain mechanism between self and others. Seventeen participants (9 males and 8 females) completed a simplified monetary gambling task in self-execution, friend-observation, and stranger-observation conditions, respectively. Actual observation paradigm was used in observation conditions, in which the electroencephalogram (EEG) participant and the partner were sitting side by side in the gambling task. The data were recorded from 64 scalp sites using tin electrodes mounted in an elastic cap. ERPs time-locked to the onset of feedback stimuli were averaged for epochs of 700ms starting 100ms prior to the stimulus (baseline). The ERPs were statistically evaluated by SPSS 15.0 with repeated measure analysis of variance (ANOVA). Results showed that there were more negative ERP responses, as indexed by the FRN, for loss trials compare to gain trials in monitoring both self and friend gambling (p<0.01, respectively). No significant difference was detected between loss and gain trials in stranger-observation condition (p>0.05), but a negative deflection was found in loss feedback. As for the oFRN, a marginally significant difference was found between friend- and stranger-observation conditions when distinct waves were statistically evaluated (p = 0.062). A correlation analysis was made to further explore the agency effect on the oFRN, and the results showed that interpersonal distance (evaluated by a subjective assessment) and the ERPs were significantly related (p<0.05). It indicates that a friend (who was rated closer) might be represented slightly more important than a stranger in “mirror” performance-monitoring system. That is, the oFRN is sensitive to interpersonal distance. The negative deflection across three agency conditions in loss trials suggested that similar monitoring mechanisms for both self- and other generated errors may be partly based on the mirror neuron system. However, the agency difference on the oFRN between friend and stranger observation conditions suggested that the vicarious experiences of others were modulated by interpersonal distance. Related Articles | Metrics

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The Effect of Psychological Distance on Intertemporal Choice and Risky Choice CHEN Haixian;HE Guibing 2014, 46 (5):  677-690.  doi: 10.3724/SP.J.1041.2014.00677 Abstract ( 2415 )   PDF (549KB) ( 5418 )   Peer Review Comments Temporal distance, social distance and probabilistic distance are three basic dimensions of psychological distance. It has been proved that different kinds of psychological distance have similar effects on cognitive representations of events. In general, distant events are represented as high-level construals, whereas near events are represented as low-level construals. As events become more distant, the high-level construals become more influential in shaping preference whereas the low-level construals become less influential (Liberman, Trope, & Stephan, 2007; Liberman, & Trope, 2008; Trope, & Liberman, 2010). This study investigates the effects of temporal, social and probabilistic distance on intertemporal choice and risky choice. We hypothesize that different kinds of distance have similar effects on intertemporal and risky choice, based on the assumptions that these three kinds of distance share the same nature as psychological distance, and that intertemporal choice and risky choice have common processes of option representation and weighting. When psychological distance increases, money magnitude as high-level construal becomes more influential while time and probability as low-level construals become less influential (Sagristano, Trope, & Liberman, 2002; Trope & Liberman, 2003). Therefore, participants in distant conditions would choose delayed and risky alternatives with larger monetary value. Experiment 1 investigated the effect of temporal distance on intertemporal and risky choices. Participants were told that they would participate in a visual experiment, but before that they needed to make an intertemporal choice as their rewards between “￥50 immediately” and “￥90 in 3 months” (experiment 1a), or between “￥50 for sure” and “￥200 with the probability of 20%” (experiment 1b). In near condition, the experiment would be conducted soon, and in distant condition the experiment would be conducted in 6 months. Experiment 2 investigated the effect of social distance. In near condition, participants would make choice for themselves, and in distant condition, for other people. Experiment 3 investigated the effect of probabilistic distance. In near condition, participants were told that they would participate in the experiment with 90% probability, and in distant condition, with 10% probability. The options of intertemporal choice and risky choice are similar to experiment 1. The results show that no matter what kind of distance was involved, there were more participants in distant condition who chose delayed or risky alternatives than those who did in near condition, which confirms the hypotheses. The similar effects of temporal, social and probabilistic distance on intertemporal and risky choices suggest that intermporal and risky choices share common psychological process, and these three kinds of distance are homogeneous psychological distance. Related Articles | Metrics

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The Mechanism of Occupational Segregation: A Social Dominance Perspective QIAO Zhihong;ZHENG Jinglu;SONG Huiting;JIANG Ying 2014, 46 (5):  691-701.  doi: 10.3724/SP.J.1041.2014.00691 Abstract ( 1437 )   PDF (419KB) ( 3893 )   Peer Review Comments The occupational segregation has been maintained for centuries in labor markets of various countries. Based on Social Dominance Theory, this research explained the occupational segregation phenomenon from social dominance orientation (SDO). And the author also aims to figure out the effect of sexism in this process. Due to the fact that each person and institution has different levels of social dominance orientation (SDO), men and women are inclined to choose the institutions whose values are identified with themselves. This process is called the self-selected mechanism of occupational segregation. Besides, when institutions face the choice of an employee, in order to maintain the priority of men, they do the same as individuals. According to Pratto et al, occupations can be divided into hierarchy enhancing ones and hierarchy attenuating ones. To explain more specifically, the hierarchy enhancing institutions are inclined to prefer men and the hierarchy attenuating institutions are more interested in women. It’s called the institution–selected mechanism of occupational segregation. We designed two studies to test the hypotheses above. In Study 1, the questionnaire survey was used to exam the relationship among gender, SDO and career choice. Data was collected from 187 students of Beijing Normal University. The result of Study 1 showed that men tended to choose hierarchy enhancing jobs and women tended to choose hierarchy attenuating jobs. Furthermore, SDO had a full mediating effect between gender and hierarchy jobs. The results indicated that occupational segregation had a self-selected mechanism, which means that men and women chose different jobs because of their different levels of SDO. In Study 2, an experiment was designed to test the relationship among SDO, sexism and hiring bias, in order to confirm the institution–selected mechanism of occupational segregation. 274 students from Beijing Normal University were recruited to do the tasks in study 2. They were asked to choose two resumes that best appeal to their respective institution in the capacity of an employer. One institution is a Securities Company, and the other is a charity organization. The results showed that hiring bias existed in different hierarchy institutions. The hierarchy enhancing institutions tended to choose male applicants and the hierarchy attenuating institutions tended to choose female applicants. Besides, both SDO and sexism could predict hiring bias, and sexism had a partial mediating effect between SDO and hiring bias. In conclusion, this research showed that during the forming process of occupational segregation, both self-selected mechanism and institution-selected mechanism are playing an indispensable part. This dynamic process provides us a new perspective to regard SDO and sexism, of which the former is not merely objective cognitions of group differences nor the latter is perceived social attitudes. In fact, they legitimize the inequality of social system. Through the connection of gender and different institutions and jobs, sexism and occupational segregation maintain in the society. Related Articles | Metrics

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a-Stratified Methods Combining Item Exposure Control and General Test Overlap in Computerized Adaptive Testing GUO Lei;WANG Zhuoran;WANG Feng;BIAN Yufang 2014, 46 (5):  702-713.  doi: 10.3724/SP.J.1041.2014.00702 Abstract ( 486 )   PDF (293KB) ( 969 )   Peer Review Comments Test security and item pool utilization rate are very important in computerized adaptive testing (CAT), especially in the high-stakes tests. Most existing methods only focus on the item exposure rate, but rarely control the test overlap rate. Way (1998) suggested that the item exposure and the test overlap rate be two indices of test security. Following this reasoning, Chen (2010) proposed an on–line version of the Sympson-Hetter procedure with general test overlap control (SHGT) that didn’t need iterative simulations. Although the SHGT method could control item exposure and general test overlap simultaneously without iterative simulations, the item pool utilization rate was not very ideal when the item exposure or test overlap rate was slightly high or the number of examinees who shared the information with another examinee was small. Thus, the test security was threatened. To address the limitation of the SHGT method, we combined the a-stratified method with the SHGT method, and proposed three new methods: SHGT_a method, SHGT_b method, and SHGT_c method. Simulation results indicated that: (1) Compared to the SHGT method, these three new methods could not only improve the item pool utilization rate, but also maintain a very high precision of ability estimate in the same experiment condition; (2) With the increase of maximum item exposure rate (rmax) and maximum general test overlap rate ( ), and the decrease of a, the precision of ability estimation increased. Compared to the SHGT method, these three new methods could maintain a higher item pool utilization rate; (3) SHGT_b and SHGT_c outperformed SHGT_a in the aspect of the precision of ability estimation when rab was high; (4) The three new methods had a good performance in respect of the precision of ability estimation; (5) Compared to the SHGT method, these three new methods could also effectively solve the problem of item exposure over-control. Some future directions of study were suggested at the end of this paper. Related Articles | Metrics

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Different Methods for Testing Moderated Mediation Models: Competitors or Backups? WEN Zhonglin;YE Baojuan 2014, 46 (5):  714-726.  doi: 10.3724/SP.J.1041.2014.00714 Abstract ( 5104 )   PDF (534KB) ( 15515 )   Peer Review Comments Mediation and moderation models are frequently used in the research of psychology and many other social science disciplines. Mediation indicates that the effect of an independent variable on a dependent variable is transmitted through a third variable, namely a mediator. For example, students’ gratitude promoted their academic achievement medially by increasing everyday academic resilience. Moderation occurs when the effect of an independent variable on a dependent variable varies according to the level of a third variable, which interacts with the independent variable. For instance, adolescents’ perceptions of their teachers’ authoritative teaching moderated the effect of antisocial disruption on peer acceptance. It is not uncommon for hypotheses about moderation and mediation relationships to occur in the same context where more than three variables are involved. When a mediation effect is moderated by a moderator, the effect is termed moderated mediation and the model is moderated mediation model. For example, everyday academic resilience acts as a mediator between gratitude and academic achievement, and this mediation process is moderated by stressful life events. There are several methods for testing moderated mediation models. The moderated mediation models being used for proposed testing methods are different. We are wondering whether different testing methods are competitors, or some of them are only backups. We discussed the different testing methods based on the most general type of model. The traditional testing method is the moderated causal steps approach, in which the regression coefficients are tested in sequence. Modern methods include the testing of the products of coefficients by using Bootstrap method or MCMC method, and testing of the difference between the maximum and minimum of the mediation effects. On the basis of the previous studies it can be summarized that the power of test with the moderated causal steps approach is the lowest among the three testing methods, whereas the testing of the difference between the maximum and minimum of the mediation effects has the highest power of test. After comparing significant results of the three testing methods by reviewing the simplification, implication, information, and explanation, we concluded that the moderated causal steps approach should be recommended first; testing of the products of coefficients by using Bootstrap method or MCMC method should be treated as a backup; testing of the difference between the maximum and minimum of the mediation effects should be the final choice. We proposed a hierarchical procedure for testing moderated mediation models as follows: Step 1. Adopt the moderated causal steps approach to test the model. If the significant result is obtained from the test, the mediating effect is moderated. Otherwise, go to Step 2. Step 2. Test the products of coefficients by using Bootstrap method or MCMC method. If any product is significantly different from zero, the mediating effect is moderated. Otherwise, go to Step 3. Step 3. Test the difference between the maximum and minimum of the mediation effects. If the difference is significant, the mediating effect is moderated. Otherwise, the mediating effect is not moderated. As an illustration, the procedure was applied to an empirical study in which everyday academic resilience played the role of a mediator between gratitude and academic achievement, and this mediation process moderated by stressful life events. The relationship and difference between moderated mediation models and mediated moderation models were also discussed. Related Articles | Metrics