The roles of edge-based and surface-based information in the dynamic neural representation of objects.

We combined multivariate pattern analysis (MVPA) and electroencephalogram (EEG) to investigate the role of edge, color, and other surface information in the neural representation of visual objects. Participants completed a one-back task in which they were presented with color photographs, grayscale images, and line drawings of animals, tools, and fruits. Our results provide the first neural evidence that line drawings elicit similar neural activities as color photographs and grayscale images during the 175-305 ms window after the stimulus onset. Furthermore, we found that other surface information, rather than color information, facilitates decoding accuracy in the early stages of object representations and affects the speed of this. These results provide new insights into the role of edge-based and surface-based information in the dynamic process of neural representations of visual objects.

Multisensory transfer effects in implicit and explicit category learning.

In category learning, transfer emerges when individuals apply the knowledge or strategy learned with one set of stimuli to a novel set. Under multisensory circumstances, it remains unclear whether the transfer occurs differently in implicit and explicit category learning, as it remains controversial whether explicit knowledge is indispensable for transfer. To address this issue, we adopted multisensory stimuli in implicit (i.e., information integration, II) and explicit (i.e., conjunctive rule-based, RB) category learning tasks. Experiment 1 showed that when training and novel sets shared the same feature modalities, spontaneous transfer without feedback was perfect in the II condition but impaired in the RB condition. However, with feedback, the dependent transfer occurred equally between conditions. Experiment 2 revealed that when across different feature modalities, no spontaneous transfer was observed in any of the two conditions. A dependent transfer occurred in the RB but not in the II condition. Experiment 3 found that delayed feedback disrupted II task performance but not RB task performance, indicating that people did not learn the II task using an explicit rule. The current study demonstrated that transfer to novel stimuli could emerge in explicit and implicit category learning within feature modalities. However, the transfer across feature modalities could only arise with feedback in explicit learning. We further discuss these findings' meaning with the current category learning theory.

Crossmodal Correspondence Mediates Crossmodal Transfer from Visual to Auditory Stimuli in Category Learning.

This article investigated whether crossmodal correspondence, as a sensory translation phenomenon, can mediate crossmodal transfer from visual to auditory stimuli in category learning and whether multimodal category learning can influence the crossmodal correspondence between auditory and visual stimuli. Experiment 1 showed that the category knowledge acquired from elevation stimuli affected the categorization of pitch stimuli when there were robust crossmodal correspondence effects between elevation and size, indicating that crossmodal transfer occurred between elevation and pitch stimuli. Experiments 2 and 3 revealed that the size category knowledge could not be transferred to the categorization of pitches, but interestingly, size and pitch category learning determined the direction of the pitch-size correspondence, suggesting that the pitch-size correspondence was not stable and could be determined using multimodal category learning. Experiment 4 provided further evidence that there was no crossmodal transfer between size and pitch, due to the absence of a robust pitch-size correspondence. These results demonstrated that crossmodal transfer can occur between audio-visual stimuli with crossmodal correspondence, and multisensory category learning can change the corresponding relationship between audio-visual stimuli. These findings suggest that crossmodal transfer and crossmodal correspondence share similar abstract representations, which can be mediated by semantic content such as category labels.

Correlation of proliferating cell nuclear antigen expression with the clinical and biological characteristics and prognosis of hypopharyngeal carcinoma.

OBJECTIVE: To study the association of proliferating cell nuclear antigen (PCNA) with the biological characteristics and clinical behavior of hypopharyngeal carcinoma and with the prognosis of the malignancy. METHODS: SP-immunohistochemical method was used to detect the expression of PCNA in 48 cancer tissue specimens and 15 specimens of the adjacent tissue of primary hypopharyngeal carcinomas. The number of PCNA-positive cells was represented by proliferating index (PI) of the antigen. RESULTS: PCNA expression was correlated with the clinical stage, histological grade and clinical recurrence of hypopharyngeal carcinoma as well as the prognosis of the patients, but was not significantly related with the tumor location or the presence of metastasis to the cervical lymph nodes. CONCLUSION: PCNA protein expression may help evaluate the malignancy of hypopharyngeal carcinoma and make prognostic judgement of the patients.

[Gene expression profiles in different tissues of human nasopharyngeal carcinoma].

OBJECTIVE: To screen the genes that may play an important role in the carcinogenesis of nasopharyngeal carcinoma (NPC). METHODS: Microdissection and cDNA genechip hybridization techniques were used to examine the differentially expressed genes in NPC tissue, the surrounding and adjacent tissues of NPC, and the nasopharyngeal inflammation tissue. The fluorescent signals on cDNA chip were scanned and the results of hybridization analyzed by image processing software. RESULTS: Many differentially expressed genes were identified between the three samples, including many different types of genes, such as those responsible for signal and protein transmission, oncogene and tumor suppression genes, immune-associated genes, apoptosis genes and DNA binding and transcription factor genes. CONCLUSION: The carcinogenesis of NPC involves many genes of a variety of types, suggesting its complex process.

[The study of expression of proliferating cell nuclear antigen and its gene in hypopharyngeal carcinoma].

OBJECTIVE: To study the relationship of proliferating cell nuclear antigen (PCNA) and the biological and clinical characteristics of hypopharyngeal carcinoma and its value of clinical prognosis. METHOD: The SABC-immunohistochemical method and in situ hybridization were correspondingly used to detect the expression of PCNA and its gene in 48 cases of cancer tissue and 15 cases of nearby cancer tissue of primary hypopharyngeal carcinoma. The number of positive cells of PCNA in 63 cases of tissue was represented by proliferating index (PI). RESULT: The expression of PCNA correlated with the clinical stage, histological grade and clinical recurrence of hypopharyngeal carcinoma and prognosis of the patients, but did not correlate significantly with tumor location and whether metastasis of cervical lymph nodes or not. CONCLUSION: The expression of PCNA protein may provide a reference in evaluating the malignancy level of hypopharyngeal carcinoma and prognosis of the patients.

[Expression of matrix metalloproteinase-2,9 in hypopharyngeal carcinoma and its relationship with lymphatic metastasis].

OBJECTIVE: To study the relationship between matrix metalloproteinase-2,9 (MMP-2,9) and the biology behavior, lymphatic metastasis of hypopharyngeal carcinoma by investigating the expression of MMP-2,9. METHOD: Two-step immunohistochemical method was used to examine the expression of monoclona antibody in hypopharyngeal carcinoma tissues. RESULT: It was found that the positive rate of MMP-2 in 32 hypopharyngeal carcinoma tissues was 53.12% (17/32),and the positive rate of MMP-9 was 59.38% (19/32). The difference of the expression in tumor tissue and normal mucosa beside the tumor was significant. The positive rate in those carcinoma with cervical lymph node metastasis was much higher than that in cases without cervical lymph node metastasis. And there was no significant difference found in the expression of MMP-2 and MMP-9. CONCLUSION: MMP-2 and MMP-9 may relate with the lymph node metastasis in hypopharyngeal carcinoma.