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1.
Chem Commun (Camb) ; 60(71): 9626-9629, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39150353

RESUMO

Pd-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest. Herein, a palladium-catalyzed and ligand-controlled strategy for the Markovnikov selective oxidative amination of 4-pentenoic acid has been described. The protocol effectively reverses the carboxylic acid-directed anti-Markovnikov selectivity in oxidative amination of 4-pentenoic acid, successfully constructing γ-ketoamide derivatives.

2.
Chem Commun (Camb) ; 60(70): 9404-9407, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39135493

RESUMO

Herein, a palladium-catalyzed 1,1-aminoxylation of 3-butenoic acid and 2-alkynylanilines has been developed, achieving the installation of two distinct heteroatom motifs across an olefin skeleton. The strategy features a high step and atom economy and good functional group tolerance, which outlines an efficient approach for simultaneously building up γ-butylactone and indole skeletons. Notably, an external ligand, 2,9-dimethyl-1,10-phenanthroline, has been used to succeed in this protocol to effectively suppress the production of indole byproducts.

3.
Psych J ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39019467

RESUMO

Patients with lesions in the visual cortex are blind in corresponding regions of the visual field, but they still may process visual information, a phenomenon referred to as residual vision or "blindsight". Here we report behavioral and fMRI observations with a patient who reports conscious vision across an extended area of blindness for moving, but not for stationary stimuli. This completion effect is shown to be of perceptual and not of conceptual origin, most likely mediated by spared representations of the visual field in the striate cortex. The neural output to extra-striate areas from regions of the deafferented striate cortex is apparently still intact; this is, for instance, indicated by preserved size constancy of visually completed stimuli. Neural responses as measured with fMRI reveal an activation only for moving stimuli, but importantly on the ipsilateral side of the brain. In a conceptual model this shift of activation to the "wrong" hemisphere is explained on the basis of an imbalance of excitatory and inhibitory interactions within and between the striate cortices due to the brain injury. The observed neuroplasticity indicated by this shift together with the behavioral observations provide important new insights into the functional architecture of the human visual system and provide new insight into the concept of consciousness.

4.
Birth Defects Res ; 116(6): e2366, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38872403

RESUMO

BACKGROUND: In addition to the potential for multiple pregnancies, natural conception occurring in preimplantation genetic testing (PGT) increases undesired genetic risk. Some studies showed that a dichorionic diamniotic twin pregnancy after a single blastocyst transfer could be caused by embryo splitting or concurrent spontaneous conception. CASE: We describe a patient undergoing PGT who had a dichorionic diamniotic twin pregnancy after single blastocyst transfer in a natural cycle. In this case, we recommended to determine genetic status of the twins by prenatal diagnosis. The results showed that karyotype, chromosome copy number variation, and parental ACAT1 variation of the twins were all normal and similar. To investigate the origin of pregnancy, we used the genotype data of single-nucleotide polymorphisms typical of genome-wide association studies. Dizygotic twins were inferred by robust estimation of kinship coefficients, which confirmed the occurrence of a spontaneous conception. CONCLUSIONS: This case strengthens the importance of genetic counseling to inform couples with reproductive genetic risk, such as those who undergo PGT, that intercourse should be avoided, especially in natural transfer cycles. Moreover, prenatal diagnosis remains essential and is strongly recommended to avoid genetic risks.


Assuntos
Transferência Embrionária , Testes Genéticos , Gravidez de Gêmeos , Diagnóstico Pré-Implantação , Humanos , Feminino , Gravidez , Diagnóstico Pré-Implantação/métodos , Testes Genéticos/métodos , Gravidez de Gêmeos/genética , Adulto , Transferência Embrionária/métodos , Gêmeos Dizigóticos/genética , Fertilização in vitro/métodos , Polimorfismo de Nucleotídeo Único/genética , Transferência de Embrião Único/métodos
5.
Reprod Biomed Online ; 46(3): 502-510, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36681555

RESUMO

RESEARCH QUESTION: Is it feasible to apply conventional IVF to couples undergoing preimplantation genetic testing for aneuploidies (PGT-A) with non-severe male infertility? DESIGN: The last wash fluid of biopsied trophectoderm (TE) cells was collected for whole genome amplification (WGA). A method was developed to determine parental contamination. Using single-nucleotide polymorphism (SNP) analysis, two standard curves were established; further mixtures were used for verification. Finally, 29 WGA products from couples undergoing conventional IVF were used to evaluate parental contamination. RESULTS: The WGA results of the last wash fluid of biopsied TE cells revealed almost no free DNA. By adopting two strategies based on maternally and paternally biased SNP in the mixture, data from bioinformatics analysis were analysed to determine the relationship between maternal (Index M) and paternal (Index F) bias statistics. Two standard curves were successfully established based on these indices that allowed the prediction of maternal and parental contamination, which correlated well with actual ratios of known composition mixtures during validation. The average contamination level was 10.6% determined from 10 WGA products that featured maternal contamination, whereas that of the other 19 products that featured paternal contamination was less than 10%. CONCLUSIONS: This study confirmed the feasibility of applying conventional IVF to couples undergoing PGT-A with non-severe male infertility.


Assuntos
Infertilidade Masculina , Diagnóstico Pré-Implantação , Humanos , Gravidez , Feminino , Masculino , Diagnóstico Pré-Implantação/métodos , Estudos de Viabilidade , Testes Genéticos/métodos , Aneuploidia , Fertilização in vitro
6.
J Oncol ; 2022: 9672773, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36276282

RESUMO

Glioblastoma (GBM) is the most common intracranial tumor with characteristic of malignancy. Resveratrol, a natural originated polyphenolic compound, has been reported to act as a potential radiosensitizer in cancer therapy. Magnetic resonance imaging (MRI) is the first choice for the diagnosis, pathological grading, and efficacy evaluation of GBM. In this study, MRI was applied to observe whether resveratrol could intensify the anti-GBM tumor effect by enhancing antitumor immunity during radiotherapy. We established an intracranial C6 GBM model in SD rats, treated with radiation and resveratrol. The increased body weight, the inhibition on mortality, and tumor volume in radiated- GBM rats were further enhanced by resveratrol addition, while the pathological damage of brain was alleviated. The modulation of radiation on inflammation, cell cycle, and apoptosis was strengthened by resveratrol; and Ki-67, PD-L1, and cell cycle- and apoptosis-related protein expressions were also improved by cotreatment. Besides, cotreatment attenuated DNA damage and induced G0/G1-phase cell arrest of GBM rats, accompanied with the changed expression of ATM-AKT-STAT3 pathway-related proteins. Moreover, the percentages of CD3+CD8+T cells and IFN-γ +CD8+T cells were enhanced, while (CD4+CD25+Foxp3)/CD4+T cells were decreased by radiation or resveratrol, which was strengthened by cotreatment. The modulation effect of cotreatment on CD3, Foxp3, and IFN-γ levels was also stronger than radiation or resveratrol alone. To conclude, resveratrol enhanced the effect of radiotherapy by inducing DNA damage and antitumor immunity in the intracranial C6 GBM.

7.
Perception ; 51(12): 859-870, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36046981

RESUMO

It has been shown that the perceived duration of an object in the subsecond range is closely associated with its nontemporal perceptual properties, the mechanism under which remains unclear. Previous studies have revealed a modulatory effect of early visual feature processing on the apparent duration. Here, we further examined the relationship between perceptual confidence and subjective time by asking participants to simultaneously perform temporal and nontemporal perceptual judgments. The results revealed a significant effect on confidence levels. When participants' confidence in judging the coherent motion direction or relative dot numerosity increases, their perceived duration of the stimulus also appears longer. These results are discussed in the context of perceptual evidence accumulation and evaluation for the decision-making of perceptual properties. They suggest a profound contribution of object processing to the computation of subjective time and provide further insights into the mechanism of event timing.


Assuntos
Julgamento , Percepção Visual , Humanos
8.
Reprod Biomed Online ; 45(3): 491-500, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35843780

RESUMO

RESEARCH QUESTION: What factors affect the incidence of mosaic embryos resulting from assisted reproductive technology? DESIGN: A retrospective analysis of data from preimplantation genetic testing for aneuploidies in 544 couples was conducted using data from an electronic medical record database. RESULTS: Of 1910 embryos studied, 127 (6.6%) were mosaic. In multivariable logistic regression analysis, mosaicism incidence increased in embryos from IVF versus intracytoplasmic sperm injection (ICSI) (odds ratio [OR] 4.560, 95% confidence interval [CI] 2.800-7.424, P < 0.001), and in embryos from abnormal versus normal semen (OR 3.496, 95% CI 2.455-4.979, P < 0.001). Embryos tested using SurePlex 24Sure had lower mosaicism percentages than those tested using MALBAC-NGS and PicoPLEX GenetiSure (OR 2.726, 95% CI 1.532-4.852, P = 0.001; OR 2.389, 95% CI 1.537-3.711, P < 0.001, respectively). CONCLUSIONS: Semen quality, fertilization method and detection system are independent factors associated with embryonic mosaicism.


Assuntos
Mosaicismo , Diagnóstico Pré-Implantação , Aneuploidia , Blastocisto , Feminino , Fertilização in vitro , Testes Genéticos/métodos , Humanos , Masculino , Gravidez , Diagnóstico Pré-Implantação/métodos , Estudos Retrospectivos , Sêmen , Análise do Sêmen
9.
Front Immunol ; 13: 921317, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35720415

RESUMO

Colorectal cancer (CRC) is currently the third most common cancer with a high mortality rate. The underlying molecular mechanism of CRC, especially advanced CRC, remains poorly understood, resulting in few available therapeutic plans. To expand our knowledge of the molecular characteristics of advanced CRC and explore possible new therapeutic strategies, we herein conducted integrated proteomics and metabolomics analyses of 40 serum samples collected from 20 advanced CRC patients before and after treatment. The mass spectrometry-based proteomics analysis was performed under data-independent acquisition (DIA), and the metabolomics analysis was performed by ultra-performance liquid chromatography coupled with time-of-flight tandem mass spectrometry (UPLC-TOF-MS/MS). Trace elements including Mg, Zn, and Fe were measured by inductively coupled plasma spectrometry (ICP-MS) analysis. Four of the 20 patients had progressive disease (PD) after treatment, and clinical test results indicated that they all had impaired liver functions. In the proteomics analysis, 64 proteins were discovered to be significantly altered after treatment. These proteins were enriched in cancer-related pathways and pathways participating immune responses, such as MAPK signaling pathway and complement/coagulation cascades. In the metabolomics analysis, 128 metabolites were found to be significantly changed after treatment, and most of them are enriched in pathways associated with lipid metabolism. The cholesterol metabolism pathway was significantly enriched in both the proteomics and metabolomics pathway enrichment analyses. The concentrations of Mg in the serums of CRC patients were significantly lower than those in healthy individuals, which returned to the normal range after treatment. Correlation analysis linked key lipids, proteins, and Mg as immune modulators in the development of advanced CRC. The results of this study not only extended our knowledge on the molecular basis of advanced CRC but also provided potential novel therapeutic targets for CRC treatment.


Assuntos
Neoplasias Colorretais , Oligoelementos , Cromatografia Líquida de Alta Pressão , Neoplasias Colorretais/metabolismo , Humanos , Metaboloma , Proteoma/metabolismo , Espectrometria de Massas em Tandem
10.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 845-848, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487527

RESUMO

OBJECTIVE: To assess the application value of mapping allele with resolved carrier status (MaReCs) technique for preimplantation genetic testing (PGT). METHODS: The characteristics of MaReCs for PGT and outcome of patients were retrospectively analyzed. RESULTS: Compared with those who could not use the technique, carriers who have used the MaReCs technique were younger, had significantly higher level of anti-Mullerian hormone, more antral follicles, occytes, mature occytes, biopsied embryos and euploid embryos, and lower risks for de novo chromosomal abnormality (P<0.05). It was necessary for couples with fewer oocytes, mature oocytes and balstocyst to preserve discarded embryos to facilitate the test. Carriers who have used the MaReCs technique had higher clinical pregnancy rate and abortion rate compared with those undergoing routine PGT, albeit no significant difference was found between the two groups (P> 0.05). Carriers undergoing MaReCs test could preferentially select embryos with normal chromosome structures for the transfer. CONCLUSION: Application of MaReCs has a prerequisite for having a minimum number of occytes and biopsied embryos and using discarded embryos sometimes. MaReCs is efficient for the detection of carrier status of embryos and attaining higher rate of pregnancy and live birth, which can significantly improve the outcome for couples carrying chromosomal translocations.


Assuntos
Diagnóstico Pré-Implantação , Translocação Genética , Alelos , Aneuploidia , Blastocisto , Feminino , Fertilização in vitro , Testes Genéticos , Humanos , Gravidez , Estudos Retrospectivos
11.
Medicine (Baltimore) ; 100(35): e27144, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477170

RESUMO

ABSTRACT: This study aimed to evaluate the diagnostic performance of diffusion kurtosis imaging (DKI) and prostate-specific antigen (PSA) biomarkers in differentiating prostate cancer (PCa) and benign prostatic hyperplasia (BPH).A total of 43 cases of prostate diseases verified by pathology were enrolled in the present study. These cases were assigned to the BPH group (n = 20, 68.85±10.81 years old) and PCa group (n = 23, 74.13 ±â€Š7.37 years old). All patients underwent routine prostate magnetic resonance imaging and DKI examinations, and the mean diffusivity (MD), mean kurtosis (MK), and fractional anisotropy (FA) values were calculated. Three serum indicators (PSA, free PSA [fPSA], and f/t PSA) were collected. We used univariate logistic regression to analyze the above quantitative parameters between the 2 groups, and the independent factors were further incorporated into the multivariate logistic regression model. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic efficacy of the single indicator and combined model.The difference in PSA, f/t PSA, MK, and FA between PCa and BPH was statistically significant (P < .05). The AUC for the combined model (f/t PSA, MK, and FA) of 0.972 (95% confidence interval [CI]: 0.928, 1.000) was higher than the AUC of 0.902 (95% CI: 0.801, 1.000) for f/t PSA, 0.833 (95% CI: 0.707, 0.958) for MK, and 0.807 (95% CI: 0.679, 0.934) for FA.The MK and FA values for DKI and f/t PSA effectively identify PCa and BPH, compared to the PSA indicators. Combining DKI and PSA derivatives can further improve the diagnosis efficiency and might help in the clinical setting.


Assuntos
Imageamento por Ressonância Magnética/métodos , Antígeno Prostático Específico/sangue , Hiperplasia Prostática/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/sangue , Neoplasias da Próstata/sangue , Estudos Retrospectivos
12.
Molecules ; 26(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33669144

RESUMO

A broadband visible light-absorbing [70]fullerene-BODIPY-triphenylamine triad (C70-B-T) has been synthesized and applied as a heavy atom-free organic triplet photosensitizer for photooxidation. By attaching two triphenylmethyl amine units (TPAs) to the π-core of BODIPY via ethynyl linkers, the absorption range of the antenna is extended to 700 nm with a peak at 600 nm. Thus, the absorption spectrum of C70-B-T almost covers the entire UV-visible region (270-700 nm). The photophysical processes are investigated by means of steady-state and transient spectroscopies. Upon photoexcitation at 339 nm, an efficient energy transfer (ET) from TPA to BODIPY occurs both in C70-B-T and B-T, resulting in the appearance of the BODIPY emission at 664 nm. Direct or indirect (via ET) excitation of the BODIPY-part of C70-B-T is followed by photoinduced ET from the antenna to C70, thus the singlet excited state of C70 (1C70*) is populated. Subsequently, the triplet excited state of C70 (3C70*) is produced via the intrinsic intersystem crossing of C70. The photooxidation ability of C70-B-T was studied using 1,5-dihydroxy naphthalene (DHN) as a chemical sensor. The photooxidation efficiency of C70-B-T is higher than that of the individual components of C70-1 and B-T, and even higher than that of methylene blue (MB). The photooxidation rate constant of C70-B-T is 1.47 and 1.51 times as that of C70-1 and MB, respectively. The results indicate that the C70-antenna systems can be used as another structure motif for a heavy atom-free organic triplet photosensitizer.


Assuntos
Compostos de Anilina/química , Compostos de Boro/química , Fulerenos/química , Luz , Fármacos Fotossensibilizantes/química , Estrutura Molecular , Oxirredução , Processos Fotoquímicos , Fármacos Fotossensibilizantes/síntese química
13.
Front Psychol ; 10: 1849, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496969

RESUMO

Humor has been a hot topic for social cognition in recent years. The present study focused on the social attribute of humor and showed different stories to participants, which were divided into four types according to the model of humor style, to explore the underlying neural mechanism of point-to-self aggressive humor and how individual differences modulated it. Measuring the degree of anger and funniness, results suggested that aggressive humor helped us in social communication by reducing the degree of anger. The neural activities showed that bilateral temporal lobes and frontal lobes played a synergistic role in the point-to-self aggressive humor processing, while point-to-self non-aggressive humor was dominant in the left-side brain. Results from the region of interest (ROI) analysis showed that the individual differences of the self-control level and the self-construal level may influence the neural processing of point-to-self aggressive humor by modulating the activated levels and patterns of the right inferior orbital frontal gyrus, the right superior temporal lobe, and the right superior frontal lobe.

14.
J Cancer ; 10(3): 672-681, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30719165

RESUMO

Cervical cancer is the most common and lethal gynaecological tumor. Long noncoding RNAs (lncRNAs) have critical roles in various cancers, including cervical cancer. However, few studies investigated the diagnostic value of lncRNAs for cervical cancer. In this study, we investigated the expression pattern of a recently identified lncRNA GIHCG in cervical cancer tissues, cell lines, and serums by qRT-PCR. Furthermore, we explored the roles of GIHCG in cervical cancer using gain-of-function and loss-of-function assays. Our results revealed that GIHCG is up-regulated in cervical cancer tissues and cell lines compared with adjacent normal tissues and normal cervical epithelial cell line, respectively. Furthermore, serum GIHCG is significantly up-regulated in cervical cancer patients compared with healthy controls. ROC curve analysis revealed that serum GIHCG could accurately discriminate cervical cancer patients from healthy controls. Functionally, we found that overexpression of GIHCG promotes cell proliferation, inhibits cell apoptosis, and promotes cell migration of cervical cancer cells. Conversely, depletion of GIHCG inhibits cell proliferation, induces cell apoptosis, and inhibits cell migration of cervical cancer cells. Mechanistically, we found that GIHCG represses the expression of miR-200b. The expression of miR-200b is inversely correlated with the expression of GIHCG in cervical cancer tissues. Moreover, overexpression of miR-200b attenuates the roles of GIHCG in promoting cervical cancer tumor growth in vivo. In summary, this study demonstrated that GIHCG functions as an oncogene in cervical cancer via repressing miR-200b. This study also suggested that GIHCG may be a non-invasive diagnostic biomarker and a potential therapeutic target for cervical cancer.

15.
Scand J Psychol ; 57(4): 288-91, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27153177

RESUMO

Recent research has shown that poverty directly impeded cognitive functions because the poor could be easily distracted by monetary concerns. We argue that this effect may be limited to functions relying on working memory. For functions that rely on proceduralized processes however, monetary concerns elicited by reminding of financial demands would be conducive rather than harmful. Our results supported this hypothesis by showing that participants with lower income reached the learning criterion of the information-integration categorization task faster than their more affluent counterparts after reminding of financial demands.


Assuntos
Aprendizagem , Pobreza/psicologia , Adulto , Comportamento de Escolha , Feminino , Humanos , Masculino , Memória de Curto Prazo , Fatores Socioeconômicos , Adulto Jovem
16.
BMJ Open ; 6(2): e008558, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26868940

RESUMO

OBJECTIVE: This study was designed to examine the prevalence of unilateral and bilateral diagonal earlobe creases (DELCs) with respect to the diagnosis of coronary heart disease (CHD). METHODS: A total of 558 consecutive participants (402 males and 156 females) aged 36-91 years who underwent coronary angiography were enrolled in this study. The participants were classified as being without a DELC, having a unilateral DELC and having bilateral DELCs; participants with either a unilateral DELC or bilateral DELCs were defined as participants with DELCs. Significant CHD was defined as at least one major vessel with >50% stenosis, and coronary atherosclerosis severity was defined using the Gensini scoring system. RESULTS: In the present study, bilateral DELCs were more frequently among male (p=0.001), CHD (p=0.000), older people (p=0.000) and those with more severe coronary artery atherosclerosis (p=0.000). The results of the multiple regression analyses indicated that DELCs (OR, 4.861; 95% CI 3.093 to 7.642, p=0.000) remained independently associated with a risk of CHD. It was assumed that participants without a DELC have a certain background risk for CHD (OR is assumed to be 1); the results of the multivariate logistic regression indicated that the relative risk of CHD among participants with bilateral DELCs was 5.690 among all participants (OR, 5.690; 95% CI 3.450 to 9.384, p=0.000), 5.436 among male participants (OR, 5.436; 95% CI 2.808 to 10.523, p=0.000) and 7.148 among female participants (OR, 7.148; 95% CI 3.184 to 16.049, p=0.000). Moreover, a positive association between DELC and age (SI=1.21, SIM=1.65, AP =0.132), gender (SI=2.09, SIM=0.81, AP=0.49) and smoking status (SI=1.49, SIM=0.73, AP=0.29) was found, respectively. CONCLUSIONS: The results of the present study indicated that DELCs are a simple and a feasible means of identifying CHD. However, the exact mechanism underlying the relationship between DELCs and CHD warrants further study.


Assuntos
Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Orelha Externa/anatomia & histologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais
17.
Int J Psychophysiol ; 99: 121-4, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26620929

RESUMO

Initial exertion of self-control impairs subsequent self-regulatory performance, which is referred to as the ego depletion effect. The current study examined how individual differences in dopamine level, as indexed by eye blink rate (EBR), would moderate ego depletion. An inverted-U-shaped relationship between EBR and subsequent self-regulatory performance was found when participants initially engaged in self-control but such relationship was absent in the control condition where there was no initial exertion, suggesting individuals with a medium dopamine level may be protected from the typical ego depletion effect. These findings are consistent with a cognitive explanation which considers ego depletion as a phenomenon similar to "switch costs" that would be neutralized by factors promoting flexible switching.


Assuntos
Piscadela/fisiologia , Dopamina/fisiologia , Ego , Eletroculografia/métodos , Individualidade , Estimulação Luminosa/métodos , Feminino , Humanos , Masculino , Autoimagem , Adulto Jovem
18.
Cogn Process ; 16 Suppl 1: 443-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26224276

RESUMO

Subjective time of an event in the sub-second range is often compressed or dilated by the situational context created by preceding and succeeding stimuli. How such context distorts psychological time is still an open question. Here, we pursued this issue by examining whether the perceptual grouping among successive visual stimuli modulates the perceived duration. Using a duration comparison task, we asked observers to judge the relative duration of a target and a comparison item, and estimated the apparent duration of the target from the corresponding psychometric function. The target was temporally flanked by a preceding item and a succeeding item. In different conditions, the target was more similar to either the preceding or the succeeding item. Results showed that perceptual grouping based on similarity modulated perceived duration. Specifically, when the target was grouped with the preceding item, its subjective duration was shorter than when it was grouped with the succeeding item. Interestingly, this pattern was observed when the preceding and target items were kept constant while the succeeding item was manipulated, suggesting that the effect depends, to some degree, on the holistic perceptual grouping rather than on fragmented processes. These results demonstrate that the situational context is an important factor in shaping temporal codes, thus bridging the seemingly independent perceptual feature processes and temporal representation.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Percepção do Tempo/fisiologia , Adulto , Análise de Variância , Atenção/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Psicometria , Tempo de Reação/fisiologia , Fatores de Tempo , Adulto Jovem
19.
Front Psychol ; 6: 521, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25964774

RESUMO

Accumulated evidence has shown that the subjective time in the sub-second range can be altered by different factors; some are related to stimulus features such as luminance contrast and spatial frequency, others are processes like perceptual grouping and contextual modulation. These findings indicate that temporal perception uses neural signals involved in non-temporal feature processes and that perceptual organization plays an important role in shaping the experience of elapsed time. We suggest that the temporal representation of objects can be treated as a feature of objects. This new concept implies that psychological time can serve as a tool to study the principles of neural codes in the perception of objects like "reaction time (RT)." Whereas "RT" usually reflects the state of transient signals crossing decision thresholds, "apparent time" in addition reveals the dynamics of sustained signals, thus providing complementary information of what has been obtained from "RT" studies.

20.
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