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F Tong

Publications and source records attributed to F Tong.

12 recordsLinked to original sources
PubMed2001

Interocular rivalry revealed in the human cortical blind-spot representation.

To understand conscious vision, scientists must elucidate how the brain selects specific visual signals for awareness. When different monocular patterns are presented to the two eyes, they rival for conscious expression such that only one monocular image is perceived at a time. Controversy surrounds whether this binocular rivalry reflects neural competition among pattern representations or monocular channels. Here we show that rivalry arises from interocular competition, using functional magnetic resonance imaging of activity in a monocular region of primary visual cortex corresponding to the blind spot. This cortical region greatly prefers stimulation of the ipsilateral eye to that of the blind-spot eye. Subjects reported their dominant percept while viewing rivalrous orthogonal gratings in the visual location corresponding to the blind spot and its surround. As predicted by interocular rivalry, the monocular blind-spot representation was activated when the ipsilateral grating became perceptually dominant and suppressed when the blind-spot grating became dominant. These responses were as large as those observed during actual alternations between the gratings, indicating that rivalry may be fully resolved in monocular visual cortex. Our findings provide the first physiological evidence, to our knowledge, that interocular competition mediates binocular rivalry, and indicate that V1 may be important in the selection and expression of conscious visual information.

Adult↗
PubMed2001

[Clinical evaluation of effects and improvement in quality of life from palliative therapy of combination chemotherapy with Furtulon and consecutive low-dose cisplatin in cases of unresectable advanced gastrointestinal carcinoma].

Combination chemotherapy of Furtulon/low-dose cisplatin (CDDP) was administered to 13 patients with unresectable advanced gastrointestinal carcinoma (including 4 cases of gastric cancer, 6 of colorectal cancer, 1 of pancreatic cancer, 1 of hepatic cancer, and 1 of esophageal cancer). All patients were unresectable due to poor performance status (PS > 3) or metastasis. They were treated with Furtulon 1,200 mg/day orally on days 1-10 followed by 4 drug-free days, every 2 weeks, and CDDP 3.5 mg/m2/day, on days 1-5 by i.v. followed by 2 drug-free days every 4 weeks repeatedly. An average of 2-3 cycles were used. Six out of 13 patients had a partial response, 5 had no change, and 2 had progressive disease. The response rate was 46% and median survival time was 320 days. After chemotherapy, there was an increase in appetite and body weight in 11 patients (85%), and the patients maintained a good performance status and quality of life. Moreover no renal dysfunction occurred after treatment with CDDP. There was no high-grade toxicity over grade 2, only slight nausea, vomiting and diarrhea. From the present study, combination chemotherapy of Furtulon/low-dose CDDP seems to be effective for patients with advanced gastrointestinal cancer, and to have improved their quality of life (QOL).

Adult↗
PubMed1999

Robust representations for faces: evidence from visual search.

We report evidence from visual search that people can develop robust representations for highly overlearned faces. When observers searched for their own face versus the face of an unfamiliar observer, search slopes and intercepts revealed consistently faster processing of self than stranger. These processing advantages persisted even after hundreds of presentations of the unfamiliar face and even for atypical profile and upside-down views. Observers not only showed rapid asymptotic recognition of their own face as the target, but could reject their own face more quickly as the distractor. These findings suggest that robust representations for a highly overlearned face may (a) mediate rapid asymptotic visual processing, (b) require extensive experience to develop, (c) contain abstract or view-invariant information, (d) facilitate a variety of processes such as target recognition and distractor rejection, and (e) demand less attentional resources.

Adolescent↗
PubMed1999

[The influence of interferon alpha neutralizing antibodies on the therapeutic effectiveness in patients with chronic viral hepatitis].

OBJECTIVE: To study the influence of interferon alpha (IFN-alpha) neutralizing antibody (NA) on the therapeutic effectiveness of IFN-alpha. METHODS: 30 healthy persons and 116 patients with chronic viral hepatitis treated with IFN-alpha were studied, and the NA in their sera were tested by using the antiviral neutralizing bioassay (ANB). RESULTS: None was positive for NA in sera of the healthy persons and patients before IFN-alpha treatment, 20 of 116 patients developed NA after IFN-alpha therapy, the positivity was 17.2% (20/116). NA appeared after 2 months of alpha IFN treatment, all 20 patients were positive after 6 months. The NA positivity in treated groups of IFN-alpha 2a, IFN-alpha 2b and IFN-alpha 1b were 34.6%, 13.2% and 11.5% respectively. The clearance rates of virus in NA-positive group and NA high-titered group were significantly lower than those in NA-negative group and NA low-titered group (P < 0.01 and P < 0.05, respectively) In contrast, the relapse rates of virus in NA-positive group was markedly higher than that in NA-negative group (P < 0.05). CONCLUSION: NA may develop with its regularity in the chronic viral hepatitis patients treated with alpha IFN. The frequencies of NA development are related with the subtypes of alpha IFN used. NA can inhibit IFN activity, thereby affecting the therapeutic effectiveness of IFN.

Adult↗
PubMed1998

The effect of face inversion on the human fusiform face area.

Inversion severely impairs the recognition of greyscale faces and the ability to see the stimulus as a face in two-tone Mooney images. We used functional magnetic resonance imaging to study the effect of face inversion on the human fusiform face area (FFA). MR signal intensity from the FFA was reduced when greyscale faces were presented upside-down, but this effect was small and inconsistent across subjects when subjects were required to attend to both upright and inverted faces. However when two-tone faces were inverted, the MR signal from the FFA was substantially reduced for all subjects. We conclude that (i) the FFA responds to faces per se, rather than to the low-level visual features present in faces, and (ii) inverted greyscale faces can strongly activate this face-specific mechanism.

Adult↗
PubMed1998

Binocular rivalry and visual awareness in human extrastriate cortex.

We used functional magnetic resonance imaging (fMRI) to monitor stimulus-selective responses of the human fusiform face area (FFA) and parahippocampal place area (PPA) during binocular rivalry in which a face and a house stimulus were presented to different eyes. Though retinal stimulation remained constant, subjects perceived changes from house to face that were accompanied by increasing FFA and decreasing PPA activity; perceived changes from face to house led to the opposite pattern of responses. These responses during rivalry were equal in magnitude to those evoked by nonrivalrous stimulus alternation, suggesting that activity in the FFA and PPA reflects the perceived rather than the retinal stimulus, and that neural competition during binocular rivalry has been resolved by these stages of visual processing.

Adult↗
PubMed1998

Diagnosis and treatment of pulmonary hamartoma.

From 1970 to 1997, 67 patients with pulmonary hamartoma were operated on in our hospital. There were 38 men and 29 women with a M/F ratio of 1.3:1. The mean age was 47 years (range 21 to 82 years). The peak incidence was 40 to 60 years. 39% patients had pulmonary symptoms: hemoptysis, cough, phlegm and chest pain. All were solitary. 68.7% tumors were located in right lung and 64.2% in upper or middle lobe. 80.6% hamartomas were less than 3 cm in transverse diameter. On chest films, the opacity was homogeneous in 79.1% cases, heterogeneous in 20.9% and calcifications in 9.0%. The vast majority of shadows were heterogeneous on CT films. Operation is the best treatment for hamartomas. Postoperative mortality was 1.5%. There was none recurrences and canceration during the follow-up (mean 14 years).

Adult↗
PubMed1995

Respiratory rate and signs in roentgenographically confirmed pneumonia among children in China.

A clinical study was conducted in three Chinese community hospitals to investigate the reliability of respiratory rate and various clinical signs in the diagnosis of pneumonia among 54 children less than 5 years of age. Anteroposterior chest film was used as the diagnostic standard. The cutoff criterion for rapid breathing was 50 breaths/minute for infants ages 2 to 11 months and 40/minute in children 1 to 5 years old. Rapid breathing was a better predictor of pneumonia than rales (positive predictive values of 74.5 and 66.9%). Nasal flaring, chest indrawing, stridor and cyanosis of the tongue had predictive values of > 86%, but these clinical signs were observed in only a small proportion of patients. We recommend that village health workers use rapid breathing for diagnosis of pneumonia, rather than auscultation which is difficult and has proved unreliable. Sensitivity, specificity and positive and negative predictive values are presented for seven signs and symptoms of pneumonia.

Auscultation↗