No abstract available.
Face ; Pattern Recognition, Visual ; Human ; Sociology, Medical ; Facial Expression ; Facial Muscles ; Animals ; Biological Evolution ; Species Specificity

The method of event-related potentials (ERP) was used to study the gender difference in face recognition. The stimuli in the experiment were 10 upright and 10 inverted face photos. The subjects, half female and half male, were asked to judge whether the face was upright or inverted. The results showed that the N170 wave forms were observed in the occipito-temporal regions and they were found exhibiting brain's right hemispheric dominance. The stimuli of different gender photos were noticed to have no significant impact on the N170 wave forms, but there were significant differentce in the amplitude and latency period of N170 between different gender participants. Moreover, there was marked difference in the latency period of the male participants watching the same gender face and different gender face. Similar results were not found in the ERP's latency period of female participants.
Adult ; Brain ; physiology ; Electroencephalography ; Evoked Potentials ; Face ; Facial Expression ; Female ; Form Perception ; physiology ; Humans ; Male ; Pattern Recognition, Visual ; physiology ; Recognition (Psychology) ; Sex Factors ; Young Adult

A modified "cross-modal delayed response" paradigm was used to investigate whether the visual mismatch negativity can be elicited by cartoon facial expressions, and to define the mechanism underlying automatic processing of facial expressions. Subjects taking part in the tests were instructed to discriminate the type of the tones they heard as quickly and accurately as possible, and to act merely when they heard the response imperative signal. Neutral, happy and angry faces were presented during intervals between a tone and a response imperative signal. Visual mismatch negativity (VMMN) was obtained by subtracting the event - related potential (ERP) elicited by neutral faces from that elicited by happy faces or angry faces. The angry-related VMMN was more negative than happy-related VMMN, and both were more negative in the left than in the right cerebral hemisphere. The results indicated that VMMN can be elicited by the cartoon facial expressions, and the facial expressions can be processed automatically.
Adult ; Brain ; physiology ; Cartoons as Topic ; Evoked Potentials, Visual ; physiology ; Facial Expression ; Female ; Humans ; Male ; Pattern Recognition, Visual ; physiology ; Photic Stimulation ; Visual Perception ; physiology ; Young Adult

The human visual system efficiently extracts local elements from cluttered backgrounds and integrates these elements into meaningful contour perception. This process is a critical step before object recognition, in which contours often play an important role in defining the shapes and borders of the to-be-recognized objects. However, the neural mechanism of the contour integration is still under debate. The investigation of the neural mechanism underlying contour integration could deepen our understanding of perceptual grouping in the human visual system and advance the development of the algorithms for image grouping and segmentation in computer vision. Here, we review two theoretical frameworks that were proposed over the past decades. The first framework is based on hardwired horizontal connection in primary visual cortex, while the second one emphasizes the role of recurrent connections within intra- and inter-areas. At the end of review, we also raise the unsolved issues that need to be addressed in future studies.
Form Perception ; Humans ; Models, Neurological ; Pattern Recognition, Visual ; Visual Cortex ; physiology ; Visual Perception

How the brain perceives objects and classifies perceived objects is one of the important goals of visual cognitive neuroscience. Previous research has shown that when we see objects, the brain's ventral visual pathway recognizes and classifies them, leading to different ways of interacting with them. In this paper, we summarize the latest research progress of the ventral visual pathway related to the visual classification of objects. From the perspective of the neural representation of objects and its underlying mechanisms in the visual cortex, we summarize the current research status of the two important organizational dimensions of object animacy and real-world size, provide new insights, and point out the direction of further research.
Brain Mapping/methods* ; Magnetic Resonance Imaging ; Pattern Recognition, Visual ; Photic Stimulation ; Visual Cortex ; Visual Pathways

OBJECTIVES: To study the characteristic of contrast visual evoked potentials （CVEP） in patients with ocular trauma. METHODS: Sixty patients defined as ocular trauma by forensic clinical examination in our center were selected, and split into 0.2-0.3 （Group A）, 0.3-0.5 （Group B） and ≥0.5 （Group C） according to the best corrected visual acuity. The variation characteristics of wave amplitude and latency of CVEP under 100%, 25% and 10% contrast were observed and analyzed statistically. RESULTS: （1） Under the same contrast, the wave amplitude of P₁₀₀ decreased with the decrease of stimulus perspective. （2） Under the same stimulus perspective, the wave amplitude of P₁₀₀ decreased with the decrease of contrast （P<0.05）. （3） Under the contrast of 100% and 25% with the same stimulus perspective （except 100% 7' perspective stimulus）, the difference between group A and group B had no statistical significance （P>0.05）. Between group A and group C, group B and group C, the wave amplitude of P₁₀₀ gradually increased with the increase of vision （P<0.05）. Under the contrast of 10% with 15' stimulus perspective, the wave amplitude of P₁₀₀ increased with the increase of vision （P<0.05）. （4） Under the same contrast with the same stimulation perspective, the latency of P₁₀₀ wave shortened with the increase of vision, while the difference had no statistical significance （P>0.05）. Under the same stimulus perspective, the latency of P₁₀₀ wave was prolonged with the decrease of contrast （P>0.05）. CONCLUSIONS CVEP may become one of the possible methods for the evaluation of contrast visual acuity.
Evoked Potentials, Visual/physiology* ; Eye Injuries/physiopathology* ; Humans ; Pattern Recognition, Visual/physiology* ; Photic Stimulation ; Vision, Ocular ; Visual Acuity

OBJECTIVETo compare the shade matching accuracy between tabs of shade guide and tabs out of shade guide by prosthodontists.

METHODSSixty-two graduate students who had 1 to 5 years clinical experience without color blindness were included in this study. Twenty-nine tabs from Vita 3D-Master shadeguide and 7 tabs out of Vita 3D-Master shade guide but from Vita Bleachedguide 3D-Master were taken as the targets of shade matching and observed under the standard light. Subjects' shade matching accuracy on tabs of shadeguide and tabs out of shadeguide was recorded. Frequency of right match was analyzed using Monte Carlo exact probability-test. Wilcoxin test was used to analyze the difference between each group on ranked data of value, chroma and hue.

RESULTSThe shade matching accuracy of tabs of shade guide [45.9% (199/434)] was significantly higher than that of tabs out of shade guide [9.0% (39/434)]. There was significant difference between the two kinds of tabs of ranked data of value [0.2 (0.1 - 0.3), 0.4 (0.4 - 0.5)] and chroma [0.2 (0.1 - 0.4), 0.5 (0.4 - 0.6), P < 0.01, but there was no significant difference in hue data [0.3 (0.1 - 0.4), 0.3 (0.1 - 0.4)].

CONCLUSIONSThe shade matching ability of prosthodontists on tabs out of shade guide is lower than that on tabs of shadeguide. To fulfill clinical need, more training is necessary.

Animal's numerical competence has been one of the central issues in comparative psychology, cognitive psychology and cognitive neuroscience. A great number of studies indicate that animals have the capability to subitize small numerousness and judge relative numerousness. However, it is pendent if they have the counting ability. There is no evidence that animals can estimate numerousness. Neurophysiological studies show that the posterior parietal cortex and the prefrontal cortex in monkeys are involved in the neural mechanisms underlying numerical competence.
Animals ; Behavior, Animal ; Cerebral Cortex ; physiology ; Cognition ; Macaca mulatta ; Mathematics ; Mental Competency ; Pattern Recognition, Visual ; physiology ; Verbal Behavior ; physiology

The pupil auto-tracking system is a key component of the full-automatic perimeter. Taking the advantage of integral image in counting characteristic value rapidly, we studied the relationship between training stages and total error detection rate based on the training of Adaboost strong classifier. Besides, a testing strategy of amplification detection window was introduced, and a multi-stage cascaded eye classifier for eye detection was proposed finally. It kept the same detection rate as the commonly trained strong classifier with a much lower error detection rate. In the meantime, the present article explaines the main arithmetic implement functions, as well as designs the motion control program for the jaw bracket system.
Algorithms ; Automation ; instrumentation ; Equipment Design ; methods ; Humans ; Image Processing, Computer-Assisted ; Pattern Recognition, Automated ; methods ; Pupil ; Visual Field Tests ; instrumentation

OBJECTIVE: To explore the different brain areas activated by Chinese, English, and Nepali word tasks in Nepalese by using the functional magnetic resonance image (fMRI). METHODS: To determine the neuroanatomic functional brain areas responsible for Chinese, English and Nepali reading as well as sentence-formation, blood oxygenation level dependent (BOLD) block design by fMRI was performed in 6 healthy Nepalese volunteers. RESULTS: During Chinese reading, the activated areas included bilateral motor area, subfrontal gyri, superior temporal gyri, and superior parietal lobule; during English reading, the activated areas were left motor area, left subfrontal gyrus, left supra temporal gyrus, left insula and bilateral cerebellum; and the Nepali task demonstrated the activation of left anterior central gyrus, superior frontal gyrus, superior temporal gyrus. Aside from the bilateral occipital lobes, both English and Nepali activated areas were the left cerebral hemisphere dominant. CONCLUSION The more familiar with the language, the fewer areas are activated. Superior temporal gyrus might be involved in sentence-formation.
Adult ; Brain ; physiology ; China ; England ; Female ; Humans ; Image Processing, Computer-Assisted ; Language ; Magnetic Resonance Imaging ; Nepal ; Pattern Recognition, Visual ; Reading