Non-Linearity of Visual Sensitivity and Pursuit Velocity during Smooth Pursuit Eye Movements

During pursuit eye movements, whether the relationships among the visual sensitivity, pursuit velocity, and target velocity are linear or non-linear is an old issue. In this study, we reexamined their relationships with seven speeds by a simple character discrimination task using an infrared eye tracker. Our results found that the pursuit velocity and accuracy were non-linearly related with the target velocity. Besides, the perceptual sensitivity was not linearly related with the pursuit velocity either. A significant difference existed between lower （less than 20 deg/s） and higher speeds （greater than 20 deg/s）. In addition, we found there was no position bias of visual sensitivity between ahead of and behind the pursuit target, but there was a significant perceptual dissymmetry between horizontal and vertical directions at lower pursuit speeds.

How the coevolution of language and sociality has helped to shape the human brain

Understanding how neural circuits contribute to cognitive differences between hum ans and other species,including macaque monkeys,is a major issue in neuroscience.Language and tool use are the most prominent differences between humans and other primates.Many neuroimaging-based studies have explored the brain mechanisms un-

PHYPred:a tool for identifying bacteriophage enzymes and hydrolases

Dear Editor,Bacteriophages are viruses that attack bacteria and kill them through the lytic replication cycle.Many studies have reported that phages are more specific to bacteria than antibiotics are;thus,phage therapy has many potential applications in human medicine,with the advantage of having few side effects(Keen,2012).Investigating the mechanisms of bacteria-killing phages will therefore

Contextual influence on the tilt after-effect in foveal and parafoveal vision

A sensory stimulus can only be properly interpreted in light of the stimuli that surround it in space and time. The tilt illusion （TI） and tilt after-effect （TAE） provide good evidence that the perception of a target depends strongly on both its spatial and temporal context. In previous studies, the TI and TAE have typically been investigated separately, so little is known about their co-effects on visual perception and information processing mechanisms. Here, we considered the influence of the spatial context and the temporal effect together and asked how center- surround context affects the TAE in foveal and para- foveal vision. Our results showed that different center-surround spatial patterns significantly affected the TAE for both foveal and para-foveal vision. In the fovea, the TAE was mainly produced by central adaptive gratings. Cross-oriented surroundings significantly inhibited the TAE, and iso-oriented surroundings slightly facilitated it; surround inhibition was much stronger than surround facilitation. In the para-fovea, the TAE was mainly decided by the surrounding patches. Likewise, a cross-oriented central patch inhibited the TAE, and an iso-oriented one facilitated it, but there was no significant difference between inhibition and facilitation. Our findings demonstrated, at the perceptual level, that our visual system adopts different mechanisms to process consistent or inconsistent central-surround orientation information and that the unequalmagnitude of surround inhibition and facilitation is vitally important for the visual system to improve the detectability or discriminability of novel or incongruent stimuli.