Research areas

Currently, we are studying vision related topics in five areas (retinal neurobiology, visual camouflage, visual ecology, visual perception, and retinal prosthesis). Brief summary of what we have done or issues we are currently addressing are listed below.

 

Retinal neurobiology

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Retina is a layered neural tissue in the back of the eye. We are interested in their circuitry and development. In past few years, we have identified a new type of blue-off cone bipolar cells (Liu & Chiao, 2007), and showed an intricate relationship between starburst amacrine cells (SACs) and direction selective ganglion cells (DSGCs) in the adult rabbit retina (Chen & Chiao, 2008). In the retina development, we have demonstrated that visual deprivation can delay the bipolar cell maturation (Wu & Chiao, 2007), but does not seem to affect the trigger feature of DSGCs, though some receptive field properties are altered (Chan & Chiao, 2008). Furthermore, we also characterized and functionally mapped the temporal expression pattern of AMPA receptors in the developing retina, and lay a ground work to study glutamate’s role in retina maturation (Chang & Chiao, 2008). We are currently using a variety of different techniques to tackle both circuit and developmental questions using the rabbit retina. Some ongoing projects include: (1) electrical synapse and receptive field of ganglion cells (2) functional role of gap junction in retinal development and DSGC maturation (3) spatiotemporal characterization of ganglion cells in developing retinas (4) NMDA receptors and retinal development. Fully understanding of retinal circuit and development is the underpinning of retinal prosthesis and ophthalmological treatments.

 

Visual camouflage

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Cephalopods use neural control to dynamically change body patterns for camouflage. We are interested in understanding how cuttlefish (a group of cephalopods) use visual features to achieve this daunting task. In past years, we have showed that a set of basic visual characters (e.g., contrast, size, intensity, etc) is important to evoke certain body patterns (Chiao and Hanlon, 2001a,b; Chiao et al., 2005, 2007; Mäthger et al., 2007; Barbosa et al., 2008). This work is in collaboration with Roger Hanlon at Marine Biological Laboratory (USA). In NTHU, we also setup a cuttlefish lab to study the effect of visual experience on body patterning as well as some cognitive behavior development. The fact that cephalopods equip with large brain and sophisticate behavior emphasizes its role in comparative neuroscience.

 

Visual ecology

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We are interested in studying the co-evolution of color signals and color vision systems in animal communication. Particularly, we are focusing on how bees see their predators (spiders) and their foraging targets (flowers). In EC Yang’s lab (NTU), we developed a bee camera system, which allows us to capture UV, Blue, and Green images that simulate the inputs of bee photoreceptors. With this device, we are currently acquiring the spatial and spectral information available for bees. We will address various issues in the context of behavioral ecology and visual ecology. This work is in collaboration with En-Cheng Yang and Chun-Neng Wang at National Taiwan University, and I-Min Tso at Tung Hai University.

 

Visual perception

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I am just beginning to explore human visual texture perception by using the scramble random dots paradigm. Several issues are currently under investigation, including the contrast range and adaptation effects on the blackshot visual mechanism, and dimensions of visual mechanisms in color space, etc. This work is in collaboration with Charlie Chubb at UC Irvine (USA).

 

 

 

 

Retinal prosthesis

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We are doing in-vitro test of silicone based solar cell chip as a mean of sub-retinal prosthesis device in the isolated mammalian retinas (rabbits and rats). We have so far proven the principle of this design by showing spiking responses of ganglion cells upon electrical stimulation. This is an ongoing project, and we are still in the early phase of this research. This work is in collaboration with Chung-Yu Wu at National Chiao Tung University,

 

Last updated Oct 29, 2008