Leopard frogs (Rana pipiens) rely on vision to recognize behaviorally meaningful aspects of their environment. The optic tectum has been shown to mediate the frog's ability to recognize and respond to moving prey and looming objects. Nonetheless, atectal frogs are still able to appropriately respond to non-moving aspects of their environment. There appears to be independent visual systems operating in the frog: one system for recognizing moving objects; and another system for recognizing stationary objects. Little is known about the neural mechanisms mediating the recognition of stationary objects in frogs. Our laboratory showed that a retino-recipient area in the anterior lateral thalamus--the NB/CG zone--is involved in processing visual information concerning stationary aspects of the environment. This thesis aims to characterize the frog's responses to a range of stationary stimuli, and to elucidate the thalamic visual system that mediates those responses. I tested leopard frogs' responses to different stationary stimuli and found they respond in stereotypical ways. I discovered that leopard frogs are attracted to dark, stationary, opaque objects; and tested the extent of this attraction under different conditions. I found that frogs' preference to move toward a dark area versus a light source depends on the intensity of the light source relative to the intensity of ambient light. Unilateral lesions applied to the NB/CG zone of the anterior lateral thalamus resulted in temporary deficits in frogs' responses to stationary stimuli presented in the contralateral visual field. Deficits were observed in response to: dark objects, entrances to dark areas, light sources, and gaps between stationary barriers. However, responses to moving prey and looming stimuli were unaffected. Interestingly, these deficits tended to recover after about 6 days in most cases. Recovery time ranged from 2 - 28 days. The NB/CG zone is anatomically and functionally connected to a structure in the posterior thalamus called the "PMDT." The PMDT has no other connections in the brain. Thus, I have discovered a "satellite" of the NB/CG zone. Preliminary evidence suggests that the PMDT is another component of the visual system mediating stationary object recognition in the frog. / Biology

Este projeto busca articular visualmente as paisagens urbanas, as ocupações de edifícios abandonados e as grafias do centro de São Paulo com a linguagem fotográfica: mediante intervenções gráficas sobre as fotografias propõe-se uma reflexão a respeito das transformações que vem sofrendo a visualidade do centro antigo. Isto é, o colapso de um tipo de urbanismo, o derretimento da \"utopia\" moderna e da visão cartão postal da cidade fazem parte de um mesmo contexto de crise, em que também se questiona a fotografia como representação realista. O trabalho final é um livro de fotografia com uma linguagem híbrida com outros meios de representação. / This project aims to visually articulate urban landscapes, empty buildings occupations and graphic symbols of Sao Paulo\'s city center, using photography. A reflection based on graphic interventions about the changes undergone in the old city center\'s visuality and in the photographic language is proposed. That is, the collapse of a kind of urbanism, the melting of modern \"utopia\" and city postcard view are part of the same crisis context, which also questions realism in photography. The outcome is a photo book that uses hybrid language and other forms of representation.

Este projeto busca articular visualmente as paisagens urbanas, as ocupações de edifícios abandonados e as grafias do centro de São Paulo com a linguagem fotográfica: mediante intervenções gráficas sobre as fotografias propõe-se uma reflexão a respeito das transformações que vem sofrendo a visualidade do centro antigo. Isto é, o colapso de um tipo de urbanismo, o derretimento da \"utopia\" moderna e da visão cartão postal da cidade fazem parte de um mesmo contexto de crise, em que também se questiona a fotografia como representação realista. O trabalho final é um livro de fotografia com uma linguagem híbrida com outros meios de representação. / This project aims to visually articulate urban landscapes, empty buildings occupations and graphic symbols of Sao Paulo\'s city center, using photography. A reflection based on graphic interventions about the changes undergone in the old city center\'s visuality and in the photographic language is proposed. That is, the collapse of a kind of urbanism, the melting of modern \"utopia\" and city postcard view are part of the same crisis context, which also questions realism in photography. The outcome is a photo book that uses hybrid language and other forms of representation.