While it is known that primitive, low-level visual stimuli such as abrupt visual onsets or luminance changes can bias attentional orienting without willful intent on the part of the observer, comparatively little is known about how attention functions in rich, dynamic, meaningful contexts, such as those that comprise our everyday lives. The primary motivating hypothesis of this investigation is that, given our intrinsic needs as evolved social organisms, as well as our capability for behavioral flexibility, the attention system should be sensitive not only to low-level stimulus features, but also to complex stimuli that provide behaviorally relevant information. Three separate lines of research will be presented, each one providing a unique perspective on this issue. The first examined attentional orienting to socially relevant stimuli, finding that eye gaze serves as particularly potent cue for attentional orienting, driving the cortical orienting network more robustly than non-social stimuli, and resulting in a larger attention-related modulation of the early visual processing of stimuli appearing at attended locations. The second line of inquiry investigated patterns of eye movements while participants viewed naturalistic navigational scenes, revealing a dynamic interplay of orienting to the various behaviorally relevant aspects of the scene. The third set of studies specifically addressed whether, given the relevance of heading information for guiding navigational behavior, there is evidence that attention can be oriented automatically to the heading point in an optic flow field simulating the patterns of visual stimulation that accompany self-motion. Together, the results converge on the conclusion that attention can be oriented automatically in a dynamic, flexible, and continuous manner on the basis of complex visual stimuli that provide behaviorally relevant information.

While it is known that primitive, low-level visual stimuli such as abrupt visual onsets or luminance changes can bias attentional orienting without willful intent on the part of the observer, comparatively little is known about how attention functions in rich, dynamic, meaningful contexts, such as those that comprise our everyday lives. The primary motivating hypothesis of this investigation is that, given our intrinsic needs as evolved social organisms, as well as our capability for behavioral flexibility, the attention system should be sensitive not only to low-level stimulus features, but also to complex stimuli that provide behaviorally relevant information. Three separate lines of research will be presented, each one providing a unique perspective on this issue. The first examined attentional orienting to socially relevant stimuli, finding that eye gaze serves as particularly potent cue for attentional orienting, driving the cortical orienting network more robustly than non-social stimuli, and resulting in a larger attention-related modulation of the early visual processing of stimuli appearing at attended locations. The second line of inquiry investigated patterns of eye movements while participants viewed naturalistic navigational scenes, revealing a dynamic interplay of orienting to the various behaviorally relevant aspects of the scene. The third set of studies specifically addressed whether, given the relevance of heading information for guiding navigational behavior, there is evidence that attention can be oriented automatically to the heading point in an optic flow field simulating the patterns of visual stimulation that accompany self-motion. Together, the results converge on the conclusion that attention can be oriented automatically in a dynamic, flexible, and continuous manner on the basis of complex visual stimuli that provide behaviorally relevant information.

While it is known that primitive, low-level visual stimuli such as abrupt visual onsets or luminance changes can bias attentional orienting without willful intent on the part of the observer, comparatively little is known about how attention functions in rich, dynamic, meaningful contexts, such as those that comprise our everyday lives. The primary motivating hypothesis of this investigation is that, given our intrinsic needs as evolved social organisms, as well as our capability for behavioral flexibility, the attention system should be sensitive not only to low-level stimulus features, but also to complex stimuli that provide behaviorally relevant information. Three separate lines of research will be presented, each one providing a unique perspective on this issue. The first examined attentional orienting to socially relevant stimuli, finding that eye gaze serves as particularly potent cue for attentional orienting, driving the cortical orienting network more robustly than non-social stimuli, and resulting in a larger attention-related modulation of the early visual processing of stimuli appearing at attended locations. The second line of inquiry investigated patterns of eye movements while participants viewed naturalistic navigational scenes, revealing a dynamic interplay of orienting to the various behaviorally relevant aspects of the scene. The third set of studies specifically addressed whether, given the relevance of heading information for guiding navigational behavior, there is evidence that attention can be oriented automatically to the heading point in an optic flow field simulating the patterns of visual stimulation that accompany self-motion. Together, the results converge on the conclusion that attention can be oriented automatically in a dynamic, flexible, and continuous manner on the basis of complex visual stimuli that provide behaviorally relevant information. / Arts, Faculty of / Psychology, Department of / Graduate

Criar um ambiente experimental capaz de medir a resposta neural da visão (térmica) - em serpentes - quando estimulada por radiação infravermelha. Tratou-se da criação de estímulos dinâmicos artificiais dos quais a temperatura e a velocidade de deslocamento foram controlados. A resposta da cobra, quanto a esses estímulos, foi captada diretamente do cérebro da mesma (teto óptico), que corresponde aos processos visuais e infravermelhos do sistema nervoso central da cascavel. Mostramos que com esses estímulos criados, foi possível obter dados experimentais capazes de viabilizar analises de sensibilidade do sistema sensorial infravermelho em relação a contraste em temperatura e velocidade de movimento de presas artificiais. / The present work describe a creation of an experimental environment capable of measuring the neural response of vision (thermal) -in snakes -when stimulated by infrared radiation. There will be a creation of artificial dynamic stimuli of which the temperature and displacement velocity can be controlled. The response of the snake, when presented to these stimuli, captured directly from the brain (tecto optic), which corresponds to visual and infrared process in the central nervous system of the rattlesnake. We showed that with these stimuli created, it is possible to obtain experimental data which will allow analysis of sensitivity of the infrared sensory system in relation to contrast in temperature and speed of movement of false prey.

Criar um ambiente experimental capaz de medir a resposta neural da visão (térmica) - em serpentes - quando estimulada por radiação infravermelha. Tratou-se da criação de estímulos dinâmicos artificiais dos quais a temperatura e a velocidade de deslocamento foram controlados. A resposta da cobra, quanto a esses estímulos, foi captada diretamente do cérebro da mesma (teto óptico), que corresponde aos processos visuais e infravermelhos do sistema nervoso central da cascavel. Mostramos que com esses estímulos criados, foi possível obter dados experimentais capazes de viabilizar analises de sensibilidade do sistema sensorial infravermelho em relação a contraste em temperatura e velocidade de movimento de presas artificiais. / The present work describe a creation of an experimental environment capable of measuring the neural response of vision (thermal) -in snakes -when stimulated by infrared radiation. There will be a creation of artificial dynamic stimuli of which the temperature and displacement velocity can be controlled. The response of the snake, when presented to these stimuli, captured directly from the brain (tecto optic), which corresponds to visual and infrared process in the central nervous system of the rattlesnake. We showed that with these stimuli created, it is possible to obtain experimental data which will allow analysis of sensitivity of the infrared sensory system in relation to contrast in temperature and speed of movement of false prey.