Abstract
Selective attention is a property of the human visual system, a collection of sophisticated psychological mechanisms that necessarily arose over an evolutionary time span. An ecological perspective suggests that some objects of persisting biological importance should quickly and reliably capture visual attention, irrespective of viewers' present goals and intentions. Previous research has demonstrated that items such as spiders and faces are more easily detected by parietally-damaged individuals when presented in largely neglected areas. To test the ability of biologically important objects to capture visual attention in normal individuals, our study has used the inattention blindness paradigm. In this experiment an unexpected stimulus is displayed peripherally to a participant while they estimate the relative lengths of two central, bisecting lines. We found that a biologically-important object (i.e. spider) is detected, localized, and identified above chance performance while a stimuli that is comparably perceived as threatening in the modern environment (i.e. hypodermic needles) is not. Additional conditions suggest that the spider detection, while not discriminating between curvilinear and rectilinear depictions, is highly sensitive to the spatial configuration of features.