title: Fast Detector/First Responder: Interactions between the Superior Colliculus-Pulvinar Pathway and Stimuli Relevant to Primates.
abstract: Primates are distinguished from other mammals by their heavy reliance on the visual sense, which occurred as a result of natural selection continually favoring those individuals whose visual systems were more responsive to challenges in the natural world. Here we describe two independent but also interrelated visual systems, one cortical and the other subcortical, both of which have been modified and expanded in primates for different functions. Available evidence suggests that while the cortical visual system mainly functions to give primates the ability to assess and adjust to fluid social and ecological environments, the subcortical visual system appears to function as a rapid detector and first responder when time is of the essence, i.e., when survival requires very quick action. We focus here on the subcortical visual system with a review of behavioral and neurophysiological evidence that demonstrates its sensitivity to particular, often emotionally charged, ecological and social stimuli, i.e., snakes and fearful and aggressive facial expressions in conspecifics. We also review the literature on subcortical involvement during another, less emotional, situation that requires rapid detection and response-visually guided reaching and grasping during locomotion-to further emphasize our argument that the subcortical visual system evolved as a rapid detector/first responder, a function that remains in place today. Finally, we argue that investigating deficits in this subcortical system may provide greater understanding of Parkinson's disease and Autism Spectrum disorders (ASD).
authors.affiliation: Department of Education and Psychology, CINTESIS.UA, University of AveiroAveiro, Portugal; Division of Psychology, Department of Clinical Neuroscience, Karolinska InstituteStockholm, Sweden; William James Research Center, Instituto Superior de Psicologia AplicadaLisbon, Portugal.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Soares
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska InstituteStockholm, Sweden; Department of Physiological Sciences, Primate Center, Institute of Biology, University of BrasíliaBrasília, Brazil.
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Maior
authors.affiliation: Department of Anthropology, University of California, Davis Davis, CA, USA.
authors.forename: Lynne A
authors.initials: LA
authors.lastname: Isbell
authors.affiliation: Department of Physiological Sciences, Primate Center, Institute of Biology, University of BrasíliaBrasília, Brazil; Ceuma University, Neuroscience Research CoordinationSão Luis, Brazil.
authors.forename: Carlos
authors.initials: C
authors.lastname: Tomaz
authors.affiliation: System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Toyama, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishijo
keywords: evolution; faces; primates; pulvinar; snake detection theory; superior colliculus