Evidence has accumulated that rod activation under mesopic and scotopic light levels alters visual perception and performance. Here we review the most recent developments in the measurement of rod and cone contributions to mesopic color perception and temporal processing, with a focus on data measured using the four-primary photostimulator method that independently controls rod and cone excitations. We discuss the findings in the context of rod inputs to the three primary retinogeniculate pathways to understand rod contributions to mesopic vision. (...) Additionally, we present evidence that hue perception is possible under scotopic, pure rod-mediated conditions that involves cortical mechanisms. (shrink)

ABSTRACT The problem of “scotopic vision”, or vision under conditions of partial or total darkness, is one of the most enigmatic and least studied topics in Aristotelian psychology. In the article we present the exegesis of Averroes on this matter. We point out a dificulty that arises in the Great Commentary around some terms used to designate the obscurity in the whole of the theory. We propose as a solution a moderate interpretation of the matter, in accordance with the (...) “principle of economy” and the traditional exegesis of the commentators. (shrink)

Resumen: La “visión escotópica” desarrollada por Aristóteles en De Anima II 7 es la primera formulación sistemática de este fenómeno clave para las actuales neurociencias. En la teoría aristotélica surge una aparente contradicción entre el “compromiso ontológico” de la oscuridad como privación y el “realismo gnoseológico” que considera visible esa misma oscuridad. Tomás de Aquino en su Sententia libri De Anima propone una interpretación que establece la relación analógica entre luz y oscuridad a través del color. Esta estrategia permite disolver (...) cualquier contrariedad y establecer una percepción visual de la oscuridad en sentido realista.: The “scotopic vision” developed by Aristotle in De Anima II 7 is the first systematic formulation of this key phenomenon for current neurosciences. In this theory an apparent contradiction arises between the “ontological commitment” of darkness as deprivation and the “gnoseological realism” that considers that same darkness visible. Tomás de Aquino in his Sententia libri De Anima proposes an interpretation that establishes the analogical relationship between light and darkness through color. This strategy allows to dissolve any annoyance and establish a visual perception of darkness in a realistic. (shrink)