Target detection and driving behaviour measurements in a driving simulator at mesopic light levels

During night-time driving hazardous objects often appear at mesopic light levels, which are typically measured using light meters with a spectral sensitivity that is only valid for photopic light levels. In order to develop suitable mesopic models a target detection experiment was performed in a driving simulator. While subjects drove along a...

Edge integration and the perception of brightness and darkness

How do induced brightness and darkness signals from local and remote surfaces interact to determine the final achromatic color percept of a target surface? An emerging theory of achromatic color perception posits that brightness and darkness percepts are computed by weighting and summing the induction signals generated at edges in a scene. This...

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Spatiotemporal configuration dependent pairing of nerve events in dark-adapted human vision

In the model presented here, in the dark any single quantum absorption in a rod or cone produces a subliminal excitation. Subliminal excitations from both halves of a twin unit pair in the retina for the perception of light from the stimulus. A twin unit contains either two red or two green cones. The twin units are intertwined in triples of two...

De Vries-Weber gain control and dark adaptation in human vision

Thresholds for seeing light from a stimulus are determined by a mechanism that pairs subliminal excitations from both halves of a twin unit. Such excitations stem from a package of k ≥ 1 receptor responses. A half-unit contains one red or one green cone and P rods. The receptor's "Weber machine" controls the receptor's gain. Each half of a twin...

Origin of the electroretinogram in the intact macaque eye. I. Principal component analysis

Responses to 400 msec flashes of white light were recorded at various depth in the retina of the intact macaque eye. A statistical technique, principal component analysis (PCA), was used to isolate independent components from the LERG, using the changing contribution of a cell's response to the LERG with retinal depth. Two approaches were...

Quantum coincidence requirements during dark-adaptation

Subjective brightness during dark-adaptation

The course of dark-adaptation was studied with threshold measurements and with measures of the luminance required to maintain a constant supraliminal brightness. A stimulus in the light-adapted right eye was matched in brightness to a stimulus presented to the left eye, which was dark-adapted. Two different methods were used and several levels...