Reacting to Emotion: Anger Arrests and Happiness Helps.

Using a new method of affect priming, we find that a face with an angry expression slows a participant's performance; that is, we find anger inferiority. Our task presents a participant with a sequence of 2 visual stimuli. The first stimulus (Sl) and the second stimulus (S2) represent anger or happiness. The S1 s were words, schematic faces, or gray-scale faces, and the S2s were gray-scale faces. Participants performed an affect congruency task, judging whether S1 and S2 represent the same emotion. With standard affective priming, using identical stimulus param- eters, superior performance is found when S1 and S2 represent the same affect. With our task, comparing the 2 stimuli results in anger inferiority. With both congruent and incongruent S1 and S2 the response times depend more strongly on the affect of S1 rather than that of S2. An angry S1 produced longer decision times and more errors than a happy S1.

Nonmonotone backward masking functions and brightness reversals.

Increasing the target-field luminance aids detection for a simultaneously presented black target disc and a black masking annulus. At an intermediate interval separating the onset of the target from the mask, increasing the target-field luminance reduces target detection. This decrease in performance occurs with both temporal and spatial forced choice tasks. With a spatial forced choice, an observer's performance can fall below chance. We associate below-chance performance with a brightness reversal of the black target disc, such that the target disc appears brighter than its surround. The occurrence of brightness reversals follows from our model of the Broca-Sulzer effect, and nonmonotone masking functions result from a generalization of luminance summation.

Still another confounded face in the crowd.

Experiments using schematic faces developed by Öhman (Öhman, Lundqvist, & Esteves, 2001) seem to document an anger-superiority effect, although we have come to question these experiments. Our work shows that the low-level features of these schematic faces interact with the face's surround to produce effects that have been attributed to facial affect. Using relatively neutral faces that preserved the feature and surround spatial relationships of angry and happy schematic faces, we produced reaction times (RTs) that were indistinguishable from those found with angry and happy faces. We also found that the target face's position within the crowd determined the magnitude of the advantage for angry faces as well as for relatively affect-neutral faces. Removing the facial surround reduces the advantage for angry faces, largely by improving performance on happy faces. There was an apparent small advantage for angry features without a surround. Öhman faces avoid the problems associated with modified grayscale faces only to introduce an equally troubling confound.

Hermite acuity gratings and models of space-variant acuity.

A coherent mathematical framework for the psychophysics of contrast perception emerges when contrast sensitivity is posed as an eigenvalue problem. This more general mathematical theory is broad enough to encompass Fourier analysis as it is used in vision research. We present a model of space-variant contrast detection to illustrate the main features of the theory, and obtain a new contrast sensitivity function using acuity gratings based on the Hermite functions. The Hermite gratings have several advantages: they represent a complete orthogonal basis, are easy to manipulate, and are of finite extent. A theoretical Hermite csf results from posing contrast perception as an eigenvalue problem. Surprisingly, the theoretical Hermite csf is determined by a single empirical parameter.