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Research Interests 

Below are some examples of the kinds of questions we are exploring about visual perception and adaptation. 
For a full list of our studies see our 

Publications

Stare at the center of the 4 colored squares for several seconds and then look at the center of the white squares

A 2 panel image of 4 squares in each panel. Left panel: top left square red, top right square green, bottom left square blue, bottom right square yellow. Right panel: All 4 squares show no color so that when you stare at left image you see color aftereffects in right image

The color afterimages you see result because each part of your eye adapts to the average color it is exposed to.

If your perception can change so dramatically in a matter of moments, how is it affected by the visual world you are currently surrounded by? What properties of that world do you adapt to? And what are the consequences of that adaptation for how you see and what you see?

These are the questions we are addressing by studying the visual characteristics of the world and the states of adaptation they hold us in.

Adaptation and the color characteristics 
of the natural world

Would you see color differently if you lived in a forest or desert? Do our own color percepts cycle with the seasons? 
We have studied these questions by measuring the color statistics of outdoor scenes and by using psychophysics and modeling to probe how the visual system adapts, and what this adaptation reveals about the neural encoding of color.

A 4 panel display of images adapted to different environments. Left: image of a lush environment and a muted version simulating post-adaptation. Right: image of an arid environment and a more vivid version simulating post-adaptation

We also use models to simulate very longterm and theoretically optimal states of adaptation, in order to assess the function and consequences of adaptation. For example, the images below simulate how Mars might appear to someone living there. 
Our work shows that features of the world become more salient once we are adapted to our current visual environment.

2 panel image. Left panel: simulated image of how Mars may look if you are adapted to colors on Earth. Right panel: simulated image of how Mars may look if you are adapted to colors on Mars. The right image looks much duller in color.

We use similar models to predict the consequences of sensitivity variations in observers. For example, as we age our lens yellows, but adaptation acts to filter this sensitivity bias from our color percepts. This is consistent with findings that older and younger observers, or color percepts between the fovea and periphery, are much more similar than the differences in spectral sensivity predict.

3 panel image, each showing a young girl carrying a pale. Left: how the image may look to a young observer. Middle panel: how the image may look to an older observer with an aged lens (more yellowing). right panel: how the image may look to an older observer who is adapted to their lens (similar to the first image).

We compare these predictions with actual measurements of color vision in the lab and in the field.

Image of a young woman wearing red and using a pen to point to a color from a series of colors on a paper, while a young girl watches from the side

Our studies suggest that the extent to which we see similarly or differently depends importantly 
on the extent to which we are adapted to the same or different environments.

Adaptation adjusts not only to low-level features of the image, but also to high-level or abstract characteristics of our world. 
We have studied how the appearance of someone's face is biased by the faces you have seen previously. 
For example, after adapting to a distorted face, a normal face appears distorted in the opposite direction.

An image depicting 9 faces of the same identity, but each version of the face is distorted in different ways. The center face is undistorted, while surrounding faces are either pinched or pulled along the x or y-axis of the nose

Work in our lab and many others shows that adaptation is important in calibrating most of the characteristics we notice about the face, from identity to expression. We are using these adaptation effects to understand the visual codes for representing faces.