New imaging techniques used on macaque monkeys explains why we find it so easy to scan many items quickly when we’re focused on one attribute, and how we can be so blind to attributes and objects we’re not focused on.

The study reveals that a region of the visual cortex called V4, which is involved in visual object recognition, shows extensive compartmentalization. There are areas for specific colors; areas for specific orientations, such as horizontal or vertical. Other groups of neurons are thought to process more complex aspects of color and form, such as integrating different contours that are the same color, to achieve overall shape perception.

[1998] Tanigawa, H., Lu H. D., & Roe A. W.
(2010).  Functional organization for color and orientation in macaque V4.
Nat Neurosci. 13(12), 1542 - 1548.

Older news items (pre-2010) brought over from the old website

Which color boosts brain performance depends on task

Previous research has produced contradictory results as to which color helps memory the most: some have said blue or green; others red. A series of six experiments has found that the answer depends on the task. Red boosted performance on detail-oriented tasks such as memory retrieval and proofreading by as much as 31% compared to blue, while blue environmental cues produced significantly more creativity in such tasks as brainstorming. The effects are thought to be due to learned associations, such that red is associated with danger, mistakes and caution, while blue is associated with calm and openness. The study also found that these effects carry over to consumer packaging and advertising.

[1405] Mehta, R., & Zhu R(J).
(2009).  Blue or Red? Exploring the Effect of Color on Cognitive Task Performances.
Science. 323(5918), 1226 - 1229.

Seeing red worsens test performance

Perhaps because teachers usually mark in red pen, resulting in a lot of red on a page indicating a lot of mistakes, a study has found that seeing the color red before a test results in worse performance. Although the effect isn’t huge, it does appear consistently in different contexts. In one experiment, students were given a quiz that had a number in either red or green on the corner, while in another, students saw a glimpse of red, green, or grey on the cover of an IQ test. Those who saw red got fewer answers right on average. The researchers suggest the color produces anxiety. Red is of course also associated with danger, and with stopping.

Elliot, A.J., Maier, M.A., Moller, A.C., Friedman, R. & Meinhardt, J. 2007. Color and Psychological Functioning: The Effect of Red on Performance Attainment. Journal of Experimental Psychology: General, 136(1), 154-168.

Why are uniforms uniform? Because color helps us track objects

Laboratory tests have revealed that humans can pay attention to only 3 objects at a time. Yet there are instances in the real world — for example, in watching a soccer match — when we certainly think we are paying attention to more than 3 objects. Are we wrong? No. Anew study shows how we do it — it’s all in the color coding. People can focus on more than three items at a time if those items share a common color. But, logically enough, no more than 3 color sets.

[927] Halberda, J., Sires S. F., & Feigenson L.
(2006).  Multiple spatially overlapping sets can be enumerated in parallel.
Psychological Science: A Journal of the American Psychological Society / APS. 17(7), 572 - 576.

Scenes in natural color remembered better than black and white

In a series of experiments, subjects were found to remember photographs of colored natural scenes significantly better than black and white images, regardless of how long they saw the images. Falsely colored natural scenes were remembered no better than scenes in black and white. If shown the images in color but tested on them in black and white (and vice versa), the images were not remembered as well. It may be that color helps by providing an extra 'tag' on the stored memory code stored.

[341] Wichmann, F. A., Sharpe L. T., & Gegenfurtner K. R.
(2002).  The Contributions of Color to Recognition Memory for Natural Scenes.
Journal of Experimental Psychology: Learning, Memory, and Cognition. 28(3), 509 - 520.