Does your brain have a binding problem?
Binding is the ability to perceive how visual features are paired.
Many researchers have theorized that perceiving feature pairings requires additional processing beyond that required to perceive the features alone (Treisman & Gelade, 1980). But a few have suggested that there is no binding problem (di Lollo, 2012; Lennie, 1998).
What color are the dots when moving leftward? At the slow alternation rate it's easy, but in the rapid case, it's difficult. Click here for a high-quality version. At rates above about six per second, people perform near chance.
Perceiving the individual features- the constituent colors and motions- is easy even in the rapid case. The difficulty is specific to binding the colors and motions.
The binding difficulty persists even when the relative time of the colors and motions are adjusted to compensate for a perceptual asynchrony (Arnold, 2005; Holcombe, 2009; related demonstrations).
Although the cause of the phenomenon is uncertain, an obvious possibility is that color and motion are processed somewhat independently, with a distinct process required to pair them. For more failures to bind features that are themselves clearly perceived, see Clifford, Holcombe, & Pearson (2004) and Seymour, McDonald, & Clifford (2009).
If you want to play with this stimulus (varying the alternation rate, relative phase of alternation, etc), go to an interactive version.
Created by Alex Holcombe.