Does the Object-Based Attention Effect Reflect a Benefit or a Cost?

Object-based attention would result if target appearing at an invalid location on the same object is detected more quickly than target on an equidistant location on different object (e.g., Egly, Driver, & Rafal, 1994). Three experiments examined the form of object-based attention typical object-based attention paradigms elicit (object-based benefits from the spread of attention across objects or object-based costs for switching attention between objects). Without a measurement of the time to switch attention from one location to another in the absence of objects, it is not possible to assess the relative costs or benefits of objects on attention. By adding an object-absent condition to typical object-based attention paradigms, the present experiments found that object-based attention is best described in terms of the cost to switch attention between objects.