Priming in visual search

In the last twenty years a growing bunch of literature has showed the way we scan our environment and we look for target objects is heavily influenced by what we have viewed or looked for in the recent past. For example, the repeated presentation of an object’s feature or position in a visual search task leads to a facilitation in the detection, discrimination or identification of that object. This phenomenon is named priming and seems to be due to a primitive short-term memory system encoding and enhancing the response to features or objects recently encountered, therefore facilitating the response to the same or similar objects in successive presentations. This process is implicit and involuntary, it can occur for basic stimulus features as well as for objects or whole visual scenes, but also for higher-order characteristics of the stimulus such as attentional, temporal or emotional consistencies. Priming in visual search is probably not a unitary phenomenon. Rather, it seems to reflect activity modulations at various levels of the hierarchy of perceptual processing, ranging from lower to higher levels, depending on the stimulus, task, and context.