Introduction to Competitive Visual Processing Across Space and Time: Attention, Memory, and Prediction

According to the biased competition framework,1–3 competition, selection, and priority control are essential processing characteristics of the brain. For instance, in the visual modality, only a limited number of objects and features from a single eye fixation are available for perception, action, and memory. In one interpretation of this framework, competition between visual objects is biased by attentional resources that are distributed according to priorities.4,5 Thus, factors controlling priority, such as the current task or salience of environmental information, play a crucial role in selective visual processing across space and time. In this view, selective processing is an emergent property of attentional processes. Recently, interactions of memory with attentional selection processes in vision have become a key topic in cognitive neuroscience. First, the relationship between visual working memory and selective visual processing seems to be bidirectional.6,7 On the one hand, working-memory contents are often assumed to result from preceding competitive visual processing. A stronger version of this claim states that acting on visual information presupposes its working-memory representation.8 In any case, competitive visual processing determines the probability of representations in working memory. On the other hand, contents of visual working memory can bias ongoing competitive visual processing.9 Under certain conditions, currently encoded visual working-memory objects modulate which new sensory objects will reach the highly restricted “space” of working memory. For instance, several studies have shown that efficiency in a visual-search task can be influenced by working-memory contents that are retained for different concurrent tasks.6 Second, the same type of argument has been formulated for the role of long-term memory and knowledge in visual attentional selection. On the one hand, it has been claimed that long-term memory encoding of environmental information presupposes its attentional selection and working memory encoding.2 On the other hand, long-term memory has been considered one important origin of control signals that bias ongoing competitive visual processing.10 One form of such a long-term memory bias refers to context information. A context-based biasing signal can, for instance, come from a constant target template in a visual-search task, or from semantic and syntactic knowledge biasing selection during reading. In each case, long-term memory information is used for biasing visual competition. Moreover, selection in the sense of retrieving information from long-term memory has been considered as an attentional process.2 Third, based on working and long-term memory representations, predictions play a crucial role in biasing competitive visual processing in space and time.11–13 Findings from the Posner cueing paradigm14 are an example in which location expectations guide attentional selection.4 Moreover, violations of predicted context information (e.g., unexpected objects in a certain scene or a task sequence) are another factor influencing attentional selection.15 Several lines of evidence demonstrate that unexpected visual events influence the allocation of attentional priority in space and time.16,17 Competitive Visual Processing Across Space and Time: Attention, Memory, and Prediction is based on talks of the closing conference of the ZiF research group “Competition and priority control in mind and