Goodyear and Kamil (2004) assessed the ability of Clark’s nutcrackers to find buried food based on a cross-shaped array of landmarks at different distances from the goal. Their findings suggested that proximal landmarks overshadowed learning about distal landmarks, and this was attenuated when assessing the effect of distal landmarks on learning about proximal landmarks. In this study, we aimed to replicate their findings in human spatial navigation by using a virtual environment. Three groups of participants were trained in an open environment featuring orientation cues, and they had to find a hidden goal with reference to four landmarks that were arranged in the shape of a cross and placed at different distances from the goal. Two of the four landmark distances were common across all three groups to allow a comparison of the extent of overshadowing under comparable conditions. Following training, all participants were tested with each of the four landmarks individually. Consistent with the results in birds, we observed better performance in the groups with more distal landmarks, suggesting that overshadowing was greater in the groups with closer landmarks and thus dependent on the spatial distance between the landmarks and the goal. Landmarks near the goal more effectively overshadowed landmarks far from the goal. A second experiment, in which landmarks and orientation cues were misaligned in order to prevent the use of a straightforward solution to the task, replicated the results. The results are discussed in terms of a modification of Pearce’s configural model.In any domain of daily life and cognition, humans solve tasks and make decisions by using information that comes from multiple, different sources. It is quite obvious that we learn from previous experiences. We then use multiple sources of information to guide our behaviour in environments, make decisions about what is beneficial for us, and act in social situations (attributions, imitation). Most times however, not all information in the environment is useful. For example, if we eat fish and chips and later become ill, it is difficult to know which of the two made us ill, and people tend to select one or the other based on quantity. In fact, humans are particularly adept at selecting and learning from those sources which provide information about relevant outcomes. Hence, the idea of competition between different sources of information has been prominent in theories of learning. A wealth of data in the social sciences and psychology supports this assertion. Yet, the finding that multiple sources of information compete during learning is not ubiquitous. In some fields (i.e., spatial learning, category learning) and in experiments using animals, researchers have found facilitation (the opposite of competition) between multiple sources of information, and this has led to the development of specific theories that explain those findings, by assuming they are "exceptions". Thus, there are theories aimed at explaining competition, and theories aimed at explaining facilitation, but no consensus regarding the circumstances that lead to either of these opposite outcomes. Based predominantly on experiments conducted in nonhuman animals, Urcelay has recently hypothesized that competition and facilitation are two extremes of a continuum which is determined by multiple variables. The objective of this proposal is to test whether contiguity (that is, the temporal and spatial separation of events) is a critical determinant of these opposite findings. We predict that competition and facilitation are phenomena that can be observed across different tasks and domains of cognition. Therefore, we will test this general prediction across different learning preparations with increasing complexity. First, we wish to determine whether competition and facilitation are observed as a function of temporal separation between hypothetical food consumption and sickness in a predictive scenario such as the food-disease example mentioned above. The second objective is to extend these findings to an action-outcome task. Action-outcome learning underlies the sense of agency, free will and responsibility. We will investigate whether competition or facilitation are observed in a task in which participants' actions (i.e., press a button) and other environmental events (a signal) are presented simultaneously during learning. We will do this whilst manipulating the time between action and the outcome. We predict that when outcomes are presented soon after the action, stimuli will compete with action-outcome learning, but that the opposite will occur when outcomes are delayed. This is relevant to human behaviour because most of our actions are followed by delayed outcomes (e.g., saving for retirement; preparing for a child's birth). The final objective of this proposal is to investigate this prediction in spatial learning, which integrates the above mentioned objectives in a more complex and ecologically valid setting, whilst extending the prediction to spatial separation. Notably, in spatial learning both competition and facilitation have been observed, but the exact reasons for these discrepant findings have not been elucidated. In all three objectives, we will further investigate the psychological mechanisms (whether participants process different bits of information as separate elements, or as a whole) underlying competition and facilitation in these three scenarios. These findings have important implications for theories of learning, and for education.

Online data collection. Participants were recruited through Prolific.