Visual Working Memory (VWM) underlies infants' ability to manipulate, learn from, and reason about the objects around them. The study of VWM therefore affords precious insight into object cognition and cognitive development in general. VWM is typically evaluated by the likelihood that an infant will react to a change in a to-be-remembered object; this work argues that it is only legitimate to compare VWM for object changes that are equally 'noticeable' or 'interesting' to the infant, that is, equally salient. After all, the more salient a change, the greater the likelihood of an infant reacting to that change. The broad goal of this research program is to formalize the study of VWM in infants by introducing an innovative Inter-dimensional Salience Mapping paradigm that allows for the precise measurement of the relative salience of visual stimuli. We propose to reevaluate basic questions of VWM (e.g. is memory for shape better than for color? are familiar objects, like faces, better remembered than garish ones?), but with the specific goal of testing an Ecological Memory hypothesis: that infants are more likely to react to changes along feature dimensions that are reliable object identifiers - like shape and familiarity - rather than unreliable ones, like size or luminance. This ability to precisely specify the salience differences between objects has applications and significance beyond memory research, in domains such as visual attention and eye movements. Critically, though, since this method provides a metric by which to calibrate stimulus changes, it can equalize task difficulty between different groups, thereby allowing for a fair comparison of visual abilities between age groups and clinical populations. ? ? ?