Recognition Memory

     The process of recognition is central to human cognition. In an attempt to get a handle on this process, we are studying several phenomena that occur when two recognition judgments occur in sequence. For example, we have observed that a positive recognition judgment to a word is impeded following a positive or negative recognition judgment to a superficially similar word and that a negative recognition judgment to a word is impeded following a positive or negative recognition judgment to a semantically similar word. We are exploring the implications of these phenomena with respect to the processes that underlie positive and negative recognition judgments and the nature of the representations that are involved in such judgments.
 

Spatial Memory

     To navigate within an environment, a human must continually update a sense of the locations of the objects that comprise the environment. The memory representation that makes this possible must be pieced together from distinct views of the environment, each of which captures the objects from a particular point of view. The representation probably has a component in which the locations of the objects are recorded relative to the observer as well as a maplike component, in which the object locations are recorded independently of the observer. We are studying the form of this memory representation and the process whereby it is created. 
 

Dimensional Analysis 

     Humans tend to characterize the world in terms of quantitative attributes. As a consequence, human perception unfolds within a framework of perceptual dimensions. Psychologists have long been interested in the processes by which perceptual input is analyzed in terms of these dimensions. Under certain speeded-processing situations, an analytical understanding of the difference between two stimuli on a particular dimension emerges from a prior understanding of the differences between the stimuli on all dimensions. We have been attempting to model this emergence using General Recognition Theory, an all-purpose language for thinking about the representation and processing of multidimensional stimuli.