This project examines the memory for relational information across eye movements. Identifying the information that bridges the discontinuity caused by saccadic eye movements is an important step in determining how information from successive fixations is combined to produce our perception of a stable visual world. Understanding how this perceptual stability is achieved is a classical question in visual perception. Much evidence suggests that visual information presented in one fixation is encoded and retained across the eye movement for use in subsequent fixations. This memory has been referred to as """"""""transsaccadic"""""""" memory. This information seems to be abstract rather than highly detailed, point- by-point information. Recent work has shown that structural descriptions may be used to represent such information across saccades. A structural description is a hierarchical representation of a stimulus, in which distinct parts of the stimulus are represented as nodes, and the relations among the parts are represented as connections among the nodes. As the hierarchy is traversed, the figure decomposes, with the top node representing the whole figure, nodes at the next level down representing distinct parts, and nodes further down representing elements that form the parts. The previous work in support of the transsaccadic use of structural descriptions has focused on the retention of parts across saccades. The goal of the current project is to provide additional evidence that structural descriptions are used in transsaccadic memory by determining whether relational information that specifies the connections among the parts of a stimulus are also encoded and retained across saccades. A same/different comparison task will be used within a transsaccadic memory paradigm. Specifically, a stimulus will be presented in one eye fixation. Upon elicitation of a saccade, the first stimulus will be removed and a second stimulus will be presented. Participants will decide whether the two stimuli are the same or different. This paradigm is transsaccadic because an eye movement intervenes between the presentation of the stimuli, thus requiring the retention of information from the first fixation for comparison with information from the subsequent fixation. The critical manipulation will be whether the stimuli share the same relational structure. The dependent measures will be response time and accuracy for """"""""same"""""""" and """"""""different"""""""" responses. Understanding whether relational information is represented in transsaccadic memory is important because it further clarifies the nature of the information surviving from one eye fixation to the next. Moreover, identifying the representational form of this information should offer constraints on characterizations of how information from subsequent fixations is combined to produce a sense of perceptual stability. This could have important consequences for diagnosing and treating individuals suffering from attentional and oculomotor disorders involving the inability to maintain visual continuity and/or stability.
| Carlson-Radvansky, L A (1999) Memory for relational information across eye movements. Percept Psychophys 61:919-34 |
