Boundary Extension Is Sensitive to Hand Position in Young and Older Adults.

Objectives: Based on preliminary reports, we expected an age-related increase in boundary extension (BE), a phenomenon in which people falsely remember seeing more of a scene than was presented. Given recent data suggesting hand-centered attentional frames in young adults contrasted with body-centered attentional frames in older adults, we predicted hand-position effects on BE in young adults only. Method: Participants (59 young, 60 older adults) viewed photographs of complex scenes (e.g., a market) and answered yes/no questions about each. Half answered with key presses while their hands were framing the computer monitor; half while their hands were on a lapdesk. At test, participants indicated whether photographs were the same as, or at a closer or wider angle than at study. Results: Both age groups demonstrated BE. When study-test angles were the same, participants rated test pictures as closer than at study. When study-test angles differed, older adults showed less BE than young adults. For both same- and different-angle conditions, there was a main effect of hand position (less BE when hands framed the monitor than when on participants' laps). Discussion: The data confirm older adults show BE but show no age-related increase. Surprisingly, both young and older adults showed hand-centered attention.

No imagination effect on boundary extension.

Boundary extension (BE) occurs when people falsely remember perceiving beyond the edges of a presented scene. Theorists argue that BE occurs because people mistakenly attribute information they have generated to the study stimulus-that is, they make a source memory error. Inspired by this idea, in six experiments we tested whether scene details resulting from explicit imagination would be misremembered as actual visual perceptions, resulting in increased BE as compared with standard instructions. In four experiments, undergraduates completed a BE task with separate study and test blocks; in two further experiments, undergraduates completed a trial-by-trial BE task (N = 290). Half of the participants elaborated on the study pictures (imagined smells and sounds, or what was to the left and right of the scene, or what a photographer would see by zooming in or out). Robust BE was found in all experiments, but none of the elaborations modified the size of BE; therefore, BE is not to be affected by explicit elaboration and may be related to spatial rather than visual imagery ability.

Representational momentum in scenes: learning spatial layout.

In four experiments, we examined whether watching a scene from the perspective of a camera rotating across it allowed participants to recognize or identify the scene's spatial layout. Completing a representational momentum (RM) task, participants viewed a smoothly animated display and then indicated whether test probes were in the same position as they were in the final view of the animation. We found RM anticipations for the camera's movement across the scene, with larger distortions resulting from camera rotations that brought objects into the viewing frame compared with camera rotations that took objects out of the viewing frame. However, the RM task alone did not lead to successful recognition of the scene's map or identification of spatial relations between objects. Watching a scene from a rotating camera's perspective and making position judgments is not sufficient for learning spatial layout.