| |
Abstract:
A fundamental distinction between has been established in the
literature on spatial processing between route knowledge, based in
the perspective of the observer, and survey knowledge, based on the
global perspective (e.g., Siegel & White, 1975). The question
of encoding and imagining route and survey information has recently
received attention in functional neuroimaging (e.g., Shelton &
Gabrieli, 2000; Mellet et al, 2000). In this study, we turned our
focus to the role of route and survey information during retrieval
tasks. In particular, we explored how brain activation differs when
one is required to switch perspectives between encoding and
retrieval versus when the same perspective is maintained between
encoding and retrieval. Participants learned two virtual reality
(VR) environments through desktop VR tours, one at ground level
(route perspective) and one from an aerial view (survey
perspective). In the scanner participants performed scene
recognition for each environment separately. The recognition test
for each environment contained target and distracter images taken
from both the route and survey perspectives. The task was to
determine whether or not each scene was from the learned
environment, even if the presented perspective differed from the
perspective at study. Analyses revealed an interaction between
encoding type and test type during retrieval, suggesting that both
the prior knowledge and current perspective of presentation
influence how information is processed in the brain.
|
