| |
Abstract:
Abstract: The cortical asymmetry of reflective activity
hypothesis (CARA) proposesthat relatively simple episodic
remembering engages right prefrontalcortex (PFC) and more
reflectively demanding episodic remembering ismore likely to engage
both right and left PFC (Nolde, Johnson, & Raye,1998). The
present experiment (N=10 young adults) used fMRI to comparea more
reflectively complex episodic memory task (sequential
yes/norecognition) to a simpler, less reflectively demanding
episodic memorytask (forced-choice recognition). For generality, we
used abstractwords and colored textures. Compared to each other,
these materialshave been shown to produce hemispheric modality
effects in sequentialyes/no recognition (greater left inferior PFC
activity for abstractwords and greater right inferior PFC activity
for textures; Wagner,Poldrack, Eldridge, et al., 1998). The present
study examined whetherthe processing demands of the memory task
(simple vs complex reflectiveprocessing) would lead to differences
in PFC activity beyond thoseassociated with stimulus modality. The
results are consistent with theidea that the relative contribution
of left and right PFC depends on thecomponent processes engaged by
specific episodic memory tasks. Clarifying these processes and
underlying brain mechanisms depends oncontrasting memory conditions
that vary in task demands as well as typeof material.
|
