Encoding novel face-name associations: a functional MRI study

Abstract

The process of forming new associations between previously unrelated items of information, such as a name and a face, likely requires the integration of activity within multiple brain regions. The hippocampus and related structures in the medial temporal lobe are thought to be particularly critical in binding together items of information. We studied eight healthy young subjects with functional magnetic resonance imaging (fMRI) during the encoding of novel face-name associations compared to viewing repeated face-name pairs. A consistent pattern of activation was observed in the hippocampus, pulvinar nucleus of the thalamus, fusiform and dorsolateral prefrontal cortices across individual subjects. The location of the activation within the hippocampus was more anterior than previously reported in studies using similar novel vs. repeated paradigms with stimuli that did not specifically require relational processing among unrelated items. These data suggest that the process of forming new face-name associations is supported by a distributed network of brain regions, and provide additional evidence for the essential role of the hippocampus in associative memory processes.

Copyright 2001 Wiley-Liss, Inc.

Figures

Figure 1

Diagram of “Block Design” fMRI paradigm, showing Novel Face‐Name Pairs, Repeated Face‐Name Pairs and Fixation (+) conditions. Each functional “Run” lasted for 4 min and 5 sec, and a total of six runs were shown to each subject.

Figure 2

Activation map for group averaged data for the Novel vs. Repeated contrast is shown superimposed on the group averaged structural SPGR image (above), showing significant activation in the right anterior hippocampus (Talairach coordinates 21, −18, −12). Color scale indicating significance values is shown on the right. The MR signal from the voxel showing most significant activation (P < 1.3 × 10−9) within the right hippocampus (below).

Figure 3

Activation maps for individual subjects shown superimposed on individual SPGR coronal images re‐oriented into standardized coordinate system. Images showing the greatest extent of significant activation (P < 0.001 at individual subject level) in medial temporal regions are shown for each subject for the Novel vs. Repeated (NvR, above) and the Novel vs. Fixation (NvF, below) contrasts. Although the extent and magnitude of activation varied, all subjects demonstrated significant activation within the hippocampal formation for the NvR contrast. The NvF contrast yielded a less consistent pattern of activation within the medial temporal lobe.

Figure 4

Activation map for group averaged data for the Novel vs. Repeated contrast showing significant activation in two locations within prefrontal cortex (shown on left) Brodmann areas 9/44, (Talairach coordinates for peak activated voxel x,y,z −43, 9, 31) and (shown on right) Brodmann areas 45/46 (28, 21, 6).

Figure 5

Activation map for group averaged data for Novel vs. Fixation contrast in the fusiform gyri (Brodmann areas 37/20, Talairach coordinates for peak activated voxel 43, −48, −18).