Article Figures & Data
Figures
- Figure 1.
A, Overview of the paradigm. After presentation of 12 consecutive words, a number between 80 and 90 was presented and subjects had to count backward by three aloud. After 30 s of this distraction task, there was a free recall phase in which subjects loudly pronounced all words they remembered. B, C, Timing of the paradigm in the iEEG (B) and fMRI (C) version of the experiment.
- Figure 2.
Recall performance as a function of list position. A, Primacy effect in the group of healthy control subjects which were investigated with fMRI. B, Primacy and recency effects in the group of epilepsy patients with intracranial EEG electrodes.
- Figure 3.
Position-dependent shifts of DC potentials. The slope of the DC potential in the hippocampus depends on list position for subsequently forgotten items, but not for subsequently remembered items.
- Figure 4.
Position-dependent BOLD responses in the hippocampus. Time course of BOLD activity in anatomically defined regions of interest in the bilateral hippocampus (A). B, For subsequently forgotten items, there was a deactivation during presentation of the first item, which was reduced for later list positions. C, For subsequently remembered items, no deactivation was apparent. The time period selected for statistical analysis is marked in light gray.
- Figure 5.
Position effects in the anterior cingulate cortex. For both subsequently forgotten and remembered items, we observed an increased activation of the anterior cingulate cortex (remembered: MNI −3/39/15; forgotten: MNI −3/36/15).
- Figure 6.
Alternative model: position effects in the hippocampus and cingulate cortex. Contrast of activity during presentation of the seventh and first item in anatomically selected regions of interests in bilateral hippocampus (left and middle column) and anterior cingulate cortex (right column). For subsequently forgotten items presented at the first list position, there was a negative BOLD response in the left hippocampus, which was absent at the seventh list position (A, left column). No negative BOLD responses occurred in the right hippocampus (A, middle column) and for subsequently remembered items (B, left and middle column). On the whole-brain level, there was an increased activation in the anterior cingulate cortex at the seventh as compared with the first list position regardless of subsequent memory (right column).
Tables
L/R t value MNI coordinates x y z Incorrect 3 > 1 Anterior cingulate cortex R 4.231 18 30 15 Medial frontal gyrus R 4.205 27 30 21 Inferior frontal gyrus R 4.186 33 39 3 Cingulate gyrus R 3.901 9 33 30 Middle frontal gyrus R 3.772 30 9 42 Cingulate gyrus L 3.749 −9 18 33 Parahippocampal gyrus R 3.665 30 −33 6 Medial frontal gyrus L 3.664 −21 48 12 Thalamus L 3.656 −9 −30 15 Thalamus R 3.632 9 −18 18 Correct 3 > 1 Cingulate gyrus R 4.314 9 33 30 Inferior frontal gyrus R 4.241 33 39 3 Thalamus L 3.981 −9 −30 15 Thalamus R 3.912 9 −18 18 Middle frontal gyrus R 3.885 30 9 42 Anterior cingulate cortex L 3.866 −21 45 12 Caudate nucleus L 3.616 −6 9 9 Parahippocampal gyrus R 3.478 30 −33 6 Caudate nucleus L 3.271 −9 −3 21 -
All regions showing significantly increased activation for presentation at the third as compared to the first position are indicated. L, Left; R, right.
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Supplemental Data
Files in this Data Supplement:
- supplemental material - Supplemental Material
