1. Performance-Related Sustained and Anticipatory Activity in Human Medial Temporal Lobe during Delayed Match-to-Sample
Rosanna K. Olsen,1 Elizabeth A. Nichols,1 Janice Chen,1 Jack F. Hunt,1 Gary H. Glover,2,3 John D. E. Gabrieli,4
and Anthony D. Wagner1,

2. Introduction
The relationship between short-delay memory performance and MTL
While which with long delays is well established

3. Introduction
fMRI data also reveal the importance of MTL in the short-delay recognition memory
Ranganath and D’Esposito, 2001
Schon et al., 2004
Ranganath et al., 2005
7~13s DMS
Nichols et al., 2006
Piekema et al., 2006
Axmacher et al., 2007

4. Introduction These study are Relatively short delay periods
Trial-unique stimuli

5. Introduction
Within the MTL, short-delay recognition memory may be differentially subserved by distinct subregions
Ex. Persistent activity in entorhinal cortex
May underlie active maintenance of goal-relevant stimuli
Study of human brain deficits
Study of rodent

6. Introduction
The characterization of delay period response in specific human MTL requires higher spatial resolution fMRI

7. Materials and Methods 25 subjects Right handed Native English speakers
10 female
18-32 years old
Paid 70$ for the participation
5 subjects data were excluded because
3 -> poor behavioral performance
2 -> functional data artifacts

8. Before the in-scanner DMS task
A target detection task
330 face trials
30 DMS faces for 10times
2 “targets “(faces) for 15 times
To make the stimuli non-trial-unique
It means to make them familiarized

9. Procedure of DMS task

10. Behavioral data

11. fMRI analysis (Anatomical ROI)
Sustained activity
Differ from correct to incorrect

13. fMRI analysis (Anatomical ROI)
Anticipatory effect
(preparatory effect)
Examine the linearity of delay-period activity
WHY?

14. Across-region functional dissociations
Pattern of delay-period activation
Parahippocampal cortex
Perirhinal and entorhinal cortex

15. Across-region functional dissociations
Performance-independent interaction
Perirhinal cortex  Entorhinal cortex
Perirhinal cortex more active during study
Entorhinal cortex more active during delay

16. Across-region functional dissociations
Also, functional dissociation of hippocampus subregions
Parallel previous studies of human hippocampus during declarative memory encoding and retrieval

17. fMRI voxel-level group analysis

18. fMRI voxel-level group analysis

19. Discussion
Two patterns of delay-period acitivity across distinct MTL subregions
Sustained
anticipatory

20. Discussion Sustained delay period activity predicts DMS performance
Further research
Systematic investigation of the influence of stimulus novelty/familiarity

21. Discussion Stimulus class effects in MTL cortex
Ventral visual cortex  perirhinal cortex
Deficits studies
Object recognition memory
Visual discrimination of complex objects and faces
fMRI studies
Both object and location/scene encoding
Dorsal visual cortex  parahippocampal cortex
Memory for topographical and spatial stimuli
Clear preference for location/scene encoding

22. Discussion
Does the MTL mediate working memory?