Interactions between medial temporal lobe, prefrontal cortex, and inferior temporal regions during visual working memory: A combined intracranial EEG and functional magnetic resonance imaging study

被引:158
作者
Axmacher, Nikolai [1 ,2 ]
Schmitz, Daniel P. [1 ,3 ]
Wagner, Tobias [1 ]
Elger, Christian E. [1 ,2 ]
Fell, Juergen [1 ]
机构
[1] Univ Bonn, Dept Epileptol, D-53105 Bonn, Germany
[2] Life & Brain Ctr Acad Res, D-53105 Bonn, Germany
[3] Univ Appl Sci Remagen, Dept Appl Math, D-53424 Remagen, Germany
关键词
working memory; hippocampus; synchronization; directional coupling; functional connectivity; intracranial EEG;
D O I
10.1523/JNEUROSCI.1778-08.2008
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
It is a fundamental question whether the medial temporal lobe (MTL) supports only long-term memory encoding, or contributes to working memory (WM) processes as well. Recent data suggest that the MTL is activated whenever multiple items or item features are being maintained in WM. This may rely on interactions between the MTL or the prefrontal cortex (PFC) and content-specific areas in the inferior temporal (IT) cortex. Here, we investigated the neural mechanism through which the MTL, PFC, and IT cortex interact during WM maintenance. First, we quantified phase synchronization of intracranial EEG data in epilepsy patients with electrodes in both regions. Second, we used directional coupling analysis to study whether oscillatory activity in the IT cortex drives the MTL or vice versa. Finally, we investigated functional connectivity in functional magnetic resonance imaging data of healthy subjects with seeds in the MTL and PFC. With increasing load, EEG phase synchronization between the IT cortex and anterior parahippocampal gyrus and within the MTL increased. Coupling was bidirectional in all load conditions, but changed toward an increased top-down (anterior parahippocampal gyrus -> IT) coupling in the high gamma range (51-75 Hz) with increasing load. Functional connectivity between the MTL seed and the visual association cortex increased with load, but activity within the MTL and the PFC correlated with fewer voxels, suggesting that more specific neural networks were engaged. These data indicate that WM for multiple items depends on an increased strength of top-down control of activity within the IT cortex by the MTL.
引用
收藏
页码:7304 / 7312
页数:9
相关论文
共 55 条
[1]   THE PERFORMANCE OF POSTENCEPHALITIC AMNESIC SUBJECTS ON 2 BEHAVIORAL-TESTS OF MEMORY - CONCURRENT DISCRIMINATION-LEARNING AND DELAYED MATCHING-TO-SAMPLE [J].
AGGLETON, JP ;
SHAW, C ;
GAFFAN, EA .
CORTEX, 1992, 28 (03) :359-372
[2]   FACE RECOGNITION IN HUMAN EXTRASTRIATE CORTEX [J].
ALLISON, T ;
GINTER, H ;
MCCARTHY, G ;
NOBRE, AC ;
PUCE, A ;
LUBY, M ;
SPENCER, DD .
JOURNAL OF NEUROPHYSIOLOGY, 1994, 71 (02) :821-825
[3]   Memory formation by refinement of neural representations: The inhibition hypothesis [J].
Axmacher, Nikolai ;
Elger, Christian E. ;
Fell, Juergen .
BEHAVIOURAL BRAIN RESEARCH, 2008, 189 (01) :1-8
[4]   Sustained neural activity patterns during working memory in the human medial temporal lobe [J].
Axmacher, Nikolai ;
Mormann, Florian ;
Fernandez, Guillen ;
Cohen, Michael X. ;
Elger, Christian E. ;
Fell, Juergen .
JOURNAL OF NEUROSCIENCE, 2007, 27 (29) :7807-7816
[5]   Memory formation by neuronal synchronization [J].
Axmacher, Nikolai ;
Mormann, Florian ;
Fernandez, Guillen ;
Elger, Christian E. ;
Fella, Juergen .
BRAIN RESEARCH REVIEWS, 2006, 52 (01) :170-182
[6]  
Baddeley A., 1975, The Psychology of Learning and Motivation, V8, P47, DOI [DOI 10.1016/S0079-7421(08)60452-1, 10.1016/S0079-7421(08)60452-1]
[7]  
Buzaki G., 2006, Rhythms of the Brain
[8]  
Cohen N. J., 1993, Memory, amnesia, and the hippocampal system
[9]   THE WAVELET TRANSFORM, TIME-FREQUENCY LOCALIZATION AND SIGNAL ANALYSIS [J].
DAUBECHIES, I .
IEEE TRANSACTIONS ON INFORMATION THEORY, 1990, 36 (05) :961-1005
[10]   Human memory formation is accompanied by rhinal-hippocampal coupling and decoupling [J].
Fell, J ;
Klaver, P ;
Lehnertz, K ;
Grunwald, T ;
Schaller, C ;
Elger, CE ;
Fernández, G .
NATURE NEUROSCIENCE, 2001, 4 (12) :1259-1264