 |
Previous Article | Next Article 
Volume 16, Number 11,
Issue of June 1, 1996
pp. 3753-3759
Copyright ©1996 Society for Neuroscience
Network Analysis of Positron Emission Tomography Regional
Cerebral Blood Flow Data: Ensemble Inhibition during Episodic Memory
Retrieval
Received Oct. 30, 1995; revised Feb. 28, 1996; accepted March 6, 1996.
Lars Nyberg1, 2,
Anthony R. McIntosh1,
Roberto Cabeza1,
Lars-Göran Nilsson3,
Sylvain Houle4,
Reza Habib1, and
Endel Tulving1
1 Rotman Research Institute of Baycrest Centre,
University of Toronto, Toronto, Canada, 2 Department of
Psychology, University of Umeå, Umeå, Sweden,
3 Department of Psychology, Stockholm University,
Stockholm, Sweden, and 4 PET Centre, Clarke Institute of
Psychiatry, University of Toronto, Toronto, Canada
Two important objectives in the neuroscience of memory are (1)
identification of neural pathways involved in memory processes; and (2)
characterization of the pattern of interactions between these pathways.
Functional neuroimaging can contribute to both of these goals. Using
image subtraction analysis of regional cerebral blood flow data
measured with positron emission tomography, we identified brain regions
that changed activity during episodic memory retrieval (visual word
recognition). Relative to a baseline reading task, decreased activity
was observed in bilateral prefrontal, bilateral anterior and posterior
temporal, and posterior cingulate cortices. Brain regions showing
increased activity were the right prefrontal (different from
deactivated regions), left anterior cingulate, and left occipital
cortices, and vermis of cerebellum. We then performed a network
analysis with structural equation modeling to test the hypothesis that
regional decreases came about through active inhibition by regions
showing increased activity during retrieval. This analysis demonstrated
that the influence of activated regions on deactivated regions was more
negative during retrieval than during reading, confirming the
inhibition hypothesis. Such confirmation could not have been made from
the subtraction analysis alone because decreases can come about, at the
very least, through reduction of functional influences as well as by
active inhibition. The concepts of ensemble excitation and inhibition,
as defined through network analysis, are introduced. We argue that it
is critical to examine the combined pattern of excitatory and
inhibitory influences to fully appreciate the neural basis of episodic
memory.
Key words:
human;
episodic memory;
positron emission
tomography;
neuroimaging;
network;
inhibition;
structural equation
modeling;
covariances
This article has been cited by other articles:

|
 |

|
 |
 
S. J. Sara and B. Hars
In memory of consolidation.
Learn. Mem.,
September 1, 2006;
13(5):
515 - 521.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Solodkin, P. Hlustik, E. E. Chen, and S. L. Small
Fine Modulation in Network Activation during Motor Execution and Motor Imagery
Cereb Cortex,
November 1, 2004;
14(11):
1246 - 1255.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. F. Glabus, B. Horwitz, J. L. Holt, P. D. Kohn, B. K. Gerton, J. H. Callicott, A. Meyer-Lindenberg, and K. F. Berman
Interindividual Differences in Functional Interactions among Prefrontal, Parietal and Parahippocampal Regions during Working Memory
Cereb Cortex,
December 1, 2003;
13(12):
1352 - 1361.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. D. Honey, J. Suckling, F. Zelaya, C. Long, C. Routledge, S. Jackson, V. Ng, P. C. Fletcher, S. C. R. Williams, J. Brown, et al.
Dopaminergic drug effects on physiological connectivity in a human cortico-striato-thalamic system
Brain,
August 1, 2003;
126(8):
1767 - 1781.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
I. Toni, J. Rowe, K. E. Stephan, and R. E. Passingham
Changes of Cortico-striatal Effective Connectivity during Visuomotor Learning
Cereb Cortex,
October 1, 2002;
12(10):
1040 - 1047.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Rowe, K. E. Stephan, K. Friston, R. Frackowiak, A. Lees, and R. Passingham
Attention to action in Parkinson's disease: Impaired effective connectivity among frontal cortical regions
Brain,
February 1, 2002;
125(2):
276 - 289.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Valla, J. D. Berndt, and F. Gonzalez-Lima
Energy Hypometabolism in Posterior Cingulate Cortex of Alzheimer's Patients: Superficial Laminar Cytochrome Oxidase Associated with Disease Duration
J. Neurosci.,
July 1, 2001;
21(13):
4923 - 4930.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
N. J. Shah, J. C. Marshall, O. Zafiris, A. Schwab, K. Zilles, H. J. Markowitsch, and G. R. Fink
The neural correlates of person familiarity: A functional magnetic resonance imaging study with clinical implications
Brain,
April 1, 2001;
124(4):
804 - 815.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Della-Maggiore, A. B. Sekuler, C. L. Grady, P. J. Bennett, R. Sekuler, and A. R. McIntosh
Corticolimbic Interactions Associated with Performance on a Short-Term Memory Task Are Modified by Age
J. Neurosci.,
November 15, 2000;
20(22):
8410 - 8416.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. J. Sara
Retrieval and Reconsolidation: Toward a Neurobiology of Remembering
Learn. Mem.,
March 1, 2000;
7(2):
73 - 84.
[Full Text]
|
 |
|

|
 |

|
 |
 
P. Thier, T. Haarmeier, S. Treue, and S. Barash
Absence of a common functional denominator of visual disturbances in cerebellar disease
Brain,
November 1, 1999;
122(11):
2133 - 2146.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. J. Seitz, N. P. Azari, U. Knorr, F. Binkofski, H. Herzog, and H.-J. Freund
The Role of Diaschisis in Stroke Recovery
Stroke,
September 1, 1999;
30(9):
1844 - 1850.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Backman, J. L. R. Andersson, L. Nyberg, B. Winblad, A. Nordberg, and O. Almkvist
Brain regions associated with episodic retrieval in normal aging and Alzheimer's disease
Neurology,
June 1, 1999;
52(9):
1861 - 1861.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B S Everitt and S Landau
The use of multivariate statistical methods in psychiatry
Statistical Methods in Medical Research,
June 1, 1998;
7(3):
253 - 277.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Cabeza, C. L. Grady, L. Nyberg, A. R. McIntosh, E. Tulving, S. Kapur, J. M. Jennings, S. Houle, and F. I. M. Craik
Age-Related Differences in Neural Activity during Memory Encoding and Retrieval: A Positron Emission Tomography Study
J. Neurosci.,
January 1, 1997;
17(1):
391 - 400.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A Uecker, E M Reiman, D L Schacter, M R Polster, L A Cooper, L S Yun, and K Chen
Neuroanatomical correlates of implicit and explicit memory for structurally possible and impossible visual objects.
Learn. Mem.,
January 1, 1997;
4(4):
337 - 355.
[Abstract]
[PDF]
|
 |
|
|

|