TY  - JOUR
A1  - Kuhnert, Marie-Therese
A1  - Bialonski, Stephan
A1  - Noenning, Nina
A1  - Mai, Heinke
A1  - Hinrichs, Hermann
A1  - Helmstaedter, Christoph
A1  - Lehnertz, Klaus
T1  - Incidental and intentional learning of verbal episodic material differentially modifies functional brain networks
JF  - Plos one
N2  - Learning- and memory-related processes are thought to result from dynamic interactions in large-scale brain networks that include lateral and mesial structures of the temporal lobes. We investigate the impact of incidental and intentional learning of verbal episodic material on functional brain networks that we derive from scalp-EEG recorded continuously from 33 subjects during a neuropsychological test schedule. Analyzing the networks' global statistical properties we observe that intentional but not incidental learning leads to a significantly increased clustering coefficient, and the average shortest path length remains unaffected. Moreover, network modifications correlate with subsequent recall performance: the more pronounced the modifications of the clustering coefficient, the higher the recall performance. Our findings provide novel insights into the relationship between topological aspects of functional brain networks and higher cognitive functions.
Y1  - 2013
U6  - http://dx.doi.org/10.1371/journal.pone.0080273
VL  - 8
IS  - 11
PB  - PLOS
CY  - San Francisco
ER  - 
TY  - JOUR
A1  - Horstmann, Marie-Therese
A1  - Bialonski, Stephan
A1  - Noenning, Nina
A1  - Mai, Heinke
A1  - Prusseit, Jens
A1  - Wellmer, Jörg
A1  - Hinrichs, Hermann
A1  - Lehnertz, Klaus
T1  - State dependent properties of epileptic brain networks: Comparative graph–theoretical analyses of simultaneously recorded EEG and MEG
JF  - Clinical Neurophysiology
N2  - Objective
To investigate whether functional brain networks of epilepsy patients treated with antiepileptic medication differ from networks of healthy controls even during the seizure-free interval.

Methods
We applied different rules to construct binary and weighted networks from EEG and MEG data recorded under a resting-state eyes-open and eyes-closed condition from 21 epilepsy patients and 23 healthy controls. The average shortest path length and the clustering coefficient served as global statistical network characteristics.

Results
Independent on the behavioral condition, epileptic brains exhibited a more regular functional network structure. Similarly, the eyes-closed condition was characterized by a more regular functional network structure in both groups. The amount of network reorganization due to behavioral state changes was similar in both groups. Consistent findings could be achieved for networks derived from EEG but hardly from MEG recordings, and network construction rules had a rather strong impact on our findings.

Conclusions
Despite the locality of the investigated processes epileptic brain networks differ in their global characteristics from non-epileptic brain networks. Further methodological developments are necessary to improve the characterization of disturbed and normal functional networks.

Significance
An increased regularity and a diminished modulation capability appear characteristic of epileptic brain networks.
Y1  - 2010
U6  - http://dx.doi.org/10.1016/j.clinph.2009.10.013
SN  - 1388-2457
VL  - 121
IS  - 2
SP  - 172
EP  - 185
PB  - Elsevier
CY  - Amsterdam
ER  -