1. Ongoing brain activity in patients
with visual system damage
Michał Bola
Institute of Medical Psychology
Otto-von-Guericke University of Magdeburg

2. Visual field charts
Detection rate
Introduction

3. Introduction
Perception:
-bottom-up and top-down proces
-modulated by instantenous brain state
Hanslmayr et al., 2007; van Dijk et al., 2008; Weisz et al., 2014
EEG – synchronous activity
of cortical circuits

4. Aim of the study:
to characterize visual cortex activity at rest and relate it to perception
Sample:
19 patients with pre-chiasmatic visual system damage (lesion in adulthood; partial vision loss)
13 age-matched control subjects
Methods:
Resting state eyes-closed EEG recorded (30 channels)
Alpha band activity divided into low alpha (alpha I; 7-11Hz) and high alpha (alpha II; 11-14Hz).
Hypotheses:
1. Spontaneous cortical synchronization is impaired in patients
2. Stronger spontaneous synchronization is related to better perceptual abilities
Study

5. Methods I
Spectral power represents efficiency of
neural synchronization.
Changes in spectral power are related to
grate number of brain pathologies.

6. Bola et al., accepted, NEUROLOGY
Results I

7. Bola et al., accepted, NEUROLOGY

8. Methods II
Neural synchronization exhibits complex
temporal patterns.
Temporal coordination and stability-
flexibility balance are crucial for cognition.
Loss of complexity is related to a number
of pathological conditions.
Linkenkaer-Hansen et al., 2001; Montez et al., 2009

9. Methods II

10. Methods II

11. Methods II

12. Results II

13. Results II

14. • In patients resting-state high alpha activity exhibits:
- lower amplitudes
- less complex, more noise-like temporal patterns
• Although cortex is intact it‘s functional activity is permanently impaired
• Spontaneous cortical synchronization is related to perceptual abilities
Conclusions
Visual system lesion
Vision loss
Impaired
synchronization

15. Thank you for
attention!
Collaborators:
Dr. Carolin Gall
Christian Moewes
Anton Fedorov
Prof. Hermann Hinrichs
Prof. Bernhard Sabel
michalbola@gmail.com