title: EEG responses to visual landmarks in flying pigeons.
abstract: BACKGROUND
  GPS analysis of flight trajectories of pigeons can reveal that topographic features influence their flight paths. Recording electrical brain activity that reflects attentional processing could indicate objects of interest that do not cause changes in the flight path. Therefore, we investigated whether crossing particular visual landmarks when homing from a familiar release site is associated with changes in EEG.
  
  
  RESULTS
  Birds carried both data-loggers for recording GPS position and EEG during flight. First, we classified characteristic EEG frequencies of caged birds and found five main bands: A: 0-3, B: 3-12, C: 12-60, D: 60-130, and E: 130-200 Hz. We analyzed changes in these activity bands when pigeons were released over sea (a featureless environment) and over land. Passing over the coastline and other prominent landmarks produced a pattern of EEG alterations consisting of two phases: activation of EEG in the high-frequency bands (D and/or E), followed by activation of C. Overlaying the EEG activity with GPS tracks allowed us to identify topographical features of interest for the pigeons that were not recognizable by distinct changes of their flight path.
  
  
  CONCLUSIONS
  We provide evidence that EEG analysis can identify landmarks and objects of interest during homing. Middle-frequency activity (C) reflects visual perception of prominent landmarks, whereas activation of higher frequencies (D and E) is linked with information processing at a higher level. Activation of E bands is likely to reflect an initial process of orientation and is not necessarily linked with processing of visual information.
authors: Institute of Anatomy, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland. alexei@ini.phys.ethz.ch
authors: Alexei L
authors: AL
authors: Vyssotski
authors: Giacomo
authors: G
authors: Dell'Omo
authors: Gaia
authors: G
authors: Dell'Ariccia
authors: Andrei N
authors: AN
authors: Abramchuk
authors: Andrei N
authors: AN
authors: Serkov
authors: Alexander V
authors: AV
authors: Latanov
authors: Alberto
authors: A
authors: Loizzo
authors: David P
authors: DP
authors: Wolfer
authors: Hans-Peter
authors: HP
authors: Lipp
mesh_terms: D000818:Animals; D001288:Attention; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D010856:Columbidae / Q000502:physiology*; D003463:Cues; D004569:Electroencephalography; D005426:Flight, Animal / Q000502:physiology*; D040362:Geographic Information Systems; D006702:Homing Behavior / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*