Electrophysiological correlates of figure-ground segregation directly reflect perceptual saliency.
In a figure identification task, we investigated the influence of different visual cue configurations (spatial frequency, orientation or a combination of both) on the human EEG. Combining psychophysics with ERP and time-frequency analysis, we show that the neural response at about 200ms reflects perceptual saliency rather than physical cue contrast. Increasing saliency caused (i) a negative shift of the posterior P2 coinciding with a power decrease in the posterior theta-band and (ii) an amplitude and latency increase of the posterior P3. We demonstrate that visual cues interact for a percept that is non-linearly related to the physical figure-ground properties.
Straube
Sirko
S
Department of Human Neurobiology, University of Bremen, Hochschulring 18, 28359 Bremen, Germany. sirko.straube@uni-bremen.de <sirko.straube@uni-bremen.de>
Grimsen
Cathleen
C
Fahle
Manfred
M
D000328:Adult; D003463:Cues; D004192:Discrimination, Psychological; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology; D012684:Sensory Thresholds; D017603:Signal Detection, Psychological / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult