Figure 5. Early gamma band response for real-world (red) and non-sense objects (blue).

Data from stimulus Set A (schematic black and white line drawings) are shown on the left; data from stimulus Set B (more detailed, colored images) are shown on the right. The top row of each panel shows topographic maps of the averaged activity from all conditions. Response frequencies and maps were determined from the time range 60–140 ms respectively. In the second row, responses for the speeded response task are shown. In the third row, responses for the delayed response task are shown. All time course data are taken from Pz. Note that eGBRs to real-world object stimuli are enhanced only if participants need to perform a speeded response. Stimulus onset is at 0 ms. Responses are normalized by subtracting the average activity between 200 and 100 ms before stimulus onset from the entire time course.