Fig. 4.

fMRI activation timecourses from the scene-selective ROI as a function of task condition and WM load. A) Trial-averaged BOLD timecourses from the three task conditions are shown separately for low load and high load trials. Stimulus presentation timing is indicated by the white boxes below the plots, and BOLD responses to these trial events are delayed due to the inherent hemodynamic lag. Activation in response to the images achieves a similarly high peak in the Remember Scenes condition (red), regardless of load, and this response remains elevated above the Passively View level (yellow) for the duration of the trial. On low load trials, Ignore Scenes activity (blue) peaked at the same level as Passively View before diminishing in strength, whereas on high load trials, Ignore Scenes activity peaked well above the Passively View level before dropping below it. The second activation peak reflects the response of this region to the probe stimuli. B) Direct comparisons of the low load (lighter hue) and high load (darker hue) timecourse for each task condition demonstrate that the WM load manipulation minimally influenced the response profile of the Remember Scenes and Passively View conditions, whereas Ignore Scenes activity was increased under high load. Error bars indicate standard error of the difference (low load vs. high load).