Interactions Between Visual Working Memory and Face Perception

Visual working memory (VWM) is a process by which visual information is temporarily maintained and manipulated. The sensorimotor recruitment model posits a shared recruitment of the sensorimotor cortices by both perception and VWM. Previous studies show that this bidirectional relationship exists for simple and low-level features, like orientation, color, and motion. However, few studies investigated whether this bidirectional relationship is unique to low-level features or extends to high-level and complex stimuli, like faces. We hypothesized that faces held in VWM influence perception of faces we see later, consistent with the common recruitment of face-selective regions for VWM and perception. In the experiment, two discrimination conditions are shown to the participants: middle and side. In the middle condition, two discrimination stimuli are equidistant from the maintained face image, whereas in the side condition, they are both off to one side. We hypothesized and found that in the middle condition, both discrimination faces would be pulled inwards towards the maintained face, reducing the perceived difference in the two faces, resulting in a higher discrimination threshold. In the side condition, the closer discrimination face would be more biased towards the maintained face, resulting in a greater perceived difference and lower thresholds. Further, based on the continuous report, the discrimination faces in the side condition introduced a systematic bias towards themselves, demonstrating directional interference between perception and the face held in VWM. We also established the specificity of these effects to actively maintained information, by asking participants to maintain the orientation of a gabor patch in the center and then make a same/different judgment on the faces, which eliminated any difference in the discrimination thresholds between the middle and side conditions. Overall, this bidirectional interference suggests that face-selective areas are involved in VWM maintenance, further eroding the distinction between supposed perceptual and cognitive processes.