Attentional selection and illusory surface appearance.
William J HarrisonAlvin J AyeniPeter J BexPublished in: Scientific reports (2019)
The visual system is required to compute objects from partial image structure so that figures can be segmented from their backgrounds. Although early clinical, behavioral, and modeling data suggested that such computations are performed pre-attentively, recent neurophysiological evidence suggests that surface filling-in is influenced by attention. In the present study we developed a variant of the classical Kanizsa illusory triangle to investigate whether voluntary attention modulates perceptual filling-in. Our figure consists of "pacmen" positioned at the tips of an illusory 6-point star and alternating in polarity such that two illusory triangles are implied to compete with one another within the figure. On each trial, observers were cued to attend to only one triangle, and then compared its lightness with a matching texture-defined triangle. We found that perceived lightness of the illusory shape depended on the polarity of pacmen framing the attended triangle. Our findings thus reveal that, for overlapping illusory surfaces, lightness judgements can depend on voluntary attention. Our novel stimulus may prove useful in future attempts to link neurophysiological effects to phenomenology.
Keyphrases
- working memory
- depressive symptoms
- physical activity
- deep learning
- mental health
- electronic health record
- study protocol
- social support
- staphylococcus aureus
- gene expression
- phase ii
- escherichia coli
- genome wide
- computed tomography
- phase iii
- dna methylation
- pseudomonas aeruginosa
- open label
- biofilm formation
- contrast enhanced