How visual imagery representations are formed: Through suppression, not activation

Voluntary imagery is described as "weak perception" and is thought to be represented through activating the neurons corresponding to imagined features, that is, activation hypothesis. However, direct evidence for this hypothesis is lacking. Inspired by Pace et al. (2023), we examine an alternative suppression hypothesis, which states imagery involves suppression of neurons favoring nearby nonimagined features. While the activation hypothesis predicts a bell-shaped tuning curve of the neural representation for the imagined feature, the suppression hypothesis predicts a W-shaped tuning curve. To test these two hypotheses, we combined an imagery task with a discrimination task following the logic that different imagery-induced tuning curves would differently bias the perceived difference in the discrimination task. We probed the bias pattern by systematically manipulating the physical orientation difference and the discrimination-imagery relation condition. A series of psychophysical experiments were conducted. Results showed that after an imagery prior, bias pattern in the discrimination task followed the prediction of suppression hypothesis (Experiment 1a). By contrast, when substituting the imagery prior with a strong/weak perceptual prior, bias pattern was consistent with the prediction of activation hypothesis (Experiments 2a and 2b). Confounding effects of visual attention and perceptual imagery cue were excluded (Experiments 1b and 1c). We further constructed mathematical models and again validated our findings. In conclusion, behavioral and modeling results coherently suggested that the suppression hypothesis was a better explanation for imagery than the activation hypothesis. Our study challenges the traditional activation theory and provides novel empirical evidence for the suppressive representation of voluntary visual imagery. (PsycInfo Database Record (c) 2026 APA, all rights reserved).