Vividness of mental imagery: Individual variability can be measured objectively

When asked to imagine a visual scene, such as an ant crawling on a checkered table cloth toward ajar of jelly, individuals subjectively report different vividness in their mental visualization. We show that reported vividness can be correlated with two objective measures: the early visual cortex activity relative to the whole brain activity measured by functional magnetic resonance imaging (fMRT) and the performance on a novel psychophysical task. These results show that individual differences in the vividness of mental imagery are quantifiable even in the absence of subjective report. (c) 2006 Elsevier Ltd. All rights reserved.