We commonly assume that our perception of the world is constant and seamless. This intuition belies the dramatic differences in the perceived quality of a stimulus even within the same individual when it is shown at different spatial locations or different times. Conventional studies of perception treat such unique patterns of perceptual variability as noise and seek to eliminate them by averaging across individuals; however, studying individual heterogeneity in perceptual function can reveal insights into how the brain makes our subjective view of the world unique and personal. All perception must arise in the brain. Despite that, the neural substrates underlying this perceptual heterogeneity remain unknown.Here, I therefore propose a project to investigate cortical and perceptual heterogeneity in human volunteers using a combination of behavioural psychophysics, functional magnetic resonance imaging and transcranial magnetic stimulation. I will explore the heritability of these maps to better understand the factors underlying perceptual heterogeneity. Together, these experiments will provide convergent evidence about how the functional architecture of human sensory cortex gives rise to an individual's unique perception of the world. This will make it possible to reconstruct how an individual perceives the environment, thus giving an insight into their “mind's eye,” and has implications for patients with pathological sensory discontinuities (such as scotomas) or hallucinations, as it will enable us to reveal how they perceive their environment.