Aphantasia research upends the 'reversed vision' model of imagination
Original: People who can't picture anything are rewriting the science of imagination
Why This Matters
Reframing imagination as a network function reshapes how we study perception, memory, and conditions like PTSD and aphantasia.
A new review in Consciousness and Cognition argues that mental imagery is built by a distributed brain network, not by running visual signals backward through the primary visual cortex. People with aphantasia — who cannot form mental images — and patients who lost their primary visual cortex but can still imagine are the key evidence.
The popular model, formalized by Joel Pearson in 2019, treats imagination as vision in reverse: frontal planning regions send a request, memory fills in the details, and the resulting image is painted onto the primary visual cortex — the same patch at the back of the brain where signals from the eyes first land. Brain scanner studies that decode which image someone is picturing by reading activity in that region have been cited as confirmation.
A new review by Derek Arnold, Loren Bouyer, Blake Saurels, and Samuel Schwarzkopf challenges that account directly. Their paper, published in Consciousness and Cognition, points to two awkward facts for the reversed-vision model. First, patients who lost large portions of their primary visual cortex can still generate mental images. Second, people with aphantasia — a lifelong inability to visualize, and often to mentally hear, smell, or feel things either — show no single damaged spot; instead, a set of regions spread across the front and sides of the brain fails to coordinate.
Two of the paper's authors have aphantasia themselves. The authors write that scanner studies showing correlations between primary visual cortex activity and imagery content 'ignore the adage that correlation' does not establish causation or architecture. Their alternative: a mental image is something many distributed regions construct together, and no single area owns it. Because the network can fail in multiple ways, individual differences in inner experience — vivid, dim, or absent — are the expected outcome, not an anomaly.