Key Findings from the 2026 Cortex Review
Stefano Zago, Dounia Hajhajate, Alice Naomi Preti, Teresa Difonzo, Silvia Cattaneo, and Paolo Bartolomeo have published a detailed review examining 55 published cases of cortical blindness in which visual mental imagery abilities were specifically assessed. The study appears in the journal Cortex and is available at https://www.sciencedirect.com/science/article/pii/S001094522600170X. Their analysis reveals a clear double dissociation: many individuals with cortical blindness retain vivid visual mental imagery despite extensive damage to the primary visual cortex, while cases in which imagery is impaired typically involve lesions extending into higher-order visual areas such as the ventral temporal cortex.
Cortical blindness refers to vision loss resulting from damage to the brain's visual processing regions rather than the eyes themselves. Aphantasia describes the inability to voluntarily generate visual mental imagery, often described as lacking a "mind's eye." The review challenges earlier assumptions that the primary visual cortex, known as V1, serves as an essential substrate for generating such imagery.
Background on Visual Mental Imagery and Cortical Blindness
Visual mental imagery involves creating percept-like experiences in the absence of external visual stimuli. Researchers have long debated whether this process requires reactivation of early visual areas, particularly V1, which receives direct input from the eyes and maintains a retinotopic map of visual space. Cortical blindness occurs when bilateral lesions affect the visual cortex, often due to stroke, trauma, or other neurological events, leading to complete or near-complete loss of conscious vision.
Prior case reports had hinted at preserved imagery in some cortically blind patients, but systematic analysis was lacking. The current review aggregates data from 55 cases where imagery was formally tested, providing robust evidence that vivid imagery frequently survives even when V1 is largely or completely destroyed on both sides.
Methodology and Case Analysis
The authors systematically searched published literature for reports of cortical blindness accompanied by assessments of visual mental imagery. For each case they recorded the etiology of blindness, precise lesion locations when available, presence of associated symptoms such as Anton syndrome (denial of blindness), and the nature of imagery testing. Imagery was evaluated through self-report, behavioral tasks, or both. The dataset allowed statistical conclusions about the relationship between lesion site and imagery capacity.
Results showed that in the majority of cases with documented bilateral V1 damage, patients reported or demonstrated preserved vivid imagery. When imagery deficits appeared, the lesions consistently extended beyond V1 into regions such as the ventral temporal cortex, which is implicated in higher-level visual recognition and semantic processing. This pattern supports a double dissociation: cortical blindness can occur without aphantasia, and impairment of imagery requires damage outside primary visual cortex.
Implications for Theories of Mental Imagery
These findings carry significant weight for models of visual cognition. Traditional views sometimes posited that imagery operates as "perception in reverse," requiring top-down reactivation of V1. The review instead points to higher-level visual regions and frontoparietal networks as sufficient for generating imagery content. This aligns with functional imaging studies showing imagery-related activity in ventral stream areas even when early visual cortex is not engaged.
The data also refine understanding of aphantasia. Congenital or acquired aphantasia may arise from disruptions in connectivity or access mechanisms rather than absence of visual representations per se. In the context of cortical blindness, the preserved imagery cases demonstrate that V1 is not necessary for the subjective experience of seeing with the mind's eye.
Clinical and Research Perspectives
Clinicians working with patients who have sustained occipital lobe damage may find these results useful when counseling about preserved cognitive functions. Rehabilitation programs that rely on mental imagery techniques could remain viable even in the presence of cortical blindness. Researchers studying aphantasia now have additional lesion evidence clarifying the minimal neural requirements for imagery generation.
Stakeholders including neuropsychologists, neurologists, and cognitive scientists have noted the value of large-scale case reviews in resolving debates that single-case studies cannot settle. The 55-case dataset provides statistical power that strengthens causal inferences about brain regions necessary for imagery.
Future Directions and Related Research
Future work could incorporate advanced imaging in living patients or expand the dataset with unpublished cases. Integration with studies on hyperphantasia, where imagery is exceptionally vivid, may further map the spectrum of imagery abilities. Links to broader topics such as memory, dreaming, and spatial navigation remain active areas of investigation.
Academic institutions and research centers continue to explore these phenomena through interdisciplinary approaches combining neuropsychology, neuroimaging, and computational modeling. Resources on academic career paths in cognitive neuroscience are available through established platforms.
Photo by Shalone Cason on Unsplash
Broader Context in Neuroscience
The dissociation observed here echoes other neurological dissociations, such as those between perception and action or between different memory systems. It underscores the distributed nature of visual processing and the brain's capacity for functional reorganization or parallel pathways supporting imagery.
Public interest in aphantasia has grown in recent years, with increased awareness leading more individuals to recognize and report variations in their own imagery vividness. Scientific publications continue to attract attention from both specialists and the wider public interested in how the brain constructs internal experiences.
