Visual imagination does not originate in a single brain region as long believed, according to a new scientific review published in the journal Consciousness and Cognition.
Researchers examining studies of patients with brain damage and individuals with aphantasia found that mental pictures are created through coordinated activity across multiple brain areas rather than inside a single visual hub.
The findings challenge a long-standing model in neuroscience that treated human visual memory as a reverse visual system.
For decades, scientists explained visual imagination by proposing that remembering a face or a place reactivated the exact regions used during physical sight. Under that traditional theory, the primary visual cortex, located at the back of the brain, acted as an internal projection screen receiving signals from memory and planning centers.
Flaws in the visual screen model
The new review notes that several key pieces of clinical evidence fail to fit the traditional screen model. Patients with extensive damage to the primary visual cortex who have lost their physical sight can still generate mental images.
Experimental data also demonstrated that temporarily suppressing activity in the primary visual cortex can prompt some individuals to describe more vivid mental imagery. Brain imaging scans further show that when people visualize objects, frontal brain areas and regions dedicated to recognizing faces, words, and objects become active, while the primary visual cortex often shows no distinct activity.
The primary visual cortex is an anatomical region in the occipital lobe at the rear of the skull, responsible for receiving raw visual signals from the eyes. In peer-reviewed academic literature, Consciousness and Cognition publishes research examining cognitive psychology, neuroscience, and how the brain structures conscious experience.
The authors of the review stated that the primary visual cortex is not useless in visualization. They indicated that the region may help refine the detail of imagined images, but it does not serve as the canvas where mental pictures are drawn.
Insights from aphantasia research
Data from people with aphantasia provided key evidence for how the brain builds mental images without direct visual input. People with the condition know the spatial layout of their home or which item sits beside their television, but they do not see those objects in their mind.
Some individuals describe their thought processes as knowing spatial facts without experiencing an internal photograph. Aphantasia is a neurological trait in which a person cannot voluntarily generate mental imagery, though affected individuals retain normal memory and factual knowledge.
The reviewed research suggests that aphantasia stems from a breakdown in communication between different brain regions. When those areas fail to work in concert, stored information exists within the brain but fails to translate into a conscious visual experience.
That communication model also explains variation among people with the condition. The authors noted that disrupted neural links explain why some individuals with aphantasia can mentally recreate sounds, smells, or physical movements, while others cannot recreate any sensory experiences at all.
Brain networks and future research
The authors proposed viewing human imagination as an emergent property of an entire neural network, comparing the process to a musical chord that requires multiple strings to sound at the same time. They stated that no single isolated region of the brain creates mental images on its own.
The frontal cortex, situated at the front of the brain, manages complex cognitive functions including planning, memory retrieval, and sensory integration. Brain scanning technologies, such as functional magnetic resonance imaging, allow neuroscientists to map these distributed patterns of neural activity during mental tasks.
The scientific review acknowledged that key questions remain unanswered. Researchers still lack an objective diagnostic test for aphantasia, and science cannot yet explain why some individuals experience exceptionally vivid mental imagery while others experience none.
Scientists view the shift in perspective as an important step forward for neuroscience. Rather than searching for a single origin point for mental pictures, research is focusing on how distinct brain areas collaborate to allow human beings to see objects that are not physically present.
