Aphantasia is characterized by a lack of low-level sensory visual imagery. Support that it is not a lack of metacognition.
Aphantasia is better at spatial images than average. Spatial image seems to correlate with the performance of the mental rotation task. Also, relatedly, people with hallucinations have this score perfect. Regarding the structure of the brain, the dorsal side (early visual cortex from the early visual cortex to the parietal lobe) contains information about the position of objects in space. The ventral (early visual cortex from the early visual cortex to the temporal lobe) or "what" flow contains information about the identity of the object. The two become more complicated as the hierarchy goes up.
What is the ability to rotate an object in your mind? → Activates the parietal cortex (specifically, the parietal cortex) in addition to the motor areas such as the auxiliary motor area and the primary motor area. In contrast, when participants imagine still images, the visual cortex tends to show increased activity. Imagine an image → Combined from the visual cortex. The higher the response level of the visual cortex, the more it correlates with the subjective sharpness of the image.
These two pieces of evidence suggest the separation of the neural network used for static object images and mental rotation and spatial images. When a person imagines a landscape or an object → A large-scale network that extends not only to the visual cortex but also to the crown and prefrontal cortex is activated. Drives feedback connections that activate sensory representations of the prefrontal cortex → visual cortex (Aphantasia may not be able to do this) The excitability of both the visual cortex and the prefrontal cortex has been shown to play an important role in controlling image strength. From the above, phantasia may have higher activity levels in the visual area, prefrontal cortex area, or both areas. It will also help us understand the neurological differences that are responsible for the vast differences in our ability and experience with the inner world.