I'm studying the phenomenon of acquired savant syndrome, and the literature I've read till now frames it as such (not a quote, just my understanding):
Savant syndrome occurs when the left anterior temporal lobe (LATL), also known as the left frontotemporal lobe, is underdeveloped. A person may acquire savant syndrome by incurring brain damage or illness in the LATL, such as frontotemporal dementia (FTD) or a head trauma. The reason this can give people savant-like talents lies in the LATL's function. It suppresses details in order to grasp the bigger picture, or rather, the bigger picture relevant to survival. One's brain does notice all the minute details of an animal, but this minutia is not accessible to the conscious mind because the LATL suppresses it in order to efficiently inform the body and mind about whether the animal is dangerous or food.
By diminishing the LATL's ability to function, one diminishes its active suppression of details, allowing for a much more in-depth understanding. What's a bit paradoxical to me is that by suppressing the part of the brain that removes everything but the "big picture meaning" of auditory and visual stimuli, you're able to see the "big picture meaning", only a different kind. You may be able to see the philosophical, mathematical or scientific big picture (i.e. the implications and position of the stimuli within these fields). Basically, the LATL is concerned with survival and focuses on the implications the stimuli has on this, not allowing for a more abstract perspective on the stimuli. With the LATL working 100%, music would just be a collection of sounds with different danger signalling, but with the LATL not working 100%, the sounds, and their composition, can be abstracted further into the land of non-survival related emotion and they can be abstracted into auditory representations of concepts.
Not sure if my understanding is correct. Also, if I'm not mistaken, there is some discussion about whether the LATL sees the bigger picture in relation to survival, or if it sees the bigger picture in relation to social interaction (or both).
So, given that this is the reason for acquired savant syndrome; why does OCD often come along with it, why is the communication between the frontal lobe and visual cortex strengthened by injury to the LATL (this is the mechanism which allows those with savant syndrome to visualize and visually remember memories at a greater level) and why is semantic memory devastated with those with FTD. It would make sense to me that injury to the LATL would strengthen semantic memory, given how pieces of semantic memory may gain more significance meaning-wise, since there no longer is a suppression of the nuances in said memory that don't pertain to survival and/or social interaction. Is the destruction of semantic memory only present in people with FTD, perhaps implying that this destruction of semantic memory happens for a different reason that damage to the LATL? Since the part of the brain that (at least potentially) processes the meaning of things relevant to social interaction, does this lower the EQ of people with acquired savant syndrome?