Abstract

Pica is one of the most enigmatic behaviors for human beings and its neural basis and underlying mechanisms have yet to be elucidated. We have addressed this issue by investigating patients with acquired brain injury who presented with pica and found that semantic memory deficits are associated with pica rather than frontal release signs or changes in eating behaviors. The brain region specific for pica in our study was the posterior part of the left middle and inferior temporal gyri. Our findings suggest that semantic memory deficits as a result of temporal lobe damage are associated with pica. For degenerative diseases, case reports and our data in this article suggest that Alzheimer’s disease and semantic dementia are the two main etiologies that cause pica. Considering the temporal lobe involvement and semantic memory deficits for both etiologies, our findings on pica for acquired brain injury might also be applied to degenerative diseases. The most common items involved in pica are daily necessities that are easy to swallow or drink, such as lipstick or shampoo. These items should be avoided for patients with pica.

Keywords: Pica; Semantic memory deficits; Temporal lobe; Alzheimer’s disease; Semantic dementia