ConclusionsΒΆ
In accordance with the pathological, neuroimaging, cognitive, and behavioral data on temporal FTD we here reviewed, converging lines of evidence illustrate the extreme structural and functional heterogeneity of the temporal lobe. Cellular, neurochemical, and pathological markers, allows isolation of at least seven distinct regions with the ATL (Ding et al., 2009). Moreover, similar parcellations have been proposed based on structural (Papinutto et al., 2016) and functional (Pascual et al., 2015) connectivity patterns. The most widely adopted theoretical framework, the hub-and-spoke model, Most of widely adopted framework = bilateral semantic systems but important specialization along gradient (Lambon-Ralph) Overall, left ATL computations and representations appear to be critical to assign meaning to verbal, linguistic, external inputs. They allow integration of sounds and letters into words. They support and enable goal-oriented, action-related behaviors. Conversely, the right ATL appears to support meaning assignment to nonverbal, social, visceral inputs. Its computations are needed to integrate feelings and sensations into emotions, and its representations attribute values to personally and socially relevant behaviors. From the cognitive neuroscience point of view, PPA is emerging as a model for understanding the link between clinical, neuroimaging and neurobiological vulnerability in focal neurodegenerative disorders