Anterior Temporal Sulcus Research Articles

Sentence understanding depends on contextual use of semantic and real world knowledge

Human language allows us to express our thoughts and ideas by combining entities, concepts and actions into multi-event episodes. Yet, the functional neuroanatomy engaged in interpretation of such high-level linguistic input remains poorly understood. Here, we used easy to detect and more subtle “borderline” anomalies to investigate the brain regions and mechanistic principles involved in the use of real-world event knowledge in language comprehension. Overall, the results showed that the processing of sentences in context engages a complex set of bilateral brain regions in the frontal, temporal and inferior parietal lobes. Easy anomalies preferentially engaged lower-order cortical areas adjacent to the primary auditory cortex. In addition, the left supramarginal gyrus and anterior temporal sulcus as well as the right posterior middle temporal gyrus contributed to the processing of easy and borderline anomalies. The observed pattern of results is explained in terms of (i) hierarchical processing along a dorsal-ventral axis and (ii) the assumption of high-order association areas serving as cortical hubs in the convergence of information in a distributed network. Finally, the observed modulation of BOLD signal in prefrontal areas provides support for their role in the implementation of executive control processes.

Anterior Temporal Sulcus: A Reliable Intraoperative Landmark for Accurately Delineating the Superior Limit of Amygdala Resection during Anterior Temporal Lobectomy

Background: Reliable anatomical landmarks are essential to avoiding injuries to the optic tract, anterior choroidal artery and basal ganglia during anterior temporal lobectomy (ATL). We describe an anatomic landmark, specifically the anterior temporal sulcus (ATS), as a reliable method to define the anterior portion of the endorhinal sulcus and the superior limit of amygdala resection. Methods: A total of 25 consecutive patients undergoing ATL at Rush University Medical Center (RUMC) were identified, and their preoperative brain magnetic resonance imaging (MRI) studies were analyzed. Results: All patients underwent successful ATL without any complication. There was no injury to the optic tract, anterior choroidal artery or basal ganglia using ATS as the landmark for the superior limit of amygdala resection. The ATS was clearly identifiable on coronal preoperative MRI in 48 out of 50 temporal lobes (96%). The ATS was present in all 25 left temporal lobes (100%); 2 of the 25 right temporal lobes had absent ATS (8%). Following the ATS posteriorly on coronal MRI, it led to the endorhinal sulcus and accurately predicted the superior extent of amygdala resection in all 25 patients (48 temporal lobes). Conclusion: The ATS is a reliable anatomical landmark that accurately delineates the superior border of the amygdala during ATL.

Growing up blind does not change the neural bases of Theory of Mind

Humans reason about the mental states of others; this capacity is called Theory of Mind (ToM). In typically developing adults, ToM is supported by a consistent group of brain regions: the bilateral temporoparietal junction (TPJ), medial prefrontal cortex (MPFC), precuneus (PC), and anterior temporal sulci (aSTS). How experience and intrinsic biological factors interact to produce this adult functional profile is not known. In the current study we investigate the role of visual experience in the development of the ToM network by studying congenitally blind adults. In experiment 1, participants listened to stories and answered true/false questions about them. The stories were either about mental or physical representations of reality (e.g., photographs). In experiment 2, participants listened to stories about people's beliefs based on seeing or hearing; people's bodily sensations (e.g., hunger); and control stories without people. Participants judged whether each story had positive or negative valance. We find that ToM brain regions of sighted and congenitally blind adults are similarly localized and functionally specific. In congenitally blind adults, reasoning about mental states leads to activity in bilateral TPJ, MPFC, PC, and aSTS. These brain regions responded more to passages about beliefs than passages about nonbelief representations or passages about bodily sensations. Reasoning about mental states that are based on seeing is furthermore similar in congenitally blind and sighted individuals. Despite their different developmental experience, congenitally blind adults have a typical ToM network. We conclude that the development of neural mechanisms for ToM depends on innate factors and on experiences represented at an abstract level, amodally.