Understanding mechanisms of semantic memory through intracranial recording and stimulation

天空的颜色，水果的清单，法国的首都-以惊人的速度访问事实和其他一般信息的能力是人类的一个显着和重要的部分。众所周知，我们巨大的知识储备分布在大脑的多个广泛区域。然而，当一个人听到一个问题并得到一个答案时，这些不同的区域会根据需要协调和筛选大量的细节和关联，以提取具体的事实。这种能力有时会随着年龄的增长而受损，并且在许多神经系统疾病中显着恶化-例如语义痴呆症，阿尔茨海默病和癫痫。尽管语义记忆的重要性显而易见，也有多项科学研究，但语义记忆的实际机制一直是一个难以捉摸且持久的谜团。了解它的神经基础可能会导致教育的转型进步，改善衰老对语义记忆的影响，并帮助治疗破坏记忆的神经系统疾病。除了这些更广泛的影响外，该项目还将通过公共科学讲座参与社区外展，并为促进妇女和代表性不足的少数民族在神经科学STEM职业中的发展创造机会。这项研究涉及一个独特而宝贵的数据来源：直接来自清醒的行为人类大脑的记录，这些记录用于临床（医疗，外科）目的，以治疗难治性癫痫。利用这些颅内记录，研究人员将试图破译关键皮层枢纽中的神经群如何处理语义信息，而参与者则执行定制设计的言语和非言语语义记忆任务。研究人员将测量来自高密度电极（颅内脑电图-iEEG）的神经群体反应，并使用机器学习来理解和预测信息如何在语义系统中的关键区域和大脑中的内侧时间记忆区域之间流动。该项目还将直接测试在认知任务期间对脑组织的电刺激是否会产生可预测的效果，揭示这些相同的结构是否在语义记忆处理中发挥因果作用。总之，这项人类iEEG研究将更好地了解语义知识检索是如何编码的，并由分布式语义和记忆电路以及更广泛的大脑网络中的局部神经元群体提供支持。这项工作也可能导致未来的治疗，包括新兴的脑刺激方法，可能有助于挽救记忆丧失的神经系统疾病。这个奖项反映了NSF的法定使命，并已被认为是值得支持的评估使用基金会的智力价值和更广泛的影响审查标准。

The color of the sky, a list of fruits, the capital of France—the ability to access facts and other general information at astonishing speed is a remarkable and vital part of being human. Our vast stores of knowledge are known to be spread throughout multiple widespread regions in the brain. Yet, when a person hears a question and retrieves an answer, these disparate areas coordinate and sift through an ocean of details and associations, on-demand, to pull up specific facts. This ability is sometimes impaired with aging, and markedly deteriorates in a host of neurological conditions -- such as semantic dementia, Alzheimer’s disease, and epilepsy. Despite its clear importance, and multiple scientific studies, the actual mechanisms of semantic memory have been an elusive and enduring mystery. Understanding its neural basis could lead to transformational advances in education, ameliorate the effects of aging on semantic memory, and help treat neurological diseases that ravage memory. In addition to these broader impacts, this project will engage in community outreach through public science talks and create opportunities for the promotion of women and underrepresented minorities in STEM careers in neuroscience. This research involves a unique and precious source of data: recordings directly from the brain in awake, behaving humans, that are being performed for clinical (medical, surgical) purposes to treat intractable epilepsy. Using these intracranial recordings, researchers will seek to decipher how neural populations in key cortical hubs process semantic information while participants perform custom-designed tasks of both verbal and non-verbal semantic memory. The researchers will measure neural population responses from high-density electrodes (intracranial electroencephalography – iEEG) and use machine learning to understand and predict how information flows between key regions in the semantic system and medial temporal memory regions in the brain. The project will also directly test whether electrical stimulation of brain tissue during cognitive tasks results in predictable effects, revealing whether these same structures play causal roles in semantic memory processing. Together, this human iEEG research will yield a better understanding of how semantic knowledge retrieval is encoded and supported by local neuronal populations across distributed semantic and memory circuits and broader brain networks. This work may also lead to future therapies, including emerging brain stimulation approaches that may help rescue memory loss in neurological disease.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.