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Subjective Cognitive Effort Indexes Sub-Criticality in the Brain

主观认知努力指数大脑的次临界度

基本信息

批准号：
10840121
负责人：
John Andrew Westbrook
金额：
$ 24.9万
依托单位：
RUTGERS BIOMEDICAL AND HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2026-08-31
项目状态：
未结题

项目摘要

Project Summary Cognitive effort is subjectively costly. It can cause people to discount valuable goals and avoid thoughtful planning and careful deliberation. Effort avoidance can thus be problematic, especially in disorders like depression and schizophrenia where excessive cost sensitivity undermines cognitive motivation. To address cost sensitivity, we first need to understand what the brain treats as costly. Traditional indices, like lateral frontal functional magnetic resonance imaging signals, and parietal alpha desynchronization in electroencephalography data, track cognitive load to a point, but often plateau or decline, even when subjective effort continues to rise. This project will examine a promising candidate mechanism underlying the experience of subjective cognitive effort: divergence from criticality. Criticality characterizes cortical dynamics at rest, and prior studies have shown that brains become increasingly sub-critical under the very conditions known to increase subjective effort: increasing working memory load, fatigue, sleep deprivation, novelty, and cognitive aging. In the Applicant’s K99 training phase, they found that brain dynamics diverge from a critical point, the harder that tasks become. Most importantly, however, people whos’ brains diverge the most from that critical point experience tasks as more subjectively effortful than people whos’ brains more closely approximate criticality. It is hypothesized that proximity to a critical point depends on the balance of cortical excitatory versus inhibitory signaling. Consistent with this hypothesis, the Applicant also found that artificially perturbing cortical excitability using transcranial magnetic stimulation also pushes brains farther away from a critical point and increases subjective effort on a subsequent cognitive task. The direction of the effect of transcranial magnetic stimulation was surprising, however, opening doors to new hypotheses about the effects of transcranial magnetic stimulation on brain function from the perspective of critical dynamics. This project will test the hypothesis that the cortical excitatory inhibitory balance regulates how closely to a critical state the brain operates, and thereby how sensitive people are to effort costs. In so doing, the project will also re-examine the effects of common transcranial magnetic stimulation protocols on cortical excitability with respect to critical, sub-critical, and super-critical dynamics. Thus, Aim 1 will combine electroencephalography and transcranial magnetic stimulation to test hypothesized mechanisms which may underlie cognitive effort, working memory, and cognitive motivation and also re-assess longstanding assumptions about the effects of transcranial magnetic stimulation on cortical plasticity.

项目摘要认知努力在主观上是昂贵的。它会导致人们对有价值的目标打折扣，避免深思熟虑的计划和仔细的审议。因此，避免努力可能是有问题的，特别是在抑郁症和精神分裂症等疾病中，过度的成本敏感会破坏认知动机。为了解决成本敏感性问题，我们首先需要了解大脑认为什么是昂贵的。传统的指标，如侧额叶功能磁共振成像信号和脑电图数据中的顶叶α去极化，跟踪认知负荷到一个点，但往往是高原或下降，即使主观努力继续上升。这个项目将研究一个有前途的候选机制的主观认知努力的经验：偏离临界。临界性是休息时皮质动力学的特征，先前的研究表明，在已知增加主观努力的条件下，大脑变得越来越亚临界：增加工作记忆负荷，疲劳，睡眠剥夺，新奇感和认知老化。在申请人的K99训练阶段，他们发现大脑动力学偏离临界点，任务变得越难。然而，最重要的是，那些大脑偏离临界点最多的人比那些大脑更接近临界点的人更主观地经历任务。据推测，接近一个临界点取决于皮质兴奋与抑制信号的平衡。与该假设一致，申请人还发现，使用经颅磁刺激人为地扰动皮质兴奋性也将大脑推离临界点更远，并增加了对随后的认知任务的主观努力。然而，经颅磁刺激效果的方向令人惊讶，从临界动力学的角度为经颅磁刺激对大脑功能的影响打开了新的假设之门。这个项目将测试皮质兴奋抑制平衡调节大脑运作到临界状态的程度，从而对人们对努力成本的敏感程度的假设。在这样做的过程中，该项目还将重新研究常见的经颅磁刺激协议对皮质兴奋性的影响，关键，亚临界和超临界动力学。因此，目标1将结合联合收割机和经颅磁刺激来测试可能是认知努力、工作记忆和认知动机的基础的假设机制，并重新评估关于经颅磁刺激对皮质可塑性影响的长期假设。