Dynamic changes in brain activation during task-switching: the effects of development and practice

认知控制是指在面对意想不到的挑战时能够快速调整感知和运动的过程，它与大脑皮层和皮层下区域的广泛网络活动有关。例如，在任务转换范式中，参与者以一种方式（例如，通过颜色）对刺激进行分类，并定期要求他们以一种新的方式（例如，通过形状）对相同的刺激进行转换和分类。任务转换范式是具有挑战性的，特别是对幼儿来说，与重复试验相比，他们在切换时表现出夸张的行为反应时间和准确性成本。随着开发，这种调整变得更容易，因为它们需要更小的性能成本。尽管最近取得了进展，但关于转换成本的性质和其中与年龄有关的变化的基本问题仍然悬而未决。例如，发育认知神经科学模型将开关成本大小的年龄相关变化与外侧前额皮质（lPFC）功能组织的变化联系起来。对于快速行为调整至关重要的lPFC，在其局部解剖结构以及与更大的认知控制网络的功能和结构整合方面都遵循一个漫长的发展轨迹。因此，大脑组织的成熟限制使儿童难以调节由任务驱动的各种感知和运动区域的活动。与此同时，孩子们在进行任务转换等心理操作方面的经验较少。这是相关的，因为通过实践可以降低转换成本。因此，拟议的计划将解决4个基本问题。首先，在任务转换过程中发生的感知和运动适应的本质是什么？其次，这些适应的性质（即速度、强度）是否存在与年龄相关的差异？第三，这些适应性是否受到实践的影响？第四，练习对年轻人和老年人的影响是否相当？了解认知和行为自我调节的发展是重要的科学目标。拟议的研究将有助于实现这一目标，通过阐明为什么随着年龄的增长，儿童能够更快地适应意想不到的认知行为挑战。

Cognitive control refers to processes that enable rapid perceptual and motor adjustments in the face of unexpected challenges and are associated with activity in a broad network of cortical and subcortical brain areas. In task-switching paradigms, for example, participants classify stimuli one way (e.g., by colour) and are periodically required to switch and classify the same stimuli in a new way (e.g., by shape). Task-switching paradigms are challenging, especially for young children, who show exaggerated behavioral response time and accuracy costs on switch as compared to repeat trials. With development, adjustments of this kind become easier insofar as they exact smaller performance costs. Despite recent progress, basic questions concerning the nature of switch costs and age-related changes therein remain open. Developmental cognitive neuroscience models, for example, link age-related changes in the magnitude of switch costs to changes in the functional organization of lateral prefrontal cortex (lPFC). lPFC, critical for rapid behavioural adjustments, follows a protracted developmental trajectory both in terms of its local anatomy and its functional and structural integration with larger cognitive control networks. On this account, maturational constraints in brain organization make it difficult for children to modulate activity in various perceptual and motor regions driven by a task. At the same time, children have less experience performing mental operations such as task-switching. This is relevant given that switch costs are attenuated by practice. The proposed program will therefore address 4 basic questions. First, what is the nature of perceptual and motor adaptations that occur during task-switching? Second, are there age-related differences in the nature (i.e., rate, strength) of these adaptations? Third, are these adaptations influenced by practice? And fourth, does practice exert comparable effects on younger and older participants? Understanding the development of cognitive and behavioral self-regulation are important scientific objectives. The proposed studies would help achieve this goal, by clarifying why, with age, children can more rapidly adapt to unexpected cognitive-behavioural challenges.