Infant Cortisol Reactivity and its Relationship to Learning and Memory

描述（由申请人提供）：本研究将通过检查各种因素如何影响幼儿在学习情况下肾上腺皮质反应的方向和程度，为研究不足的婴儿认知发展主题做出贡献。皮质醇是一种肾上腺类固醇激素，在身体和情绪压力下分泌，也与高唤醒状态有关。我们以前的研究表明，那些在母亲分离/学习事件中表现出皮质醇下降的婴儿表现出对目标刺激的学习和记忆。皮质醇反应性下降和更好的学习/记忆之间的联系是预期的结果，因为情绪和认知过程的控制都存在于共同的大脑区域。然而，我们以前的研究结果与肾上腺皮质和婴儿认知功能之间的关系的一些其他调查不一致。拟议的实验的主要目的是确定跨研究的差异结果的性质，通过探索几个假设影响皮质醇反应的方向在学习活动，包括生理活动，社会情绪困扰，和母亲的努力，以协助婴儿的情绪调节的因素。计划进行两项短期纵向研究。将收集这些婴儿年龄（2个月、3个月和6个月）的母婴配对数据。将从婴儿和母亲身上采集唾液皮质醇样本，以评估皮质醇对分离/学习事件的反应方向和程度。婴儿将参加四个实验，旨在评估婴儿学习和记忆语言和声音刺激的各个方面。在第二组实验中，母亲将被训练表现出旨在帮助婴儿调节肾上腺皮质反应模式的行为。据预测，这种母亲的敏感性训练将促进婴儿更好的学习和记忆。行为同步性将通过观察母亲和婴儿在短的相互作用期间以10秒间隔的特定行为来测量。我们将继续调查这些关系的人口是在相关文献中代表性不足。这项研究将为婴儿期认知过程、母亲和婴儿的肾上腺皮质功能以及照顾者对婴儿的敏感性之间的关系的文献增加有价值的数据。

DESCRIPTION (provided by applicant): This study will make contributions to a very under-researched topic of infant cognitive development by examining how various factors affect the direction and degree of adrenocortical response in young infants in learning situations. Cortisol, an adrenal steroid hormone, is secreted in response to physical and emotional stress and is also associated with high states of arousal. Our previous research showed that those infants who exhibited declining cortisol during a maternal separation/learning event showed learning and memory for the target stimuli. A link between declining cortisol reactivity and better learning/memory was the expected outcome given the argument that the control of both emotion and cognitive processes resides in common brain areas. However, our previous results were inconsistent with some other investigations of the relationship between adrenocortical and infant cognitive functioning. The primary aim of the proposed experiments is to ascertain the nature of the differential results across studies by exploring several factors hypothesized to affect the direction of cortisol reactivity during learning events, including physiological activity, socioemotional distress, and maternal efforts to assist infant emotional regulation. Two short longitudinal studies are planned. Data will be collected on mother-infant pairs at these infant ages: 2 months, 3 months, and 6 months. Salivary cortisol samples will be taken from the infant and the mother to assess the direction and degree of cortisol reactivity to a separation/learning event. Infants will participate in four experiments, designed to assess various aspects of infant learning and memory for language and voice stimuli. In a second set of experiments, mothers will be trained to exhibit behaviors intended to assist their infants in regulating their adrenocortical response patterns. It is predicted that this maternal sensitivity training will promote better learning and memory in infants. Behavioral synchrony will be measured by observing specific behaviors of the mother and infant in 10-sec intervals across a short interaction period. We will continue to investigate these relationships in a population that is underrepresented in the related literature. The research will add valuable data to the literature on the relationship between cognitive processing in infancy, adrenocortical functioning in mothers and infants, and sensitivity of the caregiver to the infant.