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Related Experiment Video

Updated: Jun 7, 2026

Eye Tracking, Cortisol, and a Sleep vs. Wake Consolidation Delay: Combining Methods to Uncover an Interactive Effect of Sleep and Cortisol on Memory

Eye Tracking, Cortisol, and a Sleep vs. Wake Consolidation Delay: Combining Methods to Uncover an Interactive Effect of Sleep and Cortisol on Memory

Published on: June 18, 2014

The cortisol awakening response in context.

Angela Clow¹, Frank Hucklebridge, Lisa Thorn

¹Department of Psychology, University of Westminster, London W1B2UW, UK.

International Review of Neurobiology

|October 26, 2010

Summary

This summary is machine-generated.

The cortisol awakening response (CAR) is a key part of the daily cortisol rhythm, peaking shortly after waking. Its regulation is distinct and linked to awakening processes.

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Area of Science:

Endocrinology
Neuroscience
Chronobiology

Background:

The cortisol awakening response (CAR) is a significant marker in the healthy cortisol circadian rhythm.
Cortisol secretion typically peaks 30-45 minutes after waking.

Purpose of the Study:

To review the history and regulation of the CAR.
To explore the CAR's distinct regulatory mechanisms compared to other daily cortisol secretion.
To examine the CAR's role in awakening-induced physiological processes.

Main Methods:

Literature review of historical investigations into the CAR.
Analysis of evidence on CAR regulation by the suprachiasmatic nucleus and sympathetic nervous system.
Examination of the CAR's relationship with other physiological changes upon awakening.

Main Results:

CAR regulation is distinct from cortisol secretion throughout the rest of the day.
The CAR is initiated by awakening, influenced by the suprachiasmatic nucleus.
The sympathetic nervous system fine-tunes CAR via direct neural input to the adrenal cortex.

Conclusions:

The CAR is initiated by awakening and influenced by central and neural pathways.
The CAR plays a potential role in processes like regaining consciousness, alertness, hormonal shifts, immune balance, and motor system activation.
Further research is needed to fully elucidate the CAR's functional significance.