Reconstructing Consciousness and Cognition

Status:	Completed
Conditions:	Cognitive Studies, Hospital
Therapuetic Areas:	Psychiatry / Psychology, Other
Healthy:	No
Age Range:	20 - 40
Updated:	12/2/2017
Start Date:	July 2013
End Date:	February 9, 2015

Currently it is unknown how the human brain reorganizes its network organization to generate
conscious experience and cognitive activity after a period of unconsciousness. Therefore, the
purpose of this study is to assess how cognitive activity is reconstructed after general
anesthesia. The investigators hypothesize that the brain's transition from unconsciousness to
consciousness and full cognition is a complex process that occurs over an extended period of
time. Specifically, the investigators hypothesize the following order of cognitive
reconstitution: responsiveness to command, attention, complex scanning and visual tracking,
working memory, and executive function.

Volunteers will be healthy participants who are anesthetized with commonly used anesthetic
drugs as well as a non-anesthetized group to control for circadian influences. A total of 60
subjects will be recruited for this study. All subjects (male and female) will perform basic
tests for cognition on a laptop computer at 30-minute intervals during this study. The
testing battery to be administered was assembled to assess multiple cognitive functions in
order to determine whether and how cognitive processes return to baseline function.
Electroencephalogram (measuring brain electrical activity) data will be monitored and
recorded during both anesthesia and cognitive testing, for subsequent analysis.

This study is significant because it could lead to a better understanding of the neural
correlates of human consciousness, as well as normal and abnormal conscious state transitions
(including barriers to such transitions).

Inclusion Criteria:

- Healthy 20-40 year old volunteers,

- American Society of Anesthesiologists Physical Status I or II (i.e., healthy),

- Body mass index < 30 kg/m2,

- Easily visualized uvula,

- With anticipated equal recruitment of males and females.

Exclusion Criteria:

- Physical signs suggestive of difficult airway (e.g., mouth opening <3cm, short
distance between the chin and neck, poor mandibular subluxation, thick neck),

- History of obstructive sleep apnea,

- Reactive airway disease,

- Neuropsychiatric disorders,

- History or current use of psychotropic medications,

- Current tobacco and alcohol use,

- History of hypertension or current medication for blood pressure control,
cardiovascular disease or arrhythmias,

- Positive urine toxicology screen,

- History of reflux,

- Pregnancy,

- Family history of problems with anesthesia (including but not limited to malignant
hyperthermia),

- Sleep disorders,

- History of postoperative nausea/vomiting or motion sickness,

- Allergy to eggs, egg products or soy.

We found this trial at

sites

University of Michigan

500 S State St
Ann Arbor, Michigan 48109

(734) 764-1817