Reconstructing Consciousness and Cognition

Summary

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).

Conditions

• Postoperative Cognitive Dysfunction

Interventions

DRUG

ISOFLURANE- Experimental Arm

The experimental group will be given the anesthetic isoflurane for three hours, and will undergo cognitive tests immediately following emergence from general anesthesia while connected to an EEG machine.

OTHER

Control Group: Cognitive Testing

The control group will undergo cognitive testing while connected to an EEG machine following a comparable rest period, but will not receive general anesthesia.

Sponsors & Collaborators

• University of Pennsylvania

  collaborator OTHER

• Washington University School of Medicine

  collaborator OTHER

• James S McDonnell Foundation

  collaborator OTHER

• University of Michigan

  lead OTHER

Principal Investigators

• George A Mashour, MD, PhD · University of Michigan

• Michael Avidan, MBBCh · Washington University School of Medicine

• Max Kelz, MD, PhD · University of Pennsylvania

• Mathias Basner, MD, PhD, MSc · University of Pennsylvania

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-07-31

Primary Completion

2015-02-09

Completion

2015-02-09

Countries

• United States

Study Locations