Sleep
Conditions
Brief summary
Sleep leads to consolidation of learning in humans, restoring memories that were forgotten over a waking day and protecting memories against future forgetting. Although theories of consolidation have linked sleep spindles seen on electroencephalography to consolidation due to their putative role in hippocampal transfer to the neocortex (Antony et al, 2019; Antony & Paller, 2017), spindles have not yet been linked to consolidation of perceptual learning or generalized learning. Prior research by a collaborator on this project has shown that sleep specifically aids in the consolidation of generalized perceptual learning of speech (Fenn, Nusbaum, & Margoliash, 2003). Subjects show a 10-point reduction in performance after a waking retention period, while no loss is found after a retention period containing sleep (Fenn et al., 2003). Various measurable activities in the brain are associated with memory consolidation during sleep. This project intends study the effect of dexmedetomidine on memory consolidation during sleep Hypothesis 1 The gain in perceptual learning after a 90 minute natural sleep nap will also occur after 90 minutes of a sufficient dose of IV dexmedetomidine to replicate sleep. This result would suggest that consolidation can occur under this anesthetic state of consciousness. Hypothesis 2 The number and quality of sleep spindles seen on EEG in subjects administered dexmedetomidine will correlate with this gain in perceptual learning. This result would suggest that biomimetic sleep spindles are sufficient for producing memory consolidation. Only those subjects capable of giving their own consent will be considered for this study. The study will enroll 20 healthy subjects for this study between the ages of 18 and 35. All volunteers will be fit and healthy, meeting the American Society of Anesthesiologists (ASA) physical status classification ASA 1 (normal healthy subjects) and ASA 2 (stable chronic condition) and of normal body habitus. Prior to the study enrollment, each volunteer will sign an informed consent form. A standard anesthetic medical history will be taken in addition to performing a focused standard pre-anesthetic physical examination in order to rule out active and chronic medical problems.
Interventions
DRUGDexmedetomidine
All subjects will receive Dexmedetomidine to induce sedation between their pre-sedation and post-sedation perceptual learning tests.
Sponsors
University of Chicago
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
Primary Inclusion Criteria for Healthy volunteers * Age between 18-35 * Native English speaking * No hearing or speech difficulties * No psychiatric, neurologic, or sleep disorders * No chronic medical conditions, as reflected below under Primary
Exclusion criteria
and above in 'Medical History' * Non-smokers (within 3 months) * Non-users of recreational or illicit drugs (including marijuana) * Must be willing and able to pass the drug tests (no psychoactive substances), no ingestion of alcohol or sleep-altering drugs for the 48 hours prior to the study session. * Normal weight Primary
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Perceptual Learning Protocol | 1 day | Subjects are tested in the morning for word recognition on hard-to-understand speech, then trained on this speech (never hearing the same words twice) which produces about 20 percentage points of improvement. After sedation subjects are re-tested. During the morning, afternoon and evening post-tests, subjects will be tested on new spoken words. At each time point where the perceptual learning protocol is administered the number of words correctly perceived out of 50 will be measured. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Dexmedetomidine Arm Dexmedetomidine: Administration of a 0.5 mcg/kg bolus followed by an infusion of 0.5-0.7 mcg/kg/hr, titrated up by 0.1 mcg every 1 minute until the subject spontaneously closes his or her eyes. When the subject spontaneously closes his or her eyes the infusion continues for 90 minutes from that point.
Dexmedetomidine: All subjects will receive Dexmedetomidine to induce sedation between their pre-sedation and post-sedation perceptual learning tests. | 9 |
| Total | 9 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Physician Decision | 5 |
Baseline characteristics
| Characteristic | Dexmedetomidine Arm |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 9 Participants |
| Memory consolidation | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 9 Participants |
| Race (NIH/OMB) White | 0 Participants |
| Sex: Female, Male Female | 6 Participants |
| Sex: Female, Male Male | 3 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 0 |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Perceptual Learning Protocol
Subjects are tested in the morning for word recognition on hard-to-understand speech, then trained on this speech (never hearing the same words twice) which produces about 20 percentage points of improvement. After sedation subjects are re-tested. During the morning, afternoon and evening post-tests, subjects will be tested on new spoken words. At each time point where the perceptual learning protocol is administered the number of words correctly perceived out of 50 will be measured.
Time frame: 1 day
Population: Study terminated, no data was collected.