Signal Propagation and Its Relationship to Cognitive Performance in the Aging Human Brain (Focus or Spread)

October 4, 2021 updated by: University Hospital Inselspital, Berne

Better to Focus or to Spread? Signal Propagation and Its Relationship to Cognitive Performance in the Aging Human Brain

In the next three decades, the world's population over 60 years old is expected to more than double its size. Even in the absence of an obvious pathology (i.e., healthy aging), advancing age is typically associated with a progressive decline in cognitive performance. Although pathophysiological changes in age-related neurodegenerative disorders have received much attention over the past years, far less is known about the neural processes affecting cognition in healthy ageing. One of these postulated processes is neural dedifferentiation (i.e., a decrease in neural selectivity, by which neural representations of processed information become less univocally distinguishable), possibly accompanied by the recruitment of additional cortical areas in the healthy aging brain. To date, these processes have been extensively studied on the neural level, yet their functional significance for cognitive behaviour remains largely unclear. This project will investigate neural dedifferentiation and its relationship to cognitive performance in the healthy aging brain. To this end, the investigators will use a combination of state-of-the-art technologies including simultaneous transcranial magnetic stimulation (TMS) and high-density electroencephalography (hd-EEG) as well as diffusion tensor imaging (DTI). Perspectives include a better understanding of the relationship between neurophysiological mechanisms and cognitive performance in the healthy aging brain.

Study Overview

Status

Completed

Conditions

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Berne, Switzerland, 3010
        • Department of Neurology, Inselspital, Bern University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Informed consent as documented by signature
  • Age between 20-30 or 65-75 years
  • Neurologically healthy, i.e., with no documented or present neurological disease or brain injury
  • Normal or corrected-to-normal visual acuity

Exclusion Criteria:

  • Any instable medical condition, in particular epilepsy (past or present, including seizures or febrile convulsions)
  • Any surgical intervention to the brain
  • Heart diseases
  • Implanted medical devices (e.g., cochlear implants, infusion pumps, neurostimulators, pacemakers)
  • History of migraine or strong headaches
  • Sleep deprivation
  • Presence of non-MRI safe metal in the body
  • Drug or alcohol abuse
  • Intake of any medication that is likely to lower seizure threshold
  • Claustrophobia
  • For female participants: in order to participate in the study, female participants in reproductive age need to take a pregnancy test (a standard urine pregnancy test will be provided).
  • For female participants: breastfeeding
  • Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, etc. of the participant
  • Lack of knowledge of the German language
  • Participation in another study with investigational drug within the 30 days preceding and during the present study
  • Previous enrolment into the current study
  • Enrolment of the investigator, his/her family members, employees and other dependent persons

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Healthy younger participants (20-30y)
Within-subject design. In a visual discrimination task participants will be asked to identify specific features of visual stimuli (i.e., the gender of a face, or the motion direction of a grating). During this task, single-pulse TMS will be applied in one-third of the trials; sham stimulation will be applied in a further third of the trials; and no stimulation will be applied in the remaining third of the trials, while hd-EEG will be continuously measured. The order of these three stimulation conditions (i.e., single-pulse TMS, sham, or no stimulation, during the 1st, 2nd, or 3rd third of the trials) will be counterbalanced over participants.
Medical Device (MD): MagPro X100
Sham stimulation is delivered with a dedicated coil, which is magnetically shielded and thus produces only approx. 20% of the nominal magnetic field. This is not enough to reach and stimulate the cortex, but the produced sound and scalp sensation are the same as with a real TMS coil.
Experimental: Healthy older participants (65-75y)
Within-subject design. In a visual discrimination task participants will be asked to identify specific features of visual stimuli (i.e., the gender of a face, or the motion direction of a grating). During this task, single-pulse TMS will be applied in one-third of the trials; sham stimulation will be applied in a further third of the trials; and no stimulation will be applied in the remaining third of the trials, while hd-EEG will be continuously measured. The order of these three stimulation conditions (i.e., single-pulse TMS, sham, or no stimulation, during the 1st, 2nd, or 3rd third of the trials) will be counterbalanced over participants.
Medical Device (MD): MagPro X100
Sham stimulation is delivered with a dedicated coil, which is magnetically shielded and thus produces only approx. 20% of the nominal magnetic field. This is not enough to reach and stimulate the cortex, but the produced sound and scalp sensation are the same as with a real TMS coil.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Age-related differences in the spatio-temporal patterns of signal propagation
Time Frame: 2 hours
The spatiotemporal patterns of signal propagation, as measured with a combined TMS-hd-EEG approach, in younger and older healthy participants, reflecting age-related differences on the neural level.
2 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Association between the performance in a cognitive test battery and patterns of signal propagation in younger and older participants
Time Frame: 4 hours
The association between the performance in a specific cognitive test and the aforementioned patterns of signal propagation in younger and older healthy participants, reflecting the functional significance of these age-related patterns on the cognitive level.
4 hours
Association between the performance in a cognitive test battery and patterns of signal propagation in better- and worse-performers
Time Frame: 4 hours
The association between the performance in a specific cognitive test and the aforementioned patterns of signal propagation in better- and worse-performers, reflecting the functional significance of these age-independent patterns on the cognitive level.
4 hours
Association between the patterns of signal propagation and the structural properties of the white matter
Time Frame: 4 hours
The association between the aforementioned patterns of signal propagation and the structural properties of the white matter interconnecting the involved cortical areas, as measured by DTI.
4 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: René M. Müri, Prof. Dr., Department of Neurology, Inselspital, Bern University Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 25, 2020

Primary Completion (Actual)

April 8, 2021

Study Completion (Actual)

May 18, 2021

Study Registration Dates

First Submitted

April 22, 2020

First Submitted That Met QC Criteria

April 22, 2020

First Posted (Actual)

April 24, 2020

Study Record Updates

Last Update Posted (Actual)

October 5, 2021

Last Update Submitted That Met QC Criteria

October 4, 2021

Last Verified

October 1, 2021

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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