Causal Role of the Aperiodic Signal for Working Memory
Florida State University
Summary
Working memory (WM) is the ability to hold relevant information in mind in the absence of sensory input. The capacity for WM is a foundation for cognitive control and higher cognitive function more broadly. Previous research demonstrated that during the delay period of WM tasks, oscillatory electrical activity in the prefrontal cortex in the theta-frequency band (4-8 Hz) increased in amplitude. However, other groups found that the slope of the aperiodic signal in the brain was positively correlated with individual differences in WM capacity. Since low-frequency power and a steeper slope of the aperiodic signal are confounded in many analyses, it is not clear whether the slope of the aperiodic signal or the amplitude of low-frequency oscillations underlie WM capacity. With many studies investigating the causal role of theta oscillations in WM, the purpose of this project is to investigate the role of the aperiodic signal in WM performance.
Description
The experiment comprises two experimental sessions. The first session serves as a baseline session where electroencephalography (EEG) is recorded during working memory (WM) task performance. The difficulty of the task is titrated to the individual participant and they are familiarized with the task. In the second session, the participant receives each type of transcranial random aperiodic stimulation (tRAS): steep-tRAS, flat-tRAS, sham-tRAS. Stimulation is delivered in one of these three waveforms for each block while the participant performs the WM task. The type of stimulation that is receiv…
Eligibility
- Age range
- 18–35 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Between the ages of 18 and 35 * Able to provide informed consent * Normal or corrected-to-normal vision * Willing to comply with all study procedures and be available for the duration of the study * Ability to speak, read and understand English without a translator * Not color-blind Exclusion Criteria: * ADHD/ADD (currently under treatment) * Neurological disorder and conditions * Medical or neurological illness or treatment for a medical disorder that could interfere with study participation, e.g., unstable cardiac disease, HIV/AIDS, malignancy, liver or renal impairm…
Interventions
- DeviceSteep-tRAS
Stimulation will be delivered via the NeuroConn Direct Current Stimulator Plus Multiple Channels, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research.
- DeviceFlat-tRAS
Stimulation will be delivered via the NeuroConn Direct Current Stimulator Plus Multiple Channels, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research.
- DeviceSham-tRAS
Stimulation will be delivered via the NeuroConn Direct Current Stimulator Plus Multiple Channels, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research.
Location
- Florida State UniversityTallahassee, Florida