Schizophrenia, Cognitive Impairment
Conditions
Brief summary
The purpose of this study is to investigate the cognitive effects of different electrical stimulation modalities, such as transcranial direct and random-noise stimulation over the dorsolateral prefrontal cortex, in schizophrenia.
Interventions
DEVICEtranscranial direct current stimulation (tDCS) active stimulator
In tDCS the electrical current is applied directly between electrodes mounted on the head which can can de-or hyperpolarizes resting membrane potential and thereby modulate cortical excitability
Here, an alternating electrical current is applied at a mix of frequencies it is called transcranial random noise stimulation (tRNS), which can be delivered in low (between 0.1-100 Hz) or high (between 101-640 Hz) frequency stimulation
DEVICEtranscranial direct current stimulation (tDCS) sham stimulator
Here a sham electrical current is applied directly between electrodes mounted on the head which can can de-or hyperpolarizes resting membrane potential and thereby modulate cortical excitability
Sponsors
The National Brain Mapping Laboratory (NBML)
Leibniz Research Centre for Working Environment and Human Factors
Payame Noor University
RWTH Aachen University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Diagnosis of schizophrenia based on Diagnostic and Statistical Manual (DSM)5 * Being 18-50 years old (male and female) * If female, negative urine pregnancy test * feasibility for tDCS/tRNS interventions according to safety guidelines * stable medication regime, especially for classical neuroleptics and all central nervous system activating medications, if taken, 4-6 weeks before the experiment * fluency in the native language * right-handed * Required written informed consent signed by patients' guardian
Exclusion criteria
* pregnancy * alcohol or substance dependence * comorbid bipolar disorder and mood disorder * history of seizure * history of neurological disorder * history of head injury * Presence of ferromagnetic objects in the body that are contraindicated for brain stimulation of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Spatial Working Memory behavioral performance | During procedure (4 minutes) | The test begins with a number of coloured squares (boxes) shown on the screen. The aim of this test is that by selecting the boxes and using a process of elimination, the participant should find one yellow 'token' in each of a number of boxes and use them to fill up an empty column on the right-hand side of the screen. |
| executive function behavioral performance | During procedure (8-10 minutes) | The participant is shown two displays containing three coloured balls. The test administrator first demonstrates to the participant how to move the balls in the lower display to copy the pattern in the upper display and completes one demonstration problem, where the solution requires one move. The participant must then complete three further problems, one each requiring two moves, three moves, and four moves. Next, the participant is shown further problems and must work out in their head how many moves the solutions require and then select the appropriate box at the bottom of the screen to indicate their response |
| The Positive and Negative Affect Schedule (PANAS) | through study completion, an average of 3 weeks | The Positive and Negative Affect Schedule (PANAS) is a self-report questionnaire that consists of two 10-item scales to measure both positive and negative affect. Each item is rated on a 5-point scale of 1 (not at all) to 5 (very much). |
Countries
Iran
Outcome results
None listed