Investigating the Cognitive Source of Visual Working Memory Impairment in Schizophrenia

The investigators plan to investigate the effect of enhancement on visual working memory (VWM) in patients of chronic schizophrenia and determine the predictive factors of effective treatment.

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Key information

Conditions

Memory Deficits Schizophrenia Neurostimulator; Complications Mental Disorders Schizophrenia Schizophrenia Spectrum and Other Psychotic Disorders

Age range

20 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Taipei Medical University Shuang Ho Hospital

New Taipei City, 231, Taiwan

About this study

Schizophrenia is a complex neuro-psychiatric disorder that affects a significant portion of total population worldwide. The disease impairs multiple aspects of human cognition, of which visual working memory (VWM) impairment is known to be one of the pivotal cognitive dysfunction in schizophrenic patients. Despite of several attempts that have been made to establish competent treatment strategies to impede cognitive dysfunction of schizophrenia, till date no such studies exhibited satisfactory outcomes. In this context, numbers of studies have been carried out to utilize transcranial direct current stimulation (tDCS) as a treatment option to enhance working memory deficit in various neuropsychiatric populations, but with very limited success. To this end, the present proposal will focus on the use of transcranial alternating current stimulation (tACS) to better target the oscillatory mechanisms underlying VWM. Our specific aims are twofold, namely, 1) Does DLPFC tACS work on schizophrenic patients in terms of VWM improvement, and 2) how is tACS facilitating patients' VWM? This is because VWM deficit can be caused by poor encoding, poor maintenance, or poor retrieval (or any combination between them). Failure at any of those steps will make the patients appear to have poor VWM from clinical observation, but the cognitive process that is impaired may not be the same across populations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Inform consent acquired
Age 20 to 65
Right-handed
Patients with schizophrenia diagnosed according to DSM-5 criteria

Exclusion criteria

Participants who are pregnant or breastfeeding
Participants who have metal implants
Participants who have alcohol/substance use disorder or received electro-convulsive therapy within the past 6 months.
Participants who have history of head injury with loss of consciousness
Participants who have history of brain lesions, infection, or epilepsy
Skin lesions on the electrodes placed
Cancer patients
Patients with high fever
Patients with significant sensory loss

Treatment and study plan

STARSTIM

Device

In order to evaluate the working memory ability of schizophrenic participants, a task was designed that needs to be performed by them. Firstly, a stimulus of six different color circles of same size in a gray background would be given for 500ms. This would be followed by 2000ms delay phase and then a test array would be appeared. The test array would be exactly same to the stimulus array but with or without change in color of only one circle. The test array would appear on the screen till the participants record their response and they would be asked to respond if the test array matches to the stimulus or not.

Primary outcomes

VWM dysfunction

Time frame: up to one hour

Using the VWM task, investigate at which time point (encoding stage, maintenance stage, or retrieval stage) is VWM dysfunction occurring in schizophrenia patients.

Sponsors and collaborators

Lead sponsor

Taipei Medical University Shuang Ho Hospital

Other

Collaborators

Taipei Medical University

Registry information

Important dates

Study start: 2022
Primary completion: 2023
Study completion: 2023
First posted: Aug 11, 2022
Registry last updated: Oct 1, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed