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Investigating the Cognitive Source of Visual Working Memory Impairment in Schizophrenia

Investigating the Cognitive Source of Visual Working Memory Impairment in Schizophrenia

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05496413
Enrollment
31
Registered
2022-08-11
Start date
2022-08-11
Completion date
2023-09-25
Last updated
2024-10-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Memory Deficits Schizophrenia Neurostimulator; Complications

Keywords

schizophrenia

Brief summary

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.

Detailed description

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.

Interventions

DEVICESTARSTIM

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.

Sponsors

Taipei Medical University
CollaboratorOTHER
Taipei Medical University Shuang Ho Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
20 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

1. Inform consent acquired 2. Age 20 to 65 3. Right-handed 4. Patients with schizophrenia diagnosed according to DSM-5 criteria

Exclusion criteria

1. Participants who are pregnant or breastfeeding 2. Participants who have metal implants 3. Participants who have alcohol/substance use disorder or received electro-convulsive therapy within the past 6 months. 4. Participants who have history of head injury with loss of consciousness 5. Participants who have history of brain lesions, infection, or epilepsy 6. Skin lesions on the electrodes placed 7. Cancer patients 8. Patients with high fever 9. Patients with significant sensory loss

Design outcomes

Primary

MeasureTime frameDescription
VWM dysfunctionup to one hourUsing the VWM task, investigate at which time point (encoding stage, maintenance stage, or retrieval stage) is VWM dysfunction occurring in schizophrenia patients.

Countries

Taiwan

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026