UMIN-ICDS Clinical Trial

Unique ID issued by UMIN UMIN000061694
Receipt number R000070590
Scientific Title Visual Adaptation and tDCS for Sensory Motor Function in Healthy Adults A Randomized Controlled Trial (VAST-RCT)
Date of disclosure of the study information 2026/05/26
Last modified on 2026/05/26 15:05:48

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Basic information

Public title

Understanding How Vision and Brain Stimulation Affect Spatial Awareness and Movement (VISTA)

Acronym

VISTA

Scientific Title

Visual Adaptation and tDCS for Sensory Motor Function in Healthy Adults A Randomized Controlled Trial (VAST-RCT)

Scientific Title:Acronym

VAST-RCT

Region

Japan


Condition

Condition

Healthy Volunteers

Classification by specialty

Adult

Classification by malignancy

Others

Genomic information

NO


Objectives

Narrative objectives1

The objective of this research is to elucidate the effects of prism adaptation therapy (PA) and transcranial direct current stimulation (tDCS) applied to the parietal cortex on the Where Bias and Aiming Bias, which constitute spatial cognitive biases. The Where and Aiming Components will be quantified using a line bisection task and its reverse condition, and a randomized, double-blind, crossover trial will be conducted with healthy adult participants. Study 1 aims to examine the influence of PA on the Aiming Component, whereas Study 2 investigates the effect of tDCS on the Where Component. Through these investigations, the research seeks to clarify the sensory-motor characteristics underlying spatial cognition.

Basic objectives2

Others

Basic objectives -Others

To investigate how prism adaptation therapy and transcranial direct current stimulation modulate the sensory motor components of spatial cognition, specifically the Where and Aiming Components derived from line bisection performance. The study aims to clarify the underlying mechanisms of spatial cognitive biases by quantifying these components in healthy adults.

Trial characteristics_1

Confirmatory

Trial characteristics_2

Explanatory

Developmental phase

Not applicable


Assessment

Primary outcomes

- Study 1: Change in Aiming Component
Difference in Aiming Component before and after intervention, derived from line bisection and reversed conditions.
- Study 2: Change in Where Component
Difference in Where Component before and after intervention, derived from line bisection and reversed conditions.

Key secondary outcomes

- Change in the Component not defined as the primary outcome
(Study 1: Where Component; Study 2: Aiming Component)
- Change in line bisection deviation (mm)
- Reaction time and task performance time in line bisection
- Performance on the cancellation task (Study 2)
- Eye movement metrics during tasks (Study 2)
- Persistence of intervention effects immediately and at short follow-up
- Success of blinding (post-experiment questionnaire)


Base

Study type

Interventional


Study design

Basic design

Cross-over

Randomization

Randomized

Randomization unit

Individual

Blinding

Double blind -all involved are blinded

Control

Placebo

Stratification

YES

Dynamic allocation

NO

Institution consideration

Institution is not considered as adjustment factor.

Blocking

YES

Concealment

No need to know


Intervention

No. of arms

4

Purpose of intervention

Educational,Counseling,Training

Type of intervention

Device,equipment

Interventions/Control_1

Study 1: Right-eye prism glasses (washout period) placebo glasses
Study 2: Anodal tDCS to the right parietal lobe (washout period) sham tDCS to the parietal lobe

Interventions/Control_2

Study 1: Placebo glasses (washout period) right prism glasses
Study 2: Parietal sham tDCS (washout period) right parietal anodal tDCS

Interventions/Control_3

Study 1: Left prism glasses (washout period) placebo glasses
Study 2: Anodal tDCS to the left parietal lobe (washout period) sham tDCS to the parietal lobe

Interventions/Control_4

Study 1: Placebo glasses (washout period) Left prism glasses
Study 2: Parietal sham tDCS (washout period) Left parietal anodal tDCS

Interventions/Control_5


Interventions/Control_6


Interventions/Control_7


Interventions/Control_8


Interventions/Control_9


Interventions/Control_10



Eligibility

Age-lower limit

18 years-old <=

Age-upper limit

30 years-old >

Gender

Male and Female

Key inclusion criteria

- Healthy adults aged 18 to 30 years
- Right-handed, confirmed by the Edinburgh Handedness Inventory
- No history of neurological or psychiatric disorders
- Not meeting any contraindications for tDCS (Study 2 only)
- Able to understand the study procedures and provide written informed consent

Key exclusion criteria

- History of neurological or psychiatric disorders
- Orthopedic conditions affecting upper limb motor function
- Visual impairments interfering with task performance
- History of epilepsy or increased seizure risk
- Contraindications for tDCS (Study 2)
- Pregnant or possibly pregnant (Study 2)
- Under the influence of alcohol or drugs
- Deemed unsuitable by the principal investigator

Target sample size

88


Research contact person

Name of lead principal investigator

1st name Toshiyuki
Middle name
Last name ISHIOKA

Organization

Kobe University

Division name

Graduate School of Medicine

Zip code

654-0142

Address

7-10-2, Tomogaoka, Suma-ku, Kobe, Hyogo, Japan

TEL

078-792-2555

Email

tsykisok@port.kobe-u.ac.jp


Public contact

Name of contact person

1st name Toshiyuki
Middle name
Last name ISHIOKA

Organization

Kobe University

Division name

Graduate School of Medicine

Zip code

654-0142

Address

7-10-2, Tomogaoka, Suma-ku, Kobe, Hyogo, Japan

TEL

078-792-2555

Homepage URL


Email

tsykisok@port.kobe-u.ac.jp


Sponsor or person

Institute

Kobe University

Institute

Department

Personal name

Toshiyuki ISHIOKA


Funding Source

Organization

None

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization



Other related organizations

Co-sponsor


Name of secondary funder(s)



IRB Contact (For public release)

Organization

Research Ethics Review Committee, Graduate School of Medicine, Kobe University (Myodani)

Address

7-10-2, Tomogaoka, Suma-ku, Kobe, Hyogo, Japan

Tel

078-792-2555

Email

syomu2@ams.kobe-u.ac.jp


Secondary IDs

Secondary IDs

NO

Study ID_1


Org. issuing International ID_1


Study ID_2


Org. issuing International ID_2


IND to MHLW



Institutions

Institutions



Other administrative information

Date of disclosure of the study information

2026 Year 05 Month 26 Day


Related information

URL releasing protocol


Publication of results

Unpublished


Result

URL related to results and publications


Number of participants that the trial has enrolled


Results


Results date posted


Results Delayed


Results Delay Reason


Date of the first journal publication of results


Baseline Characteristics


Participant flow


Adverse events


Outcome measures


Plan to share IPD


IPD sharing Plan description



Progress

Recruitment status

Preinitiation

Date of protocol fixation

2026 Year 04 Month 09 Day

Date of IRB


Anticipated trial start date

2026 Year 06 Month 01 Day

Last follow-up date

2028 Year 03 Month 31 Day

Date of closure to data entry


Date trial data considered complete


Date analysis concluded



Other

Other related information



Management information

Registered date

2026 Year 05 Month 26 Day

Last modified on

2026 Year 05 Month 26 Day



Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000070590