Interruption of Dorsal Visual Stream Using TMS

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Device: No TMS intervention; Device: TMS over the PO3 EEG site; Device: TMS over the vertex

• Registration Number: NCT00418652
• Lead Sponsor: Sheba Medical Center

Brief Summary

Trans Cranial Magnetic Stimulation (TMS) over dorsal visual system will disturb the ability to identify objects with decreased level of fragmentation

Detailed Description

The participants performed two tasks under three different TMS conditions: no TMS, 10Hz TMS for over the dorsal stream (PO3 EEG site) or over the vertex.

First they performed a perceptual closure task which asked them to identify an object in a series of six progressively less degraded pictures.

Then, they also performed a control task previously shown not to be mediated by the LOC and not to be impaired in schizophrenia: The perception of illusory contours.

Study Timeline

• Study Start: 2006-01
• Study First Submitted: 2007-01-04
• Study First Submitted QC: 2007-01-04
• Study First Posted: 2007-01-05
• Primary Completion: 2010-07
• Status Verified: 2011-08
• Last Update Submitted: 2011-08-03
• Last Update Posted: 2011-08-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 12

Inclusion Criteria

• Normal controls

Exclusion Criteria

• neurological, ophthalmological or psychiatric problems
• family history of schizophrenia
• left handed

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
No TMS stimulation	No TMS intervention	The patients performed 2 tasks: a study and a control assignments with no TMS stimulation.
TMS over the dorsal stream	TMS over the PO3 EEG site	The patients performed 2 tasks: a study and a control assignments under TMS stimulation over the dorsal stream area (PO3 EEG site).
TMS over the vertex	TMS over the vertex	The patients performed 2 tasks: a study and a control assignments under TMS stimulation over the vertex area.

Primary Outcome Measures

Name	Time	Method
Results of the study assignments performed by the participants during the study.	The participants performed the tasks once during their study visit	The subjects performed 2 tasks: The primary dependent measures consisted of the level of detail needed for correct object identification, response accuracy, and response time in milliseconds for correct responses.; Illusory Contour Task: Subjects also performed a pulsed pedestal task, Participants were shown 55 drawings for 500 ms each. Some drawings contained partial contours which defined a geometric shape, while in others the contours did not define a shape. Participants were asked to indicate whether they recognized a geometric shape or not. Accuracy and response time were measured.

Trial Locations

Locations (1)

Psychiatry Clinic - Sheba Medical Center; 🇮🇱 Tel-hashomer, Israel