How to use NeuroJSON.io

NeuroJSON.io website provides an intuitive interface for users of any experience level to easily navigate across potentially vast amount of public/free datasets curated by NeuroJSON developers and contributors. It offers web-based interfaces to preview the data items before download, and provides convenient search functionalities to help users identify the desired datasets for their analyses.

Before we start, please always keep in mind that NeuroJSON.io contains many databases; each database contains many datasets; each dataset contains one or many subjects.

1. Navigate databases in a browser

1.1. Landing page

1.2. Database information

1.3. Browse and query a database

1.4. Display a dataset

2. Access data using RESTful APIs

1. Navigate databases in a browser

1.1. Landing page

The NeuroJSON.io main page serves as the entry point for exploring NeuroJSON free datasets, referred to as the "data constellation", showing a self-organizing map of existing data collections in the form of a 3-D force graph (thanks to the open-source 3d-force-graph Javascript library). Key features of this graph include

• each node on the graph is a "data collection", containing many datasets
• the size of each node is correlated to the number of datasets contained
• the color of each node is computed based on the included data modalities (MRI, EEG, MEG, fNIRS etc)
• links are added between nodes containing the same modality, bundling them together; the color of the link is modality specific
• use your cursor, you can drag, rotate, zoom in/out of the graph; clicking on any of the nodes, you could see the detailed metadata of the data collection in a side bar

1.2. Database information

A side panel is shown on the left whenever a user select a database (a node) on the "data constellation". In this panel, additional details regarding the data collection are listed, including the upstream website, data modality types, standards etc. Specifically, if such data collection has been curated by NeuroJSON, an additional block is shown on the

1.3. Browse and query a database

When clicking on the "Browse Database" button in the database information panel, your browser will load a webpage that help you navigate and search different datasets within the selected database.

If a database is conforming to the BIDS specification, such as openneuro, a summary table for each containing datasets will be shown. By default, 25 databases is shown on a page; one can click on the page numbers on the top to navigate between different pages to browse the summary for each dataset.

1.4. Display a dataset

When selecting a dataset from a database, a page, in the URL format of https://neurojson.org/db/dbname/dsname, is shown to display the entire searchable content of the full dataset in a tree-like viewer. You can think of the tree as a folder structure, with each item representing a data file or a subfolder. As a matter of fact, that's how we convert BIDS datasets to the JSON format.

By expanding each items in the JSON tree, the content or sub-folder is shown.

2. Access data using RESTful APIs

One can access all datasets from all public databases hosted on NeuroJSON.io using the CouchDB supported RESTful APIs. Because RESTful APIs are URL-based, all the data resources on NeuroJSON.io can be virtually accessed from any programming environments, including web and cloud applications.

Here are the RESTful API formats to access the data on NeuroJSON.io