Author Archive

## Find cheapest flight

April 26th, 2018

I booked a direct flight (non-stop) from San Francisco to Beijing for my father last October. The cost is ~\$300. It’s fairly cheap.

The tool I used was https://matrix.itasoftware.com/. If your departure date can be flexible, this website will give you the price on a range of days. Then I would pick up the cheapest date, and view details such as airline names/time.

You can’t book tickets on this website directly; but with the names of airlines you can go to the website of airlines and book there.

ITA software

Xu Cui Categories: life Tags:

## Recommend 3blue1brown

April 24th, 2018

When I was in high school and saw the following equation, my mind was blown!

Why is Pi here? Isn’t it supposed to show up only in circle related problem? But the left-hand has nothing to do with circle. And it’s Pi squared!

Even today I still do not have an intuitive understanding why the above equation is true, until I watched a visual explanation from 3blue1brown. This video provide an elegant and visual proof of the equation. Go ahead and watch it:

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## To beginner: task-based fNIRS study design (2)

March 19th, 2018

This is a guest post by Ning Liu from Stanford University.

A basic block design includes two conditions: task condition and control condition. The two conditions present alternatively, thus is also called ‘AB block’ (Fig. 1A). This design assumes that the two conditions can be cognitively added, implying no interactions among the cognitive components of a task. A subtraction comparison strategy then can be used in the data analysis to assess the brain regions involved in the performance of the task. Although, in most cases, this assumption is invalid, many people still use it because it usually produces robust and reproducible results. A block design task often includes more than five epochs per condition, and each epoch lasts 10 to 30 seconds. As an example, we used the following block-designed emotional face task in one of our studies: R-F-S-F-S-F-S-F-S-F-S-F-S-R, where R, F and S represent rest, fearful face and scrambled face epochs respectively. Each task epoch (both F and S) lasts 20 s, and each rest epoch lasts 30 s. (Liu, et al. 2015)
Event-related design (Fig.1B) allows the order of conditions present randomly and the time intervals between stimuli vary. This design is more naturalistic and allows for detecting transient variations in hemodynamic responses (HRF). However, event-related design usually needs more number of stimuli in order to enhance the statistical power, and the experiments are often longer than blocked designs.
Mixed design (Fig. 1C) combines block and event-related designs. It alternates two conditions (task and control) as in a block design. Within a block, the interstimulus interval (ISI) varies as in an event-related design. It allows for extracting brain regions either exhibiting transient neural activity (item-related information processing) or sustained neural activity (task-related information processing). However, it involves more assumptions than other designs, and the estimation of the HRF is poorer than event-related design.

Fig. 1. Experiment design (A)Block design (B)Event design (C)Mixed design (ref Edson et al. 2006)

References:
Amaro E Jr, Barker GJ, “Study design in fMRI: basic principle”, Brain and Cognition, 2006, 60(3):220-32.
Liu N, Cui X, Bryant DM., Glover GH, Reiss AL, “Inferring deep-brain activity from cortical activity using functional near-infrared spectroscopy”, Biomedical Optics Express, 2015, 6(3): 1074-89. doi: 10.1364/BOE.6.001074.

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## 浅谈近红外脑成像（fNIRS）任务态实验设计（二）

March 19th, 2018

Fig. 1. 任务设计示意图。(A) 组块设计； (B)事件设计； (C)混合设计。（此图转自Edson et al. 2006)

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## To beginner: task-based fNIRS study design (1)

March 10th, 2018

This is a guest post by Ning Liu from Stanford University.

For someone who has no imaging background and just began to use fNIRS, s/he might be surprised to find out that the imaging study design is so different with study designs in other fields. For instance, task-based imaging studies usually involve bunch of repeated stimuli. This is quite different with what we usually do in a naturalistic environment in our daily life. Why not use just one stimulus? This is due to the difficulty in detecting signal changes against a much stronger background physiological noise. Thus, in order to measure brain actives, one needs to carefully design the experiment and use some clever method to analysis the data.

For task-based study, there are two types of basic design. One is called block-design and the other event-design. It worth noticing that they have something in common — the same stimulus needs to be repeated many times, and the detected signal changes are statistically tested for significance.

Another aspect that beginners usually ignore is the design of control condition. A typical task design usually contains epochs or events of interest along with control epochs or events, such that a cognitive subtraction (for instance) can be performed and resulting in robust and reproducible results.

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## 浅谈近红外脑成像（fNIRS）任务态实验设计（一）

March 10th, 2018

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## 近红外成像入门培训 —— 小型私人辅导

February 23rd, 2018

————————————————

（1） 近红外脑功能成像技术原理及理论基础
（2） 数据采集基本流程
（3） 单人扫描实验设计及数据处理
（4） 双人同步扫描（超扫描）实验设计及数据处理

：fnirs_studio@outlook.com

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## How to find NIRS experts using “Find Experts” app

January 12th, 2018

If you are a newcomer in the NIRS field, you may wonder who are the experts in this field. You might know a few already - for example your boss. But who else are there and where they are?

We developed “Find Experts” app to quickly find experts based on scientific publications in any biomedical field. Let’s see who are experts in the NIRS field.

Website: Find Experts of Stork

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## Number of PubMed papers

December 7th, 2017

From 2000 and 2010, the number of PubMed citations had grown from half million to 1 million. Today we see ~3,000 new papers everyday!

PubMed citations doubles in 10 years

 Year Number 2016 1258608 2015 1253004 2014 1201621 2013 1146180 2012 1085504 2011 1017939 2010 940347 2009 875631 2008 835283 2007 784836 2006 746487 2005 699162 2004 638433 2003 593404 2002 564380 2001 546100 2000 531703 1999 492961 1998 473304 1997 455641 1996 457788 1995 448124 1994 437709 1993 426674 1992 417191 1991 412490 1990 410185 1989 402163 1988 386534 1987 367462 1986 349127 1985 334843 1984 317837 1983 309102 1982 295041 1981 283253 1980 280186
Xu Cui Categories: writing Tags:

## How to track new NIRS publications and grants?

October 27th, 2017

Near infrared spectroscopy (NIRS) is an increasingly popular technology in brain imaging research. Compared to fMRI, NIRS can be used for more naturalistic experiments, including face to face communication, natural body movements, sports, infants, and is well suited for real-time applications.

If we count the number of NIRS publications using keyword `(NIRS OR fNIRS) AND brain`, we find the number increases steadily over the past 10 years:

With this trend, it’s expected that we will reach a speed of 1 new paper every day in the year of 2018 or 2019. This is a fast field, and it’s nearly impossible for us to search `(NIRS OR fNIRS) AND brain` every day or even every week. For a student who does not follow literature proactively, he might know of a paper a year after its publication.

The easiest way to solve this problem is to use an app to notify us of the new publications. The one I use is called Stork . All I need to do is to enter a few keywords I am interested in, e.g.:

`(NIRS OR fNIRS) AND brain`

But what if I want to follow more specific fields, such as hyperscanning, or comparison with fMRI etc? We can enter the following keywords:
`(NIRS OR fNIRS) AND brain AND hyperscanning`
`(NIRS OR fNIRS) AND brain AND fMRI `
`(NIRS OR fNIRS) AND brain AND "deep learning" `
`(NIRS OR fNIRS) AND brain AND social `

What if I want to follow some scientists in the field? We may enter their names, such as:
`David Boas`
`Allan Reiss (NIRS or fNIRS)`

After we setup the keywords, Stork, like a diligent assistant, will search for us every day. If she finds something, she will send an email to us, listing the new publications. A recent example is shown below:

fmri nirs

Papers
The Temporal Muscle of the Head Can Cause Artifacts in Optical Imaging Studies with Functional Near-Infrared Spectroscopy. by Martin Schecklmann, Alexander Mann, …, Florian B Haeussinger (2017) Front Hum Neurosci (impact factor: 3.6) Free full text

nirs brain

Papers
Enhancing Performance of a Hybrid EEG-fNIRS System Using Channel Selection and Early Temporal Features. by Rihui Li, Thomas Potter, Weitian Huang, Yingchun Zhang (2017) Front Hum Neurosci (impact factor: 3.6)Free full text

Not only does Stork search scientific publications for you, she also searches NIH grant database (this is an advanced feature). That means whenever some researchers receive a grant on NIRS, you will know it. You will know what is his research direction in the next few years, how much money he received etc. This feature is mostly useful for professors and senior graduate students and postdocs.

The link of Stork is: storkapp.me and it’s very easy to use.

Stork

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