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In this section are a description of how we processed raw EEG data, as well as an overview of how we algorithmically distinguished between the data associated with resting and reading.

The algorithm

After collecting a large amount of data related to different activities and, in theory, different levels of brain activity, we attempted to make general statements about the differences between them. Nearly all of the data we collected revealed that distinct activities resulted in distinct brain signals; however, some of these differences appeared more reliably and more markedly than others. By examining the spectrograms we created for each scenario, we determined that relaxing and reading were two of the most distinct activities with respect to measured brain activity. With this in mind, we decided to design and implement an algorithm capable of distinguishing between spectrograms associated with relaxing or reading.

The initial step in this process was an analysis of the spectrograms and power spectral density plots collected for different trials of reading and resting. Several features seemed potential candidates to be leveraged in the algorithm. One striking difference is the presence of an intense band of activity at 120 Hz, which appears in the reading spectrogram but is absent in the resting spectrogram. Despite its stark differences, we chose not to incorporate this feature into the algorithm because we felt that it does not likely indicate a true effect occurring in the brain. Rather, its ubiquity across many of our measurements (and the fact that its frequency never wavers) led us to believe that it might be an artifact of the headset. Instead, we were more interested in the fact that the resting state appears to have more energy just above baseband, in the 10-50 Hz range. Ultimately, this was the feature we selected for in the algorithm. Because this is an effect that accumulates over the entire period of the experiment, the Power Spectral Density plot provides an excellent way to quantify these differences. As is evident in the PSD plot below, the intuitions we developed from the spectrograms are clearly confirmed to hold true for the example below. After inspecting several other trials, we decided that the 10-50 Hz frequency range selected the phenomenon we observed while excluding potential sources of noise like 60 Hz noise. Thus, we wrote a script to integrate the power in this range for the two sets of data. It then attributes the higher value to the resting state and the lower to a reading state. With the appropriately set integration limits. the algorithm correctly determined the source of the data for all of the trials we performed.

A psd comparison of reading and resting

example psd plot

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Characterization of eeg signals from neurosky mindset device. OpenStax CNX. Dec 19, 2011 Download for free at http://cnx.org/content/col11392/1.1
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