Strabism and how big is the field of vision

During my presentation on university we have discussed the strabism and how big is the field of vision for different types of strabism.

Fig. Strabism (Esotropia - the upper image, Exotropia - lower image)

Strabism is the disease when both eyes cannot simultaneously gaze at the same fixation point. Therefore the image from both eyes cannot be combined in a single image and this can cause so called "double vision" = diplopia (Light from the visual input passess through lens to the retina but to not corresponding places - from one eye it reaches the fovea but in the other eye not - therefore the subsequent fusion of image is not possible). There are two main different kinds of strabism: esotropia (axis of eyes intersect before fixation point) and exotropia (axes of eyes intersect behing fixation point). Less frequent are hyper- and hypotropia which correspond to the deviation in vertical line.

Fig. Esotropia and Exotropia

But what is the cause of strabism?

Strabism can be caused by different length of extraocular muscles or by their lack of coordination. Secondly, strabism can be also caused by problems with ocular nerves and subsequent problems with neural interpretation of visual input (this is called lazy eye or amblyopia and brain will favor one of the eye and suppress the other). What I was not sure whether the strabism is somehow connected to the problems with eye lens. My collegue told me that the problem is not primarily caused by problems with lens but without any cure the problems with eye lens can appear (caused by using only one eye etc.).

How can people with strabism see and work?

This is very interesting. When you use only one eye, you cannot percieve the depth. When using both eyes they can perceive "double vision" which can be quite dangerous in normal life: people with this problem can fall from stairs or have problems with driving. Therefore they frequently cover one of their eyes (especially the ill one which can cause further problems which I will discuss beneath). The brain itself will supress deviated eye in the central visual field where we have binocular vision.

Fig. Diplopia (double vision)

Do they have bigger/smaller field of vision compared to healthy human?

You maybe know that the horizontal field of vision for normal human is something as 200° (each eye about 160°, binocullar vision ~ 120°).

We could expect that people with exotropia should have bigger field of vision than people with normal vision and similarly people with esotropia should have this field of vision smaller. Anyway, this is not exactly true. People with strabism have "bigger field of vision" when using only one eye (the second eye is covered), but while brain cannot work with "double vision", it accomodates and the central part of the field (approximatelly 20° is excluded). Sometimes one eye is completly suppressed.

What is even more interesting is that when you completelly cover one of your eyes (to improve your vision) and stop using it, the muscles which are used for accomodation of lens will loose their strength and afterwards it can also cause total "deth" of one of your eyes (also neural connection are not working anymore).

And...how big is the field of vision for birds?

Just interested, whether birds with bigger eyes (and lens) have also bigger field of vision. And the answer is YES! Yes, they have. Something as 300° compared to 200° which is the normal humens' field of vision. Furthermore they can perceive even small changes in light intensity (owl), big distances, binocularly and some birds see also colors.

OK! But how to cure strabism?

There are several methods. One of them is to cover the healthy eye which will cause that the "ill" eye will have to work more. Other methods are mainly focused on strengthening and training extraocular muscles. One of my collegue is prepares set of games which can be used for diagnosing and curing strabism: here (unfortunatelly just in Czech).

One problem with curing strabism can be that after cure, the brain is not able to supress the deviated eye in the area of binocular vision and the patient can again perceive "double vision" (dyplopia).

Joomla webpages

After long time I have opened webpages of my FRVS project created in Joomla. I have faced few problems. This is not a tutorial, just few things which I found out I have forgotten after few months...

How to edit Joomla webpages on localhost?
open localhost\...\administrator (administrator instead of index.html or index.php)

How to add new article?
Add article into article manager
- add article within existing category and into menu item which is a list of Category articles (maybe necessary to add new Category in Category manager)
- or in Menu manager add new menu item (with single article content) and link to the created article

How to link to file?
- Upload file through Media manager
- Add link to text which will link to a file (icon Link in Article editor)-> Browse for a link and select a file you want to link to

How to add zip files to Joomla:
It is not default option. Go to Media manager->Options->add ZIP and zip into list of allowed extensions

How to upload Joomla webpages on web:
1. Upload your newly created Joomla site to the server via FTP.
2. Create the MySql Database.
3. Edit the configuration.php file and set the newly created server database name, username, password correctly. U don't have to change the host name usually its "localhost" but if your server MySql is belong to a different IP u need to put that ip in the hostname.
4. upload/replace the configuration.php file.
5. Export your Local Joomla(PC) database (e.g using PhpMyadmin) and import the same in your Server Database.

Openness in Education

Today, I have been listening (on SIIE 2012 conference) to very interesting talk by Dr.Charles Severance from Michigan university who is a creator of Sakai project (a project similar to Moodle) for e-learning education.

Eventhough I'm not able to repeat his personality which is so vivid, enthusiastic and full of life, I can mention here few main ideas of the talk.

He was speaking about the history of academics and researchers. In medieval times there was a small group of academics, who were quite strange and the community was closed. They were donated by a small money from King or from important people in industry and backwards few of these academics become kings or wealthy industrialists. The ideas were coming up slowly by talking one to each other and by letting the knowledge inside the fortress of the university.

Later, mainly during the world war II, politicians spent a lot of money and donated academics, because they needed their knowledge and ideas to be the winners of the war. From this research also other things have been evolved like cars, space shuttles etc.

Afterwards during the last decades of the 20th century, government gave research money and wanted back solutions - like ARPANET. Ideas from academics also went to the outside world as ideas of networks or open source products.

Academics were still giving back something for the money they got. Today the results of academics are tons of journal papers and eventhough governments spent so much money on the research (because they think that it was always useful), they got quite little backwards. On the other site there are people in praxis, people who own big companies like Amazon, Google, Facebook...which are the ones who are the ones who pushes the knowledge forward, eventhough their idea isn't to solve problems and be curios about the nature of the world, but just to earn money.

Academics live their own closed life, publishing and trying to get enough money from government. The number of academicians has grown so quickly but the results aren't so surprising. They often discuss something what people in praxis have invited years before them and used it in their companies.

What can be the future? The first possibility is that governement will stop the money and the number of academicians will drop down quickly because they will have no fundation. It is natural, because when governement will see that the results from research aren't very useful and they got nothing which is applicable, they will stop giving money for these purposes. The research environment we have now is the result of the research of the people before 2000.

But we have a choice. We can open our ideas, cooperate with the real world and find fundation somewhere else than in governement. "new graduates have to compete all great companies in a world full of ideas instead of writing articles" Then we can work independently. We must have some direction of our research, not only to publish papers. And also, we should be openned to the whole world - create academical blog where we share our ideas, go between the people, be part of some open source community, real-world impact and tenure, create identity personality etc.

And Dr.Chuck is the one who made it happened. He got the fundation - enough money to make real cool ideas, he has his own academics blog: http://www.dr-chuck.com/csev-blog/ and his own webpages http://www.dr-chuck.com/, he leads on coursera.org the online course https://www.coursera.org/course/insidetheinternet, he is a director of Sakai project, he published many books, likes to drive motorcycle and communicate. When he saw openness in education in Stanford university, which is the first university where every course is openned to anybody who wants to participate, he thought that it could be perfect to have the same thing on Michigan university. When they said: not yet, he decided to create his own open "university" Dr.Chucks class2go. What does it mean? He says yes to things which appears infront of him. He isn't aware of the work and time he must spend on the project and he starts everything with enthusiasm. Not to be closed, be open to the whole world it is the only possiblity....

And on the end from the Joshua Kim review of his book "Chuck Severance is Crazy:When I say that Chuck Severance is crazy, I mean crazy in the very best possible way. Crazy as in completely honest. Crazy as in willing to say things that might offend other people.   Crazy in the sense that he is willing to be critical of his own actions. Crazy in that he believes in the promise of open source software in higher education more than he cares about his own career advancement. Crazy in that he is willing to take risks, to fail, and to learn from his mistakes.I don't know Chuck Severance, but I hope that I get the chance. This is a guy who quit a series of good jobs in quick succession in order to have the opportunity to work on a risky open source education project." 
I had the opportunity to see him and it was a great thing-if you will have that chance, don't miss it. What more - I had the opportunity to speak to him for a few seconds, to ask him a question and to be introduced to him. He is so full of energy that it seems to be impossible.

SQL - Different where conditions for two columns

Just some programming note. When dealing with SQL database you can face the problem how to select two or more columns with different conditions. Here is the solution based on the CASE:

This problem is also discussed on internet for example here: http://stackoverflow.com/questions/3087314/sql-two-different-where-conditions-for-two-columns

Autistic, systemizing and empathizing quotients

In my last experiment I have been investigating along with mental abilities and EEG also testosterone levels and psychological quotients. These quotients have been shown to be correlated with mental abilities and also testosteron levels. Our aim is also to focus whether we can see some differences in the EEG signal.

But what are these quotients? All of them have been proposed to better describe people with autism (mainly Asperger syndrom) and were designed by Simon Baron-Cohen ( http://en.wikipedia.org/wiki/Simon_Baron-Cohen).

It is a set of 4 questionnaires which sometimes overlap a little. In empathizing and systemizing questionnaire there are also some blind questiones which aren't consider for the quotient summation. The first 3 (autism, empathy and systemizing) have 4 answers - strongly agree, slightly agree, slightly disagree and strongly disagree where you have to choose only one answer. The fourth questionnaire is focused on empathy detection based on the ability of detecting state of the people mind from people eyes.

Autism quotient - 50 questions
Systemizing quotient - 60 questions
Empathy quotient - 60 questions
Empathy from eyes - 36 questions (normal 22-28 correct)

You can test quizes on the webpage: http://glennrowe.net/BaronCohen.aspx

The papers where the work was published and the comparison between control group and autistic children was  done can be found in:

Baron-Cohen, S, & Wheelwright, S, (2004) The Empathy Quotient (EQ). An investigation of adults with Asperger Syndrome or High Functioning Autism, and normal sex differences. Journal of Autism and Developmental Disorders, 34, 163-175. (reference)

Baron-Cohen, S, & Wheelwright, S, Skinner, R, Martin, J, & Clubley, E, (2001) The Autism-Spectrum Quotient: Evidence from Asperger Syndrome/high-functioning autism, males and females, scientists, and mathematicians. Journal of Autism and Developmental Disorders, 31, 5-17. (reference)

Baron-Cohen, S. (2003)  The systemizing quotient: an investigation of adults with Asperger syndrome or high-functioning autism, and normal sex differences;Philosophical Transactions: Biological Sciences, The Royal Society, 2003, 358, 361-374
(reference)

Brain-imaging methods - comparison

For my talk about EEG in cognitive tasks in Prague I've done a little comparison of different methods used for imaging brain functions - EEG, fMRI, PET, SPECT and NIRS. And here it is:

here are some useful links concerning about these methods:
presentation about PET and SPECT:
http://www.slideshare.net/thecausewayretreat/pet-and-spect-scanning-functional-brain-imaging-1585258
NIRS advantages over EEG and fMRI:
http://www.alivelearn.net/?p=827
EEG vs.fMRI, PET
http://www.biomedresearches.com/root/pages/researches/epilepsy/eeg_fmri_and_pet.html
and of course wikipedia can help a lot also:-)
wiki-EEG

Genetic algorithms for unsupervised clustering

This post is in Czech, but pseudocodes and References can be used by anybody (but remember to cite me:-)).