Skip to main content

Don't lie to my eyes (I.)

“Why do almost all people tell the truth in ordinary everyday life? —Certainly not because a god has forbidden them to lie. The reason is, firstly because it is easier; for lying demands invention, dissimulation and a good memory.”

– Friedrich Nietzsche, Human, All Too Human, II.54, 1878/1996

I have started this blog as my log to my master thesis. I was aiming to do some work on artificial intelligence. As it worked out, I will be working on method which should detect if people are lying when filling out online questionnaires.

But I'm still going to use this blog. The reason is that this topic is closely related to evolution and even to artificial intelligence.

The topic is still close to the idea of this blog. God-like properties, like knowing what you think, can be obtain via science and technology.

If you want to tell if someone is lying, you have to look at his physiological responses. These physiological responses have evolved over millennia and are often really hard or impossible to control by our conscious mind.

Today I am going to write about eyes. More precisely about pupil of the eye. Because your eyes can tell me if you are lying.

When you want to use pupil diameter as indicator if people are lying, you are basically trying to measure their cognitive load and emotional response.

There is still no complex theory of how our mind work, so there is lot of guess work and space for error, but if you are careful and know what you are looking for, you can get right now up to 80 percent accuracy in telling if people are lying.

Cognitive load


There are three hypothesis when it comes to cognitive load and lying. First assumes, that lying is cognitive less demanding process and so the responses to questions will be quicker and physiological measurements more subtle.

Second hypothesis assumes exact opposite. According to it lying is cognitively more demanding than telling the truth and therefore you can detect stronger physiological responses and the answers to questions will take more time.

Third hypothesis assumes, that it depends on the context. If the questions are about your personality and you want to look socially desirable, you will respond quick and will simply semantically evaluate answers and choose the most appealing.

However if you are asked different questions or you are ask the same questions in different conditions, it will be more cognitively demanding than telling the truth.

Based on the literature I have read, I will go with the third option.

Pupil dilation and what can screw your measurement

Pupil dilation is change in pupil diameter. Dilation occurs around 2-7 seconds after emotional stimuli is presented and is faster for stronger stimuli. If you want to use it in your study, you have to take into account several factors.

First you have to eliminate light disturbance. If you cannot prevent light change by controlling the environment, you can use data filters to separate the data. The pupil response to light is either rapid constriction or slow dilation, while cognitive processing triggers small but rapid increases in pupil size.

However that is not enough. Pupil dilation can be triggered by visual stimuli and even noises and that can disturb your measurement. So you have to ensure that your subjects are separated as much as possible from other stimuli than the task you have given them.

Pupil dilation can also be triggered by cognitive load, stress or even temperature. When you are using your short term memory, pupil dilate. It is dilated during the whole process of solving math problems or other cognitively demanding tasks and dilation stops when the problem is solved.

Even sound can trigger pupil dilation. Larger pupil dilation is shown when you listen to affect sounds compared to neutral sounds. The same can be told about visual stimuli. The more emotional the stimuli is, the more your pupil dilates.

Your pupil also dilates if you are waiting for an answer to even trivia question, it is enough that you are interested in the answer.

It does not matter if the emotion is positive or negative, response of the pupil is very similar.

Your pupil dilates when you are in pain, and it dilates more if you are in more pain and it also dilates if you are aroused.

Pupil dilation and deception


First study about effect of pupil dilation on deception detection comes from 1943 [2]. Since than, technology for pupil measurement has improved rapidly, our knowledge how to use it not so much.

Studies shown that pupil dilates when you are telling lies, even if you are sending deceptive messages. And the more deceptive you are trying to be, the more your pupil dilates.

Most studies shown that lying is cognitively more demanding than telling the truth. Some studies even shown, that if you tell the people that you can detect if they are lying, you are more likely to observe the signals that can tell you if they are lying.

Other however shown that lying is less cognitively demanding. Therefore I go with the third hypothesis of cognitive load.

Conclusion


Pupil dilation can be good indicator for cognitive load or emotional triggers, but on its own cannot provide all necessary information.

It is triggered by too much stimuli and therefore you have to create your experiment very carefully and eliminate all possible external stimuli outside of your task.

Also you shuld use other meassurement like tracking the gaze of the eyes or galvanic skin response. About that in future posts.

References


[1] Beatty, J. (1982). Phasic not tonic pupillary responses vary with auditory vigilance performance. Psychophysiology, 19(2), 167–172. doi:10.1037/0033-2909.91.2.276

[2] Berrien, F. K. & Huntington, G. H. (1943). An exploratory study of pupillary responses during deception. Journal of Experimental Psychology, 32(5), 443-449.

[3] Bradley, M. T., & Janisse, M. P. (1981). Accuracy demonstrations, threat, and the detection of deception: cardiovascular, electrodermal, and pupillary measures. Psychophysiology, 18(1), 307–315. doi:10.1111/j.1469-8986.1981.tb03040.x

[4] Einhäuser, W., Koch, C., & Carter, O. L. (2010). Pupil dilation betrays the timing of decisions. Frontiers in Human Neuroscience, 4(February), 18. doi:10.3389/fnhum.2010.00018

[5] Krafčíková, M. (2014). Úmyselné skresľkovanie odpovedí pri osobnostných dotaznákoch - možnosti využitia sledovania očí. Univerzita Komenského v Bratislava.

[6] Lubow, R. E., & Fein, O. (1996). Pupillary size in response to a visual guilty knowledge test: New technique for the detection of deception. Journal of Experimental Psychology: Applied, 2(2), 164–177. doi:10.1037/1076-898X.2.2.164

[7] Palinko, O., Kun, A. L., Shyrokov, A., & Heeman, P. (2010). Estimating cognitive load using remote eye tracking in a driving simulator. Proceedings of the 2010 Symposium on Eye-Tracking Research & Applications - ETRA ’10, 141. doi:10.1145/1743666.1743701

[8] Van Hooft, E. a. J., & Born, M. P. (2012). Intentional response distortion on personality tests: Using eye-tracking to understand response processes when faking. Journal of Applied Psychology, 97(2), 301–316. doi:10.1037/a0025711

[9] Wang, J. T., Spezio, M., & Camerer, C. F. (2010). Pinocchio ’ s Pupil : Using Eyetracking and Pupil Dilation To Understand Truth-telling and Deception in Games. The American Economic Review, 3, 984–1007. doi:10.1257/aer.100.3.984

[10] Webb, A. K., Honts, C. R., Kircher, J. C., Bernhardt, P., & Cook, A. E. (2009). Effectiveness of pupil diameter in a probable-lie comparison question test for deception. Legal and Criminological Psychology, 14, 279–292. doi:10.1348/135532508X398602

Comments

Popular posts from this blog

ProLinks #65 - North Korea, Cryptocurrencies, Propaganda and more

Tech The Incredible Rise of North Korea’s Hacking Army He was right. As the newspapers soon reported, more than sixteen million dollars was withdrawn from roughly seventeen hundred 7-Eleven A.T.M.s across Japan that morning, using data stolen from South Africa’s Standard Bank. The newspapers surmised that 7-Elevens had been targeted because they were the only convenience stores in Japan whose cash terminals all accepted foreign cards. Soon after the raids, the withdrawal limit for many A.T.M.s in the country was reduced to fifty thousand yen Why Cryptocurrency Is A Giant Fraud ❧ Current Affairs Schweikert is partly right: “selling it as a revolution” is a hugely important part of why cryptocurrency is succeeding. But as is generally the case when someone is trying to sell you something, the whole thing should seem extremely fishy. In fact, much of the cryptocurrency pitch is worse than fishy. It’s downright fraudulent, promising people benefits that they will not get and trying

ProLinks Biometrics #49 - How biometrics is making spying hard

In this edition the highlight for me is an article from Yahoo news about the trouble spy agencies are in because of biometrics and surveillance (I love irony). Other than that, you can read about reducing friction or using biometrics to track police (again, I love irony). Enjoy! Biometrics How biometrics has changed spying Biometrics at borders control, using it to issue documents or checking at hotels is making work of spies using fake identities hard to impossible, depending on a state. For example, Singapore will alert security forces if somebody is taking too long to check into a hotel . Read the linked article to find out much more. Source: privateinternetaccess.com Reducing friction Nowadays is all about the user experience and friction or the lack of it. User do not like to make unnecessary actions to accomplish something . Reducing friction is mostly great, but there are also downsides, as overusing social networks. Making sure that policemen are working Pol

ProLinks #11

First ProLinks edition in 2018 brings a lot of links for IT professionals including solid Ruby criticism. Also interesting links about society, science and more inside. IT Managing Engineers with Ron Lichty The Problem Solver - Good developers are good problem solvers. They turn each task into a series of problems they have to solve. Energy Efficiency: A New Concern for Application Software Developers - The prevalence and ubiquity of mobile computing platforms, such as smartphones, tablets, smart watches, and smart glasses, have changed the way people use and interact with software. Clever ideas that failed -  The cleverness of an idea is proportionate to its odds of failure. SSH Security and You - /bin/false is *not* security - I thought to myself, "Fine, no shell for me. I wonder if port forwarding works?" The 100x Engineer - If we want to be 100x engineers — engineers who have 100x the impact of ye’ old 1x engineer—how do we accomplish tha

Are there types of programmers?

As a response to my previous post about why there is so many programming languages I got very interesting answer about types of programmers. Than I have read linked article about Mort, Elvis, Einstein, and You  and subsequently post The Two Types of Programmers  which lead me to The Fourteen Types of Programmers .  As you have probably realized, there are many different opinions on this topic. So what is the reality? Let me add to the pile of opinions. It always comes down to this - How do we set the criteria on which we want to categorize. Based on these criteria we can form clusters. These clusters of programmers are than our categories. You could probably do this with clustering algorithm if you can form reasonable dataset. So basically the question how many types of programmers are there  cannot be answered without specifying your criteria. And from this misunderstanding of how the question works comes discussions about how many categories there is. There

ProLinks #62 - AI, Statistics, Tarkovsky and more

Tech Are Deep Neural Networks Dramatically Overfitted? The fundamental idea in MDL is to view learning as data compression. By compressing the data, we need to discover regularity or patterns in the data with the high potentiality to generalize to unseen samples. Information bottleneck theory believes that a deep neural network is trained first to represent the data by minimizing the generalization error and then learn to compress this representation by trimming noise. The Therapy-App Fantasy “It would clearly be naïve for psychotherapists to turn a blind eye to science, or to be ‘against’ scientific methodology,” he wrote. “But the attempt to present psychotherapy as a hard science is merely an attempt to make it a convincing competitor in the marketplace. It is a sign, in other words, of a misguided wish to make psychotherapy both respectable and servile to the very consumerism it is supposed to help people deal with.” (Psychotherapy, he points out, emerges historically just as “t