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Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33111154) Attached to: Reading Terrorists' Minds About Imminent Attack
I mean sure there are other ways of doing things. But what if they are wearing a mask. Or what if they were wearing gloves/the dye pack in the bills didn't go off. Or what if they have been gone for a while. Here is another example: what if there is an unsolved crime without up-front forensic data and you find someone who may help you guide your investigation. You ask them questions and slowly start to build a set of information that guides your re-opened investigation. You then use the newly gathered forensic data and the methodology of acquiring that information to build a case. Like I have said this whole time, this is just another tool for law enforcement to use - I am not advocating getting rid of other technologies. It is just a very useful way of getting concealed information out of people. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33110930) Attached to: Reading Terrorists' Minds About Imminent Attack
Let me give you a few examples: 1) There was a very interesting article recently that talked about the potential usefulness of this technology with, for instance, bank robberies. Let's say you are robbing a bank. Right as you are leaving the bank, a very incredibly loud noise is played over the intercom to prime your attention and a very specific, individual pattern is flashed from a central light all over the room. Later, when the police have a suspect, the test him on different patterns. If he has an incredibly high response to the pattern, you know that he was there when it was robbed (especially if you rule out everyone who is in the bank who WASN'T robbing it). 2) Let's say you have caught someone through other intelligence that you know was a terrorist but you are uncertain as to specifics of the act. However, you have certain guesses. You can display these guesses to the terrorist, and a particularly strong response indicates information-of-interest. 3) Someone claims amnesia falsely (this actually happens more than you would think). You present them with information that they should know but claim they don't. If they recognize it - they are not telling the truth. If they are actually amnesic and their hippocampus is damaged and did not encode the memory, they will not respond to a piece of information. There are a lot of potential uses. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33110770) Attached to: Reading Terrorists' Minds About Imminent Attack
It matters what you are talking about. We usually have 2 groups of people we test a "simple guilty group" and a "countermeasure group." The simple guilty group is tested without knowing what we are doing. While the "countermeasure" group is taught active ways to counter the test. We get 95%-100% accuracy on simple guilty subjects and about 83%-94% accuracy with countermeasure subjects. As always, news articles don't really do an adequate job of describing the research. --Alex Soko

Comment: Re:EPIC FAIL (Score 1) 206

by alexsoko (#33110708) Attached to: Reading Terrorists' Minds About Imminent Attack
Sure, certain individual trials are false positive trials. However, there are literally hundreds of trials conducted for each piece of information that we want to test. Also, just like any test that "assesses" something, be it HIV or Guilty Knowledge, there is a level of specificty (Type 1 error or alpha-error). Depending on where you set that cutoff, you either do or do not get false positives. The goal is to set that bar high enough that you don't generate false positives while also catching everyone above the cutoff. We would rather, in this case have FALSE NEGATIVES than false positives, and so that's where we set the bar. Additionally, we employ a statistical analysis called bootstrapping. In this, not only do we average the hundreds of trials for each piece of knowledge. But we draw, at random with replacement from the pool of available data, ~60 trials x100 rounds of bootstrapping. Only if >90 out of 100 rounds of bootstrapping come out significantly higher do we call it guilty knowledge. This statistical analysis serves to normalize even abnormal distributions (if you don't believe me read about drawing randomly from skewed pools). Not getting false positives is all about how you analyze your data. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33110586) Attached to: Reading Terrorists' Minds About Imminent Attack
Again, P300 doesn't assess "guilt" per-se. It assesses recognition. For example, if you see your birthday on the screen, or the name of the city you grew up in, you generate a P300 because it is important information to you. If you are a serial killer who killed everyone with a shotgun, or tied all of your victims up with rope, whether or not you 'feel guilty,' your brain will still recognize the salience of the item presented (even if you respond 'no' to recognizing that item). In that way, your brain is essentially giving you away. It has nothing to do with guilt or innocence and everything to do with identifying information that someone may be concealing. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33102212) Attached to: Reading Terrorists' Minds About Imminent Attack
Let me clarify. Let's say you are a terrorist and you know that a certain type of chemical weapon will be used in an attack. When you are presented with that weapon, your brain generates a p300 recognition response. In that case, we know that is a good direction to proceed/investigate etc (especially if there is other intelligence information that indicated that type of weapon is a plausible threat). Afterwards a detective may ask you if/why THAT weapon was particularly salient to you. This isn't a conspiracy this is part of the investigative process just like anything else. We are not saying you are 'guilty' in the standard sense. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 0, Redundant) 206

by alexsoko (#33102100) Attached to: Reading Terrorists' Minds About Imminent Attack
We are not accusing them of a crime, necessarily. We are looking for guilty knowledge. Like I said, P300 deception detection is looking for guilty knowledge. If we could, for example, narrow down a list of potential targets for a terrorist attack, or figure out what kind of weapon will be used, or figure out, in a forensic scenario, if someone recognizes pieces of information that weren't released to anyone - it could help drive an investigation. Like I said before, this is just one of an array of tools that can be used by law enforcement to help make their case or help drive an investigation in a certain direction. Calling someone 'guilty' is just the terminology of the field when someone is caught lying - but I'll play semantics if you want. --Alex Soko

Comment: Re:From Someone Who Works In This Lab (Score 1) 206

by alexsoko (#33102018) Attached to: Reading Terrorists' Minds About Imminent Attack
Hi FL, 1. The research is funded, in part, by the DOJ. However, this is only certain projects. At any point there can be up to 10 different experiments going on, many of them unfunded or done through volunteered time and effort. 2. Unfortunately, as with most university-based psychology studies, we are limited to the population of the University or the people that can be recruited around town (in this case Evanston, IL). Where P300 differs from most deception-detection methods is that it doesn't necessarily test guilt, but rather tests recognition. The same test could be used to identify, for instance, someone's birthday, Sister's name, or a variety of other information that the person could recognize. Other researchers are working on alternative methods that more directly test DECEPTION. That is to say, while we test whether or not someone RECOGNIZES something, they want to test the neural correlates of deception or whether or not we can use EEG to figure out whether or not someone is about to make a deceptive response. A lot of this research relies on parts of the CNV component (which precedes a behavioral response like 'yes or no' or 'true or false'). While this is a good approach, it has a lower detection rate and a higher false positive rate. I agree with that it would be very interesting to conduct a study based on this on a population with psychopathy, but that has not been conducted by us (yet). Also, who knows, maybe some US agency has already used this in the field. Can we ever really be sure? --Alex Soko

Comment: From Someone Who Works In This Lab (Score 5, Informative) 206

by alexsoko (#33101060) Attached to: Reading Terrorists' Minds About Imminent Attack
Hello, As both a) someone who works in this lab and b) someone who reads this site pretty religiously, I think I can address some of your guys concerns. 1) Specificity of questions - unlike a standard polygraph test, in a P300 CIT (concealed information test) subjects aren't asked questions as muscle movements or auditory stimuli may disrupt the electrodes ability to record P300. Instead, stimuli are presented silently on the screen and thus, if the subject 'recognizes' the stimulus he will generate a P300 whenever that stimulus is presented. However, in doing so, the list must initially be vetted with the subject who says if any of the items have specific relevance to him. (This would be like in an investigation if a police detective showed someone a list of people and asked if a POI knew any of them). 2. This isn't a 1 recognition stimulus identifies everything sort of thing. The same stimuli are shown to people literally hundreds of times and it takes a pattern of recognition to correctly identify someone as guilty. Also, there are levels of recognition. All of the responses are compared to one another to get a standard base, per each participant, of brain activity. Then each recognition pattern is compared to the pattern as a whole to determine guilty knowledge. 3. For critical information a more strict test can be performed which compares the strongest P300 to the second strongest P300. If that patters is statistically bigger then you can be certain that they have guilty knowledge of that item. 4. Several of the studies we have conducted have actually incentivized (given money) to people for trying any strategy possible to BEAT the test. 5. There ARE countermeasures for this test that you can do to try to hide your P300 responses - however this specific protocol is a COUNTERMEASURE RESISTANT TEST. Believe me, if you've thought of it - we've thought of it. 6. Yes, when using just a pure P300 analysis we don't get people with 100% accuracy. But after we adjust for countermeasure use, and analyze other behavioral and EEG data that is collected concurrently with the P300 we can get 100% accurate identification. 7. We do so without getting false positives. Like any tool in law enforcement (the polygraph, fingerprinting, etc...) it's not necessarily as important that any individual thing works as it is that of the array of tools used ONE of them catches the person. And you don't want to wrongly accuse anyone. Why our P300 research is special is because we get an extremely high detection rate with no false positives. 8. If you have more questions please respond to this comment and I will try to respond. --Alex Soko

A method of solution is perfect if we can forsee from the start, and even prove, that following that method we shall attain our aim. -- Leibnitz

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