Investigative Techniques: Federal Agency Views on the Potential
Application of "Brain Fingerprinting" (31-OCT-01, GAO-02-22).
Federal law enforcement and intelligence agencies are seeking to
add new techniques to their arsenal of investigative tools.
"Brain fingerprinting" measures brain wave responses to determine
whether an individual recognizes certain details of an event or
activity. Because the technique requires specific information
about the event that would be known only to the perpetrator and
the investigator, Brain Fingerprinting is not designed as a
screening tool--a function that involves questioning a subject
about events unknown to the investigator. Instead, an
investigator would be able to use certain information as evidence
for or against a subject. For example, the technique could be
used to determine whether a subject has knowledge of details
about a crime. Officials representing the Central Intelligence
Agency, the Department of Defense, the Secret Service, and the
Federal Bureau of Investigation do not forsee using the brain
fingerprinting technique because of its limited use. Furthermore,
given the technique's limitations, the research expenses,
equipment, and training costs are perceived to exceed benefits.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-02-22
ACCNO: A02412
TITLE: Investigative Techniques: Federal Agency Views on the
Potential Application of "Brain Fingerprinting"
DATE: 10/31/2001
SUBJECT: Law enforcement
Law enforcement information systems
Research and development
Interagency relations
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GAO-02-22
Report to the Honorable Charles E. Grassley, U. S. Senate
United States General Accounting Office
GAO
October 2001 INVESTIGATIVE TECHNIQUES
Federal Agency Views on the Potential Application of "Brain Fingerprinting"
GAO- 02- 22
Page i GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting" Letter 1
Results in Brief 1 Scope and Methodology 3 Background 4 How Brain
Fingerprinting Is Intended to Work 6 Federal Agency Views on Brain
Fingerprinting?s Potential
Application 8 Agency Comments and Our Evaluation 12
Appendix I Scientists? Views on the Brain Fingerprinting Technique 14
Appendix II Comments From the U. S. Secret Service 20
Appendix III Comments From the Federal Bureau of Investigation 22
Abbreviations
CIA Central Intelligence Agency DOD Department of Defense EEG
Electroencephalograph FBI Federal Bureau of Investigation MERMER Memory and
Encoding Related Multifaceted
Electroencephalographic Response NIH National Institutes of Health Contents
Page 1 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
October 31, 2001 The Honorable Charles E. Grassley United States Senate
Dear Senator Grassley: Federal law enforcement and intelligence agencies use
various techniques to assist them in criminal investigations and
intelligence efforts and seek to identify new techniques to enhance their
arsenal of investigative tools. You requested that we review a technique
that has been proposed for use in the federal law enforcement and
intelligence arenas, referred to as
?Brain Fingerprinting.? Its developer, Lawrence A. Farwell, Ph. D., has
indicated that Brain Fingerprinting can be used as an investigative tool,
with applications for law enforcement functions and intelligence operations.
Specifically, the technique is designed to determine whether an individual
recognizes certain details of an event or activity by measuring the
individual?s brain wave responses. In the past few years, several federal
agencies- including the Central Intelligence Agency (CIA), Department of
Defense (DOD), Federal Bureau of Investigation (FBI), and the Secret
Service- have interacted, to varying degrees, with the developer to fund
research or explore the technique for possible use in law enforcement or
intelligence operations.
This report provides information on how Brain Fingerprinting is intended to
work and federal agency views on its potential application. To obtain
information on Brain Fingerprinting, we interviewed the developer, selected
federal agency officials and three scientists in the field of
psychophysiology, 1 who were familiar with the technique. Although our
review did not constitute a technical analysis of Brain Fingerprinting, we
provide the views of those three scientists in appendix I.
Brain Fingerprinting is a proposed investigative technique that incorporates
the use of a test administered to a subject that consists of specific
information related to a particular event or activity. According to its
developer, the technique requires a sufficient amount of specific
1 Refers to a branch of psychology that studies the interactions between
physical or chemical processes in the body and mental states or behavior.
United States General Accounting Office Washington, DC 20548
Results in Brief
Page 2 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
information about the event or activity that would be known only to the
perpetrator and the investigator. The developer has indicated, therefore,
that Brain Fingerprinting is not designed as a screening tool- a function
that involves questioning a subject about events unknown to the
investigator. In administering the Brain Fingerprinting test, a subject is
shown a sequence of various stimuli on a computer screen in the form of
words, phrases, or pictures- some that are related to the event or activity
and others that are irrelevant. An electroencephalograph (EEG) 2 records the
subject?s electrical brain activity, which appears as a waveform. The
technique employs a statistical method to analyze the components of the
waveform to determine whether or not the subject recognizes the information.
According to the developer, an investigator would be able to use this
information as evidence for or against a suspect. For example, the developer
has indicated that the technique could be used to determine whether a
suspect has knowledge of details about a crime.
Officials representing CIA, DOD, Secret Service, and FBI do not foresee
using the Brain Fingerprinting technique for their operations because of its
limited application. For example, CIA and DOD officials indicated that their
counterintelligence operations and criminal investigations do not usually
lend themselves to a technique such as Brain Fingerprinting because use of
the technique requires a unique level of detail and information that would
be known only to the perpetrator and the investigators. These officials
indicated that they need a tool to screen current and prospective employees,
which as indicated above, involves questioning a subject about events
unknown to the investigator. Further, a Secret Service official indicated
that the agency has had a high success rate with the polygraph as an
interrogative and screening tool and therefore saw limited use for Brain
Fingerprinting. FBI Laboratory Division officials evaluated the technique in
1993 and 1999 and concluded that Brain Fingerprinting had limited
applicability and usefulness in FBI investigations and personnel security
and screening matters. In addition, the division concluded, among other
things, that, given the technique?s limitations, the research expenses,
equipment, and training costs were perceived to exceed benefits. However,
two FBI agents who collaborated
2 An EEG records electrical activity of the brain from electrodes placed on
the surface of the scalp.
Page 3 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
with the developer on related research 3 believe that Brain Fingerprinting
has potential as an investigative tool. One of these agents stated that use
of the technique would require a shift in FBI?s investigative and training
methods- a policy issue that would have to be addressed by FBI management.
Furthermore, the three scientists we interviewed expressed a need for more
research to demonstrate Brain Fingerprinting?s application as an
investigative tool.
In providing comments on a draft of this report, CIA, DOD, Secret Service,
and FBI generally agreed with the report and our presentation of their
views. (Written comments from the Secret Service and FBI are reprinted in
appendixes II and III). In addition, the developer of the technique, Dr.
Farwell, indicated that he had no comments or technical corrections on the
report.
As part of our data gathering efforts, we identified knowledgeable officials
from selected federal intelligence and law enforcement agencies that had
provided research funding for the Brain Fingerprinting technique, had
explored use of the technique, or had engaged in related or direct research.
Specifically, we spoke with officials at CIA; components of DOD, which
included the DOD Polygraph Institute, National Security Agency, Defense
Security Service, Army Criminal Investigation Command, Air Force Surgeon
General?s Office, and the Office of the Assistant Secretary of Defense for
Command, Control, Communications, and Intelligence; FBI; and Secret Service.
At DOD, our substantive contact focused on officials from the DOD Polygraph
Institute and Defense Security Service. For their collective views, we refer
to these components as ?DOD.? Otherwise, we refer to them by their
individual name. At FBI, we spoke with officials who had been involved in an
evaluation of the Brain Fingerprinting technique. We also spoke with two FBI
agents who had collaborated with the developer on related research. We
interviewed these individuals because they had first- hand knowledge of the
Brain Fingerprinting technique and experience with FBI investigative
procedures. In addition, we reviewed and analyzed documents provided by
those agencies that relate to Brain Fingerprinting and various forensic
applications.
3 Specifically, one of these agents conducted a graduate school research
project with the assistance of the developer. This agent indicated that her
views regarding the technique should therefore not be considered an
endorsement by the FBI. The second agent indicated that the research that he
conducted with the developer had been requested and approved by the FBI in
1992. Scope and
Methodology
Page 4 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
To gain an understanding of the science underlying Brain Fingerprinting, we
interviewed researchers at the National Institutes of Health (NIH), three
scientists in the field of psychophysiology, and the developer of the
technique. We selected these scientists on the basis of recommendations made
by the agency officials we interviewed, researchers we spoke with at NIH,
and the developer. In addition, two of the scientists we spoke with had
testified in Harrington v. Iowa, the one court case we have identified that
has addressed Brain Fingerprinting evidence. 4 In providing their views,
these scientists helped us understand the underlying methods of Brain
Fingerprinting and its potential application as an investigative tool. We
have included a summary of their views in appendix I of this report. Their
views are not meant in any way to represent the views of the scientific
community as a whole.
Furthermore, as part of our research efforts, we identified and reviewed
available documentation, including articles, studies, reports, and other
relevant materials in the related fields of psychophysiology, neuroscience,
and forensics. Our search for information related to Brain Fingerprinting
revealed that only a limited amount of independent documentation exists
about the technique and its uses for law enforcement and intelligence. We
also reviewed court documents in Harrington v. Iowa and interviewed the
prosecuting attorney in the case.
We did not perform a technical analysis of Brain Fingerprinting. That is, we
did not independently assess the hardware, software, or other components of
the technology nor did we attempt to determine independently whether Brain
Fingerprinting is a valid technique.
We performed our work from January 2001 to August 2001 in accordance with
generally accepted government auditing standards.
Several federal agencies are involved in researching, developing, or using
techniques to detect deception and have interacted, to varying degrees, with
the developer since the early 1990s. CIA?s Directorate of Science and
Technology researches, develops, and applies enabling technologies in
support of the agency?s mission to collect, process, and analyze foreign
intelligence and counterintelligence information. From 1991 to 1993, the
Directorate?s forerunner, the Office of Research and Development, funded the
developer about $1 million for research involving experimental studies
4 Harrington v. Iowa, No. PCCV 073247 (Dist. Ct. Iowa, Mar. 5, 2001).
Background
Page 5 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
designed to evaluate and improve techniques for detecting concealed
information using electrical brain wave measurements. 5
Components within DOD, including the DOD Polygraph Institute and Defense
Security Service, 6 are involved with detection of deception research, such
as brain wave research, and are knowledgeable about Brain Fingerprinting.
The Polygraph Institute?s research mission is to evaluate the validity of
psychophysiological detection of deception techniques used by DOD and other
agencies, investigate countermeasures (i. e., deliberate techniques used by
deceptive subjects to avoid detection during a polygraph examination) and
anticountermeasures, and conduct developmental research on
psychophysiological detection of deception techniques, instrumentation and
analytic methods. According to the Polygraph Institute, the agency?s most
recent contact with the developer occurred in 1999, when he met with the
Chief of Research to discuss the Polygraph Institute?s grants program.
Within FBI, the Laboratory Division researches, develops, and deploys new
forensic techniques and technologies. The Division evaluated the Brain
Fingerprinting technique in 1993 and 1999. In addition, two agents within
FBI?s Behavioral Science Unit 7 and the Laboratory Division had collaborated
with the developer on related research in 1992 and 1993.
The Secret Service?s Forensic Services Division, which manages its polygraph
programs nationwide, conducts examinations involving criminal, national
security, and employee screening matters. In 1998, a representative of the
developer had contacted the division in an effort to provide the agency with
information on the technique. The division
5 In the mid- to late 1980s, CIA also contributed funding to a collaborative
effort on brain wave detection of deception research conducted by the
developer and another scientist. 6 As a federally funded agency, the
Polygraph Institute?s purpose is to qualify DOD and nonDOD federal personnel
for careers as forensic psychophysiologists; provide continuous research in
forensic psychophysiology and credibility assessment methods; manage the
continuing education certification program for all federal agencies; and
manage the Quality Assurance Program that maintains quality standards and
provides technical assistance to the federal polygraph programs. In 1997,
operational responsibilities for the Polygraph Institute were placed within
the Defense Security Service.
7 Located in FBI?s Training Division, the Behavioral Science Unit conducts
forensic research with a focus on new and innovative investigative
approaches related to offender psychology and behavior.
Page 6 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
subsequently reviewed the information and consulted with a CIA official
because of the official?s knowledge of and experience with the technique.
According to its developer, Brain Fingerprinting is designed to determine
whether an individual recognizes specific information related to an event or
activity by measuring electrical brain wave responses to words, phrases, or
pictures presented on a computer screen. The technique can be applied only
in situations when investigators have a sufficient amount of specific
information about an event or activity that would be known only to the
perpetrator and investigator. In this regard, Brain Fingerprinting is
considered a type of Guilty Knowledge Test. 8 Only the guilty party is
expected to react strongly to the relevant details of the event or activity.
Its developer has indicated that Brain Fingerprinting, therefore, is not
designed for screening functions, which involves questioning individuals
about events unknown to the investigator. Rather, the developer has
indicated that an investigator would be able to use this information as
evidence for or against a suspect. For example, he has indicated that the
technique could be used to determine whether a suspect has knowledge of
details connecting him or her to a crime.
Brain Fingerprinting uses an EEG to record distinct patterns of brain
activity. These patterns, called event- related potentials, are measures of
the brain?s electrical activity or ?potentials? as they correspond to
stimuli or ?events? in the environment. By averaging the distinct patterns
of electrical activity, a singular waveform is created that is generally
dissected into various components associated with cognitive functions. The
event- related potential components relevant to Brain Fingerprinting are the
P300 and the Memory and Encoding Related Multifaceted
8 There are two behavioral paradigms that have been used in detecting
deception: the Guilty Knowledge Test and Control Question Test. Generally, a
Guilty Knowledge Test involves presenting a subject with a series of
questions, some of which are relevant to the crime in question and some of
which are irrelevant to the crime. It is expected that a subject who
possesses ?guilty knowledge? will respond differently to the crime- relevant
questions than to the irrelevant questions, while an innocent individual
will respond no differently to the crime- relevant than to the irrelevant
questions. A Control Question Test, in contrast, involves relevant questions
directly related to the crime, irrelevant questions unrelated to the crime,
and control questions. The control question is designed to inquire about
general criminal behavior that a large portion of the population may have
done and that has nothing to do with the crime under investigation, such as
?When you were a teenager, did you ever steal anything?? It is expected that
the control question will elicit an emotional response in the innocent
subject that exceeds the response to the relevant question, while the
relevant question will elicit the larger emotional response in the guilty
subject. How Brain
Fingerprinting Is Intended to Work
Page 7 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
Electroencephalographic Response (MERMER). The P300 component has been
recognized by the scientific community as an electrically positive charge
that peaks between about 300 and 500 milliseconds in response to rare,
meaningful, or noteworthy stimuli. The MERMER, patented by the developer,
includes the P300 and subsequent electrical changes occurring at about 800
to 1200 milliseconds after a stimulus has been presented to a subject.
According to the developer, MERMER has not undergone independent peer review
testing and is not well accepted in the scientific community.
The developer has indicated that use of the Brain Fingerprinting technique
should involve the following procedure. An examiner or investigator with
expertise in the Brain Fingerprinting technique reviews and identifies
evidence related to an event or activity through various means, such as
personal interviews, police records, court testimony, crime scene photos or
a crime scene. From this information, the examiner or investigator chooses
the stimuli to present to the subject in the form of words, phrases, or
pictures, which are flashed on a video monitor under computer control. The
three types of stimuli are categorized as ?targets,? ?irrelevants,? and
?probes.? Targets are made relevant and noteworthy to the subject by giving
him or her a list of the targets before the test is administered. Since they
are noteworthy, they should elicit a P300 response. A second set of stimuli
are irrelevant to the event or activity, although they could be plausible
substitutes for actual details of the event or activity. These stimuli
should not elicit a P300 response. Interspersed with the irrelevant stimuli
are less frequent stimuli called probes. Probes are unique details of the
event or activity that are supposed to be known only to the examiner or
investigator and the subject. For a subject with knowledge of the event or
activity, probes should elicit a P300. For a subject lacking that knowledge,
probes should be indistinguishable from the irrelevants and should not
elicit a P300.
The responses to the three types of stimuli are compared using a statistical
method, 9 which according to the developer, can yield an ?information
9 This refers to bootstrapping, which is a nonparametric statistical
technique for inferring the distribution of a statistic from a sample and
for determining how reliable that statistic is as a measure for the
population. As a type of resampling, bootstrapping randomly generates an
entire distribution of values using data from just one sample and allows one
to make inferences with an associated degree of confidence about a
population parameter, such as a mean, median, or total. Bootstrapping
provides a means to estimate standard errors of sample statistics without
requiring assumptions about the distribution of the underlying population.
Page 8 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
present? (i. e., the subject recognized the information) or ?information
absent? (i. e., the subject did not recognize the information) result.
According to the developer, Brain Fingerprinting, using P300 analysis, can
yield results with a statistical confidence level in excess of 95 percent.
He has further stated that MERMER provides the same results as the P300, but
with a higher confidence level- 99 percent or more- because it records more
data points. In addition, he has stated that his research trials have
resulted in a 100 percent accuracy rate for determinations of information
present or information absent.
In April 2000, the developer administered the Brain Fingerprinting test to
an individual convicted of murder in Iowa in 1978. In November 2000, this
individual subsequently petitioned an Iowa district court for postconviction
relief, arguing, among other things, that the Brain Fingerprinting test
results demonstrated his innocence. The court addressed the Brain
Fingerprinting evidence in a written ruling dismissing the application for
postconviction relief. The court ruled that the Brain Fingerprinting
evidence was unlikely to have changed the result of the defendant?s trial.
In this regard, the court observed that, although the P300 effect was well
established, neither the MERMER nor the developer?s mathematical model was
well accepted in the scientific community or had been subject to independent
testing or peer review. The court also remarked that the selection of probe
stimuli was subjective and did not, in this case, meet the developer?s own
selection criteria because various stimuli were not sufficiently significant
or had been disclosed to the defendant at trial. 10
CIA, DOD, FBI, and Secret Service do not foresee using the Brain
Fingerprinting technique for their operations because of its limited
application. Both CIA and DOD officials, for example, expressed the need for
a tool for screening purposes, for which Brain Fingerprinting is not
designed. The Secret Service indicated that the agency has had a high
success rate with the polygraph as an interrogative and screening tool and
therefore saw limited use for the technique. Within FBI, the Laboratory
Division concluded that Brain Fingerprinting had limited applicability to
10 See Harrington v. Iowa, No. PCCV 073247 (Dist. Ct. Iowa, Mar. 5, 2001).
The Harrington court applied Iowa law to the facts of the case. We did not
identify any federal court opinion addressing P300 or MERMER technology.
Federal Agency Views
on Brain Fingerprinting?s Potential Application
Page 9 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
FBI?s investigative and screening functions and identified other research
and operational concerns that would preclude its usefulness.
From their experiences with the developer?s research between 1991 and 1993,
CIA officials concluded that Brain Fingerprinting had limited applicability
to CIA?s operations. Accordingly, CIA decided that it was not worth
investing more funds to continue the developer?s research. Specifically, CIA
officials told us that the technique had limited application to CIA
activities because it did not have a screening capability, which is of
primary interest to CIA. These officials explained that to administer Brain
Fingerprinting, an investigator must know enough details of a particular
event to test an individual for knowledge of that event. For example, these
officials said that using Brain Fingerprinting to determine an agent?s
involvement in espionage would be difficult because the investigator would
be hard- pressed to identify unique stimuli; in counterintelligence,
specific details are not always available because spying is not always known
to have taken place. Moreover, CIA officials indicated that a perceived
operational limitation of the technique was that it required a trained
scientist to administer the Brain Fingerprinting test.
In addition, CIA officials indicated that as an ordinary step in evaluating
advanced research and development work, the agency had assembled a panel of
independent researchers in 1993 to assess the analytic methods employed by
the developer to ensure that they were scientifically sound and defensible.
CIA officials stated that while the panel indicated that the technique
appeared interesting, it was not able to assess the validity of the work
because the developer would not provide the algorithmic information that was
critical to completing such an assessment. According to CIA officials, the
developer considered the information proprietary. Those officials indicated
that no additional research funding was provided following the panel
evaluation.
Overall, DOD officials indicated that Brain Fingerprinting has limited
applicability to DOD?s operations. According to these officials, DOD
priorities are for screening prospective and current employees. However, as
acknowledged by its developer, Brain Fingerprinting is not designed as a
screening tool. DOD?s Polygraph Institute indicated that, with a limited
budget of $400,000 a year, it focuses its resources on conducting research
related to employment screening techniques, which is a major area of
interest for DOD. The Polygraph Institute also indicated that it is
currently funding other brain wave detection of deception research, which
the agency believes may lead to applications that could meet DOD?s needs.
CIA Views
DOD Views
Page 10 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
Regarding Brain Fingerprinting?s applicability to criminal investigations,
DOD officials acknowledged that DOD conducts a limited number of specific
issue examinations where the technique could be applied. DOD officials
indicated that most DOD criminal investigations do not lend themselves to a
Guilty Knowledge Test- based technique, such as Brain Fingerprinting,
because these kinds of investigations typically lack the specific
information that is needed for administering such a test and because
knowledge of the discrete elements of an event or activity may not be
limited to only the investigator and the perpetrator.
According to FBI officials, in 1993, the Laboratory Division?s Polygraph
Unit and CIA collaborated in an effort to evaluate and validate the Brain
Fingerprinting test. At that time, the Polygraph Unit concluded the
following.
The developer had not presented sufficient information to demonstrate
validity or the underlying scientific basis of his assertions. For example,
the FBI asked the developer to provide details of all tests conducted,
particularly in a law enforcement setting, which would support validation.
FBI officials indicated that the developer maintained that his technique was
proprietary.
The technique had limited applicability and usefulness to FBI
investigative and personnel security matters.
The research expenses, equipment, and training costs exceeded any
perceived benefit.
According to the developer, only individuals with advanced academic
degrees- trained in psychophysiology or a related science- could be used to
operate the system. The Polygraph Unit indicated that this eliminated a
large segment of the FBI population as potential operators.
FBI officials indicated that, in 1999, the Laboratory Division assembled a
panel of reviewers and conducted another evaluation of the technique, based
on a demonstration provided by the developer. The panel concluded that since
substantially no additional research had been done since 1993, the
conclusions that had been reached at that time had not changed.
In addition, the panel raised concerns about the technique?s limited utility
for employment screening applications and security matters. Furthermore, the
panel indicated that the developer had not done research on the effects of
external variables on brain activity, such as drugs, alcohol, or
hallucinogenic drugs. FBI officials who participated in the panel explained
that Brain Fingerprinting relies on retained memory, which they do not FBI
Views
Page 11 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
believe is always a reliable record of events. Thus, they were concerned
about possible changes or deletions from memory. These officials further
explained that, as part of evaluating the validity of Brain Fingerprinting
as an investigative technique, they must understand the effects of alcohol
and other drug use on the brain in its processes for storing and retrieving
information.
Separately, two FBI agents who had conducted research with the developer
expressed a different view. These individuals, in the Behavioral Science
Unit and Laboratory Division, believe that Brain Fingerprinting has
potential for use in FBI criminal investigations. Both agents, however,
recognize that FBI?s current investigative techniques and practices do not
require documenting the type of incidental crime scene information that
could be used in constructing the probe stimuli. Specifically, they
indicated that FBI agents and investigators do not record this kind of
detailed information on the form that FBI uses to document crime scene
information during an investigation. One of these agents pointed out that
these investigators and agents would need to be trained in collecting
specific and detailed crime scene information- such as the color of a sofa-
that may not normally appear relevant at a crime scene or that had nothing
to do with the crime committed, but could prove important as a probe
stimulus. This agent also indicated that FBI would need to establish a means
for protecting the crime scene information from public disclosure so as not
to jeopardize the integrity of the test. The agent pointed out, however,
that FBI?s use of this technique would require a shift in FBI?s
investigative and training methods, which is essentially a policy issue that
would have to be addressed by FBI management.
One of these agents believes that while Brain Fingerprinting is ready for
forensic application, it could benefit from continued research and
development, such as refining the probe stimuli and determining whether
certain types of probes are more likely to be remembered than others. 11 In
addition, this agent indicated that because drugs and alcohol are frequently
used in committing crimes, research is needed to determine what effect they
may have on memory. The second agent believes that Brain Fingerprinting is
not ready for operational use and needs more research to be able to
establish its viability in criminal cases.
11 Toward the latter part of our review, this agent retired from the FBI and
is currently a business associate of the developer.
Page 12 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
An official representing the Forensic Services Division indicated that, in
1998, the Secret Service reviewed information provided by the developer and
consulted with a CIA official because of the official?s knowledge of and
experience with the Brain Fingerprinting technique. The Service subsequently
concluded that the technique had limited application to Secret Service
activities. The official further indicated that the agency has had a high
success rate with the polygraph as an interrogative and screening tool.
In letters dated October 5, 2001, we requested comments on a draft of this
report from CIA, DOD, Secret Service, FBI, and the developer of the Brain
Fingerprinting technique, Dr. Farwell. In addition, we requested that the
three scientists we interviewed- Drs. Donchin, Iacono, and Rosenfeld- review
our summaries of their views for technical accuracy and clarification.
Overall, CIA, DOD, Secret Service, and FBI agreed with the report and our
presentation of their views. On October 17, 2001, we met with Dr. Farwell to
discuss the draft report. At that time, he indicated that he had no comments
or technical corrections on the report. In addition, Drs. Donchin, Iacono,
and Rosenfeld separately provided technical comments and clarifications,
which we have included where appropriate.
CIA and DOD provided oral comments on a draft of this report. Specifically,
CIA?s Directorate of Science and Technology indicated agreement with the
contents of the report and had no other comments. DOD?s Office of the
Assistant Secretary of Defense for Command, Control, Communications and
Intelligence indicated DOD?s concurrence with the report and restated its
position that the Brain Fingerprinting technique had limited application to
DOD?s operations.
The Forensic Services Division of the Secret Service provided written
comments that essentially reiterated its position that Brain Fingerprinting
had limited applicability to the Secret Service. Those comments are included
in appendix II.
FBI?s Office of Public and Congressional Affairs provided the Bureau?s oral
comments, which we have incorporated in this report. The Office also
submitted the Bureau?s written comments, which we have included in appendix
III. Specifically, FBI indicated that the report fairly reflected the FBI?s
position that the technique has limited applicability and usefulness to FBI
investigative and personnel security matters. Further, FBI indicated that-
on the basis of its own research in forensic science and the scientific
Secret Service Views
Agency Comments and Our Evaluation
Page 13 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
views expressed in this report- it strongly disagreed with one of its
agents? assessments of the technique. As discussed earlier in the report,
this agent had indicated that while the technique could benefit from
continued research and development, it was nevertheless ready for forensic
application.
As arranged with your office, unless you publicly announce its contents
earlier, we plan no further distribution of this report until 30 days after
its date. At that time, we will send copies to appropriate congressional
committees; the Attorney General; Secretary of DOD; Directors of CIA, FBI,
Secret Service, and Office of Management and Budget; and other interested
parties. Copies of this report will also be available to others on request.
If you or your staff have any questions, please call Linda Watson or me at
(202) 512- 8777. Key contributors to this report were Christine Davis, Sam
Hinojosa, Brenda Rabinowitz, Keith Rhodes, and Anne Rhodes- Kline.
Sincerely yours, Paul L. Jones Director, Justice Issues
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 14 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
The purpose of this appendix is to provide additional information on the
Brain Fingerprinting technique. Specifically, we interviewed three
scientists who were familiar with the technique: Emanuel Donchin, Ph. D.;
William Iacono, Ph. D.; and J. Peter Rosenfeld, Ph. D. Each scientist shared
his view of the technique, raising questions and providing insights related
to some of the methods that underlie Brain Fingerprinting. These scientists
expressed a need for more research to demonstrate Brain Fingerprinting?s
application as an investigative tool. However, these views are not
representative of scientists? views in general, nor do they represent a
complete or systematic review of the technique. The following sections
provide the views of the three scientists.
Dr. Donchin 1 co- authored a journal article with Dr. Farwell in 1991 in
which use of the P300 in a Guilty Knowledge Test was first described. 2 Dr.
Donchin believes that the procedure described in the article (labeled more
recently as ?Brain Fingerprinting? by Dr. Farwell) utilizes the
scientifically well- established observation that rare events (i. e.,
stimuli) presented within the so- called ?oddball paradigm? 3 will elicit a
P300 component of the event- related potential. He indicated that a large
body of peer- reviewed scientific literature, developed since 1965, supports
this observation. However, Dr. Donchin believes that the specific
application of the oddball
1 Dr. Donchin, Professor Emeritus of psychology at the University of
Illinois at UrbanaChampaign and current professor and chair of psychology at
the University of South Florida, has done extensive research in event-
related potentials, the P300, and memory processes. He also served as the
developer?s academic advisor during his doctorate studies at the University
of Illinois, and, in this capacity, conducted detection of deception
research with him that was funded, in part, by the CIA in the late 1980s.
2 See L. A. Farwell, and E. Donchin, ?The Truth Will Out: Interrogative
Polygraphy (? Lie Detection?) With Event- Related Brain Potentials,?
Psychophysiology 28 (5): 531- 47. 3 The Brain Fingerprinting technique is a
variant of the ?oddball paradigm,? which has been widely used by cognitive
neuroscientists to evoke a P300 wave in an event- related potential recorded
from the scalp. As indicated earlier, the P300 is an electrically positive
charge that is elicited in response to rare, meaningful stimuli, and event-
related potentials are measures of the brain?s electrical activity as they
correspond to those stimuli. The classic way to evoke the P300 is to present
stimuli to a subject using the oddball paradigm. In this paradigm, two
categories of stimuli are presented to a subject, but one of these
categories appears more infrequently than the other. Research has shown that
each time a subject is presented with the less frequent stimuli, the P300 is
elicited. For example, if a subject is viewing a random series of names- one
every 3 seconds- and occasionally, one of these names is the subject?s, a
P300 wave is evoked in response to this rarely presented, yet meaningful
stimulus. The amplitude of the P300 is inversely proportional to the
probability of the ?oddball? stimuli. As a variant of the oddball paradigm,
the Brain Fingerprinting technique uses three categories of stimuli.
Appendix I: Scientists? Views on the Brain
Fingerprinting Technique Views of Emanuel Donchin
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 15 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
paradigm for interrogations requires much further research. For example, he
believes that the effectiveness of the Brain Fingerprinting test and its
validity depends to a large extent on the events (i. e., stimuli) of which
the oddball sequence is constructed. Specifically, he believes that the
interpretation of the Brain Fingerprinting test results depends on the
selection of the probe stimuli, which is left to the examiner?s subjective
judgment and skill in utilizing the available case information. Dr. Donchin
indicated that a consequence of using a subjective method for choosing probe
stimuli is the possibility of producing ?false positives? (i. e., an
innocent subject that would test positive when presented with a probe
stimulus) or ?false negatives? (i. e., the items chosen as probes because of
their presumed association with the crime may not have been noticed by the
subject during the commission of the crime). As an example, he provided a
hypothetical case in which a person?s involvement in a crime was inferred
from the fact that the person produced a P300 response to pictures of people
who were present at the crime scene. He said that the possibility exists
that these individuals resemble close relatives of the suspect, resulting in
an elicitation of a P300 response that could be misinterpreted as an
indication of guilt. Dr. Donchin believes that a more systematic and
objective method for identifying and choosing the events for use in the
oddball sequence is needed before the technique could be trusted to yield
unambiguous determinations.
Dr. Donchin also indicated that he believes it is important to realize that
memory is an active, creative process and not a passive repository of stored
images. He believes that while the P300 is a well- established and
documented phenomenon for determining whether an event (i. e., stimulus) has
been classified as an item of a rare category, it is not clear that every
item that is classified is one to which the person has been exposed to in
the past. He referred to the phenomenon of ?false memory? and said he
believes that research has amply demonstrated that individuals can report a
vivid memory that may be quite false. For example, a subject presented with
a list of sleep- related items- such as ?bed,? ?sheet,? ?dream,? and
?snore?- will be certain that he or she had also been presented with the
word ?sleep,? even though it had not been included among the items
presented. Dr. Donchin pointed out that the ?falsely
recognized item,? however, will elicit a sizable P300 response. In addition,
Dr. Donchin believes that more research is needed to understand the effects
of age; substances, such as alcohol and drugs; and psychological disorders
on memory and the P300.
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 16 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
Dr. Iacono 4 believes that Brain Fingerprinting is based on a documented and
well- established phenomenon- the P300 response- as an indicator of a novel
or unexpected stimulus event. However, he indicated that far fewer studies
have examined the P300?s potential to identify memories that are stored in
an individual?s brain. Hence, as an indicator of memory, the technique is
less established.
Dr. Iacono believes that the Brain Fingerprinting technique is in its early
stages of development and could benefit from more field research and testing
before being applied to actual criminal investigations for the following
reasons. For one, he believes that research has shown that investigating a
murder in the field is entirely different from investigating a murder in a
lab. Further, he believes that the technique could benefit from additional
field research and testing to develop the probe stimuli. He believes that
selecting the appropriate probe stimuli can be a subjective process, which
he does not perceive as a criticism of the technique. However, he suggests
that additional field research and testing be done on real- life
applications to help identify which probes are better suited for the test.
He also suggests a need for more field research to determine the effects
that drugs and alcohol intoxication- at the time the crime is committed- may
have on subsequent measurement of the P300. In addition, he believes that it
is possible that certain drugs taken at the time of the Brain Fingerprinting
test could affect memory and thus, the validity of the test. Dr. Iacono does
not believe adequate research has been done in this area to understand the
effects of these chemicals on the Brain Fingerprinting test. He added that
although Brain Fingerprinting is unproven in the field, he is confident that
it will prove itself for many applications, such as the investigation of
carefully planned premeditated crimes.
4 Dr. Iacono, a professor of psychology and neuroscience at the University
of Minnesota, has done extensive research in the area of deception detection
and memories related to deception. Views of William Iacono
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 17 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
On a separate issue, Dr. Iacono indicated that he employed the same
statistical method 5 and decision rules the developer used in the 1991
article by Farwell and Donchin, which Dr. Iacono noted have been peer
reviewed and are well established in the scientific community. Dr. Iacono
stated that he assumes that the developer is still using those decision
rules in interpreting the results of the Brain Fingerprinting test. However,
Dr. Iacono indicated that he has not replicated the decision rules that the
developer used after the 1991 article.
Dr. Rosenfeld 6 believes that a considerable amount of research and field
testing is necessary to establish the validity of event- related potential
measures in detecting deception using a Guilty Knowledge Test. He indicated
that only one field test has applied the Guilty Knowledge Test in a law
enforcement setting, which resulted in an accuracy rate of about 44 percent.
7 In addition, Dr. Rosenfeld does not believe that the developer had done
the extensive validation of the test items for field use that has
5 Dr. Iacono refers to the previously mentioned 1991 journal article by
Farwell and Donchin that involved the feasibility of using event- related
potentials based on a Guilty Knowledge Test. That research employed a
bootstrapping method. As indicated earlier, bootstrapping is a nonparametric
statistical technique for inferring the distribution of a statistic from a
sample and for determining how reliable that statistic is as a measure for
the population. As a type of resampling, bootstrapping randomly generates an
entire distribution of values using data from just one sample and allows one
to make inferences with an associated degree of confidence about a
population parameter, such as a mean, median, or total. Bootstrapping
provides a means to estimate standard errors of sample statistics without
requiring assumptions about the distribution of the underlying population.
6 Dr. Rosenfeld, a professor of psychology and member of the Institute for
Neuroscience at Northwestern University, has done extensive research in
electroencephalograph and eventrelated potential signs of psychological
function, with a particular focus on the P300, false memory, and brain
activity in deception detection.
7 Dr. Rosenfeld refers to a 1993 study by Y. Miyake, M. Mizutani, and T.
Yamahura, ?EventRelated
Potentials as an Indicator of Detecting Information in Field Polygraph
Examinations,? Polygraph 22 (2): 131- 49. Views of J. Peter Rosenfeld
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 18 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
been recommended by the Guilty Knowledge Test?s main proponent. 8
Specifically, he believes that in administering the Brain Fingerprinting
test to the defendant in the Harrington case, the developer used ?art rather
than science? in developing the stimuli that were administered to the
defendant. He questioned how one would know whether the items selected for a
guilty knowledge scenario would be sure to work on any guilty party. In
addition, Dr. Rosenfeld said he believes there has been only one peer-
reviewed journal article- the 1991 Farwell and Donchin article previously
mentioned- that includes the developer?s methods.
Dr. Rosenfeld also indicated he does not believe that memory automatically
stores all of life?s experiences forever. He indicated that current research
has shown that memory is affected by various chemicals and conditions, such
as alcohol and drugs, brain damage, mental illness, and extreme anxiety,
during crime situations. He pointed to the example of extreme anxiety,
suggesting that if someone just killed his wife, anxiety might prevent him
from noticing what color shoes she was wearing. He does not believe the
developer has done research on these issues.
In terms of the Brain Fingerprinting?s test results, Dr. Rosenfeld
questioned the developer?s claim of a 100- percent accuracy rate. For
example, he raised concerns regarding whether the developer omitted
inconclusive results from the totals, which would affect the overall
accuracy rate. Further, Dr. Rosenfeld believes the accuracy rate would be
lower in the field, where variables cannot be so well controlled. Moreover,
he believes that the developer?s criterion for guilt is that 90 percent of
the bootstrapping iterations of his analysis be positive. Dr. Rosenfeld
stated that, in experimental psychology journals, the 95- percent criterion
is generally used and that too lenient a criterion will ordinarily make more
8 The Guilty Knowledge Test was introduced by David Lykken, Ph. D., a
psychologist and former professor of psychiatry at the University of
Minnesota, and polygraph critic. In his book, A Tremor in the Blood, Dr.
Lykken has recommended that a Guilty Knowledge Test include probes that
satisfy certain conditions. Specifically, he recommended that for each
probe, an innocent subject should have no more than a 20- percent chance of
testing positive and a guilty subject should have at least an 80- percent
chance of testing positive. Each probe should have five alternatives that
are equally plausible to an innocent subject, but, to the guilty subject,
are easily distinguishable from the probe and from each other, so that the
guilty subject is not confused about which alternative he or she has seen
before. In addition, the fact that a guilty subject recognizes a probe ?must
seem important to the guilty subject,? a condition that should always be
realized in a criminal investigation context but may not be in some
laboratory experiments.
Appendix I: Scientists? Views on the Brain Fingerprinting Technique
Page 19 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
guilty decisions but will also produce more false positives (i. e.,
innocents judged guilty).
Furthermore, Dr. Rosenfeld believes that the P300 is a good index of
recognition, but an indirect index of deception. It assumes that if the
subject states that he or she does not recognize the murder weapon, yet
elicits a P300 when he or she sees it, then the subject is lying. He adds
that such a conclusion leads to a reasonable, but not infallible inference
that the subject is lying. However, a P300 response only indicates that
there is something special and recognizable to him or her about that weapon-
maybe because the subject committed the murder, but maybe because he or she
read about the weapon in the news or because a brother has such a weapon.
Dr. Rosenfeld indicated that there are no direct deception indices known at
present but noted that researchers are working on one.
Appendix II: Comments From the U. S. Secret Service Page 20 GAO- 02- 22
Federal Agency Views on "Brain Fingerprinting"
Appendix II: Comments From the U. S. Secret Service
Appendix II: Comments From the U. S. Secret Service Page 21 GAO- 02- 22
Federal Agency Views on "Brain Fingerprinting"
Appendix III: Comments From the Federal Bureau of Investigation
Page 22 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
Appendix III: Comments From the Federal Bureau of Investigation
Appendix III: Comments From the Federal Bureau of Investigation
Page 23 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting"
Appendix III: Comments From the Federal Bureau of Investigation
Page 24 GAO- 02- 22 Federal Agency Views on "Brain Fingerprinting" (440010)
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