decoding deception - rit

Decoding Deception:Decoding Deception:Analysis of ERP and fMRI Data Relevant to the Detection of DecepAnalysis of ERP and fMRI Data Relevant to the Detection of Deceptiontion

Michael Jay Schillaci, PhDMichael Jay Schillaci, PhDManaging Director, McCausland Center for Brain ImagingManaging Director, McCausland Center for Brain Imaging

Assistant Research Professor, Department of PhysicsAssistant Research Professor, Department of Physics

Assistant Research Professor, Department of PsychologyAssistant Research Professor, Department of Psychology

ΣΣ →→ ∫∫ →→ ΣΣ

OutlineOutline

�� Introductory InformationIntroductory Information�� Anatomy, Physiology and Interview CharacteristicsAnatomy, Physiology and Interview Characteristics

�� Origins and Generation of ERPsOrigins and Generation of ERPs

�� The TwoThe Two--Stimulus ParadigmStimulus Paradigm�� Data Acquisition and Behavioral FindingsData Acquisition and Behavioral Findings

�� Standard Analysis TechniquesStandard Analysis Techniques

�� Cognitive Activity MeasuresCognitive Activity Measures�� ERP Power and EnergyERP Power and Energy

�� Attention Based LoadAttention Based Load--SwitchingSwitching

�� Continuing EffortsContinuing Efforts�� Misinformation StudyMisinformation Study

�� A Quantum HypothesisA Quantum Hypothesis

Introductory InformationIntroductory Information

�� Anatomy, Physiology and Interview CharacteristicsAnatomy, Physiology and Interview Characteristics


Basic NeurophysiologyBasic Neurophysiology

�� Frontal LobeFrontal Lobe�� Planning, Organizing, DecidingPlanning, Organizing, Deciding

�� Temporal LobeTemporal Lobe�� Sorting, ShortSorting, Short--Term MemoryTerm Memory

�� Parietal LobeParietal Lobe�� Sensory Cortex, LanguageSensory Cortex, Language

�� Occipital LobeOccipital Lobe�� Visual Reception, RecognitionVisual Reception, Recognition

Attention and PerformanceAttention and Performance

�� YerkesYerkes--Dodson Law (1908)Dodson Law (1908)�� Arousal/AttentionArousal/Attention

�� Related to Anxiety, Work CapacityRelated to Anxiety, Work Capacity

�� Motivator for changeMotivator for change

�� OptimizationOptimization�� Lower for difficult cognitive tasksLower for difficult cognitive tasks

�� Higher for tasks requiring enduranceHigher for tasks requiring endurance

�� Michael Posner (1990)Michael Posner (1990)�� Attention System of the Human BrainAttention System of the Human Brain

�� Anterior Attention Network (Anterior Attention Network (AANAAN))�� Executive ControlExecutive Control

�� Temporal Parietal Junction (Temporal Parietal Junction (TPJTPJ))�� Orienting ResponseOrienting Response

�� Posterior attention Network (Posterior attention Network (PANPAN))�� Processing (Alerting)Processing (Alerting)

Increasing

Alertness

Increasing

Arousal

Test for Espionage and Sabotage (TES)Test for Espionage and Sabotage (TES)

�� Two Series of QuestionsTwo Series of Questions

�� Relevant and IrrelevantRelevant and Irrelevant

�� DirectedDirected--Lie Comparison, and Sacrifice Relevant Lie Comparison, and Sacrifice Relevant

�� Examples:Examples:

�� Irrelevant Irrelevant

�� Are you now in Virginia?Are you now in Virginia?

�� Sacrifice RelevantSacrifice Relevant

�� Do you intend to answer these questions truthfully?Do you intend to answer these questions truthfully?

�� Directed Lie ComparisonDirected Lie Comparison

�� Have you ever stolen office supplies for your personal use? Have you ever stolen office supplies for your personal use?

�� RelevantRelevant

�� Have you committed sabotage against the United States?Have you committed sabotage against the United States?

Current ScreeningCurrent Screening

�� Screening Applications (Polygraph)Screening Applications (Polygraph)

�� PrePre--employment Screening (law enforcement)employment Screening (law enforcement)

�� PrePre--clearance Screening (national security)clearance Screening (national security)

�� Ongoing Screening of employeesOngoing Screening of employees

�� SexSex--offender Statusoffender Status

�� Known IssuesKnown Issues

�� Not singleNot single--issue testsissue tests

�� Range of behaviors can be largeRange of behaviors can be large

�� ExamineeExaminee’’s may be unclear of their guilts may be unclear of their guilt

Physiological Mechanisms of DeceptionPhysiological Mechanisms of Deception

�� Orienting Response (Salience) Orienting Response (Salience) �� Generalized descending arousal Generalized descending arousal

�� Likely generates the responses Likely generates the responses measured by the polygraph measured by the polygraph (Pollina & Ryan, 2003)(Pollina & Ryan, 2003)

�� Attention Shifting Attention Shifting �� ReflexReflex--like attention switch to like attention switch to

new stimulusnew stimulus

�� Associated with heart rate Associated with heart rate decelerations, delays in breathing, decelerations, delays in breathing, and cessation of ongoing behaviors and cessation of ongoing behaviors (N(Näääättäänen, 1992)nen, 1992)

�� National Academy of SciencesNational Academy of Sciences�� ““Report on PolygraphReport on Polygraph”” states that states that Base RateBase Rate very low such that that very low such that that several hundred innocent found several hundred innocent found deceptive (false positives) for deceptive (false positives) for every correct identification of a every correct identification of a guilty individualguilty individual

SALIENCE

EMOTION

AROUSAL

ATTENTION

OrientingResponse

Gen

era

lized

Descen

din

g A

rou

sal

Attention Shifting

Cortical Control of Evoked Cortical Control of Evoked

Electrodermal ActivityElectrodermal Activity (EDA)(EDA)

�� Emotion: Emotion: IpsiIpsi--laterallateral�� Hypothalamus and Limbic SystemHypothalamus and Limbic System

�� Attention: Attention: ContraContra--laterallateral�� Prefrontal and PrePrefrontal and Pre--motor Cortexmotor Cortex

�� Control: Control: ContraContra--laterallateral�� Reticular Activating SystemReticular Activating System

Introductory InformationIntroductory Information

�� Anatomy, Physiology and Interview CharacteristicsAnatomy, Physiology and Interview Characteristics


EEG Spectrum and MorphologyEEG Spectrum and Morphology

}

}Theta (5 – 7 Hz)

Affective/Temporal

}Alpha (8 – 12 Hz)

Relaxed/Parietal

}

Gamma (35 – 50 Hz)

Sleep/Frontal

ERPs from EEGsERPs from EEGs

�� Time Lock to StimulusTime Lock to Stimulus�� Average Across TrialsAverage Across Trials ( )( )

�� Data FilteringData Filtering�� Butterworth ( Butterworth ( “Maximally Flat”; ))

��Extract variance related Extract variance related dimensionsdimensions�� Segment and exportSegment and export

NSNR ∝

Images Adapted from: http://neurocog.psy.tufts.edu/images/

123 −−= nnGd

dGω

ω

Origin and Generation of ERPsOrigin and Generation of ERPs

~ 100 Billion Neurons

Human Cortex

~ 100 Trillion Synapses

Single Neuron

snqNg

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vNn e

20

42

3

10~)(1 −=≅

στ

Quantum Decoherence

~ 10 Million / Neuron

Microtubules

sNgq

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13

2

2

10~−≅τ

State Collapse

Importance of quantum decoherence in brain processes – Tegmark (1999) PRE 61.

Quantum computation in brain microtubules: Decoherence and biological feasibility – Hagan (2002) PRE 65.

�� Two Theories of OriginationTwo Theories of Origination

�� Originate from Originate from eventevent--related activationsrelated activations of of neural assemblies distinct from neural assemblies distinct from background dynamicsbackground dynamics

�� Produced by Produced by phase resettingphase resetting of ongoing of ongoing oscillatory neuronal activityoscillatory neuronal activity

Aspects of Deception in the ERPAspects of Deception in the ERP

These three waveforms may work together in a process of deception in which a question is asked, attention is switched, workload demands are assessed, memory for the truthful information is accessed, motivation to deceive is considered, and then a decision to deceive is made.

0 250 500 750 ms

P3aAnterior waveform positive distribution

latency ~250-350 ms

N4anterior waveform negative deflection latency ~400 ms

P3bparietal distribution positive deflection

latency ~350-600 ms

The TwoThe Two--Stimulus ParadigmStimulus Paradigm

�� Data Acquisition and Behavioral FindingsData Acquisition and Behavioral Findings


Data AcquisitionData Acquisition

128 Channels (Vertex Reference)

Amplifier(Isolated Common)

“Netstation”(Pre-Processing)

EGI Systems“Geodetic Sensornet”

Data Display(4*40*225*39 = 1404000 pts)

The Directed Lie ParadigmThe Directed Lie Paradigm

Participants respond truthfully to one color and lie to the other.

ResponseAgree

ResponseDisagree

ResponseDisagree

750ms

The grass Is green.

The grass

Is green.

The grass Is green.

The grass Is green.

+

+

+

+

TRUE

FALSE

TRUE

FALSE

ResponseAgree

2500ms 2000ms

CT

IT

IL

CL

TASK BUTTONSTIM 2STIM 1 FIXATION

� Directed Lie Procedure� Participants view autobiographical statements that are true or false

(randomly presented; 40 of each response type) followed by a second stimulus to which they respond with a key press (agree/disagree).

� Experiment 1: Low Workload� Know truth value and task at stimulus 1� Demographics: Aged 18-43 (M = 21.38); N=39

� Experiment 2: High Workload

� Experiment: Know truth value only at stimulus 1� Demographics: Aged 18 to 21 (M = 19); N=15

Experimental ProcedureExperimental Procedure

Signal ProcessingSignal Processing

Stimulus 1

(2500ms)Fixation

Prompt

(750 ms) Stimulus 2

(Response Termination)

1 Raw Segment

2 Filter Segment 3 Correct Segment

4 Average Segment

}

Reaction Time FindingsReaction Time Findings

� Reaction time (RT) � Latency between STIM 2 and subject response

� RT less for truthful responses

� No Interaction� Congruity and deception not related

� Incongruent data not discussed here

The TwoThe Two--Stimulus ParadigmStimulus Paradigm

�� Data Acquisition and Behavioral FindingsData Acquisition and Behavioral Findings


� Channels for Posner Networks

� ROI Averaged Waveforms

Region of Interest (ROI) WaveformsRegion of Interest (ROI) Waveforms

DECEPTIVE TRUTHFUL

EX

P 2

: H

IGH

EX

P 1

: L

OW

�� Waveform PeakWaveform Peak�� Determine maximum amplitude in chosen Determine maximum amplitude in chosen ““windowwindow””

�� Waveform LatencyWaveform Latency�� Time from stimulus onset to waveform peak amplitudeTime from stimulus onset to waveform peak amplitude

Waveform Peak and LatencyWaveform Peak and Latency

Cognitive Activity MeasuresCognitive Activity Measures

�� ERP Power and EnergyERP Power and Energy


ERP Power and EnergyERP Power and Energy

� We integrate the instantaneous channel-power over successive time

intervals to obtain a measure of the energy emitted during individual response trials:

where z is the impedance value.

∫ −=t

CCC

n dttVtVz

tEnn0

)()()()()(

1),( ττ

Voltage

( ~10 MicroVolts )

Power

( ~100 eV / ms )

Energy

( ~10 KeV )

Cognitive ActivityCognitive Activity

� We define the Cognitive Activity for an ROI with a weighted sum of the ratio of the channel-energy for one state to the total energy from both states:

The sum over all channels is unity. i.e.,

,)(21

∑∈ +

=ROIn

C

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ROIEE

Et

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=+n

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Cognitive Activity MeasuresCognitive Activity Measures

�� ERP Power and EnergyERP Power and Energy


““AttentionAttention--SwitchingSwitching””

minmax AANPANls ttt −=

� Attention Based Activity� Cognitive activity over the AAN tends toward a minimum value at nearly the same time that activity over the PAN reaches its maximal value.

� Load-Switching Time� We assess neocortical interaction times by determining the latency for extrema of the regional activity values. The load-switching time is the difference in the maximal PAN and minimal AAN latency values. i.e.,

““Neocortical CircuitsNeocortical Circuits””

� Compare Latency of Activity Extrema in ROIs� A straight forward model of cognition wherein access to memory

(TPJ) precedes stimulus processing (PAN) and task execution (AAN) illustrates that truth and deception utilize similar neocortical circuits with different timing.

� It is plausible to assert that attention switching between executive control functions in the frontal areas and access to language processing skills in posterior regions may account for this.

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248248132132220220CTCT22

276276136136188188CLCL11

244244124124200200CTCT11

AAN AAN

MIN MIN

(ms)(ms)

TPJ TPJ

MIN MIN

(ms)(ms)

PAN PAN

MAX MAX

(ms)(ms)TASKTASKEXPEXP

EX

P 1

: H

IGH

EX

P 2

: L

OW

CT CL

Continuing EffortsContinuing Efforts

�� The Misinformation ParadigmThe Misinformation Paradigm


Misinformation Paradigm Misinformation Paradigm -- BehavioralBehavioral

Truth Tellers

Deceivers

SlideShow

Narrative 1

Narrative 2

Narrative 2

Narrative 1

RespondTruthfully

RespondDeceptively

Filler Task: STAI Filler Task: CFQ

500

600

700

800

900

1000

Factual Information Misinformation

Narrative Content

Avera

ge R

eaction T

ime (

ms)

***

The man put out his cigarette The man put out his cigarette

in an ashtray next to a copy of in an ashtray next to a copy of

_____ magazine._____ magazine.

VogueVogue ElleElle

Misinformation Paradigm Misinformation Paradigm -- ERPERP� Participants (N=8) in two groups were shown 70 slides in which a

repairman comes into an office and steals several items. Afterward participants performed a filler task for five minutes. Then they read a narrative of the slides to “refresh” their memories. The narratives each misnamed two items from slides.

� Early executive control (AAN) appears evident in our pilot data for Deceivers. Responding deceptively to misinformation still takes

longer: Ratio = - 60/40.

CLCT

Misinformation Paradigm Misinformation Paradigm -- fMRIfMRI� 200 trials of the two-stimulus type were presented to a participant (N=1). On 100

trials he was directed to lie (LIE) and on 100 trials he was directed to tell the truth (TRUE); balanced across these trials were 100 trials in which he told a lie after telling the truth or told the truth after telling a lie (SWITCH), and 100 trials in which lies followed lies or truths followed truths (NO SWITCH). Z (Gaussian T/F) statistic images were threshold weighted using clusters determined by z >2.3 and a (corrected) cluster significance threshold of p=0.05. All scans collected at 3T with Siemens Magnetom Trio System.

Greater activation in right frontal and regions of the precuneous during deceptive trials than truthful trials.

Greater activations in PAN suggest there will be differences when one switches between lying and truth telling.

Greater activations related specifically to switching to lie, suggests areas that may allocate resources during deception.

Greater activation during deceptive no-switch trials occurs in Brodmann’s Area 10, and suggests that multiple internal comparisons during deception.

Continuing EffortsContinuing Efforts

�� The Misinformation ParadigmThe Misinformation Paradigm


Theory Meets ApplicationTheory Meets Application

�� Refine Refine ROIsROIs (18 Regions)(18 Regions)�� Assess LoadAssess Load--Switching TimesSwitching Times

�� Portable Deception Detection?Portable Deception Detection?�� Collect ERPs with a Palm PilotCollect ERPs with a Palm Pilot

�� How robust is the effect?How robust is the effect? g.MOBIlab (www.CortechSolutions.com)

IPS ?

ACC ?

A Quantum HypothesisA Quantum Hypothesis

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REpEp

Ept

)()()()(

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� What do these ERP Energies look like?� What is their wavelength?

� What is transition rate among states?Subject Classification?

Transition Rate – Cognitive Activity Phase Diagrams

CL

CT

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+=

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AcknowledgementsAcknowledgements

�� Dr. Jennifer VendemiaDr. Jennifer Vendemia

�� COCO--PI (PI (USAMRAA))

�� Testified before the senate to help get the $!Testified before the senate to help get the $!

�� Finds time to write awesome sciFinds time to write awesome sci--fi too!fi too!

�� Graduate StudentsGraduate Students

�� PsychologyPsychology

�� Rob Buzan, Eric Green, Scott Meek, Michelle PhillipsRob Buzan, Eric Green, Scott Meek, Michelle Phillips

�� PhysicsPhysics

�� Richard FosterRichard Foster

decoding deception - rit

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