PSYC 3500: Deception

What is a polygraph?

A device for recording an individual’s autonomic nervous system responses. Measurement devices are attached to the upper chest and abdomen to measure breathing, electrodes are attached to the fingertips to measure the amount of sweat on the skin, and heart rate is measured by a partially inflated blood pressure cuff attached to an arm

What is the underlying principle behind polygraphy?

That deception is associated with physiological change

What are polygraph tests used for?

A range of purposes, such as to help police in their criminal investigations, to help verify whether a crime has occurred, to verify the claims of the insured, to assess and monitor sexual offenders on probation, to uncover information about an offender’s past behaviour, to determine whether the offender is violating the conditions of probation or to test for evidence of risky behaviour

What is the Comparison Question Test (CQT)?

A type of polygraph test that includes neutral questions that are unrelated to the crime, relevant questions concerning the crime being investigated, and comparison questions concerning the person’s honesty and past history prior to the event being investigated

What is the Concealed Information Test (CIT)?

A test to determine whether the suspect knows details about a crime that only the person who committed the crime would know. The general form of the CIT is a series of questions in multiple-choice format

How do polygraph examiners detect deception using the CQT?

By comparing reactions to the relevant and comparison questions. Guilty suspects are assumed to react more to relevant questions than comparison questions, whereas innocent suspects are assumed to react more to comparison questions than relevant questions

What are some limitations of polygraph tests?

The physiological states associated with lying share much in common with many other states, including anxiety, anger, embarrassment, and fear. The CQT is quite accurate at detecting guilt but is not very good at determining a suspect’s innocence, whereas the CIT is quite accurate in detecting innocence but is not very good at determining a suspect’s guilt. It is possible to use countermeasures to beat the polygraph

What is a polygraph disclosure test?

Polygraph tests that are used to uncover information about an offender’s past behaviour

What is ground truth in polygraph research?

The knowledge of whether the person is actually guilty or innocent

What are countermeasures in polygraph research?

Techniques used to try to conceal guilt

What are the two types of studies used to assess the validity of polygraph techniques?

Laboratory and field studies

What do laboratory studies involve when assessing the validity of polygraph techniques?

Simulated crimes or situations where researchers know the truth, allowing them to measure corresponding physiological responses to true and false information

What do field studies involve when assessing the validity of polygraph techniques?

Real-life situations and actual criminal suspects, together with actual polygraph examinations

What is 'ground truth' in the context of polygraph research?

The knowledge of whether the person is actually guilty or innocent

What is a typical experiment to assess verbal and nonverbal behavior cues to lying?

It involves one group of participants (called the message source) who are told to provide either true or deceptive messages and another group of participants is asked to detect when the message source participants were truthful or deceptive

What are the three basic designs used to study malingering?

Case study, simulation, and known groups

What are simulation designs in malingering research?

These involve experimental and control groups where participants are asked to feign symptoms of a disorder. They may be coached with information about genuine mental disorders or detection strategies

What are known-groups designs in malingering research?

This compares genuine patients and malingerers attempting to fake the disorder the patients have

What is thermal imaging?

Thermal imaging is a technique that measures the amount of facial warming, which is linked to regional blood flow. This can be done quickly, and the individual may not even know their facial temperature is being measured

What did Pavlidis, Eberhardt, and Levine (2002) find in their study on thermal imaging and deception?

They found that the use of thermal imaging (in particular around the eyes) correctly classified 6 of the 8 (75 percent) guilty participants and 11 of the 12 (92 percent) innocent participants. This accuracy rate was similar to a polygraph exam administered to participants

What did Warmelink and colleagues (2011) find in their study on thermal imaging and deception at an international airport?

They found that liars' facial skin temperature increased during the interview whereas truth-tellers remained stable. Using skin temperature, 69 percent of the liars and 64 percent of the truth-tellers were identified. However, the interviewer did a better job at identifying deception, correctly classifying 77 percent of the liars and 74 percent of the truth-tellers

What conclusion did Warmelink and colleagues (2011) come to regarding the use of thermal imaging as a general screening device at airports?

They concluded that "it is unlikely that thermal imaging can be used effectively at airports as a general screening device

What recommendation does the source make regarding security or customs officers and thermal imaging?

Unless there is more research supporting the use of thermal imaging, security or customs officers should still focus more on what you say than on how red your face gets

What is fMRI?

fMRI stands for functional magnetic resonance imaging. It's a technique that measures the cerebral blood flow (a marker of neurological activity) in different areas of the brain

What is the appeal of using fMRI as a brain-based lie-detection approach?

Researchers hope that instead of measuring emotional arousal, it measures the actual process of deception

Which areas of the brain have shown greater activation in lie conditions compared to truth conditions in fMRI studies?

The prefrontal and anterior cingulate regions

What are some limitations of fMRI research in deception detection?

It is typically based on averaging fMRI data across multiple participants, which constrains its use for detecting deception in individuals.

Studies have used healthy volunteers who have been screened for neurological and psychiatric disorders, who have been instructed to lie, and who do not face any serious consequences.

It remains to be investigated how well this technique will generalise to real-life cases

Have brain-imaging techniques been used extensively in forensic settings?

These techniques have not yet been used extensively in forensic settings

What impact does brain-imaging evidence have on juror decision making?

Simply seeing pictures of brain images makes people believe that scientific results are more valid compared to when other images (such as figures or tables) are presented

Can countermeasures impact the accuracy of fMRI in a concealed information paradigm?

Yes. When participants did not use a simple covert movement as a countermeasure, deception-detection accuracy was 100 percent, but it was only 33 percent when the countermeasure was used

What are microexpressions?

Brief facial expressions that reflect the emotion a person is feeling

What is one of the most reliable verbal indicators of deception?

That liars provide fewer details than truth-tellers. Liars also tell less compelling accounts compared with truth-teller

What verbal indicator has been most strongly associated with deception?

Voice pitch. Liars tend to speak in a higher-pitched voice than those telling the truth

Are some people better at detecting deception than others?

Across studies, the ability to distinguish lies from truth tends to be only slightly better than chance

What is the accuracy rate for detecting deception for “professional lie catchers?"

On average, 55.5 percent, a rate that is not much more accurate than that of students and other citizens (who had 54.2 percent accuracy)

What is a truth-bias?

Most lie catchers have a truth-bias, and in most studies, truthful messages were identified with more accuracy than deceptive ones

What is "malingering"?

Intentionally faking psychological or physical symptoms for some type of external gain

What are the key components of malingering?

The psychological or physical symptoms are clearly under voluntary control.

There are external motivations for the production of symptoms

According to the adaptational model, when is malingering likely to occur?

Malingering is likely to occur when:

There is a perceived adversarial context.

Personal stakes are very high.

No other viable alternatives are perceived