Temperature effects on polygraph detection of concealed information.

Thermoregulatory influences on electrodermal and cardiovascular activity may interfere with the detection of concealed information using a polygraph. This possibility was assessed by means of a mock terrorism scenario. Seventy-two participants were assigned to either a guilty or an innocent role. They were given a polygraph test at one of three ambient temperatures: 10°C, 22°C, or 34°C. Among guilty participants, electrodermal and cardiovascular measures were least effective at 10°C. Electrodermal results were optimal at 22°C, whereas cardiovascular results were optimal at 34°C. Among innocent participants, the effectiveness of these same measures was not affected by ambient temperature. Temperature had no significant impact on respiration results within the guilty or the innocent groups. Taken together, these findings have implications for those who use polygraphs in uncontrolled testing environments.

Chronic baclofen desensitizes GABA(B)-mediated G-protein activation and stimulates phosphorylation of kinases in mesocorticolimbic rat brain.

The GABAB receptor is a therapeutic target for CNS and neuropathic disorders; however, few preclinical studies have explored effects of chronic stimulation. This study evaluated acute and chronic baclofen treatments on GABAB-activated G-proteins and signaling protein phosphorylation as indicators of GABAB signaling capacity. Brain sections from rats acutely administered baclofen (5 mg/kg, i.p.) showed no significant differences from controls in GABAB-stimulated GTPγS binding in any brain region, but displayed significantly greater phosphorylation/activation of focal adhesion kinase (pFAK(Tyr397)) in mesocorticolimbic regions (caudate putamen, cortex, hippocampus, thalamus) and elevated phosphorylated/activated glycogen synthase kinase 3-ß (pGSK3ß(Tyr216)) in the prefrontal cortex, cerebral cortex, caudate putamen, nucleus accumbens, thalamus, septum, and globus pallidus. In rats administered chronic baclofen (5 mg/kg, t.i.d. for five days), GABAB-stimulated GTPγS binding was significantly diminished in the prefrontal cortex, septum, amygdala, and parabrachial nucleus compared to controls. This effect was specific to GABAB receptors: there was no effect of chronic baclofen treatment on adenosine A1-stimulated GTPγS binding in any region. Chronically-treated rats also exhibited increases in pFAK(Tyr397) and pGSK3ß(Tyr216) compared to controls, and displayed wide-spread elevations in phosphorylated dopamine- and cAMP-regulated phosphoprotein-32 (pDARPP-32(Thr34)) compared to acutely-treated or control rats. We postulate that those neuroadaptive effects of GABAB stimulation mediated by G-proteins and their sequelae correlate with tolerance to several of baclofen's effects, whereas sustained signaling via kinase cascades points to cross-talk between GABAB receptors and alternative mechanisms that are resistant to desensitization. Both desensitized and sustained signaling pathways should be considered in the development of pharmacotherapies targeting the GABA system.

Cognitive and emotional reactions to questions in the Comparison Question Test.

The effect of situational factors on perceptions of items on the polygraph Comparison Question Test (CQT) was assessed. In an initial experiment, 86 students (30 men, 56 women; M age = 20.3 yr., SD = 4.0) imagined one of eight scenarios that varied by guilt or innocence, the commission of a real crime or mock crime, and interrogation by a police officer or a professor. They then rated generic CQT questions for importance and emotional concern. All participants rated crime-relevant questions as being more important than past-crime comparison questions. "Guilty" participants also rated these questions as being more emotionally concerning, but "innocent" participants showed no differences in their ratings of concern for the two question types. Interrogator or crime type did not affect the general pattern of responding. A second experiment involving 80 students (21 men, 58 women, 1 non-specified; M age = 22.5 yr., SD = 7.3) replaced the generic CQT questions with content-specific questions developed by the participant. Those imagining guilt showed no differencesin their ratings of relevant and comparison questions, whereas those imagining innocence rated comparison questions as more concerning. Again, interrogator type and crime type had little effect on results. Overall these findings indicated distinctions in cognitive and emotional appraisal for CQT questions, with the nature of emotional concern dependent on guilt/innocence status and the personal relevance of comparison questions. Evidence suggests that the CQT is robust to other situational factors, such as crime type and interrogator type.

Alpha values as a function of sample size, effect size, and power: accuracy over inference.

Tables of alpha values as a function of sample size, effect size, and desired power were presented. The tables indicated expected alphas for small, medium, and large effect sizes given a variety of sample sizes. It was evident that sample sizes for most psychological studies are adequate for large effect sizes defined at .8. The typical alpha level of .05 and desired power of 90% can be achieved with 70 participants in two groups. It was perhaps doubtful if these ideal levels of alpha and power have generally been achieved for medium effect sizes in actual research, since 170 participants would be required. Small effect sizes have rarely been tested with an adequate number of participants or power. Implications were discussed.

Memory instructions, vocalization, mock crimes, and concealed information tests with a polygraph.

Accuracy rates with polygraphs using concealed information tests (CITs) depend on memory for crime details. Some participants read instructions on murdering a dummy victim that specified exact crime details asked on the subsequent CIT. Others read instructions not stating details, but still requiring interaction with the exact same details for the crime. For example, the murder weapon was under four heavy boxes. Instructions stated either "... remove the 4 boxes ..." or "... remove the boxes ..." Thus, each group removed four boxes, but only one group was primed with the number "4" beforehand. In addition, the victim unexpectedly shouted at some participants during the crime. An innocent group was not exposed to either manipulation. Memory, detection scores, and detection rates were lower for guilty participants not primed with details. Sound affected detection scores but not memory, and there was no interaction between the two factors. Information tests are limited by how crime information is received.

Accuracy of effect size estimates from published psychological experiments involving multiple trials.

The reporting of exaggerated effect size estimates may occur either through researchers accepting statistically significant results when power is inadequate and/or from repeated measures approaches aggregating, averaging multiple items, or multiple trials. Monte-Carlo simulations with input of a small, medium, or large effect size were conducted on multiple items or trials that were either averaged or aggregated to create a single dependent measure. Alpha was set at the .05 level, and the trials were assessed over item or trial correlations ranging from 0 to 1. Simulations showed a large increase in observed effect size averages and the power to accept these estimates as statistically significant increased over numbers of trials or items. Overestimation effects were mitigated as correlations between trials increased but still remained substantial in some cases. The implications of these findings for meta-analyses and different research scenarios are discussed.

Diagnosing estimate distortion due to significance testing in literature on detection of deception.

Studies journals typically report or feature results significant by statistical test criterion. This is a bias that prevents obtaining precise estimates of the magnitude of any underlying effect. It is severe with small effect sizes and small numbers of measurements. To illustrate the problem and a diagnosis technique, results of published studies on the detection of deception are graphed. The literature contains large effect sizes affirming that deceptive responses in contrast to truthful responses are associated with more reactive Skin Resistance Responses. These effect sizes when graphed on the x-axis against n on the y-axis are distributed as funnel graphs. A subset of studies show support for predicted small to medium effects on different physiological measures, individual differences, and condition manipulations. These effect sizes graphed by sample ns follow negative correlations, suggesting that effect sizes from published values of t, F, and zeta are exaggerations.

A Monte-Carlo estimation of effect size distortion due to significance testing.

A Monte-Carlo study was done with true effect sizes in deviation units ranging from 0 to 2 and a variety of sample sizes. The purpose was to assess the amount of bias created by considering only effect sizes that passed a statistical cut-off criterion of alpha = .05. The deviation values obtained at the .05 level jointly determined by the set effect sizes and sample sizes are presented. This table is useful when summarizing sets of studies to judge whether published results reflect an accurate appraisal of an underlying effect or a distorted estimate expected because significant studies are published and nonsignificant results are not. The table shows that the magnitudes of error are substantial with small sample sizes and inherently small effect sizes. Thus, reviews based on published literature could be misleading and especially so if true effect sizes were close to zero. A researcher should be particularly cautious of small sample sizes showing large effect sizes when larger samples indicate diminishing smaller effects.

A control question test oriented towards students.

Control Question Tests were altered for 12 of 24 students who were examined with a polygraph about a mock crime which half of them had committed. The altered tests substituted control questions about students' cheating and plagiarism for the standard questions about crime issues. Responses to the altered tests were compared with those from tests using regular control questions which are usually about criminal issues. All tests were conducted by a professor. Detection scores derived from response magnitudes of skin resistance differed between innocent (M = 2.0) and guilty participants (M = -1.9). Guilt and innocence interacted with the type of test. Those examined with control questions oriented towards students scored as more innocent when actually innocent (M = 4.3) than guilty students examined with the student form (M = -3.0) or the crime form (M = -0.8) of the test and innocent students (M = -0.3) examined with control questions oriented towards crimes. The discussion is augmented by results from a direct analysis of magnitude of scores.

The Control Question Test in polygraphic examinations with actual controls for truth.

Subjects who were guilty of a mock crime, innocent and informed of the details of the crime or innocent, and uninformed of the details were examined on the polygraph with a modified version of a Control Question Test, which normally contains questions which are incriminating, ambiguous, and likely to be answered with a lie. We challenged the necessity of using incriminating, ambiguous control questions which may demand a lie as an answer. Instead, we created and tested control questions that were unambiguous and answered truthfully. The results, with the modified questions, showed correct identification of 86% of the guilty subjects and 83 to 89% of the innocent subjects.

Polygraph lie detection on real events in a laboratory setting.

This laboratory study dealt with real-life intense emotional events. Subjects generated embarrassing stories from their experience, then submitted to polygraph testing and, by lying, denied their stories and, by telling the truth, denied a randomly assigned story. Money was given as an incentive to be judged innocent on each story. An interrogator, blind to the stories, used Control Question Tests and found subjects more deceptive when lying than when truthful. Stories interacted with order such that lying on the second story was more easily detected than lying on the first. Embarrassing stories provide an alternative to the use of mock crimes to study lie detection in the laboratory.

To what extent would women prefer chorionic villus sampling to amniocentesis for prenatal diagnosis?

Sixty-six pregnant women and 46 doctors were interviewed about their preferences for chorionic villus sampling (CVS) or amniocentesis for prenatal diagnosis in a hypothetical situation where the indication was late maternal age. The standard gamble method was used to calculate each individual's degree of preference for one procedure over the other (utility) expressed in terms of the risk of miscarriage associated with the preferred procedure that would be tolerated in order to have that procedure. Utilities for each group were calculated and compared. Pregnant women nominated a median utility for CVS of a miscarriage rate of 0.9%, while doctors nominated a median utility for CVS of a miscarriage rate of 1.2%. The difference between these utilities was not statistically significant. The method described in this study can enable potential consumers of a new procedure to provide the minimum 'clinically important difference' between a new procedure and an existing procedure necessary for calculation of the sample size in a controlled clinical trial.