Regression analyses of repeated measures data in cognitive research

Repeated measures designs involving nonorthogonal variables are being used with increasing frequency in cognitive psychology. Researchers usually analyze the data from such designs inappropriately, probably because the designs are not discussed in standard textbooks on regression. Two commonly used approaches to analyzing repeated measures designs are considered in this article. It is argued that both approaches use inappropriate error terms for testing the effects of independent variables. A more appropriate analysis is presented, and two alternative computational procedures for the analysis are illustrated.     

Polygraph Testimony and Juror Judgments: A Comparison of the Guilty Knowledge Test and the Control Question Test1

The present experiment investigated the impact of the Control Question Test (CQT) and the Guilty Knowledge Test (GKT) on the verdicts of mock jurors. Although studies have indicated that polygraph evidence has little influence on jurors' verdicts (Cavoukian & Heselgrave, 1980; Spanos, Myers, Dubreuil, & Pawlak, 1992–1993), no research has previously distinguished between the different types of polygraph tests and their impact on juror verdicts. In the present study, jurors were shown a videotape of a simulated rape-murder trial that contained either CQT polygraph evidence, GKT polygraph evidence, or no polygraph evidence. No differences were found among the 3 conditions for either jury verdicts or individual juror verdicts, and jurors tended to rate both forms of polygraph testimony below other forms of equally suspect evidence, such as eyewitness testimony, in its influence on their decision-making process.     

WHO IS HAPPY?

A flood of new studies explores people's subjective well-being (SWB) Frequent positive affect, infrequent negative affect and a global sense of satisfaction with life define high SWB These studies reveal that happiness and life satisfaction are similarly available to the young and the old, women and men, blacks and whites, the rich and the working-class. Better clues to well-being come from knowing about a person's traits, close relationships, work experiences, culture, and religiosity. We present the elements of an appraisal-based theory of happiness that recognizes the importance of adaptation, cultural world view, and personal goals     

Are research subjects adequately protected? A review and discussion of studies conducted by the Advisory Committee on Human Radiation Experiments

In light of information uncovered about human radiation experiments conducted during the Cold War, an important charge for the Advisory Committee on Human Radiation Experiments was to assess the current state of protections for human research subjects. This assessment was designed to enhance the Committee's ability to make informed recommendations for the improvement of future policies and practices for the protection of research subjects. The Committee's examination of current protections revealed great improvement over those from the past, yet some problems remain. Although the data collected by the Committee highlight specific areas in need of attention, the Committee's work should be viewed in part as the beginning of a series of ongoing assessments of the adequacy and effectiveness of the protections afforded to human subjects.     

Prepulse effects on magnitude estimation of startle-eliciting stimuli and startle responses

The present studies investigated the relationship between prepulse effects on the modification of the brainstem startle reflex and magnitude estimates of startle-eliciting stimuli. In Experiment 1, startle eyeblink responses were elicited in 24 students, half of whom were instructed to estimate the loudness of the startle stimulus (actual intensities of 80, 90, and 100 dB) and half of whom were instructed to estimate the magnitude of their eyeblink. When weak acoustic prepulses preceded the startle-eliciting stimulus, eyeblink amplitude was inhibited, and estimates of response magnitude decreased, but estimates of startle stimulus magnitude decreased only when 100-dB startle stimuli were presented. In Experiment 2, the same startle stimuli were preceded on some trials by a vibrotactile prepulse to the hand. In conditions in which startle amplitude was inhibited, startle stimulus magnitude estimates were not affected. This suggests that the effect of acoustic prepulses on 100-dB startle stimuli in Experiment 1 may have been due to loudness assimilation, an effect independent of the prepulse inhibition of startle responding.     

Behavior of neonates exposed in utero to methadone as assessed on the Brazelton scale

Twenty-nine infants exposed in utero to methadone and 37 comparison infants were examined on the Neonatal Behavioral Assessment Scale at early and late neonatal ages. All infants were full-term at birth, over 2500 g, and not yet circumcised at the early assessment. None of the methadone-exposed infants were breast-fed or were being treated pharmacologically for withdrawal. During the first week of life, methadone-exposed neonates differed from comparison ones in motoric behavior. Relative to comparison-group infants, they were jerkier and more tremulous, tense, active, and better able to put hand in mouth. By the end of the first month these differences diminished, although there was still a tendency for the methadone-exposed infants to have elevated body tonus. Neither perinatal complications, birth weight, nor sex of infant could explain the early neonatal differences between the methadone and comparison groups. Past the early stage of acute withdrawal, neonates exposed prenatally to methadone behave not unlike their nonexposed peers.