Relationship between heart rate variability and cognitive function during threat of shock

The aim of the present study was to investigate the relationship between resting heart rate variability (HRV) and cognitive functions during threat of shock. A Continuous Performance Task and a Working Memory Task were used to measure cognitive functions. Sixty-five male participants from the Royal Norwegian Navy participated. HRV was measured during baseline, test conditions and recovery. Participants were randomly assigned into non-threat and threat groups. Based on the median split of the high frequency (HF) spectral power, groups were divided into two additional groups. Overall, the high HRV participants showed superior performance on cognitive tasks independent of non-threat or threat conditions. During threat condition the low HRV group showed improved performance. Thus, individuals with high HRV were more stress tolerant and resilient in the face of environmental changes. The results from the study might have implications with regard to performance in operational settings, but also for other fields of psychological research such as individual differences, anxiety and coping.     

More on EM for ML factor analysis

We address several issues that are raised by Bentler and Tanaka's [1983] discussion of Rubin and Thayer [1982]. Our conclusions are: standard methods do not completely monitor the possible existence of multiple local maxima; summarizing inferential precision by the standard output based on second derivatives of the log likelihood at a maximum can be inappropriate, even if there exists a unique local maximum; EM and LISREL can be viewed as complementary, albeit not entirely adequate, tools for factor analysis.This work was partially supported by the Program Statistics Research Project at Educational Testing Service.     

The sensitization of humor responses to cartoons

It was hypothesized that a humor response to a cartoon in a series depends upon arousal or increased salience, both of which may be produced by preceding cartoons. A humor response, however, should eventually decline owing to habituation. Three experiments were conducted in order to determine if responding to cartoons with the same theme depends upon the cartoon's serial position. Facial responses and ratings of funniness increased over the first few cartoons, reflecting the effect of arousal or salience. It appears that the initial cartoons make the person more sensitive to later cartoons. A downward trend in responding was more apparent for facial responses than for funniness ratings. The evidence for habituation was weak, however, and did not seem occur to the experimenter-defined cartoon theme. Cartoons even representing the same theme may be too variable to permit habituation. It was suggested that cartoon researchers be aware of the effect of a cartoon's serial position on humor responses.The investigators would like to thank Michael Davis, Michael Mullins, and Elizabeth Weaver for their assistance in data collection and analyses.     

Linear representation of temporal location and Stevens’s law

Ss were asked to indicate points 1 week, 7 months, 3 years, and 9 years in the past and future on two time lines representing birth to present and present to death. Data for 90 college-age Ss fit a psychophysical power function following Stevens’s law. with negatively accelerated growth indicating proportionately greater linear representation of periods nearer to the present. Variability was greater for the representations of the future than of the past, with monotonic increases in variability as distance from the present increased.     

Bayesian inference and the classical test theory model: Reliability and true scores

A general one-way analysis of variance components with unequal replication numbers is used to provide unbiased estimates of the true and error score variance of classical test theory. The inadequacy of the ANOVA theory is noted and the foundations for a Bayesian approach are detailed. The choice of prior distribution is discussed and a justification for the Tiao-Tan prior is found in the particular context of the “n-split” technique. The posterior distributions of reliability, error score variance, observed score variance and true score variance are presented with some extensions of the original work of Tiao and Tan. Special attention is given to simple approximations that are available in important cases and also to the problems that arise when the ANOVA estimate of true score variance is negative. Bayesian methods derived by Box and Tiao and by Lindley are studied numerically in relation to the problem of estimating true score. Each is found to be useful and the advantages and disadvantages of each are discussed and related to the classical test-theoretic methods. Finally, some general relationships between Bayesian inference and classical test theory are discussed. Supported in part by the National Institute of Child Health and Human Development under Research Grant 1 PO1 HDO1762. Reproduction, translation, use or disposal by or for the United States Government is permitted.     

The ability to self-tickle following Rapid Eye Movement sleep dreaming

Self-produced tactile stimulation usually feels less tickly--is perceptually attenuated--relative to the same stimulation produced externally. This is not true, however, for individuals with schizophrenia. Here, we investigate whether the lack of attenuation to self-produced stimuli seen in schizophrenia also occurs for normal participants following REM dreams. Fourteen participants were stimulated on their left palm with a tactile stimulation device which allowed the same stimulus to be generated by the participant or by the experimenter. The level of self-tickling attenuation did not differ between REM and non-REM sleep awakening conditions, where presence or absence of an accompanying dream was not controlled for. However, for the female participants, when awakening occurred from an REM sleep dream, self-stimulation ratings were higher than for external stimulation, whereas ratings after NREM sleep unaccompanied by a dream were lower for self-stimulation than for external stimulation. These results indicate deficits in self-monitoring and a confusion between self- and externally generated stimulation accompany REM dream formation.     

Exercising for mood regulation: The importance of experience

Based on the theory that mood regulation can be an important motivation for regular exercise, but only after the subtle mood effects derived from this activity are discovered, exercisers (N = 168) with varying levels of exercise experience completed the Reasons for Exercise Inventory (REI; Silberstein, Striegel-Moore, Timko & Rodin, 1988), as well as Neuroticism and Extra version measures (Costa & McCrae, 1989). A reexamination of the REI yielded a 5-factor instead of the original 7-factor structure. As expected, advanced exercisers rated the importance of Mood Improvement higher than beginners. Advanced exercisers also rated Socialization higher. Those above the median on Neuroticism rated Mood Improvement higher than lower scorers. Gender and age differences were also found. Results have implications for more effective exercise promotion.