TouchStat: A Monte Carlo program for calculating sequential touching probabilities

A growing number of child cognition researchers are using an object-manipulation, sequential-touching paradigm to explore young children’s conceptual abilities. Within this paradigm, it is essential to distinguish children’s intracategory touching sequences from those expected by chance. The sequentialtouching approach is congruent with a permutation testing model of statistical inference and is best modeled by sampled permutations as derived from Monte Carlo procedures. In this article, we introduce a computer program for generating Monte Carlo sequential-touching simulations. TouchStat permits users to determine their own specifications to simulate sequential touching to category exemplars across a wide range of task parameters. We also present Monte Carlo chance probabilities for the standard two-category, four-exemplar task, with sequences up to 30 touches long. Finally, we consider broader applications of the TouchStat program.     

Perception of different frequencies of cranial transcutaneous electrical nerve stimulation in normal and HIV-positive individuals.

Sine-wave transcutaneous electrical nerve stimulation (TENS) of varying frequencies applied across the cranium (ear to ear) has been demonstrated to evoke three different noncutaneous sensations in three discrete, nonoverlapping frequency bands in normal, healthy subjects. This report describes two studies which evaluate perception of these cranial TENS-evoked, frequency-dependent sensations in normal and HIV-positive individuals. In Exp. I, all of 50 normal, healthy subjects reported perceiving the same three noncutaneous sensations in the same three nonoverlapping frequency bands as long as stimulated and over repeated trials. In Exp. II, 34 HIV-positive individuals (14 asymptomatic, 9 ARC, 11 AIDS) who were free of neurological symptoms differed significantly from 10 normal, healthy controls, and from the norms observed in Exp. I, on perception of the three different TENS-evoked sensations. Also, inability to maintain perception of the stimulus over repeated trials, observed only in the HIV-positive individuals, increased significantly with severity of HIV infection.     

Capital punishment in Missouri: Examining the issue of racial disparity

Guided discretion statutes were designed to control arbitrariness and discrimination in capital sentencing. Using data from Supplemental Homicide Reports and Trial Judge Reports, this article examines the issue of racial disparity in Missouri's capital punishment process from 1977 through 1991. Findings from the three decision points examined suggest racial bias against the killers of whites, particularly if the offender is black, and a concomitant devaluation of black victims. The strongest effects noted are in the prosecutor's decision to charge homicide offenders with capital murder and to proceed to penalty trial in convicted capital murder cases. While the effects are not necessarily limited to the least aggravated categories, the effects of race are strongest when prosecutors and jurors are freed from the seriousness of the cases to consider other factors. The racial disparities are also apparent in mid-range cases up until the sentencing stage. However, disparities occurring earlier in the process are not rectified during sentencing. In fact, in the least aggravated cases, racial disparities are magnified at the sentencing stage.     

Legal ethics and the use of mental health experts in criminal cases

The ethical norms of attorneys in mental health law practice are guided by regulatory codes, professional standards, constitutional, evidentiary, and procedural laws, and personal moral values. This article addresses the contours of ethical practice for attorneys in their relationship with mental health experts. In particular, it examines the attorney's responsibility to zealously represent their clients and the ethical limits on such advocacy.     

Distorted cognitive maps: college students' misperceptions of nation size

On a questionnaire 256 college students reported a number of distorted views concerning the sizes of nations in the world and these distortions appeared to generalize to geographic regions. Considering that individual cognitive maps are commonly used to assess new information about the global environment, these inherent distortions could significantly bias the students' views of the world.     

Developmental changes in the multisensory temporal binding window persist into adolescence

We live in a world rich in sensory information, and consequently the brain is challenged with deciphering which cues from the various sensory modalities belong together. Determinations regarding the relatedness of sensory information appear to be based, at least in part, on the spatial and temporal relationships between the stimuli. Stimuli that are presented in close spatial and temporal correspondence are more likely to be associated with one another and thus 'bound' into a single perceptual entity. While there is a robust literature delineating behavioral changes in perception induced by multisensory stimuli, maturational changes in multisensory processing, particularly in the temporal realm, are poorly understood. The current study examines the developmental progression of multisensory temporal function by analyzing responses on an audiovisual simultaneity judgment task in 6- to 23-year-old participants. The overarching hypothesis for the study was that multisensory temporal function will mature with increasing age, with the developmental trajectory for this change being the primary point of inquiry. Results indeed reveal an age-dependent decrease in the size of the 'multisensory temporal binding window', the temporal interval within which multisensory stimuli are likely to be perceptually bound, with changes occurring over a surprisingly protracted time course that extends into adolescence.