The effect of stimulus delivery technique on perceived intensity functions for taste stimuli: Implications for fMRI studies

Classic psychophysical studies have provided significant information on the psychophysical functions for taste stimuli. With the advent of fMRI, studies are being conducted that provide insight into central processing of gustation in humans. However, fMRI experiments impose physical limitations on stimulus delivery. In the present study, we compared psychophysical functions relating perceived intensity to concentration, derived from previous studies that used the traditional sip-and-spit and dorsal flow delivery techniques, to psychophysical functions generated in this study using a simulated stimulus delivery technique (SSDT). The SSDT delivered minute quantities of taste stimuli to the dorsal surface of the tongue, just as in an fMRI scanner. As was hypothesized, the results indicated that slopes of intensity functions were dependent on the type of stimulus delivery technique. The SSDT resulted in slopes that were more similar to those generated by dorsal flow than by sip-andspit stimulus delivery techniques, suggesting the importance of considering the influence of stimulus delivery on psychophysical response in designing and interpreting experiments.     

The Pictorial Fire Stroop: A Measure of Processing Bias for Fire-Related Stimuli

Fire interest is a risk factor for firesetting. This study tested whether a fire-specific emotional Stroop task can effectively measure an information-processing bias for fire-related stimuli. Clinic-referred and nonreferred adolescents (aged 13–16 years) completed a pictorial “Fire Stroop,” as well as a self-report fire interest questionnaire and several control tasks. Results showed (a) comparatively greater fire-specific attentional bias among referred adolescent firesetters, (b) a negative relationship between Fire Stroop attentional bias and self-reported fire interest, and (c) positive correspondence between Fire Stroop attentional bias and self-reported firesetting frequency. These findings suggest that instruments that measure an automatic bias for fire-specific stimuli may usefully supplement self-report measures in the assessment and understanding of firesetting behavior.     

Racial/Ethnic Differences in Internalizing and Externalizing Symptoms in Adolescents

The prevalence of most adult psychiatric disorders varies across racial/ethnic groups and has important implications for prevention and intervention efforts. Research on racial/ethnic differences in the prevalence of internalizing and externalizing symptoms and disorders in adolescents has been less consistent or generally lacking. The current study examined the prevalence of these symptom groups in a large sample of sixth, seventh, and eighth graders in which the three major racial/ethnic groups in the U.S. (White, Black, and Hispanic/Latino) were well-represented. Hispanic females reported experiencing higher levels of depression, anxiety, and reputational aggression than other groups. Black males reported the highest levels of overtly aggressive behavior and also reported higher levels of physiologic anxiety and disordered eating than males from other racial/ethnic groups. Hispanic females also exhibited higher levels of comorbidity than other racial/ethnic groups.     

Comparison of Media-Literacy Programs to Strengthen College Women's Resistance to Media Images

This study examined whether, in comparison to no-intervention and video-only intervention control conditions, two distinct media literacy interventions could promote media skepticism and reduce negative body image in a sample of college women ( N = 110). It was expected that an externally oriented ( i.e., feminist sociocultural) media literacy intervention would have its greatest impact on measures related to media skepticism, while an internally oriented ( i.e., cognitive) intervention would have its greatest impact on measures related to negative body image. Contrary to expectations, in comparison to the no-intervention condition, both media literacy interventions were similar in effectiveness to a video-only ("Slim Hopes," Kilbourne, 1995) condition in increasing participants' skepticism about the realism, similarity, and desirability of media that depict a thin ideal of beauty. There were no between-group differences on negative body image at posttest, suggesting that negative attitudes about one's body may require more extensive, longer-term interventions.     

Reduced right hemisphere activation in severely abused violent offenders during a working memory task: An fMRI study

This study uses functional magnetic resonance imaging (fMRI) to address two important gaps in our knowledge of brain functioning and violence: (1) What are the brain correlates of adults in the community who have suffered severe physical abuse early in life and who go on to perpetrate serious violence in adulthood? (2) What characterizes those who experience severe physical abuse but who refrain from serious violence? Four groups of participants recruited from the community (controls, severe physical child abuse only, serious violence only, and severely abused, seriously violent offenders) underwent fMRI while performing a visual/verbal working memory task. Violent offenders who had suffered severe child abuse show reduced right hemisphere functioning, particularly in the right temporal cortex. Abused individuals who refrain from serious violence showed relatively lower left, but higher right, activation of the superior temporal gyrus. Abused individuals, irrespective of violence status, showed reduced cortical activation during the working memory task, especially in the left hemisphere. Brain deficits were independent of IQ, history of head injury, task performance, cognitive strategy, and mental activity during the control task. Findings constitute the first fMRI study of brain dysfunction in violent offenders, and indicate that initial right hemisphere dysfunction, when combined with the effects of severe early physical abuse, predisposes to serious violence but that relatively good right hemisphere functioning protects against violence in physically abused children. Aggr. Behav. 27:111–129, 2001. © 2001 Wiley‐Liss, Inc.     

Measuring grief: A short version of the perinatal grief scale

Despite a considerable number of studies, there are two major drawbacks in the literature on grief and bereavement. One is a lack of adequate and generally agreed upon measures for assessing grief. The second is a lack of ability to predict from existing measures the likelihood of what has been termed chronic or pathological grief reactions. This paper reports the results of the development of a bereavement measure for the study of perinatal loss which attempts to address these gaps. The measure is specific to a pregnancy-related loss, although it has the potential for adaptation to use for other types of loss. Analysis of responses from 138 women has resulted in the reduction of the original measure from 104 to a more manageable and almost equally comprehensive and reliable 33 items. In addition, a factor analysis has produced three factors, two of which indicate the possibility for longer-term and more severe grief reactions. Because of its sound psychometric qualities and interesting factor structure, the measure shows promise of being useful for both research and clinical purposes.This research was funded by National Institute of Child Health and Human Development Grant R01 H18431-04, with additional assistance from the Center for Social Research at Lehigh University. Dr. Potvin is supported by the Quebec Health Research Fund.     

Diagnosticity,confidence, and the need for information

Recent research has suggested that people prefer to use the most diagnostic available information as the basis for their choices and decisions, and are most confident in those decisions when information is highly diagnostic. However, the effect of information diagnosticity on the need for additional information has yet to be investigated; that is, in an optional stopping task, will the amount of information requested depend upon information diagnosticity? Three models of the role of diagnosticity in information use were examined; expected value, a confidence criterion, and information cost. Subjects attempted to categorize stimuli with the aid of information of varying costs and diagnosticity levels. They requested more information when it was obtained at a low cost. More importantly, across cost conditions, subjects consistently requested greater amounts of information when that information was of a low diagnosticity. These data seem most consistent with use of a confidence criterion that is adjusted for information costs.