Dissecting adrenal and behavioral responses to stress by targeted gene inactivation in mice

To define the molecular pathways modulating adrenal and behavioral responses to stress, we have generated mice with inactivation of hypothalamic neuropeptides and signaling pathways. Studies in mice deficient in corticotropin-releasing hormone (CRH) have revealed the essential role for CRH in adrenal glucocorticoid production in response to many physiological and psychological stressors. Immune system activation in CRH-deficient mice provides a unique exception to the necessity for CRH in stimulating adrenal glucocorticoid production. By analyzing mice deficient in interleukin-6 (IL-6) and CRH, we find that restoration of glucocorticoid output with inflammation is largely mediated by dysregulated IL-6 production. Current studies focus on identifying cellular and gene targets by which glucocorticoids regulate immune system function. In contrast to impaired adrenocortical responses to stress, CRH-deficient mice exhibit normal behavioral responses to stress. To determine signaling pathways that may contribute to the behavioral responses to stress, we have generated and analyzed mice deficient in adenylyl cyclase type 8 (AC8). AC8 deficient mice have intact adrenocortical responses to stress, but an inability to undergo stress-induced alterations in behavior.     

Attributional biases in the service of stereotype maintenance: a schema-maintenance through compensation analysis

Six experiments were conducted to test assumptions of a schema-maintenance through compensation analysis. The results of these experiments indicated that perceivers can compensate for the inconsistent action of one individual (the target) by altering their attribution concerning the action of a fellow group member. When the target performed an inconsistent behavior, perceivers compensated by making especially extreme stereotypically consistent attributions concerning a fellow group member's subsequent action. In addition, in Experiment 5, perceivers compensated via a fellow group member for a target's inconsistent action while maintaining their general view of group members. Experiments also provided tests of the capability and motivation assumptions of the schema-maintenance through compensation analyses.     

Empirical fear profiles among American youth

Fears among children can range from relatively innocuous fears of simple objects to significant phobias that affect youths' everyday functioning in the home, school, or community environments. This study investigated empirically derived fear profiles among American youth ages 7-19 (N=556). Based upon youths' scores on the 5 factors of the Fear Survey Schedule for Children-II (FSSC-II; Burnham & Gullone (Behav Res Ther, 35, 1997)), multistage Euclidean grouping was applied and produced 5 replicable fear cluster profiles with unique contours. Logistic regression odds ratios revealed specific associations of profile group membership with demographic characteristics such as child age, sex, and ethnicity.     

A test of object permanence in a new-world monkey species,cotton top tamarins (<Emphasis Type="Italic">Saguinus oedipus</Emphasis>)

Cotton top tamarins were tested in visible and invisible displacement tasks in a method similar to that used elsewhere to test squirrel monkeys and orangutans. All subjects performed at levels significantly above chance on visible (n=8) and invisible (n=7) displacements, wherein the tasks included tests of the perseverance error, tests of memory in double and triple displacements, and "catch" trials that tested for the use of the experimenter's hand as a cue for the correct cup. Performance on all nine tasks was significantly higher than chance level selection of cups, and tasks using visible displacements generated more accurate performance than tasks using invisible displacements. Performance was not accounted for by a practice effect based on exposure to successive tasks. Results suggest that tamarins possess stage 6 object permanence capabilities, and that in a situation involving brief exposure to tasks and foraging opportunities, tracking objects' movements and responding more flexibly are abilities expressed readily by the tamarins. Electronic Publication     

Differences from somewhere: the normativity of whiteness in bioethics in the United States

I argue that there has been inadequate attention to and questioning of the dominance and normativity of whiteness in the cultural construction of bioethics in the United States. Therefore we risk reproducing white privilege and white supremacy in its theory, method, and practices. To make my argument, I define whiteness and trace its broader social and legal history in the United States. I then begin to mark whiteness in U.S. bioethics, recasting Renee Fox's sociological marking of its American-ness as an important initial marking of its whiteness/WASP ethos. Furthermore, I consider the attempts of social scientists to highlight sociocultural diversity as a corrective in U.S. bioethics. I argue that because they fail to problematize white dominance and normativity and the white-other dualism when they describe the standpoints of African-American, Asian-American, and Native-American others, their work merely inoculates difference and creates or maintains minoritized spaces. Accordingly, the dominant white center of mainstream U.S. bioethics must be problematized and displaced for diversity research to make a difference. In conclusion, I give several examples of how we might advance the recommended endeavor of exploring our own ethnicity, class, and other social positioning and norms operating in U.S. bioethics, briefly highlighting "white talk" as one challenge.     

Frontal electroencephalogram alpha asymmetry during sleep: stability and its relation to affective style

Electroencephalogram (EEG) alpha (8-12 Hz) asymmetries were collected from the mid-frontal and central regions during presleep wakefulness and Stage 1, Stage 2, and rapid eye movement (REM) sleep in 11 healthy right-handed participants who were free of psychiatric, neurological, and sleep problems. The authors found significant correlations between presleep wakefulness and different stages of sleep in the frontal, but not central, EEG alpha asymmetry measure. The strongest correlation was between presleep waking and REM sleep, replicating and extending relation earlier work to a normal population. The high degree of association between presleep waking and REM sleep may be a result of high cortical activation common to these states and may reflect a predisposition to different styles of emotional reactivity.     

The body-inversion effect

Researchers argue that faces are recognized via the configuration of their parts. An important behavioral finding supporting this claim is the face-inversion effect, in which inversion impairs recognition of faces more than nonface objects. Until recently, faces were the only class of objects producing the inversion effect for untrained individuals. This study investigated whether the inversion effect extends to human body positions, a class of objects whose exemplars are structurally similar to each other. Three experiments compared the recognition of upright and inverted faces, houses, and body positions using a forced-choice, same/different paradigm. For both reaction time and error data, the recognition of possible human body postures was more affected by inversion than the recognition of houses. Further, the recognition of possible human body postures and recognition of faces showed similar effects of inversion. The inversion effect was diminished for impossible body positions that violated the biomechanical constraints of human bodies. These data suggest that human body positions, like faces, may be processed configurally by untrained viewers.     

Expertise in tactile pattern recognition

This article explores expertise in tactile object recognition. In one study, participants were trained to differing degrees of accuracy on tactile identification of two-dimensional patterns. Recognition of these patterns, of inverted versions of these patterns, and of subparts of these patterns was then tested. The inversion effect (better recognition of upright than inverted patterns) and the part-whole effect (better recognition of the whole than a part pattern), traditionally considered signatures of visual expertise, were observed for tactile experts but not for novices. In a second study, participants were trained as visual or tactile experts and then tested in the trained and nontrained modalities. Whereas expertise effects were observed in the modality of training, cross-modal transfer was asymmetric; visual experts showed generalization to haptic recognition, but tactile experts did not show generalization to visual recognition. Tactile expertise is not obviously attributable to visual mediation and emerges from domain-general principles that operate independently of modality.