A behavior-based circuit model of how outcome expectations organize learned behavior in larval Drosophila

Drosophila larvae combine a numerically simple brain, a correspondingly moderate behavioral complexity, and the availability of a rich toolbox for transgenic manipulation. This makes them attractive as a study case when trying to achieve a circuit-level understanding of behavior organization. From a series of behavioral experiments, we suggest a circuitry of chemosensory processing, odor-tastant memory trace formation, and the "decision" process to behaviorally express these memory traces--or not. The model incorporates statements about the neuronal organization of innate vs. conditioned chemosensory behavior, and the types of interaction between olfactory and gustatory pathways during the establishment as well as the behavioral expression of odor-tastant memory traces. It in particular suggests that innate olfactory behavior is responsive in nature, whereas conditioned olfactory behavior is captured better when seen as an action in pursuit of its outcome. It incorporates the available neuroanatomical and behavioral data and thus should be useful as scaffold for the ongoing investigations of the chemo-behavioral system in larval Drosophila.     

Reviewers and the Detection of Deceptive Information in Recorded Interviews

Being able to detect deceptive information early is worthwhile for recruiters and other information‐based organizational workers; unfortunately, people generally are not good at detecting deception successfully. We conducted an experiment to determine how successful reviewers can be at detecting deception in several types of dispersed interviews. The results indicated that reviewers were more accurate at detecting deceptive information than were participant interviewers; that a warning about deception's presence improved reviewers' detection accuracy; and that a warning did not have any effect on reviewers' number of false alarms between text and audio media. These findings imply that if reviewers are warned about the possible presence of deception, organizations might be able to minimize the chance of hiring high‐risk job applicants.     

Why additional presentations help identify a stimulus

Nosofsky (1983) reported that additional stimulus presentations within a trial increase discriminability in absolute identification, suggesting that each presentation creates an independent stimulus representation, but it remains unclear whether exposure duration or the formation of independent representations improves discrimination in such conditions. Experiment 1 replicated Nosofsky's result. Experiments 2 (masking the ISI between two-presentations) and 3 (manipulating stimulus duration without changing number of presentations or overall trial duration) ruled out an explanation in terms of extended opportunities for stimulus sampling, from either a sensory buffer during additional ISIs or increased stimulus exposure, respectively. Experiment 4 (comparing two and three-presentations, other factors controlled) provided some limited additional support for Nosofsky's original claim that additional stimulus presentations can create either independent or duplicate representations. Experiments 5 and 6 (both manipulating ISI) demonstrated that a key factor in the additional stimulus presentation effect is the overall trial duration. We discuss the results in relation to models of absolute identification, their relative emphasis on stimulus sampling versus response selection, and the mechanisms by which duplicate representations could be created.     

Error-statistical elimination of alternative hypotheses

I consider the error-statistical account as both a theory of evidence and as a theory of inference. I seek to show how inferences regarding the truth of hypotheses can be upheld by avoiding a certain kind of alternative hypothesis problem. In addition to the testing of assumptions behind the experimental model, I discuss the role of judgments of implausibility. A benefit of my analysis is that it reveals a continuity in the application of error-statistical assessment to low-level empirical hypotheses and highly general theoretical principles. This last point is illustrated with a brief sketch of the issues involved in the parametric framework analysis of tests of physical theories such as General Relativity and of fundamental physical principles such as the Einstein Equivalence Principle.     

Empathic deficits and alexithymia in trauma-related impulsive aggression

Our long term interest is to develop a developmental model of impulsive aggression based on a confluence of social, psychological and biological features. This approach incorporates neurobiological research, which has identified language processing deficits as a unique characteristic of impulsive aggressors and extends it to include emotional deficits. As an initial test of this hypothesis, we examined whether empathy and alexithymia were associated with impulsive aggression. Regressions were performed to explore the associations among impaired empathy, alexithymia, impulsive aggression, verbal and physical general aggression. Among impulsive aggressive veterans (n = 38) recruited from a VA trauma clinic, alexithymia predicted impulsive aggression and empathic deficits predicted verbal aggression. Neither emotional awareness deficit predicted general physical aggression in this middle-aged sample. Results suggested that empathic deficits were associated with general verbal aggression, but alexithymia was uniquely associated with impulsive aggression. Consideration of alexithymia in impulsive aggression has implications for its etiology, prevention and treatment. Published in 2008 by John Wiley & Sons, Ltd.     

Personal Income and Attitudes toward Redistribution: A Study of Lottery Winners

In order to estimate the effects of affluence on political attitudes, we conducted interviews with 342 people who had won the lottery between 1983 and 2000 in an Eastern state. A parallel survey of the general public was also conducted. Comparing winners of varying amounts, we find that lottery-induced affluence increases hostility toward estate taxes, marginally increases hostility towards government redistribution, but has little effect on broader attitudes concerning economic stratification or the role of government as a provider of social insurance. These results bolster previous findings suggesting that economic self-interest influences policy preferences when policy consequences are perceived as salient. At the same time, the findings suggest the limited influence that material concerns have on one's broad political outlook.     

The Use of Humor When Counseling African American College Students

According to the literature, humor is a critical tool to enhance the counseling process because it can reduce stress, build rapport, and aid in the increase of the client's self‐efficacy. In recent years, the critical nature of using humor appropriately from a cultural perspective has been explored. In this article, the authors further explore the cultural foundations, purpose, effectiveness, and implications of using humor when counseling African American college students.     

Does Friendship Matter? An Examination of Social Physique Anxiety in Adolescence1

The role of peer group composition and influence variables on social physique anxiety was examined. Peer network data were gathered on 375 adolescents (181 male, 194 female). Females reported experiencing higher social physique anxiety, more pressure and encouragement to alter their physique from peers, greater body‐related discussion, and greater identification with the peer group than did males. Regression analyses revealed 2 peer influence variables—peer pressure and relative attractiveness of peers—to be significant predictors of social physique anxiety. A third variable—extent to which the individual identified with peer network—was a significant predictor for females. Results are discussed in reference to previous research, and future research directions are identified.     

Natural variation in Drosophila larval reward learning and memory due to a cGMP-dependent protein kinase

Animals must be able to find and evaluate food to ensure survival. The ability to associate a cue with the presence of food is advantageous because it allows an animal to quickly identify a situation associated with a good, bad, or even harmful food. Identifying genes underlying these natural learned responses is essential to understanding this ability. Here, we investigate whether natural variation in the foraging (for) gene in Drosophila melanogaster larvae is important in mediating associations between either an odor or a light stimulus and food reward. We found that for influences olfactory conditioning and that the mushroom bodies play a role in this for-mediated olfactory learning. Genotypes associated with high activity of the product of for, cGMP-dependent protein kinase (PKG), showed greater memory acquisition and retention compared with genotypes associated with low activity of PKG when trained with three conditioning trials. Interestingly, increasing the number of training trials resulted in decreased memory retention only in genotypes associated with high PKG activity. The difference in the dynamics of memory acquisition and retention between variants of for suggests that the ability to learn and retain an association may be linked to the foraging strategies of the two variants.