Age differences in within-session habituation of exploratory behavior: effects of stimulus complexity

The effects of age on the habituation of exploratory behavior of 8-month- and 28-month-old male C57BL/NNia mice were examined under three different stimulus complexity conditions. Increases in the degree of stimulus complexity resulted in an attenuation of between-session habituation and an initial disruption of within-session habituation by 8-month-old mice. Although increases in stimulus complexity also resulted in an increase in the overall level of exploration by aged mice, stimulus complexity was not found to have a systematic effect on between- or within-session habituation by aged mice. No between-session habituation was observed in aged mice under any of the stimulus complexity conditions. Further, aged mice exhibited significant within-session increases, rather than decreases, in exploration under each stimulus complexity condition. This disruption of within-session habituation in aged mice was found to persist over four daily test sessions. In view of the specific patterns of exploration by aged mice, the disruption of within-session habituation was attributed to age-related differences in reactivity to the arousal-inducing properties of novel stimuli.     

CONDITIONING MODELS OF ANXIETY

A critical examination is made of some behavioristic conceptualizations and treatments of chronic anxiety which are mostly based on a classically-conditioned fear model. A new model is proposed wherein it is assumed that tonic emotional states such as anxiety are more based on instrumental conditioning. This model has been successfully tested in experiments with monkeys. Questions remain about the relevance of this model with regard to the natural actual life etiology of these disorders.     

Scaling of apparent accentedness by magnitude estimation and sensory modality matching

In each of three experiments, 24 students judged the accentedness present in the speech of eight Spanish-English bilinguals.Ss gave magnitude estimations and also squeezed a hand dynamometer to indicate the amount of accentedness in the reading of an English passage by each of the speakers. There was significant agreement amongSs regarding the speech samples with each scaling method, and interscale agreement was good. Power functions fitted to the data had exponents falling in the range expected from earlier psychophysical studies. Scale values correlated significantly with the frequency of accented pronunciations by the speakers as judged by two independent judges. The use of these scaling methods for future research on linguistic features of accent and on the relation between accent and language attitudes is discussed.     

Signal/noise ratios for domain-referenced tests

Using the assumption of randomly parallel tests and concepts from generalizability theory, three signal/noise ratios for domain-referenced tests are developed, discussed, and compared. The three ratios have the same noise but different signals depending upon the kind of decision to be made as a result of measurement. It is also shown that these ratios incorporate a definition of noise or error which is different from the classical definition of noise typically used to characterize norm-referenced tests. Part of the work leading to this paper was accomplished while the authors were assistant professors at the State University of New York at Stony Brook.     

Agonistic screams in wild chimpanzees (Pan troglodytes schweinfurthii) vary as a function of social role

Some nonhuman primates have demonstrated the capacity to communicate about external objects or events, suggesting primate vocalizations can function as referential signals. However, there is little convincing evidence for functionally referential communication in any great ape species. Here, the authors demonstrate that wild chimpanzees (Pan troglodytes schweinfurthii) of Budongo forest, Uganda, give acoustically distinct screams during agonistic interactions depending on the role they play in a conflict. The authors analyzed the acoustic structure of screams of 14 individuals, in the role of both aggressor and victim. The authors found consistent differences in the acoustic structure of the screams, across individuals, depending on the social role the individual played during the conflict. The authors propose that these 2 distinct scream variants, produced by victims and aggressors during agonistic interactions, may be promising candidates for functioning as referential signals.     

Early Adversity and the Prospective Prediction of Depressive and Anxiety Disorders in Adolescents

The current study was a prospective exploration of the specificity of early childhood adversities as predictors of anxiety and depressive disorders in adolescents. Participants were 816 adolescents (414~males, 402 females) with diagnostic information collected at age 15; information on early adversities had been collected from the mothers during pregnancy, at birth, age 6 months, and age 5~years for a related study. Adolescents with pure anxiety disorders were compared with adolescents with pure depressive disorders (major depressive disorder, dysthymia), and these groups were compared to never-ill controls. Analyses controlled for gender and maternal depression and anxiety disorders. Results indicated that adolescents with anxiety disorders were more likely than depressed youth to have been exposed to various early stressors, such as maternal prenatal stress, multiple maternal partner changes, and more total adversities, whereas few early childhood variables predicted depressive disorders. Even when current family stressors at age 15 were controlled, early adversity variables again significantly predicted anxiety disorders. Results suggest that anxiety disorders may be more strongly related to early stress exposure, while depressive disorders may be related to more proximal stressors or to early stressors not assessed in the current study.     

Chronic illness and COVID-19-related risk and protective behaviors

People with chronic illnesses are at increased risk of contracting COVID-19. Still, little is known about whether such an increased risk relates to COVID-19-related protective behaviors among those with chronic illness. This study compares the self-reported COVID-19 risky and protective behaviors—specifically physically distancing, handwashing, and having houseguests—of people (N = 936) (1) living with chronic illnesses or (2) cohabiting with someone with chronic illness to those who fall in neither category at the beginning of the COVID-19 pandemic (April 2020). Study results were mixed: people with a chronic illness were more likely to have had houseguests in the past 5 days and less likely to have increased their handwashing in response to the pandemic, but were also more likely to physical distance when outside the home. Those cohabiting with someone with a chronic illness were more likely to have had houseguests, but did not differ in other outcomes.