Absolute auditory thresholds in three Old World monkey species (Cercopithecus aethiops, C. neglectus, Macaca fuscata) and humans (Homo sapiens)

We investigated the absolute auditory sensitivities of three monkey species (Cercopithecus aethiops, C. neglectus, and Macaca fuscata) and humans (Homo sapiens). Results indicated that species-typical variation exists in these primates. Vervets, which have the smallest interaural distance of the species that we tested, exhibited the greatest high-frequency sensitivity. This result is consistent with Masterton, Heffner, and Ravizza's (1969) observations that head size and high-frequency acuity are inversely correlated in mammals. Vervets were also the most sensitive in the middle frequency range. Furthermore, we found that de Brazza's monkeys, though they produce a specialized, low-pitched boom call, did not show the enhanced low-frequency sensitivity that Brown and Waser (1984) showed for blue monkeys (C. mitis), a species with a similar sound. This discrepancy may be related to differences in the acoustics of the respective habitats of these animals or in the way their boom calls are used. The acuity of Japanese monkeys was found to closely resemble that of rhesus macaques (M. mulatta) that were tested in previous studies. Finally, humans tested in the same apparatus exhibited normative sensitivities. These subjects responded more readily to low frequencies than did the monkeys but rapidly became less sensitive in the high ranges.     

Schedule-induced polydipsia in rats living in an operant environment

The effect of variations in interreinforcement interval on the temporal and distributional relation between feeding and drinking was continuously monitored. Rats were housed continuously in an operant chamber in which water was freely available, but lever pressing was required to obtain food (45-mg pellets). Initially, pellets were delivered on a fixed-ratio 1 schedule of reinforcement, which was followed by testing on response-initiated fixed-interval 15-, 30-, and 60-second schedules. The total number of discrete, daily meals (a period in which several pellets were earned in succession) was slightly higher during the fixed-interval schedules than during the fixed-ratio 1, but there was no systematic effect of fixed-interval length on meal frequency. Total water consumption, in contrast, increased dramatically as the interval was lengthened: both subjects consumed two to three times as much water on the fixed-interval 60-second schedule as on the fixed-ratio 1. The increased water consumption was the result of an alteration in the distribution of drinking relative to eating. During the fixed-ratio 1 condition, drinking occurred infrequently following individual food pellets and represented the smallest percentage of total drinking; drinking occurred predominantly just before or after a meal. As the fixed interval was lengthened, however, the frequency of postpellet drinking gradually increased and eventually comprised the largest proportion of daily drinking.     

Genetic Counseling Outcomes: Perceived Risk and Distress After Counseling for Hereditary Colorectal Cancer

Genetic counseling may turn risk information into cancer prevention behavior by modifying health beliefs and cancer-related distress. We assessed the effect of genetic counseling on these factors in 101 adult first-degree-relatives of colorectal cancer patients from families with known or suspected hereditary nonpolyposis colorectal cancer. Before counseling and once afterward, subjects completed self-report measures of perceived lifetime risk and cancer-distress. Most persons overestimated their cancer risk, and higher perceived risk was associated with believing that colorectal cancer cannot be prevented. Individual perceived risk changed after counseling, although mean perceived risk was unchanged. After adjusting for baseline risk, older persons and those with higher estimated objective cancer risk had larger postcounseling decreases. Distress after counseling was positively correlated with baseline distress and anxiety symptoms, and inversely correlated with tolerance for ambiguity. The findings suggest counseling interventions that should increase the likelihood of screening and offer hypotheses for future research.     

Moralizing the COVID-19 Pandemic: Self-Interest Predicts Moral Condemnation of Other's Compliance,Distancing, and Vaccination

The emergence of the novel coronavirus has put societies under tremendous pressure to instigate massive and rapid behavior change. Throughout history, an effective strategy to facilitate novel behaviors has been to morally condemn those who do not behave in an appropriate way. Accordingly, here, we investigate if complying with the advice of health authorities—for example, to physically distance or vaccinate—has emerged as a moralized issue during the COVID-19 pandemic. In Study 1, we rely on data (N = 94K) from quota-sampled rolling cross-sectional online surveys from eight countries (Denmark, Sweden, Germany, France, Italy, Hungary, the United Kingdom, and the United States). We find that large majorities find it justified to condemn those who do not keep a distance to others in public and around half of respondents blame ordinary citizens for the severity of the pandemic. Furthermore, we identify the most important predictors of condemnation to be behavior change and personal concern, while institutional trust and social distrust also play large but less consistent roles. Study 2 offers a registered replication of our findings on a representative sample of Britons (N = 1.5K). It shows that both moralization and condemnation of both vaccination and general compliance are best predicted by self-interested considerations.     

PET AS PART OF AN INTERDISCIPLINARY APPROACH TO UNDERSTANDING PROCESSES INVOLVED IN READING

Abstract— Positron emission tomography (PET) is a recently developed technology that can be used to create images of brain blood flow, which is related to brain activity. By acquiring images of brain blood flow during different task conditions, investigators can isolate activity changes related to specific types of information processing. Several examples demonstrate how regions involved in reading can be identified, and how the results are most interpretable when information from other disciplines is considered.     

The Effect of Punishment Probability on Overconsumption and Stealing in a Simulated Commons1

In laboratory simulations of the commons dilemma, overconsumption depletes the shared resource, whereas allowing the players to steal from each other helps preserve the resource since players take from each other rather than from the central supply. In this study, we factorially crossed three levels of punishment probability for overconsumption (0%, 25%, 75%) with three levels of probability of punishment for stealing (0%, 25%, 75%). Subjects (n= 270) in three-person groups harvested points from a slowly regenerating central pool. Results indicated that punishment of overconsumption decreased overconsumption, increased stealing, and helped preserve the commons, whereas punishment of stealing decreased stealing, increased overconsumption, and facilitated depletion of the commons. Rather than punishment of one selfish behavior suppressing the other selfish behavior, a compensatory effect occurred: Punishment of one behavior increased the occurrence of the selfish alternative.     

The effect of exposure duration on visual character identification in single, whole, and partial report

The psychometric function of single-letter identification is typically described as a function of stimulus intensity. However, the effect of stimulus exposure duration on letter identification remains poorly described. This is surprising because the effect of exposure duration has played a central role in modeling performance in whole and partial report (Shibuya & Bundesen, 1988). Therefore, we experimentally investigated visual letter identification as a function of exposure duration. We compared the exponential, the gamma, and the Weibull psychometric functions, all with a temporal offset included, as well as the ex-Gaussian, the log-logistic, and finally the squared-logistic, which is a psychometric function that to our knowledge has not been described before. The log-logistic and the squared-logistic psychometric function fit well to experimental data. Also, we conducted an experiment to test the ability of the psychometric functions to fit single-letter identification data, at different stimulus contrast levels; also here the same psychometric functions prevailed. Finally, after insertion into Bundesen's Theory of Visual Attention (Bundesen, 1990), the same psychometric functions enable closer fits to data from a previous whole and partial report experiment.     

Measuring and modeling attentional dwell time

Attentional dwell time (AD) defines our inability to perceive spatially separate events when they occur in rapid succession. In the standard AD paradigm, subjects should identify two target stimuli presented briefly at different peripheral locations with a varied stimulus onset asynchrony (SOA). The AD effect is seen as a long-lasting impediment in reporting the second target, culminating at SOAs of 200?C500?ms. Here, we present the first quantitative computational model of the effect??a theory of temporal visual attention. The model is based on the neural theory of visual attention (Bundesen, Habekost, & Kyllingsb?k, Psychological Review, 112, 291?C328 2005) and introduces the novel assumption that a stimulus retained in visual short-term memory takes up visual processing-resources used to encode stimuli into memory. Resources are thus locked and cannot process subsequent stimuli until the stimulus in memory has been recoded, which explains the long-lasting AD effect. The model is used to explain results from two experiments providing detailed individual data from both a standard AD paradigm and an extension with varied exposure duration of the target stimuli. Finally, we discuss new predictions by the model.