The optimum decision rules in thesame-different paradigm

In this paper we derive the optimum (likelihood-ratio) decision statistic for asame-different paradigm. The likelihood ratio is dependent on the degree of correlation between the two observations on each trial. For the two extreme cases in which the observations are either independent or highly correlated, the optimum decision rule is identical to each of two previously suggested decision rules. For these two cases, the receiver-operating characteristic (ROC) curves are calculated. Finally, an experimental procedure is suggested for assessing the decision rule actually used by the observer in asame-different task.     

The optimum decision rules for the oddity task

This paper presents the optimum decision rule for an m-interval oddity task in whichm-1 intervals contain the same signal and one is different or odd. The optimum decision rule depends on the degree of correlation among observations. The present approach unifies the different strategies that occur with “roved” or “fixed” experiments (Macmillan & Creelman, 1991, p. 147). It is shown that the commonly used decision rule for anm-interval oddity task corresponds to the special case of highly correlated observations. However, as is also true for thesame-different paradigm, there exists a different optimum decision rule when the observations are independent. The relation between the probability of a correct response andd’ is derived for the three-interval oddity task. Tables are presented of this relation for the three-, four-, and five-interval oddity task. Finally, an experimental method is proposed that allows one to determine the decision rule used by the observer in an oddity experiment.     

Similarity bias in credit decisions for entrepreneurs on the brink of bankruptcy

For entrepreneurs in financial distress, it is of vital importance that investors and bankers accurately assess the viability of their business, free of unwanted biases that bear no relevance to the assessment of the chance of survival. Despite the prevalence of entrepreneurs facing financial distress, little research has yet investigated the role of cognitive biases in funding decisions in this important context. The current research attends to this issue and investigated whether entrepreneurs who are perceived by a banker as more similar are more likely to receive capital to save their business from bankruptcy than entrepreneurs who are perceived as less similar to the banker. Additionally, we investigated whether similarity bias affected bankers' attributions of what caused the financial distress as well as their perceptions of entrepreneurs' trustworthiness. Using an experimental research design, we found a similarity bias in bankers' causal attributions and trustworthiness judgments, but not in their credit decisions. We contrast our findings with similarity bias research among equity investors and discuss the implications for theory and practice.     

Affective stimulus properties influence size perception and the Ebbinghaus illusion

In the New Look literature of the 1950s, it has been suggested that size judgments are dependent on the affective content of stimuli. This suggestion, however, has been 'discredited' due to contradictory findings and methodological problems. In the present study, we revisited this forgotten issue in two experiments. The first experiment investigated the influence of affective content on size perception by examining judgments of the size of target circles with and without affectively loaded (i.e., positive, neutral, and negative) pictures. Circles with a picture were estimated to be smaller than circles without a picture, and circles with a negative picture were estimated to be larger than circles with a positive or a neutral picture confirming the suggestion from the 1950s that size perception is influenced by affective content, an effect notably confined to negatively loaded stimuli. In a second experiment, we examined whether affective content influenced the Ebbinghaus illusion. Participants judged the size of a target circle whereby target and flanker circles differed in affective loading. The results replicated the first experiment. Additionally, the Ebbinghaus illusion was shown to be weakest for a negatively loaded target with positively loaded and blank flankers. A plausible explanation for both sets of experimental findings is that negatively loaded stimuli are more attention demanding than positively loaded or neutral stimuli.     

Are There Cross-Cultural Legal Principles? Modal Reasoning Uncovers Procedural Constraints on Law

Despite pervasive variation in the content of laws, legal theorists and anthropologists have argued that laws share certain abstract features and even speculated that law may be a human universal. In the present report, we evaluate this thesis through an experiment administered in 11 different countries. Are there cross-cultural principles of law? In a between-subjects design, participants (N = 3,054) were asked whether there could be laws that violate certain procedural principles (e.g., laws applied retrospectively or unintelligible laws), and also whether there are any such laws. Confirming our preregistered prediction, people reported that such laws cannot exist, but also (paradoxically) that there are such laws. These results document cross-culturally and –linguistically robust beliefs about the concept of law which defy people's grasp of how legal systems function in practice.     

Framing prisoners and chickens: Valence effects in the prisoner’s dilemma and the chicken game

In an experimental study, we investigated how decisions in social dilemmas are affected by the valence of outcomes that are at stake. Prospect theory states that individuals are risk-averse when outcomes are framed as gains, and risk-seeking when outcomes are framed as losses. On the basis of this framework, previous research on social dilemmas has addressed the question of whether people are more cooperative in the negative domain than in the positive domain, but this research has led to inconsistent results. A possible explanation for this is that in many social dilemmas it is unclear whether cooperation or defection is the risky choice. In the current paper, we compare the well-studied prisoner’s dilemma with the less studied chicken game. Whereas in the prisoner’s dilemma it is unclear what constitutes the risky option, in the chicken game the risky option is quite clear. Consistent with predictions, we found in the chicken game more defection in the loss frame than in the gain frame, but no difference between the gain and loss frame in the prisoner’s dilemma. Moreover, choices were predicted by risk attitude in the chicken game, but not in the prisoner’s dilemma.     

Hindsight bias and outcome bias in judging directors’ liability and the role of free will beliefs

Following a corporate disaster such as bankruptcy, people in general and damaged parties, in particular, want to know what happened and whether the company's directors are to blame. The accurate assessment of directors’ liability can be jeopardized by having to judge in hindsight with full knowledge of the adverse outcome. The present study investigates whether professional legal investigators such as judges and lawyers are affected by hindsight bias and outcome bias when evaluating directors’ conduct in a bankruptcy case. Additionally, to advance our understanding of the mechanisms underlying these biases, we also examine whether free will beliefs can predict susceptibility to hindsight bias and outcome bias in this context. In two studies (total N = 1,729), we demonstrate that legal professionals tend to judge a director's actions more negatively and perceive bankruptcy as more foreseeable in hindsight than in foresight and that these effects are significantly stronger for those who endorse the notion that humans have free will. This contribution is particularly timely considering the many companies that are currently going bankrupt or are facing bankruptcy amidst the COVID-19 pandemic.     

Bypassing the gatekeeper: incidental negative cues stimulate choices with negative outcomes

The Theory of Event Coding (TEC) predicts that exposure to affective cues can automatically trigger affectively congruent behaviour due to shared representational codes. An intriguing hypothesis from this theory is that exposure to aversive cues can automatically trigger actions that have previously been learned to result in aversive outcomes. Previous work has indeed found such a compatibility effect on reaction times in forced-choice tasks, but not for action selection in free-choice tasks. Failure to observe this compatibility effect for aversive cues in free choice tasks suggests that control processes aimed at directing behaviour toward positive outcomes may overrule the automatic activation of affectively congruent responses in case of aversive cues. The present study tested whether minimising such control could cause selection of actions that have been learned to result in aversive outcomes. Results showed incidental exposure to aversive cues biased selection of behaviours with learned aversive outcomes over behaviours with positive outcomes, despite a preference to execute the positive- over the negative-outcome actions evidenced by a separate behaviour measurement and self-reports. These results suggest motivational processes to select actions with positive consequences may sometimes be bypassed.

Data and Materials: http://doi.org/10.17605/osf.io/ym7qu     

Perception of spectral changes in multi-tone complexes

Amplitude changes of the spectral components of a complex tone, relative to each other, are usually well perceived, even if the over-all intensity is kept fixed. Three experiments are reported: Experiment 1 dealt with the detectability of amplitude changes in two-tone complexes of fixed frequencies. Experiment 2 examined detection of slope changes in ramp-shaped spectral envelopes of two-and three-tone complexes as a function of spectral spacing. As a control experiment for some conditions a roving intensity level was used. Experiment 3 investigated the detectability of changes in the spectral slope of multi-tone complexes as a function of the number of components. The results of the experiments show that detection of spectral changes in a sound is strongly dependent on the frequency spacing of the components. It is concluded that the auditory system is capable of comparing the relative energy distributions over different critical bands. Within a critical band there exists an optimum frequency separation with respect to the detection of relative amplitude change.     

Norbert Paul,Medizinische Wissensbasen. Vom Wissensmodell zur Repräsentation. Ein medizintheoretischer Ansatz zur Modellierung und objectorientierten Repräsentation diagnosebezogene Domänewissens für Expertensysteme in der Medizin

Theoretical Medicine and Bioethics -