Early evidence affects later decisions: Why evidence accumulation is required to explain response time data

Models of decision making differ in how they treat early evidence as it recedes in time. Standard models, such as the drift diffusion model, assume that evidence is gradually accumulated until it reaches a boundary and a decision is initiated. One recent model, the urgency gating model, has proposed that decision making does not require the accumulation of evidence at all. Instead, accumulation could be replaced by a simple urgency factor that scales with time. To distinguish between these fundamentally different accounts of decision making, we performed an experiment in which we manipulated the presence, duration, and valence of early evidence. We simulated the associated response time and error rate predictions from the drift diffusion model and the urgency gating model, fitting the models to the empirical data. The drift diffusion model predicted that variations in the evidence presented early in the trial would affect decisions later in that same trial. The urgency gating model predicted that none of these variations would have any effect. The behavioral data showed clear effects of early evidence on the subsequent decisions, in a manner consistent with the drift diffusion model. Our results cannot be explained by the urgency gating model, and they provide support for an evidence accumulation account of perceptual decision making.     

Changing Race Boundary Perception by Reading Narrative Fiction

Participants read a story about a counterstereotypical Muslim woman and were then asked to determine the race of ambiguous-race Arab-Caucasian faces. Compared to a content-matched control condition, participants who read the narrative exhibited lower categorical race bias by making fewer categorical race judgments and perceiving greater genetic overlap between Arabs and Caucasians (Experiment 1). In Experiment 2, participants determined the race of ambiguous-race Arab-Caucasian faces depicting low and moderate anger. Emotion-related perceptual race bias was observed in the control conditions where higher intensity anger expressions led participants to disproportionately categorize faces as Arab. This bias was eliminated in the narrative condition.     

Variation of Isometric Response Force in the Rat

Hungry, unrestrained rats (N = 7) were rewarded for pressing a response beam in excess of 11 different force requirements. Changes in peak force production as a function of peak force requirement were examined by analyses of the first four moments of distributions of peak response forces: constant error, the within-subject standard deviation, skewness, and kurtosis. Results were similar to those previously obtained with human subjects: Constant error was positive at low and negative at high force requirements, the within-subject standard deviation increased as a negatively accelerating function of force requirement, and skewness and kurtosis were positive at low force requirements and decreased to negative values at the highest increments. Additional analyses of response kinetics indicated that rats, like humans, meet increasing force requirements by altering the rate of rise of force. The performance similarities suggest that common processes are engaged by the human and rat motor control systems to solve the problem of generating forces that are appropriate to the prevailing environmental constraints.     

Numeracy as a Predictor of Adaptive Risky Decision Making

Numeracy or one's ability to appropriately process and use numerical information has been shown to be an important individual difference factor in decision making. The current study utilized a risky decision‐making task (called the “cups task”) in which choices are made to both earn and avoid losing hypothetical money. Critically, this design allowed investigators to examine numeracy‐related differences in adaptive decision‐making as measured by sensitivity to expected value (EV) differences over 54 paired‐choice trials—some in which it was advantageous to take a risk and some in which it was not. Results showed that in an undergraduate sample of 114 individuals, the less numerate took more risks and were less sensitive to varying EV levels than the more numerate, especially when it was disadvantageous to take a risk and when the choice involved a potential loss (rather than a gain). These results are consistent with a dual processing account in which the more numerate are much better than the less numerate at extracting the precise affective “gist” of the numerical information, which is then used to determine the goodness or badness of a particular choice. Copyright © 2012 John Wiley & Sons, Ltd.     

Emoticons in computer-mediated communication: social motives and social context.

This study investigated the role of emoticons in computer-mediated communication (CMC). The study consisted of an online questionnaire about the social motives for emoticon use and an experimental part in which participants (N = 1,251) had to respond to short Internet chats. In these chats, the interaction partner (friend vs. stranger) and the valence of the context (positive vs. negative) were manipulated. Results showed that emoticons are mostly used to express emotion, to strengthen a message, and to express humor. Furthermore, more emoticons were used in communication with friends than in communication with strangers, and more emoticons were used in a positive context than in a negative context. Participants seem to use emoticons in a way similar to facial behavior in face-to-face communication with respect to social context and interaction partner.     

Analysis of an ambiguous-feature discrimination

An autoshaping experiment with pigeons and three appetitive Pavlovian conditioning experiments with rats investigated the course of an ambiguous-feature discrimination in which trials with stimuli A and BC were followed by food, and trials with B and AC were not. The discrimination between A and B was acquired more rapidly than the discrimination between BC and AC in all experiments. Furthermore, the acquisition of conditioned responding with A was faster than that with BC for the three rat experiments. The results of these experiments are discussed in terms of elemental and configural theories of associative learning.     

The social‐psychological bases of far‐right support in Europe and the United States

The roles of authoritarianism, social dominance orientation (SDO), and prejudice in the prediction of far‐right support were examined in Europe and the United States. A meta‐analysis shows remarkably similar, positive, and strong associations of far‐right support with these three variables in previous studies conducted in Europe, the United Kingdom, and the United States. Results from two cross‐sectional studies in the United States further indicated that higher levels of authoritarianism and SDO related to higher voting intentions and support for Trump, via increased prejudice. In a three‐wave longitudinal study in the United Kingdom, authoritarianism and SDO predicted pro‐Brexit attitudes and support for the U.K. Independence Party, again via prejudice. These results shed a new light on the widely held beliefs in “American and British exceptionalism,” as Trump and Brexit adherents share the same social‐psychological underpinnings as far‐right supporters observed in several European countries.     

The Trinitarian Metaphysics of Jonathan Edwards and Nicolas Malebranche

This paper explores both the striking similarities and also the differences between Jonathan Edwards and Nicolas Malebranche's philosophical views on the Holy Trinity and, in particular, the ways in which they both gave important roles to specific Persons of the Trinity in the various different branches of their respective metaphysical systems—ontological, epistemological and ethical. It is shown that Edwards and Malebranche were in very close agreement on ontological questions pertaining to the Trinity, both with respect to the internal, triune nature of the divine substance (characterising the Three Persons as the divine power, as the consubstantial idea of God which was generated as He eternally reflected on Himself, and as the mutual love which proceeded between the Father and this idea), and also with respect to the various roles these Three Persons played in the creation of the world. In epistemology, Malebranche postulated an illuminating union between the mind of man and the divine Word, insisting on an absolutely direct involvement of the Second Person in all human cognition, both intellectual and sensible. On this point Edwards did differ, endorsing instead an empiricist epistemology which left no room for such a direct union with the Word. However, when it came to ethics, Edwards and Malebranche both gave the Third Person an utterly central role, postulating much the same kind of union as Malebranche alone had postulated in the epistemological case, only now between the will of man and the Holy Spirit.