Armed and attentive: Holding a weapon can bias attentional priorities in scene viewing

The action-specific perception hypothesis (Witt, Current Directions in Psychological Science 20: 201–206, 2011) claims that the environment is represented with respect to potential interactions for objects present within said environment. This investigation sought to extend the hypothesis beyond perceptual mechanisms and assess whether action-specific potential could alter attentional allocation. To do so, we examined a well-replicated attention bias in the weapon focus effect (Loftus, Loftus, & Messo, Law and Human Behaviour 1, 55–62, 1987), which represents the tendency for observers to attend more to weapons than to neutral objects. Our key manipulation altered the anticipated action-specific potential of observers by providing them a firearm while they freely viewed scenes with and without weapons present. We replicated the original weapon focus effect using modern eye tracking and confirmed that the increase in time looking at weapons comes at a cost of less time spent looking at faces. Additionally, observers who held firearms while viewing the various scenes showed a general bias to look at faces over objects, but only if the firearm was in a readily usable position (i.e., pointed at the scenes rather than holstered at one’s side). These two effects, weapon focus and the newly found bias to look more at faces when armed, canceled out one another without interacting. This evidence confirms that the action capabilities of the observer alter more than just perceptual mechanisms and that holding a weapon can change attentional priorities. Theoretical and real-world implications are discussed.     

Response selection influences inhibition of return

Previous work has suggested that there may be a relationship between the magnitude of inhibition of return (IOR) and the number of possible responses in the perceptual‐motor task. To test this possibility, the present experiment used a display that contained four horizontally aligned cue/target locations. In different blocks of trials, subjects responded to the target either with a one‐response detection key press, a two‐response localisation key press, or a four‐response localisation key press. The results showed the largest magnitude of IOR was found in the one‐response condition and the least in the four‐response condition. These results suggest that IOR may be most effective in inhibiting relatively prepotent responses and the inhibitory effect weakens when responses require more intricate sensorimotor mappings.     

Patterns in the Philosophy of Mathematics

Books reviewed in this article:
Michael D. Resnik, Mathematics as a Science of Patterns
Penelope Maddy, Naturalism in Mathematics
Jerrold J. Katz, Realistic Rationalism
Jaakko Hintikka, The Principles of Mathematics Revisited     

Saving the worst for last: The effect of time horizon on the efficiency of negotiating benefits and burdens

Three experiments explored the effect of outcome delays—longer time horizons for the realization of outcomes—on the efficiency of negotiated agreements. We hypothesized that there would be a positive relationship between a longer temporal distance to the consequences of negotiated agreements and the efficiency of those agreements. Outcome delays did increase the efficiency of the negotiated agreements. In addition, type of resource, burden or benefit, moderated this relationship. Because negotiating for burdens is more difficult than negotiating for benefits in the present, the salutary discounting effects of outcome delays were greater for burdens. The multifaceted effects of time on negotiations are discussed.     

Inequity/Iniquity: Card on Balancing Injustice and Evil

Card argues that we should not give injustice priority over evil. I agree. But I think Card sets us up for some difficult balances, for example of small evils against middle‐sized injustices. I suggest some ways of staying off the tightrope.     

Modulation of cognitive flexibility by hunger and desire

Knowing when to persevere with a plan and knowing when to ditch it and change strategy is highly adaptive and breaks down in several frontal and striatal disorders. Cognitive flexibility is also susceptible to tonic influences of neuromodulators (such as dopamine) and so may be influenced by everyday fluctuations in processes known to depend upon them (such as motivation). The current study employed an attentional shifting paradigm to examine the influence of changes in food-related motivational state in healthy volunteers. Hunger was induced through fasting (physiological manipulation) or through the presentation of appetitive food cues prior to testing (desire manipulation). The desire manipulation produced a stronger effect than fasting by inducing errors when participants were attempting to shift. The results suggest that everyday fluctuations in appetite and desire can produce a significant impact on cognition, highlighting implications for our understanding of excessive motivational control including maladaptive eating behaviour.     

(ANTI)‐Anti‐Intellectualism and the Sufficiency Thesis

Anti‐intellectualists about knowledge‐how insist that, when an agent S knows how to φ, it is in virtue of some ability, rather than in virtue of any propositional attitudpaes, S has. Recently, a popular strategy for attacking the anti‐intellectualist position proceeds by appealing to cases where an agent is claimed to possess a reliable ability to φ while nonetheless intuitively lacking knowledge‐how to φ. John Bengson and Marc Moffett and Carlotta Pavese have embraced precisely this strategy and have thus claimed, for different reasons, that anti‐intellectualism is defective on the grounds that possessing the ability to φ is not sufficient for knowing how to φ. We investigate this strategy of argument‐by‐counterexample to the anti‐intellectualist's sufficiency thesis and show that, at the end of the day, anti‐intellectualism remains unscathed.     

Why Higher Working Memory Capacity May Help You Learn: Sampling,Search, and Degrees of Approximation

Algorithms for approximate Bayesian inference, such as those based on sampling (i.e., Monte Carlo methods), provide a natural source of models of how people may deal with uncertainty with limited cognitive resources. Here, we consider the idea that individual differences in working memory capacity (WMC) may be usefully modeled in terms of the number of samples, or “particles,” available to perform inference. To test this idea, we focus on two recent experiments that report positive associations between WMC and two distinct aspects of categorization performance: the ability to learn novel categories, and the ability to switch between different categorization strategies (“knowledge restructuring”). In favor of the idea of modeling WMC as a number of particles, we show that a single model can reproduce both experimental results by varying the number of particles—increasing the number of particles leads to both faster category learning and improved strategy‐switching. Furthermore, when we fit the model to individual participants, we found a positive association between WMC and best‐fit number of particles for strategy switching. However, no association between WMC and best‐fit number of particles was found for category learning. These results are discussed in the context of the general challenge of disentangling the contributions of different potential sources of behavioral variability.