How top-down and bottom-up attention modulate risky choice

We examine how bottom-up (or stimulus-driven) and top-down (or goal-driven) processes govern the distribution of attention in risky choice. In three experiments, participants chose between a certain payoff and the chance of receiving a payoff drawn randomly from an array of eight numbers. We tested the hypothesis that initial attention is driven by perceptual properties of the stimulus (e.g., font size of the numbers), but subsequent choice is goal-driven (e.g., win the best outcome). Two experiments in which task framing (goal driven) and font size (stimulus driven) were manipulated demonstrated that payoffs with the highest values and the largest font sizes had the greatest impact on choice. The third experiment added a number in large font to the array, which could not be an outcome of the gamble (i.e., a distractor). Eye movement and choice data indicated that although the distractor attracted attention, it had no influence on option selection. Together with computational modeling analyses, the results suggest that perceptual salience can induce bottom-up effects of overt selection but that the perceived value of information is the crucial arbiter of intentional control over risky choice.

Size aftereffect is non-local

It is well known that prolonged exposure to a certain size stimulus alters the perceived size of a subsequently presented stimulus at the same location. How the rest of the visual space is affected by this size adaptation, however, has not been systematically studied before. Here, to fill this gap in literature, we tested size adaptation at the adapter location as well as the rest of the visual space. We used peripherally presented solid discs (Experiment 1) and rings (Experiment 2) as adapter and target (test) stimuli. Observers adapted to a mid-sized stimulus and judged the size of the subsequently presented smaller or larger target stimuli. Results showed that the perceived sizes of target stimuli were repelled away from the adapter size, not only at the adapter location but also at distant locations. These findings demonstrate that size adaptation causes widespread distortion of the visual space and alters perceived size. We discuss possible computational models that may underpin the perceptual effect.

The Discriminability of Rapists from Non-Sex Offenders Using Phallometric Measures

The authors examined how well identified rapists could be discriminated from non-sex offenders using phallometric assessments, what variables might moderate this discrimination, and whether rapists respond more to descriptions of rape than to consenting sex. Eleven primary and five secondary phallometric studies involving 415 rapists and 192 non-sex offenders were examined using meta-analytic techniques. Study effect sizes averaged 0.82 (95% confidence interval 0.16 to 1.49). Only stimulus set was a statistically significant moderator of effect size: Stimulus sets that contained more graphic rape descriptions produced better discrimination between rapists and non-sex offenders. There was a trend for stimulus sets that contained more exemplars off rape descriptions to achieve better discrimination. Also, rapists responded more to rape than to consenting sex cues in 9 of the 16 data sets and in all 8 of those using the more effective stimulus sets.

Transposition in Dogs: Successive Reversals of the Intermediate Size Problem

18 dogs ( basenjis) were tested on 3 consecutive intermediate size-discrimination and transposition problems in a modified Wisconsin General Test Apparatus (WGTA). Solution of the discriminative task required significantly fewer trials across successive problems. Dogs generally responded to the absolute size of the stimulus. However, (a) delayed or repeated testing or (b) tests in the direction of the animal's original size preference facilitated responses to the relative middle-size stimulus.