Effects of social context and predictive relevance on action outcome monitoring

Outcome monitoring is crucial for subsequent adjustments in behavior and is associated with a specific electrophysiological response, the feedback-related negativity (FRN). Besides feedback generated by one's own action, the performance of others may also be relevant for oneself, and the observation of outcomes for others' actions elicits an observer FRN (oFRN). To test how these components are influenced by social setting and predictive value of feedback information, we compared event-related potentials, as well as their topographies and neural generators, for performance feedback generated by oneself and others in a cooperative versus competitive context. Our results show that (1) the predictive relevance of outcomes is crucial to elicit an FRN in both players and observers, (2) cooperation increases FRN and P300 amplitudes, especially in individuals with high traits of perspective taking, and (3) contrary to previous findings on gambling outcomes, oFRN components are generated for both cooperating and competing observers, but with smaller amplitudes in the latter. Neural source estimation revealed medial prefrontal activity for both FRN and oFRN, but with additional generators for the oFRN in the dorsolateral and ventral prefrontal cortex, as well as the temporoparietal junction. We conclude that the latter set of brain regions could mediate social influences on action monitoring by representing agency and social relevance of outcomes and are, therefore, recruited in addition to shared prediction error signals generated in medial frontal areas during action outcome observation.     

Velocity-based motion categorization by pigeons

To examine if animals could learn action-like categorizations in a manner similar to noun-based categories, eight pigeons were trained to categorize rates of object motion. Testing 40 different objects in a go/no-go discrimination, pigeons were first trained to discriminate between fast and slow rates of object rotation around their central y-axis. They easily learned this velocity discrimination and transferred it to novel objects and rates. This discrimination also transferred to novel types of motions including the other two axes of rotation and two new translations around the display. Comparable tests with rapid and slow changes in the objects' size, color, and shape failed to support comparable transfer. This difference in discrimination transfer between motion-based and property-based changes suggests the pigeons had learned motion concept rather than one based on change per se. The results provide evidence that pigeons can acquire an understanding of motion-based actions, at least with regard to the property of object velocity. This may be similar to our use of verbs and adverbs to categorize different classes of behavior or motion (e.g., walking, jogging, or running slow vs. fast).     

Analysis of methods to determine the latency of online movement adjustments

When studying online movement adjustments, one of the interesting parameters is their latency. We set out to compare three different methods of determining the latency: the threshold, confidence interval, and extrapolation methods. We simulated sets of movements with different movement times and amplitudes of movement adjustments, all with the same known latency. We applied the three different methods in order to determine when the position, velocity, and acceleration of the adjusted movements started to deviate from the values for unperturbed movements. We did so both for averaged data and for the data of individual trials. We evaluated the methods on the basis of their accuracy and precision, and according to whether the latency was influenced by the intensity of the movement adjustment. The extrapolation method applied to average acceleration data gave the most reliable estimates of latency, according to these criteria.     

The Persuasive Effects of Emotive Visual Imagery: Superficial Manipulation or the Product of Passionate Reason?

This study reevaluates the persuasive impact of emotional visual appeals within politics and examines two different explanations for their effects. One possibility is that the effects of emotive visual images are essentially superficial in nature, consistent with the view that feelings aroused by an affective image are transferred somewhat mechanically to a political candidate or cause with which it is paired. This transfer-of-affect explanation suggests that emotional appeals may work best among the least informed voters or those paying the least attention to a persuasive political message. The second possibility is that emotional appeals work via passionate reason, in which affective responses to an emotive image are integrated with, and potentially bias, reasoned thought about the accompanying message. This integrated approach leads to the counterintuitive prediction that individuals who are most highly involved in an issue (and who know the most about it) are most influenced by emotional imagery. This prediction arises from growing evidence that people highly involved in value-laden social issues generate the strongest emotional responses to issue-related persuasive appeals. These two models were tested in a study in which undergraduate students were presented with a picture of a cute or an ugly animal and a flyer from an organization advocating a pro- or anti-environment stance with respect to preserving the animal's habitat. The responses showed that emotive imagery was most persuasive among the most involved environment supporters, providing clear evidence of passionate reasoning.     

Americans respond politically to 9/11: understanding the impact of the terrorist attacks and their aftermath

The 9/11 terrorist attacks have had profound effect on U.S. domestic and foreign security policy, leading to several expensive wars and the erosion of civil liberties (under the USA PATRIOT Act). We review evidence on political reactions to the 9/11 attacks and conclude that subjective reactions to terrorism played an important role in shaping support for national security policy in the wake of 9/11. Support for a strong national security policy was most pronounced among Americans who perceived the nation as at threat from terrorism and felt angry at terrorists. In contrast, Americans who were personally affected by the attacks were more likely to feel anxious about terrorism, and this anxiety translated into less support for overseas military action. In addition, Americans who felt insecure after the 9/11 attacks and perceived a high future threat of terrorism were more likely than others to support strong foreign and domestic national security policies. Overall, research on American political reactions to 9/11 suggests that support for a strong government response to terrorism is most likely when members of a population perceive a high risk of future terrorism and feel angry at terrorists.     

The interaction of word frequency and concreteness in immediate serial recall

Word frequency and word concreteness are language attributes that have been shown to independently influence the recall of items in verbal short-term memory (STM). It has been argued that such effects are evidence for the action of long-term memory knowledge on STM traces. However, research to date has not investigated whether these variables interact in serial recall. In two experiments, we examined the behavior of these variables under factorial manipulation and demonstrated that the effect of word frequency is dependent on the level of concreteness of items. Serial recall performance is examined with reference to two explanatory approaches: Walker and Hulme’s (1999) dual-redintegration account and language-based models of STM. The data indicate that language-based models are more compatible with the observed effects and challenge the view that frequency and concreteness effects in STM are the products of distinct mechanisms.     

DO ELEPHANTS EVER FORGET?1

Three adult female elephants (Elephas maximus) were tested on a light-dark discrimination problem with an 8-yr intertrial interval. The first subject took only 6 min to reach criterion and made only two errors, suggesting remarkable retention. The other two subjects were found to have visual anomalies that would have gone undetected without this research.