Summation of food and shock based responding

In a multiphase experiment, dogs first received discriminative, discretetrial, barrier-jumping training with two tones (S^D, S^Δ) in a shuttle box reinforced by either shock avoidance (Group I) or by food (Group II). Then the dogs were trained on free-operant barrier-jumping reinforced by the qualitatively opposite reinforcer—food in Group I and shock avoidance in Group II. Finally, test presentations of the tone stimuli were superimposed on the free-operant behavior. The tone S^Ds markedly facilitated responding in all animals. This experiment demonstrates a summation of responding maintained by shock avoidance and food reinforcement and casts doubt on explanations of conditioned suppression outcomes that appeal solely to incompatible motivational states within the organism.     

Grasping the Nature of Pictures

The role of experience in the development of pictorial competence has been the center of substantial debate. The four studies presented here help resolve the controversy by systematically documenting and examining manual exploration of depicted objects by infants. We report that 9-month-old infants manually investigate pictures, touching and feeling depicted objects as if they were real objects and even trying to pick them up off the page. The same behavior was observed in babies from two extremely different societies (the United States and the Ivory Coast). This investigation of pictures occurs even though infants can discriminate between real objects and their depictions. By the time infants are 19 months of age, their manual exploration is replaced by pointing at depicted objects. These results indicate that initial uncertainty about the nature of pictures leads infants to investigate them. Through experience, infants begin to acquire a concept of "picture." This concept includes the fact that a picture has a dual nature (it is both an object and a representation of something other than itself), as well as knowledge about the culturally appropriate use of pictures.     

Peace and Islam: In theory and practice

The article centres on the humanistic and peace‐oriented elements in the foundational sources of Islam, the Qur'an and the Prophet's life, especially on Muhammad's attitude towards war and peace. As the Qur'an clearly attests, Muhammad continued to search for reconciliation and mutual understanding,. with Jews and Christians as well as with opponents and enemies. As to jihad, Q. 2:90 and Q. 22:39 unambiguously prohibit offensive war, in fact, any kind of aggression, cruelty and wanton destruction. The Qur'an prescribes a humane conduct of war. Wherever politically possible, peace has the priority. Finally, the author exemplifies contemporary Muslim attitudes towards war and peace and describes Muslim peace initiatives.     

Predictive coding: an account of the mirror neuron system

Is it possible to understand the intentions of other people by simply observing their actions? Many believe that this ability is made possible by the brain’s mirror neuron system through its direct link between action and observation. However, precisely how intentions can be inferred through action observation has provoked much debate. Here we suggest that the function of the mirror system can be understood within a predictive coding framework that appeals to the statistical approach known as empirical Bayes. Within this scheme the most likely cause of an observed action can be inferred by minimizing the prediction error at all levels of the cortical hierarchy that are engaged during action observation. This account identifies a precise role for the mirror system in our ability to infer intentions from actions and provides the outline of the underlying computational mechanisms.     

Behavioral methods of assessing forgiveness

One problem in forgiveness research is the reliance on one method (i.e. having people recall an offense and complete self-report measures). Thus, we present two strategies for studying forgiveness-related behavior. First, we adapted the Cyberball paradigm, which is a game of toss where two computer players (ostensibly virtual players) exclude the participant from play. We adapted Cyberball to include a second round that gave participants the opportunity to retaliate or forgive the player who excluded them. Self-reported forgiveness predicted the first toss and total number of tosses to the offender in the subsequent round. Second, we had participants describe an offense (as is typical with the recall method), but then also complete an activity in which they listed as many positive qualities as they could about the offender. Self-reported forgiveness predicted the number of positive qualities listed. We discuss the contribution of these studies to the multimodal study of forgiveness.     

Perception of the length of an object through dynamic touch is invariant across changes in the medium

Rotational inertia—a mechanical quantity that describes the differential resistance of an object to angular acceleration in different directions—has been shown to support perception of the properties of that object through dynamic touch (wielding). The goal of the present study was to examine if perception of the length of an object through dynamic touch depends on its rotational inertia, independent of the medium in which it is wielded. The participants (n = 14) wielded 12 different objects held in air or completely immersed in water and reported perceived lengths of those objects. Each object consisted of a rod of a particular density with a particular number of stacked steel rings attached at a particular location along its length. Perceived length was invariant across medium. In addition, a single-valued function of the major eigenvalue, I ₁, and the minor eigenvalue, I ₃, of the rotational inertia, I, of the 12 objects predicted the perceived lengths of those objects in both air and water, and the perceived lengths were invariant across the two media. These results support the hypothesis that the informational support for perception of the length of an object through dynamic touch is invariant across changes in the medium.     

Doxastic planning and epistemic internalism

In the following I discuss the debate between epistemological internalists and externalists from an unfamiliar meta-epistemological perspective. In doing so, I focus on the question of whether rationality is best captured in externalist or internalist terms. Using a conception of epistemic judgments as “doxastic plans,” I characterize one important subspecies of judgments about epistemic rationality—focusing on the distinctive rational/functional role these judgments play in regulating how we form beliefs. Then I show why any judgment that plays this role should be expected to behave the manner internalists predict. In this way, I argue, we can explain why our basic toolbox for epistemic evaluation includes an internalist conception of rationality.