Discrimination Learning and Multiple Reversals in Young Adult and Older Monkeys Macaca arctoides

Two groups of five young adult and older stumptailed macaques (Macaca arctoides) were tested on a visual discrimination task followed by a reversal upon attainment of criterion; task and reversal were repeated until 20 reversals with the same pair of objects had been completed. Both groups required more trials to learn the first reversal than the original discrimination, with no significant difference between the groups. Older monkeys tended to show more perseverative errors on early reversals, but a striking improvement in their scores across successive blocks of reversals culminated in performances virtually indistinguishable from those of the young group by the end of testing.     

Cognitive-Behavioral Treatment of Depression, Part IX: Confronting Predisposing Factors

Cognitive-behavioral therapy can help many depressed clients learn more effective ways of coping with problems in their lives. However, for many clients with chronic or recurrent depression, it can be helpful to examine the biological, psychological, and social/cultural factors that may predispose a person toward depressive episodes. In order to address possible biological predispositions, it is important to assess for a positive family history of depression, evaluate family members' response to previous treatments, and refer for medications when needed. In order to address possible psychological predispositions, it is useful to evaluate long-standing personality styles, identify negative events from childhood, examine the client's relationship with his or her parents, evaluate the history of abuse, and identify early loss experiences. Cultural factors may play an influential role in the etiology of depression, and can be useful to incorporate into a broad treatment plan. However, cultural factors are difficult to modify through individual psychotherapy. Hence, they are unlikely to play a central role in cognitive-behavioral therapy for depression. Overall, therapists working with depressed clients should be prepared to confront a broad range of biological, psychological, and environmental factors that can create or perpetuate a client's risk for depression.     

Stressful Life Events: A Revision and Update of the Social Readjustment Rating Scale

The widely used and cited Social Readjustment Rating Scale developed by Holmes and Rahe (1967) was comprehensively revised and updated. The new instrument, containing 51 major life events, was administered to a national sample of 5000. Respondents were asked to rate the stressfulness of each life event on a 1–100 scale. Completed surveys were returned by 3122 individuals (62.4%). Responses were analyzed using repeated measures MANOVA and profile analysis. Major results included: (a) statistically and practically significant differences in mean ratings for the 51 life events; (b) five overlapping themes in the top 20 rated life events—death and dying, healthcare, crime and the criminal justice system, financial/economic issues, and family-related issues; and (c) an amazing level of agreement concerning perceived life event stressfulness, regardless of gender, age, or income level.     

The perception of surface curvature from optical motion

Observers viewed the optical flow field of a rotating quadric surface patch and were required to match its perceived structure by adjusting the shape of a stereoscopically presented surface. In Experiment 1, the flow fields included rigid object rotations and constant flow fields with patterns of image acceleration that had no possible rigid interpretation. In performing their matches, observers had independent control of two parameters that determined the surface shape. One of these, called the shape characteristic, is defined as the ratio of the two principle curvatures and is independent of object size. The other, called curvedness, is defined as the sum of the squared principle curvatures and depends on the size of the object. Adjustments of shape characteristic were almost perfectly accurate for both motion conditions. Adjustments of curvedness, on the other hand, were systematically overestimated and were not highly correlated with the simulated curvedness of the depicted surface patch. In Experiment 2, the same flow fields were masked with a global pattern of curl, divergence, or shear, which disrupted the first-order spatial derivatives of the image velocity field, while leaving the second-order spatial derivatives invariant. The addition of these masks had only negligible effects on observers’ performance. These findings suggest that observers’ judgments of three-dimensional surface shape from motion are primarily determined by the second-order spatial derivatives of the instantaneous field of image displacements.     

Justification of war in Ancient China

The most defensible justifications of war in the European intellectual tradition hold that war is instrumentally necessary for the maintenance of peace and order. An investigation of Ancient Chinese philosophical attitudes towards war calls this assumption into question. The closest parallel to an instrumental concept of war is found in the Legalist school, but historical experience in China has rejected this. The Confucian school, especially Mencius and Xunxi, insists that war is not instrumental in creating social order, but derives from the prior establishing of cultural and political authority, and thus must be punitive in nature. Even the use of “punitive expeditions” is not instrumental, but rather demonstrative or performative in nature, for if coercive methods are necessary, the authority to use them is arguably absent. War for the Chinese, then, is not justified by the necessity for creating public order, but is in itself a sign of the failure to achieve such an order. This contrasts sharply with the views of the dominant Western thinkers on war, such as Michael Walzer, whose positions insist upon the instrumental necessity of armed force, even to the point of absurdity. The ancient Chinese position suggests that this necessity may be ungrounded.