What do you think I think you think?: Strategic reasoning in matrix games

In reasoning about strategic interpersonal situations, such as in playing games, an individual's representation of the situation often includes not only information about the goals and rules of the game, but also a mental model of other minds. Often such mental models involve a hierarchy of reflexive reasoning commonly employed in social situations ("What do you think I think you think..."), and may be related to the developmental notion of 'theory of mind'. In two experiments, the authors formally investigate such interpersonal recursive reasoning in college-age adults within the context of matrix games. Participants are asked to predict the moves of another player (experimenter's confederate) in a two-choice, sequential-move game that may terminate at various stages with different payoffs for each player. Participants are also asked to decide optimally on their own moves based on the prediction made. Errors concerning the prediction, or translation of those predictions into decisions about one's action, were recorded. Results demonstrate the existence of a "default" mental model about the other player in the game context that is dynamically modified as new evidence is accumulated. Predictions about this other player's behavior are, in general, used consistently in decision-making, though the opponent tends to be modeled, by default, to behave in a myopic fashion not anticipating the participant's own action.     

Sense of body and sense of action both contribute to self-recognition

Recognizing oneself, easy as it appears to be, seems at least to require awareness of one's body and one's actions. To investigate the contribution of these factors to self-recognition, we presented normal subjects with an image of both their own and the experimenter's hand. The hands could make the same, a different or no movement and could be displayed in various orientations. Subjects had to tell whether the indicated hand was theirs or not. The results showed that a congruence between visual signals and signals indicating the position of the body is one component on which self-recognition is based. Recognition of one's actions is another component. Subjects had most difficulty in recognizing their hand when movements were absent. When the two hands made different movements, subjects relied exclusively on the movement cue and recognition was almost perfect. Our findings are in line with pathological alterations in the sense of body and the sense of action.     

Children's predictions of consistency in people's actions

Past research suggests that young children are often reluctant to generalize about people's behavior. Three experiments involving 102 4-5-year-olds, 84 7-8-year-olds, and 107 adults explored the conditions under which inductive inferences about people are made. There was an age-based increase in propensity to predict consistency in psychological/intentional causal relations. Children often predicted change; people would behave differently in the future than they did in the past. Younger children limited predictions of consistency to non-psychological contexts. Older children showed some appreciation of stable motivations (e.g. traits, preferences). The results are consistent with the hypothesis that children's theories of mind emphasize situational influences, with personal influences appearing in middle-childhood.     

Treating a Chronically Depressed Adolescent Female Using the Cognitive Behavioral Analysis System of Psychotherapy: A Case Study

A case is presented of an adolescent female with double depression who was treated using the Cognitive Behavioral Analysis System of Psychotherapy (CBASP). CBASP is designed to teach a social problem-solving procedure called Situational Analysis (SA). Generalized treatment effects were measured through monitoring of diagnostic status, two administrations of the Minnesota Multiphasic Personality Inventory-Adolescent, weekly administrations of the Child Depression Inventory, and acquisition performance ratings on the SA task. The results showed that CBASP appeared to be an effective treatment. The double depressive disorder remitted, and the patient learned to identify behavioral consequences as well as target and attain her interpersonal goals. CBASP can be effective for adolescents, although modifications of the adult form of the therapy may be necessary.     

Development of rules and strategies: balancing the old and the new

The experiments described in the lead articles replicate findings from previous studies of development of knowledge about balance scales, add several new findings, and raise four key questions: (a) How can rule use best be assessed? (b) How can we reconcile systematic use of rules with variable use of strategies? (c) When do children begin to use rules? and (d) How do children generate new rules? In this Reflection, we summarize current understanding of development of knowledge about balance scales and consider each of the four questions.     

Developmental and content effects in reasoning with causal conditionals

Two predictions derived from Markovits and Barrouillet's (2001) developmental model of conditional reasoning were tested in a study in which 72 twelve-year-olds, 80 fifteen-year-olds, and 104 adults received a paper-and-pencil test of conditional reasoning with causal premises ("if cause P then effect Q"). First, we predicted that conditional premises would induce more correct uncertainty responses to the Affirmation of the consequent and Denial of the antecedent forms when the antecedent term is weakly associated to the consequent than when the two are strongly associated and that this effect would decrease with age. Second, uncertainty responding to the Denial of the antecedent form ("P is not true") should be easier when the formulation of the minor premise invites retrieval of alternate antecedents ("if something other than P is true"). The results were consistent with the hypotheses and indicate the importance of retrieval processes in understanding developmental patterns in conditional reasoning with familiar premises.     

Effects of right and left hemisphere damage on performance of the "Right Hemisphere Communication Battery"

A Hebrew adaptation of Gardner and Brownell's (1986) "Right Hemisphere Communication Battery" (HRHCB) was administered to 27 right brain-damaged (RBD) patients, 31 left brain-damaged (LBD) patients, and 21 age-matched normal controls. Both patient groups showed deficits relative to controls and overall there was no difference between the two patient groups. A factor analysis of patients' scores on the HRHCB yielded two interpretable factors, a verbal and a nonverbal one. These factors were not lateralized. Performance of patients on the HRHCB correlated significantly and positively with performance on most tests of basic language functions, measured with a Hebrew adaptation of the "Western Aphasia Battery" (HWAB) and with other cognitive functions measured with standardized neuropsychological tests. There were stronger correlations of HRHCB with subtests of the HWAB in LBD patients and with nonlanguage cognitive tests in RBD patients. In the LBD group, HRHCB subtests' scores correlated negatively with lesion extent in frontal and temporal perisylvian regions. Such localization was not observed in RBD patients. The results argue against selective right hemisphere (RH) involvement in the RHCB, alleged to measure pragmatic aspects of language use, and show, instead, bilateral involvement. The results also argue against a modular organization of these functions of language use, especially in the RH.     

Neuronal changes in normal human aging and Alzheimer's disease

This article discusses age-related changes in brain weight, total number of cortical neurons, cortical dendrites, spine, and synapse density. The conclusion is that the present outlook is less grim than it was 30 years ago. Age-related reduction appears to be specific to brain region and cortical layer rather than a general feature. In addition, we describe a different pattern of changes that occur in Alzheimer's disease patients. This review concludes that the association cortices in particular are affected in aging and Alzheimer's disease and that the primary visual and somatosensory cortices are relatively spared.     

A simulation study of the degrees of freedom of movement in reaching and grasping

The question of independently controlled components in the act of reaching and grasping has attracted interest experimentally and theoretically. Data from 35 studies were recently found consistent with simulated kinematic finger and thumb trajectories optimised for minimum jerk. The present study closely reproduces those trajectories using a discrete-time model based on minimum acceleration. That model was further used to generate two-dimensional trajectories for finger and thumb to reach and grasp an elliptical object with varying position and/or orientation. Orthogonalisation of these four trajectories revealed one degree of freedom when direction of reach was constant and two degrees of freedom when direction of reach varied, irrespective of object distance and orientation. These simulations indicate that reach and grasp movements contain redundancy that is removable by formation of task-dependent synergies. As skilled movement can be planned and executed in a low dimension workspace, control of these independent components lessens central workload.