Kripke completeness of some intermediate predicate logics with the axiom of constant domain and a variant of canonical formulas

For each intermediate propositional logicJ, J _* denotes the least predicate extension ofJ. By the method of canonical models, the strongly Kripke completeness ofJ _*+D(=x(p(x)q)xp(x)q) is shown in some cases including:

Temporal specificity of extinction in autoshaping

Three experiments investigated the effects of varying the conditioned stimulus (CS) duration between training and extinction. Ring doves (Streptopelia risoria) were autoshaped on a fixed CS-unconditioned stimulus (US) interval and extinguished with CS presentations that were longer, shorter, or the same as the training duration. During a subsequent test session, the training CS duration was reintroduced. Results suggest that the cessation of responding during an extinction session is controlled by generalization of excitation between the training and extinction CSs and by the number of nonreinforced CS presentations. Transfer of extinction to the training CS is controlled by the similarity between the extinction and training CSs. Extinction learning is temporally specific.     

Effects of Varying Load Conditions on the Organization of Postural Adjustments during Voluntary Arm Flexion

One purpose of the experiments reported here was to further clarify the effect of varying loads on postural adjustments. Another was to reevaluate whether or not the timing of electromyographic (EMG) activity in the postural muscle is preprogrammed. To accomplish these goals, we compared the effect of the presence or absence of prior knowledge of a load on the timing of EMG activity in the postural muscle (biceps femoris [BF]) with that in the focal muscle (anterior deltoid [AD]). Although the sequence of EMG activation was similar under conditions with and without a load, the timing of postural EMG activities (BFi, ipsilateral BF; BFc, contralateral BF) in associated postural adjustments was dependent on the force of arm movement, and the latencies of postural EMG activities (BFi—BFc) were dependent on the speed of arm movement. This indicates that EMG changes in the upper (focal muscle) and lower limbs (postural muscle) were triggered by different motor programs. Moreover, similar EMG activities were observed in postural muscles when the subject had advance knowledge of the presence or the absence of a load. Thus, this suggests that BFi may be centrally preprogrammed (anticipatory regulation) and BFc may be feedback regulated. Furthermore, environmental information may be a critical source of influence on those postural responses.     

Effects of anonymity on antisocial behavior committed by individuals

The present study examined association between anonymity and antisocial individual behavior without any influence from the presence of others. Anonymity was operationally defined as consisting of two components, nonidentifiability and nonaccountability. Antisocial behavior was defined as rule-breaking behavior seeking a monetary reward. It was hypothesized that anonymity would increase antisocial behavior among individuals. Undergraduate students (20 men, 50 women) were recruited from two psychology classes and were randomly assigned to four experimental conditions (Anonymous, Nonidentifiable, Nonaccountable, and Nonanonymous) to examine whether they would violate game rules to obtain the monetary reward through anonymity. Only participants in the Anonymous condition violated the rules to obtain the reward. Implications for the effects of anonymity on antisocial individual behavior are discussed.     

“To eat or not to be eaten?” Collective risk-monitoring in groups

The importance of risk-monitoring has been increasing in many key aspects of our modern lives. This paper examines how individuals monitor such risks collectively by extending a behavioral ecological model of animal foraging to human groups. Just as animals must forage for food under predatory risk, humans must divide valuable material and psychological resources between foraging activity and risk-monitoring activity. We predicted that game-theoretic aspects of the group situation complicate such a trade-off decision in resource allocation, eventually yielding a mixed equilibrium in a group. When the equilibrium is reached, only a subset of members engage in the risk-monitoring activity while others free-ride, concentrating mainly on their own foraging activity. Laboratory groups engaging in foraging under moderate risk provided a support to this prediction. When the risk-level was set higher, however, “herding behavior” (conforming to the dominant behavior) interfered with the emergence of equilibrium. Implications for risk management are discussed.     

Recovery from object substitution masking induced by transient suppression of visual motion processing: a repetitive transcranial magnetic stimulation study

Object substitution masking is a form of visual backward masking in which a briefly presented target is rendered invisible by a lingering mask that is too sparse to produce lower image-level interference. Recent studies suggested the importance of an updating process in a higher object-level representation, which should rely on the processing of visual motion, in this masking. Repetitive transcranial magnetic stimulation (rTMS) was used to investigate whether functional suppression of motion processing would selectively reduce substitution masking. rTMS-induced transient functional disruption of cortical area V5/MT+, which is important for motion analysis, or V1, which is reciprocally connected with V5/MT+, produced recovery from masking, whereas sham stimulation did not. Furthermore, masking remained undiminished following rTMS over the region 2 cm posterior to V5/MT+, ruling out nonspecific effects of real stimulation and confirming regional specificity of the rTMS effect. The results suggest that object continuity via the normal function of the visual motion processing system might in part contribute to this masking. The relation of these findings to the reentrant processing view of object substitution masking and other visual phenomena is discussed.     

Shaping of scientific psychology in Japan

Japanese scientific psychology began with Y. Motora's lecture on pyschophysics at the University of Tokyo in 1888. He had just received his PhD under G.S. Hall at Johns Hopkins University, in the USA. He became the first professor of psychology in 1890 and founded the first psychological laboratory at the University of Tokyo in 1903. He studied many psychological problems, including attention, experimentally and theoretically. One of his first students, Matataro Matsumoto, founded the second psychological laboratory at Kyoto University and then succeeded to Motora's position in Tokyo. Matsumoto was interested in experimental studies of human performance and their applications. He trained many able psychologists and organized the Japanese Psychological Association in 1927. Some of his students founded more psychological laboratories in major universities of Japan. They introduced psychological tests, Gestalt psychology, and behaviourism in the 1920s and 1930s. Psychoanalysis was introduced through mainly nonacademic roots and became familiar to Japanese psychologists in the 1930s. After World War II, a strong influence of American psychology came to Japanese psychologists who had already trained in scientific methodology. The areas of research and applications have been greatly widened and the number of psychologists has increased rapidly up to the present day. Promotion of international interactions and indigenous traditions are both expected.     

Rapid plastic changes of human primary motor cortex with repetitive motor practice and transcranial magnetic stimulation

Excitability changes of human primary motor cortex are assumed to be associated with motor learning processes. To examine motor behavioral and neural mechanisms in these processes, the adaptive motor learning processes of the index finger abduction were investigated using motor evoked potential (MEP) elicited from the first dorsal interosseous and extensor carpi radialis muscles. Practice effects were examined on changes of MEP amplitudes elicited from these muscles during motor imagery. Given general consensus that the MEP amplitude change during motor imagery is a useful parameter reflecting changes in excitability of the human primary motor cortex, the present results, that MEP amplitudes of both muscles increased with repeated practice by the index finger abduction and that magnitudes of MEP amplitudes of both muscles (motor learning curves) were clearly different, suggested that participation of the muscles performing the index finger abduction gradually changed with practice. Short-term plastic changes of human primary motor cortex occur with repetitive practice and such adaptive change in human primary motor cortex is expressed in human voluntary movement that becomes more automatic.     

The robust beauty of majority rules in group decisions

How should groups make decisions? The authors provide an original evaluation of 9 group decision rules based on their adaptive success in a simulated test bed environment. When the adaptive success standard is applied, the majority and plurality rules fare quite well, performing at levels comparable to much more resource-demanding rules such as an individual judgment averaging rule. The plurality rule matches the computationally demanding Condorcet majority winner that is standard in evaluations of preferential choice. The authors also test the results from their theoretical analysis in a behavioral study of nominal human group decisions, and the essential findings are confirmed empirically. The conclusions of the present analysis support the popularity of majority and plurality rules in truth-seeking group decisions.     

Visual evoked potentials to the geometric forms in the randomized presentation

Two outlined geometric figures, an equilateral triangle and a circle, of equal contour length, were randomly presented at a fixed position in the lower or upper part of the visual field (LVF and UVF). Transient visual evoked potentials (VEPs) were recorded monopolarly from the inion (I), 5, 10, 15 cm above it (I5, I10, I15) and Fz, for 12 subjects. Grand-averaged VEPs were computed. A negative (N) wave (averaged peak latency 155 ms) was identified in the LVF and a positive (P) wave (130 ms) in the UVF. In the LVF, the N amplitude of the triangle was significantly larger than that of the circle at I5 and I. Regarding the P wave in the UVF, the triangle was of a significantly longer latency than the circle at I15, I10 and I5. The enhancement of the N amplitude for the triangle in the LVF is not attributable to the arousal caused by the preparatory state for the figure, since the subject could not predict the figure to be presented next or its position.