Visual feature binding in early infancy

How does the developing brain of the human infant solve the feature-binding problem when visual stimuli consisting of multiple colored objects are presented? A habituation--dishabituation procedure revealed that 1-month-old infants have the ability to discriminate changes in the conjunction of a familiar shape and color in two objects. However, this good earlier performance was followed by poorer performance at 2 months of age. The performance improved again at 3 months of age. Detailed analysis of the oculomotor behaviors revealed that the age of 2 months was a period of drastic transition when the tendency to stay with the fixated objects disappeared and repetitive saccades between the two objects emerged. Our findings suggest that the ability to perceive conjunctions of features is available to infants very early, that the perceptual/neural basis at 1 and at 3 months of age may be fundamentally different, and that feature integration by vigorous eye movements or selective attention may be the key functional difference between the age groups.     

Interpersonal perception in Japanese and British observers

We compared performance of Japanese and British observers in deciphering images depicting Japanese interpersonal relationships. 201 Japanese and 215 British subjects were assessed by means of a test consisting of 31 photograph problems accompanied by two or three alternative solutions one of which was correct. Japanese subjects outperformed British subjects on the test overall (z = 3.981, p < 0.001). A two-factor ANOVA (culture x gender) was performed for each of the problems. A cultural effect was found in 17 problems. Surprisingly, British subjects outperformed Japanese subjects in 7 of these problems. There was a gender effect in 4 problems and a culture x gender interaction in 6 problems. The results indicate that cultural experience facilitates nonverbal appraisal of interpersonal relationships, but it may sometimes cause specific errors. Differences in the perceptual cues used suggest that British subjects had difficulty reading Japanese facial expressions.     

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.     

The effects of prompting and reinforcement on safe behavior of bicycle and motorcycle riders

A reversal design was used to evaluate the effects of vocal and written prompts as well as reinforcement on safe behavior (dismounting and walking bicycles or motorcycles on a sidewalk) on a university campus. Results indicated that an intervention that consisted of vocal and written prompts and reinforcement delivered by security guards was effective at increasing safe behavior exhibited by bicycle and motorcycle riders. No differences were observed between vehicle type or gender with regard to engagement in safe behavior.     

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.     

Metascientific foundations for pluralism in psychology

In this paper, I explore the metascientific basis for pluralism in psychology. In the first half, I outline the two levels of the metaparadigm: the epistemological and the methodological. The epistemological level includes the dichotomy between an internal, first-person point of view and an external, third-person one. The methodological level includes the dichotomy between explanation and understanding. The continuing debate regarding methodology, explanation versus understanding, has distinguished the human sciences from the natural sciences. Similarly, the continuing debate regarding the epistemological point of view has distinguished psychology from other sciences. I illustrate these points by placing various trends in psychology into the two-dimensional space formed by the two coordinate axes depicting the methodological and the epistemological dimensions. Each quadrant represents one definition of the object of psychology: quadrant 1 (internal, first-person - explanation) represents “consciousness;” quadrant 2 (internal, first-person - understanding) represents “experiences;” quadrant 3 (external, third-person - understanding) represents “meaningful acts and expressions;” and quadrant 4 (external, third-person - explanation) represents “behaviors and higher processes of the brain.” All of the trends within the history of psychology can be placed within this two-dimensional space. In the second half of the paper, I introduce the third level of the metaparadigm: the metapsychological level. This level includes the three different, and incompatible conceptions of humans: the first-person, the second-person, and the third-person conceptions. A third-person conception of humans is most compatible with trends placed in quadrant 4. A second-person conceptualization is most congruent with quadrant 3, and so on. Thus, the unification of psychologies emerges as not only difficult but actually unreasonable, because the plurality of psychological paradigms originates from the epistemological, methodological, and metapsychological levels of the metaparadigm.     

Influence of motoric encoding on forgetting function of memory for action sentences in patients with Alzheimer's disease

This study assessed whether verbal encoding and motoric encoding have different effects on the forgetting function for action sentences of patients with Alzheimer's disease. Subjects were 13 healthy elderly adults and 10 patients diagnosed with Alzheimer's disease. Three tasks were used: verbal tasks, subject-performed tasks, observed tasks. On the verbal tasks, subjects only heard the action sentences as read to them. On the subject-performed tasks, subjects heard, then performed each action sentence. On the observed tasks, subjects heard the action sentences read while observing the object mentioned in each action sentence. After presentation of each task, subjects conducted immediate and 30-min. delayed recall tests, and then a recognition test. Analysis indicated recall performance for subject-performed tasks was significantly better than that for verbal tasks and observed tasks at both immediate and delayed recall in each group. On the recognition test, carrying out the action had no effect, but for both groups recognition was enhanced by observing the object. Elderly adults performed significantly better than patients on all tasks of recall and recognition. However, the results indicate that patients with Alzheimer's disease can use multimodal resources from motoric encoding even if time passes.     

Early Personality Traits as Predictors of Mortality Risk Following Conjugal Bereavement

ABSTRACT This study explored pre-bereavement personality traits and gender as predictors of post-widowhood mortality risk, using newly derived life span data for participants originally recruited for Lewis Terman's classic study of the gifted. Personality traits measured in 1940 were used to predict mortality risk from 1940 through 2004 for married participants who were either widowed between 1940 and 1986 or who remained married. Results indicated that widowhood predicted a decrease in mortality risk for these (intelligent) individuals (relative hazard [ rh ]=0.68, N =843, p <.001) and neuroticism significantly moderated this effect. Specifically, neuroticism in young adulthood was significantly associated with decreased mortality risk among men who were later widowed ( rh =0.50, N =66, p <.02) but not among women or consistently married men. Conclusions reveal the importance of personality–situation interactions and the adoption of a long-term perspective.     

Developmental emergence of self-referential and inhibition mechanisms of body movements underling felicitous behaviors

In young infants, activation or inhibition of body movements on perception of environmental events is important to enable them to act on the world or understand the world. To reveal the development of this ability, we observed movement patterns in all four limbs under the two experimental conditions. Infants assigned to the interaction condition were provided a connection between their arm and a toy, which allowed movements of the critical arm to produce movements in the overhead mobile. Infants assigned to the stimulation condition were presented with similar movements of the toy emulated by the experimenter. In 3-month-old infants, the arm movements increased under the interaction condition, whereas they decreased under the stimulation condition. Such condition-dependent behavior dissociation was not observed in 2-month-old infants. These results suggest that the distinct behavior of an "observer" of environmental events was differentiated from that of a "player" interacting with the surroundings between 2 and 3 months of age. The emergence of differentiation of behaviors points toward the development of self-referential and inhibition mechanisms in the perceptual-motor and attention/evaluation system in the cortico-subcortical network.     

Initial-state dependency of learning in young infants

With the aim of investigating the effect of the initial state of pre-learning on subsequent infant learning (i.e., the initial-state dependency), we observed the limb movements in 3-month-old infants in the course of a motor learning task. The session comprised 2-min pre-learning and 4-min learning periods, and the infants learned to move a toy using a string attached to either an arm (arm-based learning, Experiment 1) or a leg (leg-based learning, Experiment 2). Infants were assigned to low- and high-state groups in the initial-state condition according to the average velocity of the arm (Experiment 1) or leg (Experiment 2) movements during the pre-learning period. The results revealed that, during the learning period, infants in the low-state group increased the movement of their limbs, whereas those in the high-state group showed no significant changes in the movement of most of their limbs. These results suggest that infants demonstrating a low average velocity of movement in the initial state easily observed and learned the circular causality between self-produced movements and environmental changes. On the other hand, it seemed that infants demonstrating a high average velocity of movement in the initial state could not or did not need to increase their limb movements (the toy would already be shaking enough to form striking movements).