TESTS FOR CONTROL BY EXCLUSION AND NEGATIVE STIMULUS RELATIONS OF ARBITRARY MATCHING TO SAMPLE IN A “SYMMETRY-EMERGENT” CHIMPANZEE

In the present experiments, controlling relations in arbitrary matching-to-sample performance were tested in a 9-year-old female chimpanzee who showed statistically significant emergence of symmetry in previous two-choice conditional discrimination experiments. In Experiment 1, a novel (undefined) sample stimulus was followed by a pair of trained (defined) and undefined comparison stimuli to assess the control by exclusion in arbitrary matching. The chimpanzee selected the undefined shape comparison, excluding the defined one, in color-sample-to-shape-comparison probe trials, although stimulus preferences were relatively stronger than control by exclusion in shape-sample trials. An additional test for control by relations of the sample to the positive comparison (S+ control) showed that her behavior was also under the control of relations of the sample to the positive comparison. In Experiment 2, a defined sample was followed by a pair of negatively defined and undefined comparisons to test control by the relations of the sample to the negative comparison. (S- control). The subject selected undefined comparisons in both color-shape and shape-color test trials. These results clearly indicate that the conditional discrimination behavior of this “symmetry-emergent” chimpanzee was under both S+ and S- control. Furthermore, her performance was also under control by exclusion in color-shape arbitrary matching, unlike other chimpanzees who showed no evidence of symmetry but only S+ control of arbitrary matching.     

Roots of smile: a preterm neonates' study

Twenty-two preterm neonates were observed 1 h per neonate in the NICU. Ninety-five spontaneous smiles were recorded. Younger and smaller neonates showed more and longer spontaneous smiles than older and larger. The youngest neonate was 200 days from conception on the observational day. She was 511 g. This infant showed spontaneous smiles. The roots of spontaneous smiles are discussed.     

Human gestures trigger different attentional shifts in chimpanzees (Pan troglodytes) and humans (Homo sapiens)

Brain lateralization has been the matter of extensive research over the last centuries, but it remains an unsolved issue. While hand preferences have been extensively studied, very few studies have investigated laterality of eye use in non-human primates. We examined eye preference in 14 Campbell’s monkeys (Cercopithecus c. campbelli). We assessed eye preference to look at a seed placed inside a tube using monocular vision. Eye use was recorded for 100 independent and non-rewarded trials per individual. All of the 14 monkeys showed very strong preferences in the choice of the eye used to look inside the tube (mean preference: 97.6%). Eight subjects preferred the right eye and six subjects preferred the left eye. The results are discussed in light of previous data on eye preference in primates, and compared to data on hand preference from these subjects. Our findings would support the hypothesis for an early emergence of lateralization for perceptual processes compared to manual motor functions.     

Are the windows to the soul the same in the East and West? Cultural differences in using the eyes and mouth as cues to recognize emotions in Japan and the United States

The current research investigated the hypothesis that, depending on an individual’s cultural background, facial cues in different parts of the face are weighted differently when interpreting emotions. Given that the eyes are more difficult to control than the mouth when people express emotions, we predicted that individuals in cultures where emotional subduction is the norm (such as Japan) would focus more strongly on the eyes than the mouth when interpreting others’ emotions. By contrast, we predicted that people in cultures where overt emotional expression is the norm (such as the US) would tend to interpret emotions based on the position of the mouth, because it is the most expressive part of the face. This hypothesis was confirmed in two studies, one using illustrated faces, and one using edited facial expressions from real people, in which emotional expressions in the eyes and mouth were independently manipulated. Implications for our understanding of cross-cultural psychology, as well of the psychology of emotional interpretation, are discussed.     

Spontaneous smile and spontaneous laugh: an intensive longitudinal case study

One male infant was observed from the day of his birth to the end of the 6th month. Total observation days were 171 days, and total observation time was 329 h 25 min and 35s. Five hundred and sixty-five spontaneous smiles and 15 spontaneous laughs (smiles accompanied by vocal sounds) were observed. Developmental psychologists have thought that spontaneous smiles integrate at about 3 months, but spontaneous smiles were recorded even in the 6th month. The percentage of bilateral smiles increased from the 2nd month. This is the first intensive longitudinal study on spontaneous smiles and spontaneous laughs.     

Cross-cultural differences in relationship- and group-based trust

Two experiments explored differences in depersonalized trust (trust toward a relatively unknown target person) across cultures. Based on a recent theoretical framework that postulates predominantly different bases for group behaviors in Western cultures versus Eastern cultures, it was predicted that Americans would tend to trust people primarily based on whether they shared category memberships; however, trust for Japanese was expected to be based on the likelihood of sharing direct or indirect interpersonal links. Results supported these predictions. In both Study 1 (questionnaire study) and Study 2 (online money allocation game), Americans trusted ingroup members more than outgroup members; however, the existence of a potential indirect relationship link increased trust for outgroup members more for Japanese than for Americans. Implications for understanding group processes across cultures are discussed.     

Study of a cognitive effects model in Dohsa‐hou for the elderly

This study investigates the primary factors responsible for cognitive performance improvements as a result of dohsa‐hou (Japanese body‐oriented psychotherapy) for the elderly. The study divided participants into two homogeneous groups: an experimental group that attempted to improve upright balance by performing dohsa‐hou, and a control group to establish the drop‐off period for the effect of performing the given activities. The task processing time of Stroop Test and body sway and the situational anxiety during task processing of Stroop Tests were measured before and after the dohsa‐hou and drop‐off period. The results confirm that only the experimental group improved in body sway, had a shorter Stroop Color Test processing time and lower situational anxiety. From this study, it has been identified that: (a) information‐processing capacities spared for posture control are affected by distribution of processing resources towards solving other cognitive tasks; and (b) the effect of the release of attention from threat‐related information due to a decrease in attentional bias, which accompanied the decrease in situational anxiety, are primary factors in improving cognitive task performance.     

Differential reliance of chimpanzees and humans on automatic and deliberate control of motor actions

Humans are often unaware of how they control their limb motor movements. People pay attention to their own motor movements only when their usual motor routines encounter errors. Yet little is known about the extent to which voluntary actions rely on automatic control and when automatic control shifts to deliberate control in nonhuman primates. In this study, we demonstrate that chimpanzees and humans showed similar limb motor adjustment in response to feedback error during reaching actions, whereas attentional allocation inferred from gaze behavior differed. We found that humans shifted attention to their own motor kinematics as errors were induced in motor trajectory feedback regardless of whether the errors actually disrupted their reaching their action goals. In contrast, chimpanzees shifted attention to motor execution only when errors actually interfered with their achieving a planned action goal. These results indicate that the species differed in their criteria for shifting from automatic to deliberate control of motor actions. It is widely accepted that sophisticated motor repertoires have evolved in humans. Our results suggest that the deliberate monitoring of one’s own motor kinematics may have evolved in the human lineage.     

Effects of syntactic information on semantic access of ambiguous verbs in spoken language comprehension: Evidence from a cross‐modal priming experiment1

Abstract: The aim of this study was to examine how syntactic information affects the semantic processing of ambiguous verbs in spoken Japanese. The effect of a postpositional particle on semantic access of an ambiguous verb at the end of the sentence was demonstrated in two kinds of sentences, S‐ga‐V sentences (subject, subjective postpositional particle, and ambiguous verb) and O‐wo‐V sentences (object, objective postpositional particle, and ambiguous verb). A cross‐modal priming method was used in which a target noun was presented visually in Kanji (Chinese) characters either one syllable before the end or immediately after the end of the ambiguous verb. Weak multiple priming occurred in the one‐syllable‐before condition, followed by selective access in the immediately after condition, but this multiple access was partially constrained by the preceding postpositional particle. A brief occurrence of multiple access and rapid transition to selective access were detected. Furthermore, objective particles were found to have stronger constraints on multiple access than on subjective particles. A connectionist model using a constraint‐based lexical approach was consistent with the experimental results.