Behavioural development in a matching-to-sample task and token use by an infant chimpanzee reared by his mother

We investigated the behavioural and cognitive development of a captive male infant chimpanzee, Ayumu, raised by his mother, Ai. Here we report Ayumu's achievements up to the age of 2 years and 3 months, in the context of complex computer-controlled tasks. From soon after birth, Ayumu had been present during an experiment performed by his mother. The task consisted of two phases, a matching-to-sample task in which she received token rewards, and the insertion of these tokens into a vending machine to obtain food rewards. Ayumu himself received no reward or encouragement from humans for any of the actions he exhibited during the experiment. At the age of 9 months and 3 weeks, Ayumu performed his first matching-to-sample trial. At around 1 year and 3 months, he began to perform them consistently. Also during this period, he frequently stole food rewards from his mother. At 2 years and 3 months, Ayumu succeeded for the first time in inserting a token into the vending machine. Once he had succeeded in using a token, he performed both phases of the task in sequence 20 times consecutively. The infant's behaviour was not shaped by food rewards but by a strong motivation to copy his mother's behaviour. Our observations of Ayumu thus mirror the learning processes shown by wild chimpanzees.     

Brain activation during the course of sentence comprehension

The purpose of this study is to determine, by functional magnetic resonance imaging, how the activated regions of the brain change as a Japanese sentence is presented in a grammatically correct order. In this study, we presented constituents of a sentence to Japanese participants one by one at regular intervals. The results showed that the left lingual gyrus was significantly activated at the beginning of the sentence, then the left inferior frontal gyrus and left supplementary motor area, in the middle of the sentence, and the left inferior temporal gyrus, at the end of the sentence. We suggest that these brain areas are involved in sentence comprehension in this temporal order.     

The Effect of Positive Emotions with Different Arousal Levels on Thought–Action Repertoires1,2

This study examined whether the induction of different states of arousal via positive emotions broadens thought–action repertoires. Sixty-two Japanese undergraduate and graduate students were randomly assigned to (a) high-arousal positive emotion, (b) low-arousal positive emotion, and (c) neutral groups, after which they watched a 3-min film clip. Participants completed the Affect Grid to confirm their mood state before and after watching the film. Following this, they completed the Twenty Statements Test, which measures thought–action repertoires. A one-way analysis of variance was conducted on the Twenty Statements Test score. The results showed that high-arousal positive emotion broadened thought–action repertoires to a greater extent than did low-arousal positive emotion and the neutral state, while low-arousal positive emotion broadened such repertoires to a greater extent than did the neutral state. We discuss the different effects of high- and low-arousal positive emotions on thought–action repertoires.     

A new algorithm for the least-squares solution in factor analysis

A new algorithm to obtain the least-squares or MINRES solution in common factor analysis is presented. It is based on the up-and-down Marquardt algorithm developed by the present authors for a general nonlinear least-squares problem. Experiments with some numerical models and some empirical data sets showed that the algorithm worked nicely and that SMC (Squared Multiple Correlation) performed best among four sets of initial values for common variances but that the solution might sometimes be very sensitive to fluctuations in the sample covariance matrix.Numerical computation was made on a NEAC S-1000 computer in the Computer Center, Osaka University.     

Scaling of dot numerosity

Subjective impression of numerosity of dots randomly scattered in an area of 19.5 × 24.5 cm, 36≈1,010 in number (?), was scaled by four different methods with five subjects. The absolute identification showed that the number of dots is underestimated if ? > 10. Each of two scales based uponratio judgments is a power function of $ with the exponent of 0.87, and each of two scales based upondifference judgments is also a power function of ? when the origin of the scale is appropriately defined. The relationship between the four scales and comparison with scales in other sense modalities were discussed from the viewpoint of scaling methodology.     

Self-referential processing of negative stimuli within the ventral anterior cingulate gyrus and right amygdala

Neural activity associated with self-referential processing of emotional stimuli was investigated using whole brain functional magnetic resonance imaging (fMRI). Fifteen healthy subjects underwent fMRI scanning while making judgments about positive and negative trait words in four conditions (self-reference, other-reference, semantic processing, and letter processing). Significant activity was observed in the right ventral anterior cingulate gyrus and the right amygdala in the negative-word/self-reference condition, and in the left amygdala in the positive-word/self-reference condition. Compared with the semantic-processing condition, the self-reference conditions showed significantly more activity in the medial prefrontal and temporal gyri, posterior cingulate gyrus, and precuneus. These results suggest that the medial prefrontal gyrus, posterior cingulate gyrus, and precuneus are associated with a self-referential processing, and the ventral anterior cingulate gyrus is involved in self-referential processing of negative emotional stimuli. The results also suggest that the amygdala is associated with self-referential processing of both positive and negative emotional stimuli.     

Problems of Translation for Cross-Cultural Experimental Philosophy

In this paper, first, I briefly discuss various types of obstacles and difficulties for cross-cultural study and in particular failure of translational equivalence of linguistic stimuli and questions by referring to the literature in cultural psychology. Second, I summarize the extant cross-cultural studies of semantic judgments about reference and truth-value with regard to proper names, with a focus on Sytsma et al.’s (2015) study that examined the differences between English and Japanese. Lastly, I introduce and discuss the two recent studies of semantic judgments in Japanese that my colleagues and I conducted. These two studies suggest that the translation Sytsma et al. used failed to consider the linguistic features characteristic of Japanese and other East Asian languages, and thereby failed to ensure translational equivalence.

     

Threading dislocation with b=c+2a in 4H-SiC as determined by LACBED

The Burgers vectors of the so-called threading screw dislocations (a total of 28 dislocations) in 4H-SiC were determined by large-angle convergent-beam electron diffraction. A new type of TSD, that is, b = c + 2a dislocation, was identified. Thus, all of the four types of TSD predicted by Onda et al. [Phil. Mag. Lett. 93 (2013) p.591] were identified.     

Interfacial reaction between silicon nitride and aluminium

Abstract

The microstructure of a silicon nitride/aluminium interface has been identified by analytical transmission electron microscopy. HIPed silicon nitride without any additive was bonded by pure aluminium at 800°C for 15 min. A thin (～ 5000 Å) reaction layer was recognized at the interface. It consisted of two regions. One an amorphous layer facing the aluminium; it contained aluminium, silicon and oxygen. The other was on the silicon nitride side and consisted of fine particles which were less than 100 Å in diameter. These particles were considered to have β'-sialon type structure.