Functional magnetic resonance imaging of human cognitive processes

Functional magnetic resonance imaging (fMRI) is now widely accepted as a tool for analyzing human brain function. Since the realization of fMRI in the early 1990s, numerous reports have been published. In this paper, we present three studies. The first examined syntactic processing of Japanese sentences and the results prove that Broca's area is involved in the use of grammar. The second study compared binocular with monocular stereopsis. There were significant activations in the right inferior parietal lobe. The third study concerned the encoding and retrieval processes underlying face recognition. It revealed activations mainly in the right prefrontal areas, which is contrary to the hemispheric encoding and retrieval asymmetry (HERA) theory. fMRI will continue to play an important role in the analysis of human brain function.     

Unattended exposure to components of speech sounds yields same benefits as explicit auditory training

Learning a second language as an adult is particularly effortful when new phonetic representations must be formed. Therefore the processes that allow learning of speech sounds are of great theoretical and practical interest. Here we examined whether perception of single formant transitions, that is, sound components critical in speech perception, can be enhanced through an implicit task-irrelevant learning procedure that has been shown to produce visual perceptual learning. The single-formant sounds were paired at subthreshold levels with the attended targets in an auditory identification task. Results showed that task-irrelevant learning occurred for the unattended stimuli. Surprisingly, the magnitude of this learning effect was similar to that following explicit training on auditory formant transition detection using discriminable stimuli in an adaptive procedure, whereas explicit training on the subthreshold stimuli produced no learning. These results suggest that in adults learning of speech parts can occur at least partially through implicit mechanisms.     

A solution for measuring accurate reaction time to visual stimuli realized with a programmable microcontroller

This article presents a new solution for measuring accurate reaction time (SMART) to visual stimuli. The SMART is a USB device realized with a Cypress Programmable System-on-Chip (PSoC) mixed-signal array programmable microcontroller. A brief overview of the hardware and firmware of the PSoC is provided, together with the results of three experiments. In Experiment 1, we investigated the timing accuracy of the SMART in measuring reaction time (RT) under different conditions of operating systems (OSs; Windows XP or Vista) and monitor displays (a CRT or an LCD). The results indicated that the timing error in measuring RT by the SMART was less than 2 msec, on average, under all combinations of OS and display and that the SMART was tolerant to jitter and noise. In Experiment 2, we tested the SMART with 8 participants. The results indicated that there was no significant difference among RTs obtained with the SMART under the different conditions of OS and display. In Experiment 3, we used Microsoft (MS) PowerPoint to present visual stimuli on the display. We found no significant difference in RTs obtained using MS DirectX technology versus using the PowerPoint file with the SMART. We are certain that the SMART is a simple and practical solution for measuring RTs accurately. Although there are some restrictions in using the SMART with RT paradigms, the SMART is capable of providing both researchers and health professionals working in clinical settings with new ways of using RT paradigms in their work.     

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.     

Visual snake aversion in Octodon degus and C57BL/6 mice

Animal Cognition - Phobia against spiders or snakes is common in humans, and similar phobia-like behaviors have been observed in non-human animals. Visual images of snakes elicit phobia in humans,...     

A neural network model for development of reaching and pointing based on the interaction of forward and inverse transformations

Pointing is one of the communicative actions that infants acquire during their first year of life. Based on a hypothesis that early pointing is triggered by emergent reaching behavior toward objects placed at out‐of‐reach distances, we proposed a neural network model that acquires reaching without explicit representation of ‘targets’. The proposed model controls a two‐joint arm in a horizontal plane, and it learns a loop of internal forward and inverse transformations; the former predicts the visual feedback of hand position and the latter generates motor commands from the visual input through random generation of the motor commands. In the proposed model, the motor output and visual input were represented by broadly tuned neural units. Even though explicit ‘targets’ were not presented during learning, the simulation successfully generated reaching toward visually presented objects at within‐reach and out‐of‐reach distances.     

Van Gogh, Chagall and pigeons: picture discrimination in pigeons and humans

The author has previously reported that pigeons can discriminate paintings by different artists. Here, I replicated the previous findings, carried out additional tests and compared discrimination by pigeons with that of humans. In Experiment 1, pigeons were trained to discriminate between paintings by Van Gogh and Chagall. After training, the subjects were tested with different paintings by the same artists. The subjects showed generalization to these paintings. The subjects maintained their discriminative ability for black-and-white paintings and partially occluded paintings. When they were tested with mosaic paintings, the number of correct responses decreased, depending on the level of processing needed. In Experiment 2, human subjects were tested with the same paintings. The subjects showed generalization and decrement of correct responses depending on the degree of mosaic processing. These observations suggest that the visual cognitive function of pigeons is comparable to that of humans. The convergence of higher visual cognition between the two species may stem from similar selection pressures on avian ancestors and our ancestors through their evolution. Accepted after revision: 19 August 2001 Electronic Publication     

Discriminative and reinforcing properties of paintings in Java sparrows (<Emphasis Type="Italic">Padda oryzivora</Emphasis>)

Previous studies suggest that non-human animals can discriminate two different artworks (such as music or paintings) that were created by humans. However, such studies rarely examined whether those animals were reinforced by one artwork more than another. It has been shown that music composed by humans has both discriminative and reinforcing properties when played for Java sparrows. Here, we investigated the effects of another artistic medium in Java sparrows, namely paintings. The first experiment tested the reinforcing properties. Staying time at three painting categories—Japanese, cubist, and impressionist—was measured as an index of their reinforcing properties. The second experiment used operant conditioning to reveal the discriminative properties of the different artistic styles of such paintings. Results suggest that the paintings have both discriminative and reinforcing properties for Java sparrows. However, the reinforcing properties vary from individual to individual. This is the first report demonstrating reinforcing properties of visual artworks in non-human animals.     

Fading-figure tracing in Williams syndrome

Williams syndrome (WS) is a neurodevelopmental disorder characterized by severe impairment of visuospatial abilities. Figure-drawing abilities, which are thought to reflect visuospatial abilities, have yet to be fully investigated in WS. The purpose of the present study was to clarify whether drawing abilities differ between WS individuals and typically developing children (TD). We compared the performance of two groups of subjects (WS, mean age 16 years; TD, 5-6 years of age) using a fading-figure tracing task that requires subjects to trace a target figure that is gradually disappearing from a PC screen. Although the TD group exhibited clearly improved performance with long fading time, the WS group did not. Moreover, the TD group exhibited poor performance for figures with more than six angles, regardless of the figure type (e.g. closed or open), whereas the WS group exhibited generally poor performance for figures with more than five angles but relatively preserved performance for open figures. These findings indicate that a combination of decreased visuospatial span associated with incomplete development of visual scanning and disproportionate development of global processing may cause drawing disabilities in WS.     

Unbalanced triangle in the social dilemma of trust: Internet studies of real‐time,real money social exchange between China,Japan, and Taiwan

Using a dyadic game theory paradigm, three experiments on the social dilemma of trust were conducted over the Internet in real time, involving real money. It was predicted and found that in‐group favouritism in trusting behaviour was contingent on historical relationships between societies. In the China–Japan experiment, mainland Chinese but not Japanese trusted and made fair allocations to in‐group members more than out‐group members, and out‐group trust was best predicted by positive stereotypes of the out‐group for Chinese and identity for Japanese. In the China–Taiwan experiment, Taiwanese but not Mainland Chinese trusted in‐group members more than out‐group members, and in‐group trust for Taiwanese was best predicted by perceptions of current realistic threats. In the Taiwan–Japan experiment, there were slight in‐group favouring tendencies in trust, and positive stereotypes of the out‐group were the best predictors of out‐group trust. Japanese were unique in not displaying in‐group favouring behaviour at all, whereas both Chinese and Taiwanese were context specific in their in‐group favouritism. Stereotypes, social identities, perceptions of realistic threat, and historical anger made significant contributions to predicting trusting behaviour, but overall these survey measures only accounted for small and inconsistent amounts of variance across the three experiments.