Detection of invariants by haptic touch across age groups: rod length perception

This study examined the development in the detection of maximum eigenvalues and static moment as invariants, through a task of perceiving rod length without visual information by haptic touch. 34 participants ages 6 to 83 years participated in the experiment. Their exploratory behavior and perceptions of rod length were analyzed by age group (Children: 6 to 12 years old; Young Adult: 21 to 25 years old; Middle Age: 31 to 56 years old; and Older: 65 to 83 years old). A behavior analysis indicated that use of vertical swinging increased for the Young Adult group and decreased with age for the Older group, whereas Children frequently held the rod without wielding. Analysis showed that, by age, differences in coefficients on the maximum eigenvalue and static moment were parallel with an exploratory behavioral change. Finally, the effect of different exploratory behaviors on length perception was discussed.     

Alzheimer amyloid beta-peptide inhibits the late phase of long-term potentiation through calcineurin-dependent mechanisms in the hippocampal dentate gyrus

The perforant path projecting from the entorhinal cortex to the hippocampal dentate gyrus is a particularly vulnerable target to the early deposition of amyloid beta (Abeta) peptides in Alzheimer's brain. The authors previously showed that brief applications of Abeta at subneurotoxic concentrations suppressed the early-phase long-term potentiation (E-LTP) in rat dentate gyrus. The current study further examines the effect of Abeta on the late-phase LTP (L-LTP) in this area. Using multiple high-frequency stimulus trains, a stable L-LTP lasting for at least 3 h was induced in the medial perforant path of rat hippocampal slices. Bath application of Abeta(1-42) (0.2-1.0 microM) during the induction trains attenuated both the initial and late stages of L-LTP. On the other hand, Abeta(1-42) perfusion within the first hour following the induction primarily impaired the late stage of L-LTP, which resembled the action of the protein synthesis inhibitor emetine. Blockade of calcineurin activity with FK506 or cyclosporin A completely prevented Abeta-induced L-LTP deficits. These results suggest that Abeta(1-42) impaired both the induction and maintenance phase of dentate L-LTP through calcineurin-dependent mechanisms. In the concentration range effective for inhibiting L-LTP, Abeta(1-42) also reduced the amplitude of NMDA receptor-mediated synaptic currents in dentate granule cells via a postsynaptic mechanism. In addition, concurrent applications of Abeta(1-42) with the protein synthesis inhibitor caused no additive reduction of L-LTP, indicating a common mechanism underlying the action of both. Thus, inhibition of NMDA receptor channels and disruption of protein synthesis were two possible mechanisms contributing to Abeta-induced L-LTP impairment.     

Semantic processing of Arabic,Kanji, and Kana numbers: Evidence from interference in physical and numerical size judgments

Two experiments were conducted with the following objectives (1) to replicate the finding of similar semantic representation of Arabic and written-word (Kanji and Kana) numbers with a direct numerical task, (2) to investigate the automatic semantic processing of Arabic and written-word numbers, and (3) to verify whether the assumption of a common semantic representation is valid in an indirect numerical task. Subjects were asked to judge which of two numbers (e.g, 6-8) was larger either in its numerical size (Experiment 1) or in its physical size (Experiment 2) using the three notations. Effects of two factors were analyzed: the congruity between numerical and physical size and the numerical distance. The effects of these factors were very similar across the three notations in Experiment 1, but were drastically different in Experiment 2. The results of Experiment 2 demonstrated the nonsemantic processing of Kana numbers, and suggest that there may be separate semantic representations for Arabic and Kanji numbers.     

LATERAL DIFFERENCES IN DIGIT AND NONSENSE FORM RECOGNITION AMONG JAPANESE AND ISRAELI SUBJECTS

Digit and nonsense figure sequences which were arranged vertically or horizontally, were tachistoscopically presented to native Japanese and Hebrew readers to the left or right visual field. Both groups showed a right visual field superiority in the horizontal condition and a strong tendency toward a right visual field superiority in the vertical condition for the digit sequences, and no visual field difference was shown both in the vertical and horizontal conditions for the nonsense figure sequences. There was no difference between Japanese and Israelis in either the direction or the degree of the visual field differences. A slight influence of the different directional reading biases between both groups appeared in the analysis of serial position effect in recall, but this influence was not prominent. Based on these findings, cross-cultural influences on cerebral functioning were discussed.     

Time without Rate

There is a lingering objection to the idea of the passage of time. Roughly speaking, the argument runs as follows: (i) if time passes, its passage must occur at some rate, but (ii) there is no such rate; hence, the passage of time is a myth. While some philosophers try to reject premise (ii), I wish to challenge the first premise by arguing that time may pass with or without a rate. My argument addresses two cases, one that identifies the passage of time with changes in things and one that does not. I call the former view ‘the Priorian passage theory’, and the latter view ‘the pure passage theory’. I argue that each dynamic view of time is immune to the rate argument. Further, I suggest a possible extension of the Priorian passage theory, in which the passage of time is identified with the pure persistence of things.     

Relational Mobility Increases Social (but Not Other) Risk Propensity

In recent years, we have witnessed a resurgent focus on ecological features, especially various forms of mobility that afford social psychological processes. Extending this work, the current research examined whether relational mobility affects risk propensity. We conducted three studies using both correlational (Studies 1 and 3) and experimental (Study 2) methods. Results provide support for the hypothesis that perceptions of relational mobility are associated with risk propensity in the domain of interpersonal behaviors but not other risk domains (health, financial, etc.). Findings in Study 3 suggested that the association between relational mobility and propensity for risky interpersonal behaviors may stem from the effect of relational mobility in lowering subjective risk (but not in increasing expected benefits) of such behaviors. Copyright © 2015 John Wiley & Sons, Ltd.     

The inferential interference effects of environmental sounds on spoken speech in Japanese and British people

Spoken speech was paired with several kinds of environmental sounds and presented dichotically to both native Japanese and British subjects to compare the direction and degree of ear advantage. Results suggest that environmental sounds interfere in a similar manner for both groups of subjects but that there are highly significant differences in the degree of ear advantage between the Japanese and British subjects which might be due to some linguistic influences.     

The gestural repertoire of the wild bonobo (<Emphasis Type="Italic">Pan paniscus</Emphasis>): a mutually understood communication system

In animal communication, signallers and recipients are typically different: each signal is given by one subset of individuals (members of the same age, sex, or social rank) and directed towards another. However, there is scope for signaller–recipient interchangeability in systems where most signals are potentially relevant to all age–sex groups, such as great ape gestural communication. In this study of wild bonobos (Pan paniscus), we aimed to discover whether their gestural communication is indeed a mutually understood communicative repertoire, in which all individuals can act as both signallers and recipients. While past studies have only examined the expressed repertoire, the set of gesture types that a signaller deploys, we also examined the understood repertoire, the set of gestures to which a recipient reacts in a way that satisfies the signaller. We found that most of the gestural repertoire was both expressed and understood by all age and sex groups, with few exceptions, suggesting that during their lifetimes all individuals may use and understand all gesture types. Indeed, as the number of overall gesture instances increased, so did the proportion of individuals estimated to both express and understand a gesture type. We compared the community repertoire of bonobos to that of chimpanzees, finding an 88 % overlap. Observed differences are consistent with sampling effects generated by the species’ different social systems, and it is thus possible that the repertoire of gesture types available to Pan is determined biologically.     

Do pointing gestures by infants provoke comments from adults?

In the field of developmental psychology, there is speculation that pointing gestures by infants are good precursors of infant language acquisition, and some researchers have found correlations between these pointing gestures and some indices of language acquisition. Infants’ pointing gestures are presumably related to language acquisition because they provoke verbal responses from adults. To test this, seven boys and six girls were observed during free play time in a nursery classroom, and post-pointing and matched-control data were collected. Comparison between these data confirmed that the nursery staff spoke to infants at a significantly earlier stage in post-pointing sequences, compared with control sequences, indicating that pointing gestures elicit verbal responses from adult caregivers.