A social cichlid fish failed to pass the mark test

Since the pioneering work in chimpanzees, mirror self-recognition (MSR), the ability to recognise oneself in a mirror, has been reported in great apes, Asian elephants, dolphins, and some social birds using the mark test, in which animals that possess MSR touch an imperceptible mark on their own bodies only when a mirror is present. However, giant pandas, which are solitary, failed to pass the mark test, suggesting that MSR evolved solely in highly social animals. In contrast to the increasing evidence of MSR in mammals and birds, little is known about MSR in fish. A Tanganyikan cichlid, Neolamprologus pulcher, is a good candidate for study because these fish live in highly social groups and recognise conspecifics about as rapidly as primates. We examined their responses to a mirror image and tested whether N. pulcher could pass the mark test. When the mirror was first exposed, they stayed in front of the mirror and exhibited aggressive behaviour towards the mirror image. These social behaviours suggested that the focal fish perceived the mirror image as an unfamiliar conspecific. The social responses decreased over the following days, as has generally been the case in animals with MSR. After mark injection, we found no increase in scraping behaviour or prolonged observation of the marked side. These results show a lack of contingency checking and mark-directed behaviours, meaning that N. pulcher failed to pass the mark test and did not recognise their self-image in the mirror.     

Establishing compliance with liquid medication administration in a child with autism

Children with autism often display difficulty with swallowing pills and liquid medications. In the current study, stimulus fading and positive reinforcement established compliance with liquid medication administration in a young boy with autism. The boy's mother eventually administered liquid medication on her own.     

Neural enhancement and attenuation induced by repetitive recall

Learning is the process of accumulating information. Repetition can make the process of retrieving information more efficient. The mechanisms by which repetition facilitates the retrieval process, however, are not yet clear. Here, we used event-related functional magnetic resonance imaging to investigate the effects of repetition on cued recall. In this study, participants were asked to encode visually presented semantically unrelated word pairs. The word presented on the left side served as the cue, and the word presented on the right side was the target. In the first test phase, participants were presented with the cue and asked to recall the associated word (target) from the study phase. The second test phase was performed 20 min later using the same method. Participants responded orally during the interval between image acquisitions, and no feedback was provided. Neural activity for identical stimuli and responses across the two tests were compared. As compared with the first test phase, the right dorsolateral prefrontal, bilateral inferior parietal, and precuneus regions showed greater activity and the left inferior frontal areas showed reduced activity during the second test phase. These shifts in neural activity that occurred with repetition may reflect the dynamics of the retrieval process.     

Perceiving an exclusive cause of affect prevents misattribution

Affect misattribution occurs when affective cues color subsequent unrelated evaluations. Research suggests that affect misattribution decreases when one is aware that affective cues are unrelated to the evaluation at hand. We propose that affect misattribution may even occur when one is aware that affective cues are irrelevant, as long as the source of these cues seems ambiguous. When source ambiguity exists, affective cues may freely influence upcoming unrelated evaluations. We examined this using an adapted affect misattribution procedure where pleasant and unpleasant responses served as affective cues that could influence later evaluations of unrelated targets. These affective cues were either perceived as reflecting a single source (i.e., a subliminal affective picture in Experiment 1; one's internal affective state in Experiment 2), or as reflecting two sources (i.e., both) suggesting source ambiguity. Results show that misattribution of affect decreased when participants perceived affective cues as representing one source rather than two.     

Quantum-like generalization of the Bayesian updating scheme for objective and subjective mental uncertainties

In this paper we develop a general quantum-like model of decision making. Here updating of probability is based on linear algebra, the von Neumann–Lüders projection postulate, Born’s rule, and the quantum representation of the state space of a composite system by the tensor product. This quantum-like model generalizes the classical Bayesian inference in a natural way. In our approach the latter appears as a special case corresponding to the absence of relative phases in the mental state. By taking into account a possibility of the existence of correlations which are encoded in relative phases we developed a more general scheme of decision making. We discuss natural situations inducing deviations from the classical Bayesian scheme in the process of decision making by cognitive systems: in situations that can be characterized as objective and subjective mental uncertainties. Further, we discuss the problem of base rate fallacy. In our formalism, these “irrational” (non-Bayesian) inferences are represented by quantum-like bias operations acting on the mental state.     

Tensile strength and fracture of a tilt grain boundary in cubic SiC: A first-principles study

The ab initio tensile test has been applied to the non-polar interface of the {122}, Sigma = 9 tilt boundary in cubic SiC, where the tensile strength and mechanical behaviour at zero temperature are examined using the ab initio pseudopotential method based on the local density-functional theory. This interface is strong because of the reconstruction of interfacial bonds. The maximum tensile stress in the unaxial extension normal to the interface is about 42 GPa, which is about 80% of the theoretical and experimental values of the strength of bulk crystal along the <111> direction. Young's modulus and the fracture toughness are also comparable with the values of the bulk crystal. The back Si-C bond of the interfacial C-C bond is broken first because the C-C bond has a high strength and a short length like a diamond bond. Then the interfacial Si-C bonds are broken, and finally the Si-Si bond. The Si-C bonds are rapidly stretched and broken if the bond stretching exceeds about 20%, and the bond charge clearly disappears when the bond stretching exceeds about 30%. Changes in the electronic structure associated with the bond breaking are analysed.     

Visualization of stress distribution using mechanoluminescence from Sr3Al2O6: Eu and the nature of the luminescence mechanism

We have investigated the dependence of the mechanoluminescence intensity from Sr3Al2O6: Eu on compressive stress. The distribution of the mechanoluminescence intensity, which is clearly visible to the naked eye, is consistent with the calculated stress distribution. The luminescence centre has been identified as the Eu2+ ion from spectra of the mechanoluminescence and also from photoluminescence studies of Sr3Al2O6: Eu. The mechanoluminescence intensity decreases on repetitive application of stress but recovers completely on irradiation with ultraviolet light. The Sr3Al2O6: Eu is a p-type semiconductor and has hole traps of depth 0.11 eV. It is suggested that the mechanoluminescence mechanism arises from the movement of dislocations and recombination between electrons and holes released from these traps which are associated with Eu2+ centres.     

There is a fire burning in my heart: The role of causal attribution in affect transfer

The role of causal attribution in affect transfer of primes was addressed by examining the consequences of explicit evaluation of primes within the framework of the affect misattribution procedure (AMP; Payne, Cheng, Govorun, & Stewart, 2005). We reasoned that affect transfer occurs when primed affect remains diffuse and not bound to a specific object, hence capable of freely colouring subsequent evaluations of ambiguous objects. Accordingly, we propose that when people explicitly evaluate the prime, affect is clearly bound to the prime and becomes less capable of influencing subsequent judgements. Supporting this notion, affect transfer in the AMP was observed when participants ignored the primes, thereby keeping the primed affect relatively unbound. However, this effect disappeared when participants explicitly evaluated the primes before target stimuli were presented. Implications of these findings in determining how and when affect arising from one object carries over to another is discussed.     

Asymptotic distributions of the estimators of communalities in factor analysis

Asymptotic distributions of the estimators of communalities are derived for the maximum likelihood method in factor analysis. It is shown that the common practice of equating the asymptotic standard error of the communality estimate to the unique variance estimate is correct for standardized communality but not correct for unstandardized communality. In a Monte Carlo simulation the accuracy of the normal approximation to the distributions of the estimators are assessed when the sample size is 150 or 300. This study was carried out in part under the ISM Cooperative Research Program (90-ISM-CRP-9).     

Mutual liking and meta‐perception accuracy

The present study investigated the underlying mechanism yielding a positive correlation between dyad members' mutual liking and meta‐accuracy (i.e., dyad members who like each other tend to be accurate in judging how their partner sees them). Two pilot studies were first conducted to confirm the presence of the positive correlation. The main study was conducted to test several possible explanations for the observed positive correlation. In the main study, each participant took part in a series of brief interactions with an unacquainted opposite‐sex partner three times. In each interaction, participants rated their liking for the partner, evaluated their impression of the partner on 15 items, and finally inferred the partner's impression of them on the same 15 items. The meta‐accuracy was operationally defined as the correlation between the partner's impression and the participant's inference. Neither of the two types of unilateral liking (i.e., participant's liking for the partner nor the partner's liking for the participant) predicted meta‐accuracy. However, when both members found the partner likeable (i.e., mutual liking was present), the within‐dyad average meta‐accuracy tended to be high. The implications of these results for meta‐perception research are discussed on the basis of Brunswik's lens model framework. Copyright © 2008 John Wiley & Sons, Ltd.