The Rubber Hand Illusion: two's a company, but three's a crowd

On the one hand, it is often assumed that the Rubber Hand Illusion (RHI) is constrained by a structural body model so that one cannot implement supernumerary limbs. On the other hand, several recent studies reported illusory duplication of the right hand in subjects exposed to two adjacent rubber hands. The present study tested whether spatial constraints may affect the possibility of inducing the sense of ownership to two rubber hands located side by side to the left of the subject's hand. We found that only the closest rubber hand appeared both objectively (proprioceptive drift) and subjectively (ownership rating) embodied. Crucially, synchronous touch of a second, but farther, rubber hand disrupted the objective measure of the RHI, but not the subjective one. We concluded that, in order to elicit a genuine RHI for multiple rubber hands, the two rubber hands must be at the same distance from the subject's hand/body.     

Existing Challenges Associated with Offering Prenatal Genetic Diagnosis in an Arab Society in the Sultanate of Oman

The incidence of congenital anomalies and/or genetic disorders in the Omani population has reached figures greater than double the global statistics. Preference for consanguineous unions together with the fact that termination of pregnancy in Muslim communities are largely avoided, have been highlighted as contributing factors. This overview identifies a third significant aspect contributing to the elevated rate of genetic disorders in the Omani population. Namely, a lack of services that are able to offer termination of pregnancy for severe congenital anomalies, to requesting parents. In this report we select an unusual case of a family at risk for two distinct genetic disorders - 6q micro-deletion and unbalanced products of conception attributed to a balanced parental translocation involving chromosome 3 and 13, to portray and examine the current situation faced by Omani couples interested in prenatal diagnosis for termination of pregnancy. Additional challenges and pitfalls to developing a prenatal diagnostic service as part of the genetic service in Oman are discussed.     

Influence of properties of layered silicate minerals on adsorbed DNA surface affinity,self-assembly and nanopatterning

We report on the specific interaction between DNA and some mica-family minerals and other layered silicate structures. The interaction depends on mineral surface's crystallography, chemistry and potential. These properties are responsible for a remarkable variety of adsorption mechanisms and can be used to modulate surface self-assembly and nanopatterning of DNA. The controlled deposition of DNA onto non-conductive mineral regions with atomically flat boundaries has very attractive applications in nano-biotechnology (for example, microelectronics, microarrays and sensors). In addition, the extreme affinity discovered for some mineral surfaces, together with their ability to organize the DNA molecules, could be an indication of their catalytic potential. It may also have had relevance in the prebiotic environment, with important implications for the earth and life sciences.     

The Design and Evaluation of a Hope Enhancement Programme for Adults

The study evaluated the effectiveness of a hope enhancement programme for a group of adults and its impact on general psychological well-being. The intervention programme focused on participants' abilities to set feasible goals, planning ways to reach those goals (pathways) and increase determination and motivation (agency) to reach these goals. The workshop-format programme, consisted of six two-hour sessions conducted over five days. A pre and post-test design included an experimental group (n = 8), control group (n = 8) and ‘chat group’ (n = 8). Findings indicated that the programme increased hope levels of the experimental group as indicated by the Hope Scale and the Hopefulness Subscale of the Hunter Opinions and Personal Expectations Scale. Well-being also improved as indicated by a significant increase in sense of coherence along with a positive change in satisfaction with life. Recommendations for future research were made.     

Similarity chains in the transformational paradigm

Rips’ (1989) results with the transformational paradigm have often been cited as supporting accounts of categorisation not based on similarity, such as involving necessary or sufficient features (or a belief in such features), which guarantee a categorisation outcome once their presence has been established. We discuss a similarity account of the transformational paradigm based on similarity chains, which predicts that when the transformation is more gradual the identity of the transformed object is less likely to change. Conversely, we suggest that an essentialist approach to categorisation predicts that essences are more likely to change in gradual transformations, across generations, as is the case with evolutionary change of species. In two experiments we examined the scope of the similarity versus the essentialist account in the transformational paradigm. With space aliens, the similarity account was superior to the essentialist one, but the converse was true with earth creatures. We suggest that an essentialist mode of categorisation is more likely than a similarity one for stimuli that are in better correspondence with our naïve understanding of the world.     

Representational neglect for words as revealed by bisection tasks

In the present study, we showed that a representational disorder for words can dissociate from both representational neglect for objects and neglect dyslexia. This study involved 14 brain-damaged patients with left unilateral spatial neglect and a group of normal subjects. Patients were divided into four groups based on presence of left neglect dyslexia and representational neglect for non-verbal material, as evaluated by the Clock Drawing test. The patients were presented with bisection tasks for words and lines. The word bisection tasks (with words of five and seven letters) comprised the following: (1) representational bisection: the experimenter pronounced a word and then asked the patient to name the letter in the middle position; (2) visual bisection: same as (1) with stimuli presented visually; and (3) motor bisection: the patient was asked to cross out the letter in the middle position. The standard line bisection task was presented using lines of different length. Consistent with the literature, long lines were bisected to the right and short lines, rendered comparable in length to the words of the word bisection test, deviated to the left (crossover effect). Both patients and controls showed the same leftward bias on words in the visual and motor bisection conditions. A significant difference emerged between the groups only in the case of the representational bisection task, whereas the group exhibiting neglect dyslexia associated with representational neglect for objects showed a significant rightward bias, while the other three patient groups and the controls showed a leftward bisection bias. Neither the presence of neglect alone nor the presence of visual neglect dyslexia was sufficient to produce a specific disorder in mental imagery. These results demonstrate a specific representational neglect for words independent of both representational neglect and neglect dyslexia.     

Intra-female aggression in the mouse (Mus musculus domesticus) is linked to the estrous cycle regularity but not to ovulation

Intraspecific communication between mice takes place mainly via urinary chemosignals or "pheromones". Pheromones can influence aggressive and reproductive behavior as well as the neuroendocrine condition of the recipient female mice via their olfactory system. In this study, reproductively cyclic mice in the estrus phase were used to test intraspecific agonistic aggressive behavior. Data were obtained also on the count of the eggs shed in the oviducts. The results showed that (i) individually housed female mice are more aggressive toward an intruder female mouse than grouped mice, (ii) mice in which the vomeronasal organ was removed show aggressive behavior intermediate between individually housed and grouped mice, and (iii) a within group analysis did not show a positive correlation between aggression and presence of shed eggs in the oviducts.     

Change detection evokes a Simon-like effect

The present experiment studied choice response context effects on the programming of response sequences using behavioural and electrophysiological methods. Participants were asked to produce responses differing in sequence length (1-key vs. 3-key responses) with either their left or right hand in a choice reaction time (RT) task. The choice response context was manipulated by a blocked or mixed execution of 1-key and 3-key responses. A sequence length effect on RT was observed in the blocked but not in the mixed condition. The time course of the lateralized readiness potential indicates a motoric locus of the sequence length effect, suggesting that the response hand is activated before the entire motor program is established.     

Phonological priming in spoken word recognition: Task effects

In two experiments, we examined the role of phonological relatedness between spoken items using both the lexical decision task and the shadowing task. In Experiment 1, words were used as primes and overlaps of zero (control), one, two, or all four or five (repetition) phonemes were compared. Except for the repetition conditions, in which facilitation was found, phonological overlap resulted in interference on word responses. These effects occurred in both tasks but were larger in lexical decision than in shadowing. The effects that were evident in shadowing can be attributed to an attentional mechanism linked to the subjects' expectancies of repetitions. The extra effects obtained in lexical decision can be interpreted by taking into account both activation of the response corresponding to the prime's lexical status and postlexical processes that check for phonological congruency between prime and target. In Experiment 2, some modifications were introduced to prevent the involvement of strategic factors, and pseudowords were used as primes. No effect at all was observed in shadowing, whereas in lexical decision interference effects occurred, which is consistent with the hypothesis that lexical decision may be negatively affected by finding a phonological discrepancy at the same time as the primed response is reactivated. Neither experiment provided evidence for the occurrence of phonological priming in the perceptual processing of words.