Individual differences in willingness to become an organ donor: A decision tree approach to reasoned action

The promotion of organ donation requires a better understanding of the attributes associated with willingness to donate. This entails revealing complex interactions among personality attributes related to intentions and behaviors. In the present study, survey data from young adults (N = 367) were analyzed using decision tree algorithms to identify these interactions within the reasoned action framework. Within this structure, donation attitudes, intentions, and behaviors were examined in relation to individual differences such as conscientiousness, empathy, time orientation, religiosity, and interpersonal trust.     

Reduced willingness to approach genuine smilers in social anxiety explained by potential for social evaluation,not misperception of smile authenticity

ABSTRACT

We investigate perception of, and responses to, facial expression authenticity for the first time in social anxiety, testing genuine and polite smiles. Experiment 1 (N?=?141) found perception of smile authenticity was unaffected, but that approach ratings, which are known to be reduced in social anxiety for happy faces, are more strongly reduced for genuine than polite smiles. Moreover, we found an independent contribution of social anxiety to approach ratings, over and above general negative affect (state/trait anxiety, depression), only for genuine smiles, and not for polite ones. We argue this pattern of results can be explained by genuine smilers signalling greater potential for interaction – and thus greater potential for the scrutiny that is feared in social anxiety – than polite smiles. Experiment 2 established that, relative to polite smilers, genuine smilers are indeed perceived as friendlier and likely to want to talk for longer if approached. Critically, the degree to which individual face items were perceived as wanting to interact correlated strongly with the amount that social anxiety reduced willingness to approach in Experiment 1. We conclude it is the potential for social evaluation and scrutiny signalled by happy expressions, rather than their positive valence, that is important in social anxiety.     

Learning and Affect Following Near‐Miss Outcomes in Simulated Gambling

Gambling near‐misses are non‐rewarded events that resemble a winning configuration. Past research using slot machines has shown that moderate rates of near‐misses increase gambling persistence, but the mechanisms supporting this persistence are unclear. One hypothesis is that near‐misses are mistakenly interpreted as signals of skill acquisition, supporting learning and fuelling the ‘illusion of control’. A slot machine simulation was administered to 60 volunteers, with ratings of the perceived chances of winning, pleasure and motivation to play following particular outcomes. Psychophysiological measures (electrodermal activity and heart rate) were taken, and gambling persistence was measured after 30 trials. Near‐misses were similar to full‐miss outcomes in that they were regarded as unpleasant. However, near‐misses were akin to win outcomes in that they increased motivations to play and electrodermal activity. Learning was evidenced by the expectancy of winning increasing following wins and decreasing after losses. Although there was no overall change in expectancy of winning after near‐misses across all participants, those subjects reporting a greater increase in the expectancy of winning following a near‐miss showed more persistent play, consistent with the learning hypothesis. Greater heart rate acceleration following near‐misses was also associated with persistence. We also observed differential effects of near‐misses where the reel stopped either side of the winning position (‘payline’): motivational effects were restricted to near‐misses stopping before the payline, whereas near‐misses that stopped after the payline were primarily aversive. The payline effects are not predicted by the learning hypothesis and may indicate an affective component to near‐misses, possibly linked to counterfactual processing. Copyright © 2012 John Wiley & Sons, Ltd.     

Ab initio investigation of electron-phonon interaction in LaSn3 and CaSn3

ABSTRACT

We present results for the structural, electronic, vibrational, and electron-phonon coupling properties of LaSn₃ and CaSn₃ adopting the simple cubic AuCu₃-type structure obtained using the the generalised gradient approximation of the density functional theory and plane wave ab initio pseudopotential method. Our electronic results show that both materials display metallic character with several bands, which have mainly Sn 5p character, crossing the Fermi level. The calculated phonon spectrum of LaSn₃ accords very well with reported experimental measurements. The weights of the peaks in the Eliashberg spectral function of both compounds are enhanced with the use of experimental lattice constant in our electron-phonon calculation, increasing the value of average electron phonon coupling parameter from 0.876 to 0.937 for LaSn₃ (by 7%) and from 0.642 to 0.725 for CaSn₃ (by 13%). The use of experimental lattice constant also improves the agreement between theoretical and experimental values of the superconducting temperature for both compounds.     

High-efficiency single-layer organic light-emitting diode based on green fluorescent protein

We have fabricated a molecular organic light-emitting device comprising indium–tin oxide/a molecular organic layer/aluminum in which the organic layer is a green fluorescent protein. The device exhibits peak external quantum and power efficiencies of 8?±?0.2% and 13?±?0.7?lm?W?^??1 at a current of J?=?1.5?A?m^?2, respectively. In addition, the turn-on voltage is 2.5?V for 1?cd?m^?2 and the maximum luminance achieved is 1275?cd?m^?2. This good performance can be explained by the presence of singlet-excited states, leading to a high internal efficiency.     

Enhanced mental rotation ability in time-space synesthesia

Time-space synesthesia is a variant of sequence–space synesthesia and involves the involuntary association of months of the year with 2D and 3D spatial forms, such as arcs, circles, and ellipses. Previous studies have revealed conflicting results regarding the association between time-space synesthesia and enhanced spatial processing ability. Here, we tested 15 time-space synesthetes, and 15 non-synesthetic controls matched for age, education, and gender on standard tests of mental rotation ability, spatial working memory, and verbal working memory. Synesthetes performed better than controls on our test of mental rotation, but similarly to controls on tests of spatial and verbal working memory. Results support a dissociation between visuo-spatial imagery and spatial working memory capacity, and suggest time-space synesthesia is associated only with enhanced visuo-spatial imagery. These data are consistent with the time-space connectivity thesis that time-space synesthesia results from enhanced connectivity in the parietal lobe between regions supporting the representation of temporal sequences and those underlying visuo-spatial imagery.     

Decision-making deficits in drug addiction

Core aspects of addictive behaviour can be explained in terms of abnormal decision-making. Using recording of autonomic function during performance of two gambling tasks, Bechara et al. have recently identified three distinct neuropsychological subtypes in individuals with substance dependence. These subtypes may reflect dissociable patterns of disruption in limbic brain circuitry.