An investigation of spatial representation of pitch in individuals with congenital amusia

Spatial representation of pitch plays a central role in auditory processing. However, it is unknown whether impaired auditory processing is associated with impaired pitch–space mapping. Experiment 1 examined spatial representation of pitch in individuals with congenital amusia using a stimulus–response compatibility (SRC) task. For amusic and non-amusic participants, pitch classification was faster and more accurate when correct responses involved a physical action that was spatially congruent with the pitch height of the stimulus than when it was incongruent. However, this spatial representation of pitch was not as stable in amusic individuals, revealed by slower response times when compared with control individuals. One explanation is that the SRC effect in amusics reflects a linguistic association, requiring additional time to link pitch height and spatial location. To test this possibility, Experiment 2 employed a colour-classification task. Participants judged colour while ignoring a concurrent pitch by pressing one of two response keys positioned vertically to be congruent or incongruent with the pitch. The association between pitch and space was found in both groups, with comparable response times in the two groups, suggesting that amusic individuals are only slower to respond to tasks involving explicit judgments of pitch.     

Discounting by Probabilistic Waiting

In everyday life, many probabilistic situations may be characterized as probabilistic waiting. A gambler, for example, bets repeatedly at the racetrack, the casino, or the card table. The gambler may not win on the first try, but if a gamble is repeated enough times, a win is almost certain to occur eventually. If repeated gambles are structured as strings of losses ending in a win (probabilistic waiting) and the amount won is discounted by the delay caused by the series of losses, then strings with many losses will be discounted more than those with fewer losses, thereby causing subjective value of the series of gambles as a whole to increase. The current study used the opposite effect that amount has on the degree of delay and probability discounting as a marker to determine whether people evaluate situations involving probabilistic waiting as they evaluate situations involving delayed outcomes or as situations involving probabilistic outcomes. We find that the more likely a probabilistic waiting situation is to end in reward (e.g., a gamble is repeated indefinitely until reward is obtained), the more that situation conforms to delay discounting; the less likely a probabilistic waiting situation is to end in reward (e.g., a fixed, small number of gambles), the more that situation conforms to probability discounting. We argue that the former situation is applicable to pathological gambling, and that people with steep delay discount functions would therefore be more likely to have gambling problems. Copyright © 2015 John Wiley & Sons, Ltd.     

The Seller's Sense: Buying–Selling Perspective Affects the Sensitivity to Expected Value Differences

Previous work comparing pricing decisions by buyers and sellers has primarily focused on the endowment effect, the phenomenon that selling prices exceed buying prices. Here, we examine whether pricing decisions by buyers and sellers also vary in sensitivity to differences between objects' expected values (EVs). Both a loss‐aversion account (which posits that losses are weighted more heavily than gains) and a loss‐attention account (which posits increased attention to a task when it involves possible losses) predict that pricing decisions by sellers should exhibit higher sensitivity. The latter, however, additionally predicts that this pattern should only emerge under certain conditions. In studies 1 and 2, we reanalyzed two published datasets in which participants priced monetary lotteries as sellers or buyers. It emerged that sellers showed greater EV sensitivity (defined as the rank correlation between the set price for each lottery and its EV) except in a condition with an extended deliberation time of 15 seconds. In study 3, the buyer–seller difference in EV sensitivity was replicated even when the pricing task was presented repeatedly, while in study 4, it was eliminated when buying and selling trials were randomly mixed. The reduction of the “seller's sense” in long deliberation and mixed trials settings supports an attentional resource‐based account of the differences between sellers and buyers in their EV sensitivity. Copyright © 2016 John Wiley & Sons, Ltd.     

The Effect of Expected Value on Attraction Effect Preference Reversals

The attraction effect shows that adding a third alternative to a choice set can alter preference between the original two options. For over 30 years, this simple demonstration of context dependence has been taken as strong evidence against a class of parsimonious value‐maximising models that evaluate alternatives independently from one another. Significantly, however, in previous demonstrations of the attraction effect alternatives are approximately equally valuable, so there was little consequence to the decision maker irrespective of which alternative was selected. Here we vary the difference in expected value between alternatives and provide the first demonstration that, although extinguished with large differences, this theoretically important effect persists when choice between alternatives has a consequence. We use this result to clarify the implications of the attraction effect, arguing that although it robustly violates the assumptions of value‐maximising models, it does not eliminate the possibility that human decision making is optimal. © 2016 The Authors Journal of Behavioral Decision Making Published by John Wiley & Sons Ltd.     

The Reinforcing Value of Lottery Tickets,and the Synergetic Effect of Distinct Reinforcements

We present two experiments that explore the reinforcing value of lottery tickets. Participants are faced with a repeated choice task between a safe alternative and a risky prospect that provides a chance to win a lottery ticket to be played at the end of the study. Study 1 considers situations in which the risky option leads to a slightly higher expected value than the safe alternative. It shows that the risk‐taking rate increases with the probability to win the lottery ticket, but it is below 50% even when this probability is high. Study 2 shows limited sensitivity to the expected value of the risky prospect. The results can be explained with the assumption that participants rely on small samples of past experiences, and that their reaction to lottery tickets reflects large variability. The relationship between the current results and previous research on the synergetic effect of distinct reinforcements and the “pat on the back paradox” is discussed. Copyright © 2016 John Wiley & Sons, Ltd.     

The Common Ratio Effect in Choice,Pricing, and Happiness Tasks

The Allais common ratio effect is one of the most robust violations of rational decision making under risk. In this paper, we conduct a novel test of the common ratio effect in which we elicit preferences for the common ratio choice alternatives in choice, pricing, and happiness rating tasks. We find large shifts in preference patterns across tasks, both within and between subjects. In particular, we find that both the consistency and distribution of responses differ systematically across tasks, with modal choices replicating the Allais preference pattern, modal happiness ratings exhibiting consistent risk aversion, and modal prices maximizing expected value. We discuss the predictions of various cognitive explanations of the common ratio effect in the context of our experiment. We find that a dual process framework provides the most complete account of our results. Surprisingly, we also find that although the Allais pattern was the modal behavior in the choice task, none of the 158 respondents in our experiment exhibited the Allais pattern simultaneously in choice, happiness, and pricing tasks. Our results constitute a new paradox for the leading theories of choice under risk. Copyright © 2017 John Wiley & Sons, Ltd.     

Tunable wave-vector filtering in a two-dimensional electron gas modulated by magnetic barriers and δ-doping

We report a theoretical investigation on the control of wave-vector filtering (WVF) in a two-dimensional electron gas modulated by realistic magnetic barriers and δ-doping, which can be experimentally realised by depositing a ferromagnetic stripe on the surface of a GaAs/Al_xGa_1?xAs heterostructure and using atomic layer doping. Theoretical analysis demonstrates that a sizeable WVF effect still exists even if δ-doping is introduced into the device. Numerical calculation reveals that the WVF efficiency is related closely to the δ-doping. Thus, the WVF effect in a magnetic nanostructure can be conveniently manipulated by properly adjusting the weight and/or the position of the δ-doping, giving rise to a tunable momentum filter for nanoelectronics applications.     

Source memory that encoding was self-referential: the influence of stimulus characteristics

Decades of research suggest that encoding information with respect to the self improves memory (self-reference effect, SRE) for items (item SRE). The current study focused on how processing information in reference to the self affects source memory for whether an item was self-referentially processed (a source SRE). Participants self-referentially or non-self-referentially encoded words (Experiment 1) or pictures (Experiment 2) that varied in valence (positive, negative, neutral). Relative to non-self-referential processing, self-referential processing enhanced item recognition for all stimulus types (an item SRE), but it only enhanced source memory for positive words (a source SRE). In fact, source memory for negative and neutral pictures was worse for items processed self-referentially than non-self-referentially. Together, the results suggest that item SRE and source SRE (e.g., remembering an item was encoded self-referentially) are not necessarily the same across stimulus types (e.g., words, pictures; positive, negative). While an item SRE may depend on the overall likelihood the item generates any association, the enhancing effects of self-referential processing on source memory for self-referential encoding may depend on how embedded a stimulus becomes in one’s self-schema, and that depends, in part, on the stimulus’ valence and format. Self-relevance ratings during encoding provide converging evidence for this interpretation.     

亮度对空间-数字反应编码联合效应的影响

本研究探讨亮度对空间-数字反应编码联合效应（Spatial-Numerical Association of Response Codes,简称SNARC效应）的影响及其机制。通过三个实验设计不同的亮度对比水平,要求被试对阿拉伯数字1~9（5除外）进行奇偶判断。实验一将数字亮度设为最高值255时,结果出现了数字的SNARC效应。实验二将数字的亮度值分别设为255和213时,结果仍存在SNARC效应。实验三将亮度值分别设置为213和42时,数字的SNARC效应却消失了。这些结果表明亮度会激活或抑制数字的空间表征,可能与亮度对比值的高低及所消耗认知资源的多少有关。