Problem and pathological gambling has become an increasing public health concern worldwide in recent years, and individuals from China and East Asian countries may be especially vulnerable. Knowledge of how individuals make choices between outcomes that are delayed or uncertain, and of potential differences in decision making across cultures, may contribute to our understanding of factors which increase the risk of problem gambling. Our research is based on a discounting perspective in which the value of a delayed or uncertain reward decreases according to the time until or the odds against its receipt, respectively. We use experimental procedures in which individuals make a series of hypothetical choices so as to estimate an indifference point – an amount of money available immediately or with certainty – that is equal in subjective value to a delayed or uncertain reward. Our starting point is the hypothesis that reward contrast – in which the subjective value of a reward varies inversely with amount of a prior reward – plays a role in choice between delayed or probabilistic outcomes and might contribute to problem gambling. This thesis describes four experiments which investigate these ideas. Experiments 1 and 2 establish that reward contrast is a reliable phenomenon in choice. Indifference points for an intermediate reward ($475/$525) varied as predicted if its subjective value was larger when the individual had previously been making choices with a smaller amount ($50) and smaller when previously making choices with a larger amount ($5,000). Reward contrast was obtained for both delayed and probabilistic choice, using between-subjects (Experiment 1) and within-subjects (Experiment 2) designs. Experiment 3 used a computerized Card Playing Game (CPG) as an analogue gambling task and also measured delay discounting using the same task as Experiment 2. Participants began with an initial stake and could win or lose 10% of the stake with each card that they played. The critical aspect of the procedure was that the probability of winning for each card decreased as more cards were played. Participants played the CPG four times with stakes of $50, $500, $5,000 and $500 (order of $50 and $5,000 was counterbalanced). Results showed that performance on the CPG improved over successive trials, suggesting that participants learned the contingencies in the task. Although this confounded our attempt to measure reward contrast within-subjects, participants who had a $50 stake in the first deck performed better in the second deck with a $500 stake than those who had a $5,000 stake in the first deck, consistent with reward contrast. Results from the delay discounting task were correlated with CPG performance, showing that participants who had lower reward contrast and discounting rates, and greater magnitude effects won more money on the CPG task. Experiment 4 used a larger sample (N = 182) with both Chinese and Caucasian (New Zealand European) participants and recruited individuals with gambling histories, and compared performance on delay and probability discounting tasks and the CPG. Results showed that Chinese participants had higher delay discounting rates and lower probability discounting rates when data were analyzed according to the area under the discounting curve (AUC). Gamblers (those participants with scores on the South Oaks Gambling Screen [SOGS; Lesieur & Blume, 1987] > 1) were less risk averse in probability discounting and had reduced magnitude effects in delay discounting and performed more poorly on the CPG. Closer analysis of the probability discounting data showed that compared with Caucasians, Chinese were more risk averse for high probabilities of reward outcome, and less risk averse for low probabilities. Although results do not suggest that individual differences in reward contrast, as measured using our within-subjects delay discounting task, play a significant role in the maintenance of gambling behavior, the cross-cultural differences in delay and probability discounting in Experiment 4 suggest some factors that might contribute to gambling. In the General Discussion, we propose an account of the probability discounting results in terms of a tendency toward dialectical thinking and emotions in Chinese culture. Based on this result and previous research, we propose a framework for the cross-cultural analysis of risky decision making, and consider some of its broader implications for both research in decision making and issues of globalization.

Idag använder allt fler människor sina smartphones för att surfa och använda tjänster online. Detta innebär att en stor del text läses på små skärmar. Detta arbete handlar om hur text bäst utformas och struktureras för att enklast kunna läsas och uppfattas på en mobilskärm. Faktorer som berörs är typgrad, ljusrum, textlängd, teckensnittsklass, radlängd, bild i text och kontrastverkan. Arbetet utgår från en normativ, svensk person utan funktionsnedsättningar. Arbetet är grundat på litteratur, egna analyser, intervjuer med branschfolk, enkätundersökning och test med fokusgrupp. Resultatet blev att en text på smartphone bäst utformas med flera styckesindelningar i form av blankrader, med bilder där bilden tillför något i informativt syfte och textlängd baserat på ämneskategori. Bilden bör sättas ovanför brödtexten. Längre texter ska sättas med scrollfunktion. Kontrast har stor betydelse på mobiltelefoner, texter går bra att läsa även när de är satta negativt. Teckensnittsklass är enligt resultatet av denna rapport inte av betydelse. Både seriff och sanserif kan läsas utan problem på smartphones. Typgraden bör förstoras något i förhållande till telefonens default-inställningar. På grund av att text på skärm inte stödjer avstavningar rekommenderas korta ord där det är möjligt för att förhindra en allt för hackig högerkant. / This research focuses on the issue of how to best structure text on a Smartphone screen. The factors involved in this research are text size, white space, text and line lengths, serif and sans serif fonts, pictures in text and contrast.  The methodology of our research is based on a normative Swedish able-bodied person, as well as on relevant literature, personal analyses, interviews with people in the trade, an online survey, and a test performed with a focus group. The results are that a text written for Smartphones is best structured with: several paragraph divisions made with blank lines, with pictures where the picture has an informational purpose, and text length based on category of subject. The picture should be placed above the body text. Longer texts should be set with a scroll-function. Contrast is of great importance on mobile phones as texts can be read properly even when set in negative. In addition, using serif or sans serif is of no importance. According to the results both serif and sans serif can be read without difficulties on a Smartphone. Text size should be slightly enlarged in relation to the default settings on the mobile device. Since word division is not supported on screen, short words are recommended when possible to prevent a highly uneven right end.

很多行為的建構基礎是來自酬賞動機，而個體的行為表現通常是動態的歷程，其中對酬賞物的“價值”比較，是決定行為是否輸出或輸出多少的重要關鍵。在鼠類的動物行為模式中，可以利用甜液舔飲來進行這種對比(contrast)歷程的實驗。在受試可先後獲得兩次舔飲機會的實驗情境中，若兩管濃度皆為4%的蔗糖液先後間隔特定時距出現，受試會隨訓練天數增加而增加對兩管糖液的舔飲表現。若第一管4%蔗糖液之後會呈現濃度較高的32%蔗糖液，受試舔飲第一管同為濃度4%蔗糖液的表現會隨訓練天數增加而先增後減。這兩組受試對第一管糖液的舔飲量差異，即稱為預期性對比效果。一般認為此現象是受試等待與預期較高酬賞價值的糖液，而抑制當前較低酬賞價值糖液的舔飲。過去對此現象的研究主要關注在行為層面的探討，然而其相關神經機制的研究並不多，本研究的目的即在於探討與習得或形成預期性對比行為有關的神經機制。一般認為預期性對比效果的習得包含多階段的歷程，可能與多種心理行為面向有關，因此很有可能是經由多元性的神經機制參與。預期性對比效果的形成與否與兩糖液呈現的間距長短有很大的關係。本研究實驗一以0.5分鐘、2分鐘以及6分鐘三個不同的糖液間距引發的預期對比效果，從當中選取可有效形成預期性對比效果的0.5分鐘為實驗二糖液間距的依據。實驗二分別以興奮性神經毒素破壞依核核心區、眶前額皮質區以及杏仁體基側核區等三個神經區域。結果顯示杏仁核基側核區破壞不影響預期性對比效果的習得，而依核核心區以及眶前額皮質的破壞使受試無法習得預期性對比效果。綜合以上結果，預期性對比效果的習得是依靠有效的糖液呈現間距去進行酬賞比較，腦中依核核心區及眶前額皮質區與該種對比有關。 / Many types of behavior are constructed on the basis of reward motivation, which can be run in dynamic processes. Among those processes potentially involved, the reward comparison is a key determinant for the magnitude of behavioral output. The licking of sweet solution in the rat can be used as an animal model to investigate the contrast effect derived from reward comparison. In which, the subjects presented two sweet solutions in a sequential order each day may suppress intake of the first solution if the second solution is preferred. This phenomenon is termed anticipatory contrast effect (ACE). It is hypothesized that ACE could be built via an inhibition process associated with subject’s waiting for a preferred solution as presented by a less preferred solution. Most of the previous studies were mainly focused on the behavioral aspects of ACE. The present study intended to investigate the neural mechanisms of ACE. In considering that the formation of ACE requires multiple-stage processes, this study presumed that more than one brain area could be involved in mediating those psycho-behavioral processes. Experiment 1 was intended to establish behavioral model by manipulating the effectiveness of different inter-solution interval (ISI; 0.5, 2.0, and 6.0 min). The results showed that the ISI of 0.5 min is the critical parameters for the successful formation of ACE, which was then applied in Experiment 2. Experiment 2 investigated the effects of excitotoxin lesion conducted by ibotenic acid in the nucleus accumbens core (NACc), orbitofrontal cortex (OFC) or basolateral amygdala (BLA) on the acquisition of ACE. The result showed the rats with NACc or OFC lesion significantly failed to acquire ACE, but no such impairment appeared to BLA lesion. Together, these data suggest that the formation of ACE is depended upon the ISI leading to an effective reward comparison, and the NACc or OFC is involved in such a contrast processing.