Flexible contrast gain control in the right hemisphere

This study investigates whether the right hemisphere has more flexible contrast gain control settings for the identification of spatial frequency. Right-handed participants identified 1 and 9 cycles per degree sinusoidal gratings presented either to the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH). When luminance contrast was randomized across a wide range (20-60%), performance gradually improved with contrast in the LVF-RH. Conversely, performance in the RVF-LH was disrupted and saturated for 20 and 60% of contrast, respectively, leading to a LVF-RH advantage for these contrast levels. When contrast was blocked or randomized for a smaller range (30-50%), the LVF-RH advantage was diminished. Flexible contrast gain control is needed when contrast is randomized across a wide range, but not when it is blocked or randomized across a smaller range. The results therefore suggest that the right hemisphere is able to process spatial frequency information across a wider range of contrast levels than is the left hemisphere.     

Non-semantic contributions to “semantic” redundancy gain

Recently, two groups of researchers have reported redundancy gains (enhanced performance with multiple, redundant targets) in tasks requiring semantic categorization. Here we report two experiments aimed at determining whether the gains found by one of these groups resulted from some form of semantic coactivation. We asked undergraduate psychology students to complete choice RT tasks requiring the semantic categorization of visually presented words, and compared performance with redundant targets from the same semantic category to performance with redundant targets from different semantic categories. If the redundancy gains resulted from the combination of information at a semantic level, they should have been greater in the former than the latter situation. However, our results showed no significant differences in redundancy gain (for latency and accuracy) between same-category and different-category conditions, despite gains appearing in both conditions. Thus, we suggest that redundancy gain in the semantic categorization task may result entirely from statistical facilitation or combination of information at non-semantic levels.     

跨期决策中的负折扣现象及其机制

主流跨期决策模型认为, 跨期决策存在一个时间折扣过程。时间折扣是指人们会根据将来获益或损失的延迟时间对其效用进行折扣, 折扣后的效用小于原来的效用, 而负折扣现象违背了时间折扣过程。负折扣现象出现在金钱、非金钱的获益与损失领域, 其可能的解释机制为预期情绪。目前关于负折扣现象的研究, 较少验证其影响机制, 未来的研究可以结合眼动追踪和fMRI技术探讨其机制, 并丰富对负折扣现象的影响因素研究。     

The Role of Social Network Structure in the Emergence of Linguistic Structure

Social network structure has been argued to shape the structure of languages, as well as affect the spread of innovations and the formation of conventions in the community. Specifically, theoretical and computational models of language change predict that sparsely connected communities develop more systematic languages, while tightly knit communities can maintain high levels of linguistic complexity and variability. However, the role of social network structure in the cultural evolution of languages has never been tested experimentally. Here, we present results from a behavioral group communication study, in which we examined the formation of new languages created in the lab by micro-societies that varied in their network structure. We contrasted three types of social networks: fully connected, small-world, and scale-free. We examined the artificial languages created by these different networks with respect to their linguistic structure, communicative success, stability, and convergence. Results did not reveal any effect of network structure for any measure, with all languages becoming similarly more systematic, more accurate, more stable, and more shared over time. At the same time, small-world networks showed the greatest variation in their convergence, stabilization, and emerging structure patterns, indicating that network structure can influence the community's susceptibility to random linguistic changes (i.e., drift).     

Cheating: One common morality for gains and losses but two components of morality itself

Previous studies show that decision makers (DMs) lie more to avoid a loss than achieve a gain. Two compelling mechanisms might explain this observation. One assumes that lying is a risky activity and relates to the shape of the monetary value function described by prospect theory, which assumes (a) increased risk taking for loss frames and (b) an asymmetry between the perceived values of losses and gains. The other relates to the importance of self-esteem functions as expressed in self-concept maintenance models, self-esteem issues being weighed against monetary issues. This alternative explanation assumes that a loss frame serves as a factor lowering moral considerations. We report an experimental study presenting sets of lotteries to DMs, once in a moral context and once in a traditional probabilistic context. The results show that DMs take less risk when lotteries are presented in a moral context. It is also shown that DMs take more risk for losses than gains, this holding for both the moral and probabilistic contexts. This latter result suggests that loss/gain asymmetry can be completely explained by prospect theory factors, and framing makes no difference to the valuing of moral considerations.     

Arabic digit naming speed: task context and redundancy gain

There is evidence for both semantic and asemantic routes for naming Arabic digits, but neuropsychological dissociations suggest that number-fact retrieval (2x3=6) can inhibit the semantic route for digit naming. Here, we tested the hypothesis that such inhibition should slow digit naming, based on the principle that reduced access to multiple routes would counteract redundancy gain (the response time advantage expected from parallel retrieval pathways). Participants named two single digit numbers and then performed simple addition or magnitude comparison (Experiment 1), multiplication or magnitude comparison (Experiment 2), and multiplication or subtraction (Experiment 3) on the same or on a different pair of digits. Addition and multiplication were expected to inhibit the semantic route, whereas comparison and subtraction should enable the semantic route. Digit naming time was approximately 15ms slower when participants subsequently performed addition or multiplication relative to comparison or subtraction, regardless of whether or not the same digit pair was involved. A letter naming control condition in Experiment 3 demonstrated that the effect was specific to digit naming. Number fact retrieval apparently can inhibit Arabic digit naming processes.     

Asymmetry of reinforcement and punishment in human choice

The hypothesis that a penny lost is valued more highly than a penny earned was tested in human choice. Five participants clicked a computer mouse under concurrent variable-interval schedules of monetary reinforcement. In the no-punishment condition, the schedules arranged monetary gain. In the punishment conditions, a schedule of monetary loss was superimposed on one response alternative. Deviations from generalized matching using the free parameters c (sensitivity to reinforcement) and log k (bias) were compared in the no-punishment and punishment conditions. The no-punishment conditions yielded values of log k that approximated zero for all participants, indicating no bias. In the punishment condition, values of log k deviated substantially from zero, revealing a 3-fold bias toward the unpunished alternative. Moreover, the c parameters were substantially smaller in punished conditions. The values for bias and sensitivity under punishment did not change significantly when the measure of net reinforcers (gains minus losses) was applied to the analysis. These results mean that punishment reduced the sensitivity of behavior to reinforcement and biased performance toward the unpunished alternative. We concluded that a single punisher subtracted more value than a single reinforcer added, indicating an asymmetry in the law of effect.     

The association between retrospective outcome evaluations and pre-post-treatment changes in psychodynamic group-psychotherapy

In the present study of 203 patients in psychodynamic group psychotherapy, we explore associations between patient and therapist global retrospective outcome evaluations (ROE), and pre-post-treatment changes on the Symptom Check List 90 Revised (SCL-90-R) and non-symptomatic focus of therapy. There were no significant associations between ROE, diagnoses and demographic variables, and pre-treatment SCL-90-R associations were negligible (less than 4% of overlapping variance). SCL-90-R subscale improvement expressed as residual gain score explained the overall largest percent of variance in both patients and therapists (44% and 25%, respectively) when compared with raw difference scores (32% and 18%), and percent reduction from baseline (34% and 23%). Moreover, ROE/end-state adjustment associations were substantial (42% and 24%). Therapists' evaluation of change showed the strongest association with improvement in non-symptomatic focus of therapy, while patients' evaluation had the strongest association with improvement in SCL-Depression. It is concluded that retrospective evaluations reflect changes related to treatment. However, unexplained variance may be independent of symptomatic state, and associated with personality factors or domains not captured by standard questionnaires.     

得失情境下第三方惩罚决策差异的神经机制：基于rTMS的研究

本研究应用低频rTMS技术,通过在第三方惩罚（研究1）及第三方惩罚和第三方补偿（恢复性惩罚）并存的情况下（研究2）,对个体双侧vmPFC功能进行抑制,探索vmPFC在得失情境下第三方惩罚决策中的作用。研究1结果表明,rTMS抑制右侧vmPFC功能将降低损失情境下的第三方惩罚,收益情境下未发生改变。研究2得到与研究1一致的结果,且第三方惩罚减少程度更大,第三方补偿并未发生改变。这些结果强调了vmPFC与第三方惩罚紧密相关,在第三方判断得失情境的影响时起关键作用。     

A construction based analysis of child directed speech

The child directed speech of twelve English‐speaking motherswas analyzed in terms of utterance‐level constructions. First, the mothers' utterances were categorized in terms of general constructional categories such as Wh‐questions, copulas and transitives. Second, mothers' utterances within these categories were further specified in terms of the initial words that framed the utterance, item‐based phrases such as Are you …, I'll …, It's …, Let's …, What did … The findings were: (i) overall, only about 15% of all maternal utterances had SVO form (most were questions, imperatives, copulas, and fragments); (ii) 51% of all maternal utterances began with one of 52 item‐based phrases, mostly consisting of two words or morphemes (45% began with one of just 17 words); and (iii) children used many of these same item‐based phrases, in some cases at a rate that correlated highly with their own mother's frequency of use. We suggest that analyses of adult–child linguistic interaction should take into account not just general constructional categories, but also the item‐based constructions that adults and children use and the frequency with which they use them.