Unconscious cues bias first saccades in a free-saccade task

Visual–spatial attention can be biased towards salient visual information without visual awareness. It is unclear, however, whether such bias can further influence free-choices such as saccades in a free viewing task. In our experiment, we presented visual cues below awareness threshold immediately before people made free saccades. Our results showed that masked cues could influence the direction and latency of the first free saccade, suggesting that salient visual information can unconsciously influence free actions.     

Evolution and Free Will: A Defense of Darwinian Non–naturalism

In his recent book The Natural Selection of Autonomy , Bruce Waller defends a view that he calls "natural autonomy." This view holds that human beings possess a kind of autonomy that we share with nonhuman animals, a capacity to explore alternative courses of action, but an autonomy that cannot support moral responsibility. He also argues that this natural autonomy can provide support for the ethical principle of noninterference. I argue that to support the ethical principle of noninterference Waller needs either a libertarian or a compatibilist theory of autonomy. I then go on to argue that, contra Waller, the libertarian view is both compatible with Darwinism and able to make sense of how autonomous acts belong to the agents who perform them. Thus, I conclude that the libertarian position is a live option for Darwinians. If however, naturalism is taken to include a deterministic view of the universe (at least at the nonquantum level), as is often the case, then my article takes some strides in defending "Darwinian non–naturalism."     

Readiness potentials driven by non-motoric processes

An increase in brain activity known as the “readiness potential” (RP) can be seen over central scalp locations in the seconds leading up to a volitionally timed movement. This activity precedes awareness of the ensuing movement by as much as two seconds and has been hypothesized to reflect preconscious planning and/or preparation of the movement. Using a novel experimental design, we teased apart the relative contribution of motor-related and non-motor-related processes to the RP. The results of our experiment reveal that robust RPs occured in the absence of movement and that motor-related processes did not significantly modulate the RP. This suggests that the RP measured here is unlikely to reflect preconscious motor planning or preparation of an ensuing movement, and instead may reflect decision-related or anticipatory processes that are non-motoric in nature.     

Solidification thermal parameters,microstructural evolution and dendritic growth in an AlCuNi alloy

ABSTRACT

Unsteady-state upward solidification experiment was carried out with the Al-3Cu-3Ni (wt.%) alloy. Temperature profiles were obtained through a water-cooled directional solidification device. Analysis on the resulting as-cast microstructure and its adaptation to thermal solidification parameter, such as growth and cooling rates and solidification local time, V_L, T_R and t_SL, respectively, was carried out. The results showed that the resulting microstructure is constituted by an Al-rich primary phase (Al _α ), characterised by a dendritic network, and by second phases that take place within the interdendritic regions, forming a eutectic mixture composed by the β-Al₃Ni?+?θ-Al₂Cu intermetallic compounds (IMCs), whose size and morphology have been affected by V_L and T_R. The length of the microstructural scale of the Al _α phase was measured by the secondary dendritic spacing (λ ₂). The experimental mathematical expression of λ ₂ obtained in this work was compared with mathematical models proposed in the literature that associate t_SL-λ ₂ for non-equilibrium and equilibrium solidification conditions.     

The positive eating scale: relationship with objective health parameters and validity in Germany,the USA and India

Objective: The prevailing focus regarding eating behaviour is on restriction, concern, worry and pathology. In contrast, the purpose of the present studies was to focus on a positive relationship with eating in non-clinical samples from Germany, the USA and India.

Design: In Study 1, the Positive Eating Scale (PES) was tested and validated in a large longitudinal sample (T1: N = 772; T2: N = 510). In Study 2, the PES was tested in online samples from the USA, India and Germany (total N = 749).

Main Outcome Measures: Health risk status was measured in Study 1 with objective health parameters (fasting serum glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, waist circumference, BMI).

Results: Study 1 revealed acceptable psychometric properties of the PES, internal consistency (α = .87), as well as test–retest reliability after six months (r = .67). Importantly, a positive relationship with eating was associated with decreased health risk factors six months later. In Study 2, the structure of the PES was confirmed for German, Indian and US-American adults, suggesting validity across remarkably different eating environments.

Conclusion: A positive relationship with eating might be a fruitful starting point for prevention and intervention programmes promoting physical and psychological health.     

Emotional stimuli exert parallel effects on attention and memory

Because emotional and neutral stimuli typically differ on non-emotional dimensions, it has been difficult to determine conclusively which factors underlie the ability of emotional stimuli to enhance immediate long-term memory. Here we induced arousal by varying participants' goals, a method that removes many potential confounds between emotional and non-emotional items. Hungry and sated participants encoded food and clothing images under divided attention conditions. Sated participants attended to and recalled food and clothing images equivalently. Hungry participants performed worse on the concurrent tone-discrimination task when they viewed food relative to clothing images, suggesting enhanced attention to food images, and they recalled more food than clothing images. A follow-up regression analysis of the factors predicting memory for individual pictures revealed that food images had parallel effects on attention and memory in hungry participants, so that enhanced attention to food images did not predict their enhanced memory. We suggest that immediate long-term memory for food is enhanced in the hungry state because hunger leads to more distinctive processing of food images rendering them more accessible during retrieval.     

二参数逻辑斯蒂模型项目参数的估计精度

项目参数的估计精度对于测验的编制尤其是题库的建立十分重要。目前,国内外对项目参数估计精度的研究,大部分是基于在已知项目参数真值的情况下,运用各种参数估计方法产生新的估计值,再和真值进行偏度(BIAS)和均方根差(RMSE)的比较,从而说明该种估计方法的有效性。但是这种方法不能提供不同的参数真值之间的估计误差的变化规律。为了弥补这一缺陷,本文尝试从项目参数估计信息函数的角度出发研究项目参数的估计精度问题。本研究以二参数Logistic模型作为研究对象,首先定义了项目参数的估计信息函数,然后基于完全随机实验设计,通过模拟研究的方法探索影响项目参数的估计精度的因素,实验共设计了(2×3×2)种情形。研究结果表明：(1)项目参数(a,b)的估计精度均随着被试样本量的增大而提高;(2)被试的能力分布对难度参数的估计精度影响较大,对区分度参数的估计精度影响相对较小;(3)难度参数和区分度参数的估计精度都分别受到参数a和参数b的共同作用。     

Performance and Learning of Generalized Motor Programs: Relative (GMP) and Absolute (Parameter) Errors

The effects of practice (Experiment 1) and parameter variability (Experiment 2) on the learning of generalized motor programs (GMPs) and movement parameterization were investigated In each experiment, 2 tasks with different relative force-time structures were tested. Participants (N = 32, Experiment (N = 40, Experiment 2) attempted to exert a pattern of force that resembled in force and time a waveform that was displayed on a computer monitor. In both experiments, the analysis suggested that the GMP, although refined over practice, was relatively stable (i.e., resistant to decay and interference), even early in practice (after 20 trials). In addition, the results indicated that constant and variable parameter practice did not differentially affect GMP learning but did degrade the learning of the parameter that was not varied. The data provided additional evidence for the dissociation of the GMP and the parameterization processes proposed in GMP theory. Contrary to schema theory, the present data suggest an interdependence between the force and the time parameters: The manipulation of 1 of the parameters has a negative effect on the learning of the other parameter.