The homogeneity effect on figure/ground perception in infancy

We examined whether the homogeneity of the two profiles of Rubin's goblet affects figure/ground perception in infants. We modified the two profiles of Rubin's goblet in order to compare figure/ground perception under four test patterns: (1) two profiles painted with horizontal lines (horizontal-line condition), (2) two profiles painted middle gray (uni-color condition), (3) one profile painted light gray and the other dark gray (two-color condition), and (4) a goblet painted with concentric circles (concentric-circles condition). In the horizontal-line condition the homogeneity of the profile was strengthened, and in the two-color condition the homogeneity of the profile was weakened compared to the uni-color condition, which was an original Rubin's goblet. In the concentric-circles condition the homogeneity of the reversed areas of the horizontal-line were strengthened.     

Trust of an Automatic Ground Collision Avoidance Technology: A Fighter Pilot Perspective

The present study examined the antecedents of trust among operational Air Force fighter pilots for an automatic ground collision avoidance technology. This technology offered a platform with high face validity for studying trust in automation because it is an automatic system currently being used in operations by the Air Force. Pilots (N = 142) responded to an online survey which asked about their attitudes toward the technology and assessed a number of psychological factors. Consistent with prior research on trust in automation, a number of trust antecedents were identified which corresponded to human factors, learned trust factors, and situational factors. Implications for the introduction of novel automatic systems into the military are discussed.     

Exact ferromagnetic ground state of pentagon chains

We model conducting pentagon chains with a multi-orbital Hubbard model and prove that well below half filling, exact ferromagnetic ground states appear. The rigorous method we use is based on the transformation of original hamiltonian into positive semidefinite form. This technique is independent of the spatial dimension and does not require integrability of the model. The obtained ferromagnetism is connected to dispersionless bands but in a much broader sense than flat-band ferromagnetism requires, where on every site a Hubbard term is present. In our case, only a small percentage of, even randomly distributed, sites are only interacting.     

Books received: volume 11, issue 2

According to Bolzano, an object has necessary being if, and only if, there is a conceptual truth that ascribes being to it. I (Textor, 1996, chapter 5) proposed that the notion of conceptual truth bears the explanatory weight in Bolzano's theory of necessity because, ultimately, the truth of such a proposition depends only on the nature of the concepts it contains. Rusnock (2012) argues against this interpretation and proposes, in turn, that for Bolzano necessity and contingency are tied to free choice. In this article I will provide conceptual and historical background for Bolzano's view of necessity and use it to motivate my interpretation as well as to rebut Rusnock's criticism.     

Distance and Movement Time Effects on the Timing of Agonist and Antagonist Muscles

The experiment examined the effects of movement time (MT) and distance on the timing of electromyographic (EMG) activity from an agonist and antagonist muscle during rapid, discrete elbow movements in the horizontal plane. According to impulse-timing theory (Wallace, 1981) MT, not distance moved, should have a pronounced effect on the timing of EMG activity (duration of initial agonist and antagonist burst and time to onset of initial antagonist burst). The levels of MT were 100 and 160 msec and the levels of distance were 27° and 45° of elbow flexion. In general support of impulse-timing theory, the results of the three EMG timing measures showed that MT had a more pronounced effect on these measures than distance. In addition, the timing of EMG activity in relation to total MT remained fairly consistent across the four MT-distance conditions.     

Common ground on object use associates with caregivers’ gesturese

Caregivers modify their communication when interacting with infants, and these modifications have been related to children's language development. However, the factors influencing caregivers’ modification of gestures are understudied. This study examined whether infants’ object knowledge, considered as common ground shared with the caregiver, relates to caregivers’ gesturese. Six caregiver-infant dyads were videotaped every two months for 15 min in their homes, from child age 8-to-16 months, while they played with two separate objects (i.e. toys). Results indicated that the changes in infants’ object knowledge were paralleled by associated changes in caregivers’ gestures: parents increased both the amount and the complexity of their gestures.     

语言理解中的预设加工

预设是指以交际双方的共同背景(共享的知识或信念)为前提的、听话者根据特定语言标记(触发标记)及其限定的对象(计算内容)而推理出的非外显意义。例如,“张明又触发标记发表了论文计算内容”引发了“张明之前发表过论文”的预设推论。理解者依赖触发标记通达交际双方的共同背景,并在计算内容上生成完整的预设;随后,理解者连接生成的预设和共同背景,更新两者之间的关系。触发标记范畴、共同背景与预设的关联度、共同背景类型,以及理解者的参与动机会影响不同阶段的预设加工。未来研究可以从三个角度进一步探讨预设加工的认知基础：(1)采用计算建模的方法,量化交际互动中听话者理解预设的过程(如观点采择);(2)采用脑成像技术,揭示预设加工过程的神经基础;(3)以特殊人群为研究对象,检验和修正预设加工的认知模型。     

Cognitive vulnerability to depression: A comparison of the weakest link,keystone and additive models

Multiple theories of cognitive vulnerability to depression have been proposed, each focusing on different aspects of negative cognition and utilising different measures of risk. Various methods of integrating such multiple indices of risk have been examined in the literature, and each demonstrates some promise. Yet little is known about the interrelations among these methods, or their incremental validity in predicting changes in depression. The present study compared three integrative models of cognitive vulnerability: the additive, weakest link, and keystone models. Support was found for each model as predictive of depression over time, but only the weakest link model demonstrated incremental utility in predicting changes in depression over the other models. We also explore the correlation between these models and each model's unique contribution to predicting onset of depressive symptoms.     

Control of Gait Initiation

The initiation of gait from a standing posture by 6 subjects, who took controlled-length steps, was analyzed. Using an inverted-pendulum model, we found that the duration of gait initiation was independent of gait velocity. This finding suggests that subjects' biomechanical constants are the determining factors for initiating movement. Both the instantaneous velocity of the center of gravity at the end of the first step (resulting in the propulsive forces measured on the ground) and the steady-state velocity (resulting in the step length and frequency) varied with step length, whereas step frequency did not. But step frequency and progression velocity were linked, for step frequency always increased in parallel with increased progression velocity. We interpret the correlation between velocity and frequency variations to be a peripheral expression of the posturodynamic control of the step parameters by the progression forces.