The effects of presentation rate and retention interval on memory for items and associations in younger adults: A simulation of older adults’ associative memory deficit

Older adults show an associative deficit in episodic memory compared to younger adults. Previous research suggests both strategic and automatic binding deficits contribute to older adults’ poorer memory performance. Using behavioral manipulations designed to affect strategic and automatic binding of associations, three experiments attempted to simulate an associative deficit in younger adults. In these experiments participants learned face-scene pairs and then were given item and associative recognition memory tests. We manipulated the time allotted at encoding and retrieval to simulate strategic deficits, and the length of the retention interval to simulate automatic deficits. Results indicate that both manipulations separately contribute to a differential decline in associative memory, similar to the one shown by older adults, especially as reflected in the differential increase in false alarm rate in the associative memory test more than in the item memory test. Considerations of possible underlying brain mechanisms are discussed.     

Distal rhythm influences whether or not listeners hear a word in continuous speech: Support for a perceptual grouping hypothesis

Due to extensive variability in the phonetic realizations of words, there may be few or no proximal spectro-temporal cues that identify a word’s onset or even its presence. Dilley and Pitt (2010) showed that the rate of context speech, distal from a to-be-recognized word, can have a sizeable effect on whether or not a word is perceived. This investigation considered whether there is a distinct role for distal rhythm in the disappearing word effect. Listeners heard sentences that had a grammatical interpretation with or without a critical function word (FW) and transcribed what they heard (e.g., are in Jill got quite mad when she heard there are birds can be removed and Jill got quite mad when she heard their birds is still grammatical). Consistent with a perceptual grouping hypothesis, participants were more likely to report critical FWs when distal rhythm (repeating ternary or binary pitch patterns) matched the rhythm in the FW-containing region than when it did not. Notably, effects of distal rhythm and distal rate were additive. Results demonstrate a novel effect of distal rhythm on the amount of lexical material listeners hear, highlighting the importance of distal timing information and providing new constraints for models of spoken word recognition.     

血清Cys C的检测对肾移植术后患者肾功能评价的临床意义

探讨分析血清胱抑素C（Cys C）水平在肾移植术后患者肾功能监测中的应用价值.对25例肾移植成功患者在术前、术后第1、3、5、7、10天的血清Cys C、Scr、β2-MG、BUN水平进行动态监测,同时随机抽取健康体检者中的20例作为对照组.发现移植组的Cys C、Scr、β2-MG、BUN水平在术前均明显高于健康对照组（P＜0.01）.这四项指标在手术后第一天都有所下降,且术后第1、3、5、7、10天的水平都比术前低（P＜0.01）.四项指标与GFR的关系均为显著性负相关（P＜0.01）,其中血清Cys C与GFR的相关性最好.Cys C、Scr、β2-MG、BUN检测后的ROC曲线下面积分别是：0.937、0.838、0.798、0.772,其差异都具有统计学意义（P＜0.05）.血清Cys C优于Scr、β2-MG、BUN,在肾移植患者术后的动态监测中具有重要的临床应用价值.     

Baseline response rates affect resistance to change

The effect of response rates on resistance to change, measured as resistance to extinction, was examined in two experiments. In Experiment 1, responding in transition from a variable‐ratio schedule and its yoked‐interval counterpart to extinction was compared with pigeons. Following training on a multiple variable‐ratio yoked‐interval schedule of reinforcement, in which response rates were higher in the former component, reinforcement was removed from both components during a single extended extinction session. Resistance to extinction in the yoked‐interval component was always either greater or equal to that in the variable‐ratio component. In Experiment 2, resistance to extinction was compared for two groups of rats that exhibited either high or low response rates when maintained on identical variable‐interval schedules. Resistance to extinction was greater for the lower‐response‐rate group. These results suggest that baseline response rate can contribute to resistance to change. Such effects, however, can only be revealed when baseline response rate and reinforcement rate are disentangled (Experiments 1 and 2) from the more usual circumstance where the two covary. Furthermore, they are more cleanly revealed when the programmed contingencies controlling high and low response rates are identical, as in Experiment 2.     

时间知觉在老年人跨期选择中的作用

随着人口老龄化速度的加快,老年人的跨期选择问题受到越来越多的关注。时间知觉是影响跨期选择的重要因素之一。然而,目前从时间知觉的角度来探讨老年人跨期选择的研究比较有限。本文在总结国内外相关研究的基础之上,试图分析时间知觉的随龄变化如何影响老年人的跨期选择。具体而言,本文从时间长度知觉、时间成本知觉以及时间知觉相关心理动机三个方面进行探讨,并指出了时间知觉视角的局限性及今后的研究方向。     

对齐法在单因子和三因子多组比较中允许的不等参数率

在传统的多组验证性因子分析中,进行因子均值比较的前提条件是模型满足强测量不变性假设,但该假设在实证研究中很难满足。这时,Asparouhov和Muthén(2014)提出的对齐法是一种可供备选的多组分析法。通过蒙特卡洛模拟研究,探究了在对齐法精确估计模型参数前提下所允许的不等参数率范围。研究发现：在平均组样本量充足,识别算法为固定识别算法等理想状态下,对齐法在单因子模型多组比较中所允许的不等参数率可以是100%;在三因子模型中所允许的不等参数率上限是20%至30%;在此范围内,对齐法允许更多高程度不等参数;在组数目从30、15或9降至3时,对齐法能允许更多的不等参数在模型中。     

The development of attention to simple and complex visual stimuli in infants: Behavioral and psychophysiological measures

The study of visual attention in infants has used presentation of single simple stimuli, multi-dimensional stimuli, and complex dynamic video presentations. There are both continuities and discontinuities in the findings on attention and attentiveness to stimulus complexity. A continuity is a pattern of looking that is found in the early part of infancy that remains throughout adulthood. A discontinuity is an emerging sensitivity to the content of the information in the stimulus presentations and alterations in patterns of attention based upon stimulus comprehensibility. The current paper reviews some of these findings with particular application to complex video presentations.     

The surprisingly low motivational power of future rewards: Comparing conventional money-based measures of discounting with motivation-based measures

Temporal discount rates are often poor predictors of behaviors that we expect will be motivated by the future. The current research suggests this may be because conventional discounting measures are poor measures of the motivational value of future rewards. In six studies, I develop motivation-based measures of the present value (PV) of future rewards and compare the PVs obtained with those obtained using conventional money-based discounting measures. Conventional money-based PVs consistently overestimate motivation-based PVs and are discriminable from them. I explore explanations for this mismatch, including timing of effort exertion (Study 2) and loss aversion (Study 3), both features of the motivation-based measures. In Study 5, I use self-reports of valuation strategies and a time pressure manipulation to demonstrate that participants use different valuation strategies in the conventional money-based and the motivation-based measures that, in part, determine the difference in PVs obtained and the relatively low correspondence between them.