Rats’ memory for time and relational responding in the duration-comparison procedure

Rats were trained in a duration-comparison task to press one lever if the comparison duration (c) was 1.2-s shorter than a standard duration (s), and another lever if c was 1.2-s longer than s. The interval between s and c duration was 1 s. The 10 duration pairs used during training controlled for the absolute duration of c and the total duration of an s-c pair. The total duration of an s-c pair was not predictive of the correct response. In Experiment 1, during equal-duration pair test trials, rats increasingly responded long (i.e., c > s) as the s-c delay was lengthened. In Experiment 2, long responding increased as the s-c delay was lengthened, even when the illumination condition during the s-c delay differed from that during the intertrial interval (ITI). In Experiment 3, transfer to novel duration pairs was assessed. Overall accuracy for the novel duration pairs was significantly above chance, but transfer performance was also affected by the absolute value of the novel c durations. This is the first study to demonstrate that rats can acquire relational duration discriminations. As in previous studies with pigeons the evidence was consistent with subjective-shortening of the standard duration and there was also evidence of a reliance on a mixture of absolute and relational strategies in responding.     

采用词表法变式研究指向遗忘现象

在组内设计的词表法变式任务中,词表一的项目按语义或知觉特征分为遗忘项和记住项,中间指导语要求被试遗忘词表一某类项目的同时记住另一类项目,指向遗忘效应以词表一记住项与遗忘项的差异来反映。实验一中,词表一项目按语义性质分为记住项和遗忘项,结果显示:与控制组比较,标准词表法实验组词表一记忆受损显著,出现传统意义上的指向遗忘效应;变式实验组词表一记忆部分受损,与控制组差异接近.05显著水平;标准词表法实验组以及变式实验组词表二都没有表现出记忆获益;另外,变式实验组词表一记住项与遗忘项之间差异显著,反映出遗忘指导语效应。实验二发现:在变式任务中,指定被试遗忘词表一某种语义性质的项目,结果出现遗忘指导语效应;但是,在指定被试遗忘某种颜色项目时,结果没有出现遗忘指导语效应。变式任务结果比较好地支持提取抑制理论;同时也反映出,词表一记住项与遗忘项之间的区分度是影响变式情境下指向遗忘效应的重要因素。     

Using story contexts to bias children’s true and false memories

The effects of embedding standard Deese/Roediger-McDermott (DRM) lists into stories whose context biased interpretation either toward or away from the overall themes of the DRM lists on both true and false recognition were investigated with 7- and 11-year-olds. These biased story contexts were compared with the same children’s susceptibility to false memory illusions using the standard DRM list presentation paradigm. The results showed the usual age effects for true and false memories in the standard DRM list paradigm, where 11-year-olds exhibited higher rates of both true and false recognition compared with the 7-year-olds. Importantly, when DRM lists were embedded in stories, these age effects disappeared for true recognition. For false recognition, although developmental differences were attenuated, older children were still more susceptible to false memory illusions than younger children. These findings are discussed in terms of current theories of children’s false memories as well as the role of themes and elaboration in children’s memory development.     

Endogenous estradiol is associated with verbal memory in nondemented older men

This study examined the relationship between endogenous hormones and cognitive function in nondemented, ethnically-diverse community-dwelling older men enrolled in the Einstein Aging Study (EAS). All eligible participants (185 men, mean age=81 years) received neuropsychological assessment (Free and Cued Selective Reminding Test (FCSRT), Logical Memory (LM), Trail Making Test B (TMTB), block design (BD)) and provided blood samples for hormonal assays (total estradiol, total testosterone, calculated free testosterone index). Linear regression analysis adjusted for age, education, body mass index, and cardiovascular comorbidities indicated that men with high levels of total estradiol demonstrated better FCSRT verbal memory performance (β=0.17, p<0.02) compared to men with lower levels of total estradiol. The results remained unchanged when the model was further adjusted for ethnicity. We did not detect an association between testosterone and cognitive performance. These findings indicate that high levels of total estradiol in older men are associated with better performance on a cue-based, controlled learning test of verbal memory that is a sensitive predictor of dementia.     

The impact of processing time on the bizarreness and orthographic distinctiveness effects

The bizarreness effect and the orthographic distinctiveness effect (OD effect) are typical cases of secondary-distinctiveness-based effects. This study tested the simple attentional account or processing time hypothesis as a possible explanation of the bizarreness effect and the OD effect. In the bizarreness effect literature, this hypothesis gained support by some studies but was also discredited by other research. In light of these conflicting results, Experiment 1 was devised to test the processing time hypothesis in the bizarreness effect by using black-and-white concrete images and manipulating the time allotted for processing the stimuli (500 ms, 1000 ms, 3000 ms). Concerning the OD effect, no research has directly investigated the impact of processing time by examining the effect under varying amounts of study time. Experiment 2 was thus devised to investigate this same hypothesis in the OD effect and time allotted for processing the stimuli was manipulated (250 ms, 500 ms, 1000 ms, 3000 ms). Results did not support the processing time hypothesis since the magnitude of the bizarreness effect and of the OD effect was not modulated by the amount of time allotted for processing the stimuli. We refer to alternative explanations to account for these two secondary-distinctiveness-based effects.     

Effects of saccadic bilateral eye movements on memory in children and adults: an exploratory study

The effects of saccadic bilateral (horizontal) eye movements on true and false memory in adults and children were investigated. Both adults and children encoded lists of associated words in the Deese-Roediger-McDermott paradigm followed by a test of recognition memory. Just prior to retrieval, participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. For studied information, the results for adults replicated previous work; bilateral eye movements were demonstrated to increase the accuracy of memory by increasing the hit rate and reducing the false alarm rate for related and unrelated recognition test lures. The results for children also indicated an improvement in memory accuracy, and like adults, was due to both an increase in the hit rate and a reduction in the false alarm rate. In spite of these similarities, the effects of bilateral eye movements differed between adults and children for critical unstudied words; i.e., those associated with the theme of the list. Only in adults did, bilateral eye movements reduce associative false memories; children did not show a reduction in false memory for critical associates. This produced a dissociation between the effects of eye movements on associative false memory as a function of age. The results are discussed from a developmental perspective in terms of potential mechanisms underlying true and false memory.     

Recollection training and transfer effects in Alzheimer's disease: effectiveness of the repetition-lag procedure

Objective

This study was designed to extend the use of a memory training technique, known as the repetition-lag procedure, to Alzheimer patients. The specificity of this procedure is to target the process of recollection for improvement.

Method

A group of 12 patients were trained individually for 6 h. The training procedure consisted of a series of yes/no recognition tasks in which some words were repeated throughout the test list across gradually increasing delays. Their performance was evaluated on pre-and-post tests and compared with a recognition practice group and a no contact control group.

Results

Initially, recollection training patients only performed accurately when the delay between repetitions consisted of one intervening word, but by the end of training their performance increased up to four-word intervals. Interestingly, these benefits generalized to other measures of memory, such as working memory, visual memory and source recognition.

Conclusions

Effectiveness of the repetition-lag procedure in Alzheimer’s disease is discussed.     

The impact of affective and cognitive focus on attitude formation

We examined the effects of unobtrusive affective and cognitive focus on attitude formation. To induce focus, participants worked on a word-search puzzle consisting of either affective (e.g., emotion) or cognitive (e.g., reasoning) words. They then read positive and negative affective and cognitive information about a new attitude object. In the affective focus condition, evaluations were more congruent with the valence of the affective information than they were in the cognitive focus condition, where evaluations were more congruent with the valence of the cognitive information than they were in the affective focus condition. Affective focus also resulted in enhanced recall of affective information. The effects on evaluations remained stable over time, whereas effects on memory disappeared. Finally, affective focus was associated with faster response times, suggesting enhanced accessibility of affect-based attitudes. The present research shows that an affective or cognitive focus leads to the formation of different attitudes.     

视觉感觉记忆在字音选取作业中的作用

该研究通过四项实验探讨了视觉感觉记忆(VSM)在字音选取作业中的作用。实验材料为48个汉字。实验结果表明:当被试只能利用短时记忆(STM)中的信息进行选取作业时,能选取的汉字数与转换到STM中的汉字数之间无显著性差异;当被试可以同时利用VSM和STM中的信息时,能选取的汉字数要显著多于转换到STM中的汉字数。这表明,人能根据字音特征从VSM信息中选取字符。     

加工水平对不同类型内隐记忆测试的影响

许多内隐记忆研究表明 ,加工水平影响外显记忆而不影响内隐记忆 ,这样的实验结果被一些研究者认为是外显记忆与内隐记忆系统分离的重要依据之一。实际上 ,内隐记忆研究中的加工水平问题一直存在争议 ,加工水平效应作为两类记忆系统分离的依据是不充分的。在我们的这项实验中 ,结果表明 ,加工水平影响概念样例生成这种内隐记忆测试而不影响知觉辨认测试。