Resistance to change of forgetting functions and response rates

This experiment examined the effects of reinforcement probability on resistance to change of remembering and response rate. Pigeons responded on a two-component multiple schedule in which completion of a variable-interval 20-s schedule produced delayed matching-to-sample trials in both components. Each session included four delays (0.1 s, 2 s, 4 s, and 8 s) between sample termination and presentation of comparison stimuli in both components. The two components differed in the probability of reinforcement arranged for correct matches (i.e., rich, p = .9; lean, p = .1). Response rates during the variable-interval portion of the procedure were higher in the rich component during baseline and more resistant to the disruptive effects of intercomponent food and extinction. Forgetting functions were constructed by examining matching accuracy as a function of delay duration. Baseline accuracy was higher in the rich component than in the lean component as measured by differences in the gamma-intercept of the forgetting functions (i.e., initial discrimination), rather than from differences in the slope of the forgetting function (i.e., rate of forgetting). Intercomponent food increased the rate of forgetting relatively more in the lean component than in the rich component, but initial discrimination was not systematically affected. Extinction reduced initial discrimination relatively more in the lean component than in the rich component, but did not systematically affect rate of forgetting. These results are consistent with our previous data suggesting that, as for response rate, accuracy and resistance to change of discriminating are positively related to rate of reinforcement. These data also suggest that the disruptability of remembering depends on the conditions of reinforcement, but the way in which remembering is disrupted depends on the nature of the disruptor.     

胆道术后胃功能性排空障碍治疗体会

探讨胆道术后胃功能性排空障碍的诊治经验。回顾性分析32例胆道术后胃功能性排空障碍病例。结果32例胃功能性排空障碍发生于术后5天～10天,经保守治疗后均痊愈。胆道术后胃功能性排空障碍是胃的功能性病变,经综合保守治疗是可以治愈的。     

Reversing the Signaled Magnitude Effect in Delayed Matching to Sample: Delay-specific Remembering

Pigeons performed a delayed matching‐to‐sample task in which large or small reinforcers for correct remembering were signaled during the retention interval. Accuracy was low when small reinforcers were signaled, and high when large reinforcers were signaled (the signaled magnitude effect). When the reinforcer‐size cue was switched from small to large partway through the retention interval, accuracy accordingly changed from low to high. The opposite happened when the cue was switched from large to small. This dissociation of forgetting from the passage of time raises the possibility that remembering is delay‐specific. The reversal of the signaled magnitude effect during the retention interval is consistent with an attentional account in which the stimulus control of remembering is influenced by extraneous events.     

Overestimation and contraction biases of depth information stored in working memory depend on spatial configuration

Depth perception is essential for effective interaction with the environment. Although the accuracy of depth perception has been studied extensively, it is unclear how accurate the depth information is stored in working memory. In this study, we investigated the accuracy and systematic biases of depth representation by a delayed estimation task. The memory array consisted of items presented at various stereoscopic depth positions, and the participants were instructed to estimate the depth position of one target item after a retention interval. We examined the effect of spatial configuration by comparing the memory performance in the whole-display condition where non-target memory items were present during retrieval with that in the single-display condition where non-target memory items were absent. In the single-display condition, we found an overestimation bias that the depth estimates were farther than the corresponding depth positions defined by disparity, and a contraction bias that the stored depth positions near the observer were overestimated and those far from the observer were underestimated. The magnitude of these biases increased with the number of to-be-stored items. However, in the whole-display condition, the overestimation bias was corrected and the contraction bias did not increase with the number of to-be-stored items. Our findings suggested that the number of to-be-stored items could affect the accuracy of depth working memory, and its effect depended crucially on whether the information of spatial configuration of memory display was available at the retrieval stage.     

The influence of culture on children’s immediate and delayed retrieval

Culture shapes children’s memories. However, scant attention has been given to the influence of culture on specific memory stages. Thus, we conducted two controlled experiments to examine cultural differences in memory recall at immediate and delayed retrieval phases. In Studies 1 and 2 (n = 217), 7- to 10-year-old Chinese and Euro-Canadian children watched a story involving both social- and individual-focused scenarios. Participants then recalled the story immediately afterwards (Study 1) and 5–7 days later (Studies 1 and 2). Findings reveal that Chinese children accurately reported more details from the social-focused events than did their Euro-Canadian counterparts in the immediate interview, and this result was replicated after a delay in both studies. Moreover, as expected, within-country comparisons showed that Euro-Canadian children had better memory for individual- than for social-focused events in both studies. Chinese children, however, showed better memory for social- than for individual-focused events only in the immediate interview in Study 1; their delayed retrieval was not affected by event focus. These findings reveal that cultural variations in memory are evident in both immediate and delayed retrieval. Implications for future research are discussed.