意向保持间隔对时间性前瞻记忆的影响

通过两个实验来探讨意向保持间隔对时间性前瞻记忆的影响。实验一仅通过嵌入前瞻目标的背景任务来操纵保持间隔,实验二通过在背景任务之前加入不同时长的填充任务来改变意向保持间隔。结果发现,(1)背景任务中的保持间隔越长,前瞻记忆成绩越差;(2)背景任务中的保持间隔和填充任务的时长对前瞻记忆的影响存在交互作用。成绩最好的为15min-2min组,最差的为15min-15min组。结果表明,背景任务和填充任务阶段对于个体保持前瞻意向可能有不同的功能。     

任务中断对幼儿前瞻记忆的影响

本研究采用实验方法研究了年龄及当前进行任务中不同位置的中断对幼儿前瞻记忆的影响。结果发现：(1)年龄对幼儿前瞻记忆成绩有显著影响;(2)在1／4中断和无中断条件下,幼儿的前瞻记忆成绩较好,在1／2中断和3／4中断条件下．幼儿前瞻记忆成绩较差。     

注意状态、认知方式与前瞻记忆的TAP效应

采用经典实验室研究范式,实验一探讨了前瞻记忆任务为知觉加工条件下,注意状态和前瞻记忆任务与进行中任务一致和不一致时对不同认知方式个体前瞻记忆成绩的影响,实验二探讨了前瞻记忆任务为语义加工条件下,注意状态和前瞻记忆任务与进行中任务一致和不一致时对不同认知方式个体前瞻记忆成绩的影响,结果表明,（1）在前瞻记忆任务加工类型是语义加工和知觉加工两种条件下,场依存与场独立个体均发现了TAP效应的存在,而且场依存个体表现出更明显的TAP效应;（2）当前瞻记忆任务与进行中任务的加工类型不一致时,场独立个体的前瞻记忆成绩明显高于场依存个体,而在两类任务加工类型一致情况下,场独立与场依存个体的前瞻记忆成绩不存在明显差异;（3）在前瞻记忆任务是知觉加工时,分心对前瞻记忆成绩有明显不利的影响;而在前瞻记忆任务是语义加工时,只有当前瞻记忆任务与进行中任务加工类型不一致时,分心对前瞻记忆才有明显不利的影响,而且在分心条件下的TAP效应更明显。     

任务规律性对前瞻记忆的影响

采用混合实验设计,结合行为和眼动数据,探讨任务规律性对前瞻记忆的影响。行为结果显示规律已知条件下前瞻记忆成绩显著高于规律未知和无规律条件,规律未知条件下的前瞻记忆成绩在靶线索之后刺激上有高于无规律条件的趋势;眼动结果显示规律已知条件下的注视点最多,首次注视时间最长。结果说明:(1)任务规律性对前瞻记忆成绩具有促进作用;(2)任务规律性促进了对前瞻记忆任务的自动化加工;(3)在规律已知条件下前瞻记忆的加工过程呈现出动态交替的特点。     

靶目标预曝光对基于事件前瞻记忆的影响

采用双任务实验范式,以大学生为被试。实验一探讨通过在前瞻记忆任务指导语之前,对靶目标充分学习,达到靶目标的预曝光,研究靶目标预曝光对基于事件的前瞻记忆的影响。实验二探讨不同曝光率的靶目标预曝光对前瞻记忆的影响。结果表明：（1）靶目标预曝光能够提高前瞻记忆的成绩;（2）靶目标预曝光率越高,前瞻记忆成绩越好;（3）靶目标预曝光能够减少注意资源的占用。     

分散注意条件下前瞻记忆的完成水平及其影响因素初探

本研究试图探讨在分散注意条件下前瞻记忆的完成水平及其影响因素。被试为98名大学生。在实验中,当前任务为数字听写,同时放映一段无声动画短片,将前瞻记忆任务(即看到某一靶线索画面时在相应数字上做记号)嵌入其中,动画片结束后要求被试完成若干与动画片内容有关的问题(事先通过指导语告知)。结果发现：1、前瞻记忆任务的成绩与被试的性别几乎无关,与材料熟悉程度也无显著相关;2、与被试对材料的喜好程度显著相关,提示即使在分散注意条件下,被试在完成前瞻记忆任务时也可能会根据偏好自动调整注意的分配。     

任务难度对前瞻记忆TAP效应影响的研究

前瞻记忆中的TAP效应是指,当进行中任务和前瞻任务加工类型一致时,前瞻记忆成绩要好于两者工类型不一致时.该研究采用双重任务范式,以大学生为被试,探讨了进行中任务难度对前瞻记忆TAP效应的影响,以揭示注意资源在TAP效应产生中的关键作用.结果表明:当进行中任务难度较低时,没有出现TAP效应,即进行中任务和前瞻任务的加工类型是否一致不会对前瞻记忆成绩产生显著影响;当进行中任务难度较高时,TAP效应部分出现.进一步说,当进行中任务加工类型为语义型时,语义型的前瞻任务成绩要显著好于结构型的前瞻任务成绩;而当进行中任务加工类型为结构型时,前瞻任务的加工类型没有对前瞻记忆成绩产生显著影响.     

前瞻记忆类型差异及动机与任务序列对前瞻记忆的影响*

本文采用“模拟星期”范式通过3个实验分别考察了前瞻记忆任务类型的差异以及动机与任务序列对前瞻记忆的影响。结果表明：(1)规律性前瞻记忆任务的正确率显著高于非规律性的,即使本研究条件下对非规律性前瞻记忆任务进行奖励与惩罚,仍没有消除两者间的差异。(2)不论是惩罚还是奖励都可以显著提高非规律性前瞻记忆的成绩,而且动机促进作用会蔓延至非直接强化的前瞻记忆任务。(3)固定序列前瞻记忆成绩显著优于随机序列的,且在实验过程中固定序列前瞻记忆的成绩呈上升趋势,而随机序列的基本不变,固定序列在一定程度上反映了行为习惯的建立过程。(4)不论前瞻记忆任务规律与否,惩罚或奖励,任务序列如何,基于时间的前瞻记忆成绩均优于基于事件的前瞻记忆的成绩。(5)时间确认任务中,被试翻看时钟的次数与其正确率间呈显著正相关,且越临近规定时间翻看次数越多,呈J型分布。     

进行中任务变化对轻度认知功能障碍者基于事件前瞻记忆的影响

本实验采用2被试组别(MCI组、正常老年组) × 3进行中任务变化(无变化、顺序变化、随机变化)被试间设计探究进行中任务变化对轻度认知功能障碍者基于事件前瞻记忆的影响。结果表明：(1)轻度认知功能障碍者的前瞻记忆成绩显著低于正常老年人的前瞻记忆成绩; (2)进行中任务变化对两组被试前瞻记忆和进行中任务的反应时影响存在显著差异。进行中任务变化越大, 轻度认知功能障碍者完成前瞻记忆和进行中任务的反应速度越慢; 而正常老年被试则不受影响。研究支持前瞻记忆策略加工的理论观点, 认为执行功能损伤可能是导致轻度认知功能障碍者前瞻记忆失败的主要原因。     

加工焦点性和任务负荷对不同认知方式大学生前瞻记忆的影响

采用双任务范式,探讨了加工焦点性和进行中任务负荷对不同认知方式大学生前瞻记忆的影响。包括两个实验:实验一探讨进行中任务与前瞻记忆任务加工的焦点性和加工类型的一致性对不同认知方式大学生前瞻记忆的影响;实验二探讨进行中任务负荷对不同认知方式大学生在在焦点加工和非焦点加工条件下前瞻记忆的影响。结果显示:焦点加工条件下的前瞻记忆成绩高于非焦点加工,且不受进行中任务负荷的影响;不管进行中任务与前瞻记忆任务的加工类型是否一致,在进行中任务负荷较高且非焦点加工条件下,场独立大学生的前瞻记忆成绩高于场依存大学生。本研究结果支持多重加工理论。     

The effect of cue-familiarity, cue-distinctiveness, and retention interval on prospective remembering

Five experiments investigated the effects of cue familiarity, cue distinctiveness, and retention interval on prospective remembering. Results showed that (1) performance in a prospective memory task is facilitated when the cue is unfamiliar and/or distinctive; and (2) it is impaired by 3-minutes' delay between the instructions and the task (Experiment 1). A beneficial effect of distinctiveness was also found when perceptual rather than semantic distinctiveness was tested (Experiment 2). Experiments 3 and 4 ruled out the hypotheses that “unfulfilled expectancy” of an event (i.e. non-appearance of the cue during training) (Experiment 3), or some sort of “habituation” in the target context (Experiment 4), may have caused the low performance observed in the delayed conditions. Finally, results from Experiment 5 showed that delay negatively affected prospective remembering when it was filled with either a demanding interpolated activity (practice in a STM task) or an undemanding motoric activity (repetitive hands movements). Unfilled delay and an undemanding verbal activity (counting) were found not to affect prospective memory. Implications for the mechanisms underlying prospective remembering are discussed.     

Timing matters: Negative emotion elicited 5 min but not 30 min or 45 min after learning enhances consolidation of internal-monitoring source memory

Two experiments examined the time-dependent effects of negative emotion on consolidation of item and internal-monitoring source memory. In Experiment 1, participants (n = 121) learned a list of words. They were asked to read aloud half of the words and to think about the remaining half. They were instructed to memorize each word and its associative cognitive operation (“reading” versus “thinking”). Immediately following learning they conducted free recall and then watched a 3-min either neutral or negative video clip when 5 min, 30 min or 45 min had elapsed after learning. Twenty-four hours later they returned to take surprise tests for item and source memory. Experiment 2 was similar to Experiment 1 except that participants, without conducting an immediate test of free recall, took tests of source memory for all encoded words both immediately and 24 h after learning. Experiment 1 showed that negative emotion enhanced consolidation of item memory (as measured by retention ratio of free recall) regardless of delay of emotion elicitation and that negative emotion enhanced consolidation of source memory when it was elicited at a 5 min delay but reduced consolidation of source memory when it was elicited at a 30 min delay; when elicited at a 45 min delay, negative emotion had little effect. Furthermore, Experiment 2 replicated the enhancement effect on source memory in the 5 min delay even when participants were tested on all the encoded words. The current study partially replicated prior studies on item memory and extends the literature by providing evidence for a time-dependent effect of negative emotion on consolidation of source memory based on internal monitoring.     

The properties of retention intervals and their affect on retaining prospective memories

Five experiments were conducted to explore how the character of the retention interval affected event-based prospective memory. According to the canons of retrospective memory, prospective performance should have been worse with increasing delays between intention formation and the time it was appropriate to complete an action. That result did not occur. Rather, prospective memory was better with increasing retention intervals in Experiments 1A, 1B, and 3. In manipulating the nature of the retention interval, the authors found that there were independent contributions of retention interval length and the number of intervening activities, with more activities leading to better prospective memory (Experiments 2 and 3). The identical retention intervals did not improve retrospective memory in Experiment 4. Theoretical explanations for these dissociations between prospective and retrospective memory are considered.     

Large-billed crows (Corvus macrorhynchos) have retrospective but not prospective metamemory

Evidence of metamemory, the ability to monitor one’s own memory, has been obtained in some primates, but it appears to be weaker in other species. In this study, we examined whether crows flexibly modulate their behavior by monitoring the strength of memory trace in a delayed matching-to-sample task using two paradigms. First, crows performing a memory test were given an escape option to decline taking the test (prospective metamemory). Second, crows were given the escape option as a “not confident” report after completing the test (retrospective metamemory). Accurate memory performance yielded a reward with a higher probability, whereas inaccurate memory performance resulted in no such recompense. The escape option yielded a reward with a lower probability. In the prospective metamemory test, crows escaped the memory test more frequently with longer delay intervals than they did with shorter delay intervals but no more frequently in the sample-omission than the sample-present trials, indicating that the crows decided to take the test or decline it by using the delay interval as a cue. In contrast, in the retrospective metamemory test, the crows escaped the memory test more frequently when their memory-test response was incorrect than correct and more frequently in the sample-omission than the sample-present trials, indicating that the crows recognized confidence regarding their choice in the memory test and utilized the escape option to maximize reward probability. Although these results suggest that crows retrospectively monitor the strength of memory trace, their prospective metamemory ability has not yet been confirmed in the present paradigm.     

Dopaminergic modulation of the persistence of one-trial hippocampus-dependent memory

The persistence of new memory traces in the hippocampus, encoded following appropriate activation of glutamatergic receptors and the induction of synaptic plasticity, can be influenced by heterosynaptic activation of neuromodulatory brain systems. We therefore investigated the effects of a hippocampus-specific blockade of dopamine D1/D5 receptors on the persistence of spatial memory encoded in one trial using a delayed matching-to-place (DMP) task in a watermaze in which rats learn a new escape location each day. A within-subjects design was used such that both short (20 min) and long (6 h) retention intervals, and both drug (SCH23390, a D1/D5 receptor antagonist) and vehicle (aCSF) infusions were tested on different days in the same animals. Bilateral intrahippocampal infusion of SCH23390 (5 microg in 1 microL per side) prior to trial 1 (encoding) caused a differential impairment as a function of memory delay-with no effect during trial 2 (memory retrieval) after a 20-min interval, but a block of memory at 6 h. Further experiments revealed that infusion of SCH23390 immediately after trial 1 had no effect on retention 6 h later, and the poor memory seen at long retention intervals when the drug was present at encoding was not due to a state-dependent failure of retrieval. These results suggest that activation of D1/D5 receptors during memory encoding is necessary for the formation of a persistent memory trace in the hippocampus. The complementary effects of D1/D5 receptor blockade on the persistence of LTP and the duration of memory are consistent with the idea that changes in synaptic strength underlie memory.     

Forgetting curves in long-term memory: evidence for a multistage model of retention.

An experimental study with 20 normal healthy young adult subjects was performed to evaluate the interaction of type of memory tasks, type of learning modalities, and length of acquisition/recall interval. Four different tasks were employed (serial learning, paired learning, rote learning, and visuolinguistic transfer), some requiring a single trial learning modality others a multitrial learning modality. Acquisition/recall intervals were immediate, intermediate (3 min), and delayed. The experimental design allowed for the comparison of effects from five different delayed recall intervals (2, 8, 12, 24, and 48 hr). Results demonstrated a specific interaction on learning rates due to different ceiling effects for the different types of memory tasks. Forgetting rates, on the other hand, demonstrated a specific effect due to type of memory tasks and learning modalities only for differences between immediate and intermediate recall. These differences remained stable during the longer intervals and were not affected by length of interval. A multistage composition of long-term retention was suggested to explain these results, and a practical indication to build experimental procedures to study memory in the clinical field was evidenced.     

Short-term memory for temporal intervals: Contrasting explanations of the choose-short effect in pigeons

To better understand short-term memory for temporal intervals, we re-examined the choose-short effect. In Experiment 1, to contrast the predictions of two models of this effect, the subjective shortening and the coding models, pigeons were exposed to a delayed matching-to-sample task with three sample durations (2, 6 and 18 s) and retention intervals ranging from 0 to 20 s. Consistent with the coding model, the results suggested a sudden forgetting of memories for duration. In Experiment 2, to test the confusion hypothesis, the characteristics of the ITI and the retention interval differed. Contrary to the confusion hypothesis, a choose-short effect was obtained. In both experiments, a test with only two of the three comparison keys was performed. The results suggest three effects that may be controlling the birds’ responses: stimulus generalization when no retention interval is present; an increase in random responding at longer retention intervals; and, similarly, an increase in preference for the “short-sample” key at longer retention intervals.     

The cost of remembering to remember in event-based prospective memory: investigating the capacity demands of delayed intention performance

Prospective memory tasks are often accomplished during the performance of other activities. Despite the dual-task nature of prospective memory, little attention has been paid to how successful prospective memory performance affects ongoing activities. In the first 2 experiments, participants performing an embedded prospective memory task had longer response times on nonprospective memory target trials of a lexical decision task than participants performing the lexical decision task alone. In the prospective memory groups, longer lexical decision response times were associated with better prospective memory performance (Experiments 1, 2, and 3), a pattern not demonstrated with an embedded retrospective memory task (Experiment 2). The results of Experiment 3 suggest that the retrieval of a delayed intention, or the prospective component, can require capacity.     

False prospective memory responses as indications of automatic processes in the initiation of delayed intentions

To analyze the role of automatic processes in the fulfilment of delayed intentions, we extended a typical prospective memory setting with a context signal to indicate whether the intended action is to be carried out or not. Building on dual-process models of cognition, we hypothesized that automatic and controlled processes are in opposition when the action is to be suppressed, because automatic processes trigger the associated response whereas controlled processes exert inhibition. Experiment 1 demonstrates the occurrence of false prospective memory responses to cues with the "suppress" signal. Experiment 2 shows that the rate of false prospective memory responses is sensitive to a manipulation that strengthens the role of automatic processes in prospective memory. The findings support the use of false prospective memory responses for the study of automatic processes in the execution of delayed intentions.     

Perception and recognition memory in monkeys following lesions of area TE and perirhinal cortex

Monkeys with lesions of perirhinal cortex (PR group) and monkeys with lesions of inferotemporal cortical area TE (TE group) were tested on a modified version of the delayed nonmatching to sample (DNMS) task that included very short delay intervals (0.5 sec) as well as longer delay intervals (1 min and 10 min). Lesions of the perirhinal cortex and lesions of area TE produced different patterns of impairment. The PR group learned the DNMS task as quickly as normal monkeys (N) when the delay between sample and choice was very short (0.5 sec). However, performance of the PR group, unlike that of the N group, fell to chance levels when the delay between sample and choice was lengthened to 10 min. In contrast to the PR group, the TE group was markedly impaired on the DNMS task even at the 0.5-sec delay, and three of four monkeys with TE lesions failed to acquire the task. The results provide support for the idea that perirhinal cortex is important not for perceptual processing, but for the formation and maintenance of long-term memory. Area TE is important for the perceptual processing of visual stimuli.