State-Dependent Memory Effects Using Caffeine and Placebo Do Not Extend to Metamemory

The authors examined the impact of caffeine on human memory and predictions of memory (i.e., metamemory). On Day 1, 83 college students drank a sweetened beverage containing either caffeine (4 mg/kg body weight) or a placebo before they studied 40 pairs of words. While the participants studied, they predicted their future memory performance for each word pair. On Day 2, the participants again received caffeine or a placebo before the memory test. The participants who drank the same beverage on both days (either caffeine or a placebo) recalled more word pairs than did those who drank different beverages (caffeine on 1 day and a placebo on the other day). In contrast, memory predictions were more accurate when the beverages did not match on both days. These data provide evidence for state-dependent memory when caffeine is used, but not for state-dependent metamemory. People's memory and their predictions of memory can be influenced in different ways if they drink caffeine before they study or take a test.     

高强迫症状个体的定向遗忘和元记忆

将定向遗忘和FOK判断的范式相结合,探讨高强迫症状被试（HOC）和低强迫症状的控制组（LOC）在不同词语类型的条件下,线索回忆和元记忆判断的定向遗忘效应的差异。实验结果表明,HOC组在中性词语条件下比LOC组表现出更低的定向遗忘效应。FOK的结果表明HOC被试对于不同条件的元记忆的分辨能力比LOC组要差,他们在威胁性词语方面,对未来记忆任务的成绩也没有预测性。研究结果从一定程度上支持强迫症的一般记忆损伤模型     

Memory development in adolescence: Relationships between metamemory,strategy use,and performance

Eighth and tenth grade students were asked to study and recall a list of paired associates. The word pairs were available either throughout an 8 sec per word study period or only at the beginning and were composed of either high frequency or low frequency words. After recall, students were asked to indicate which of several study strategies they had used with each word pair (read pair carefully, rehearsal, visual elaboration, verbal elaboration). In addition, they were asked which of these strategies would have had the best effect on recall. Knowledge of appropriate memory strategies (metamemory) was positively related to strategy use, and strategy use was positively related to recall performance at both ages. Improved performance with materials available throughout study and with high frequency word pairs was explained by increased use of elaborative strategies. Age differences in performance were explained by increased strategy effectiveness. These results are discussed in relation to changing relationships among metamemory, strategy use, and performance with age.     

Revelation effect in metamemory

Test items are more likely to be judged as previously studied if they need to be discovered before the recognition decision. In the present experiments, this revelation effect was extended to metamemory judgments. Participants studied word pairs and then tried to recall the second word of each pair when given the first word as a cue. In Experiment 1, a fragment of the target was either gradually increased in size or held constant, and in Experiment 2, sometimes an anagram of the cue was given instead of the cue itself. Thus, for some items, there was a revelation task before a recall attempt. If recall failed, the participants gave feeling-of-knowing (FOK) ratings. In both experiments, the participants gave higher FOK ratings after a revelation task, even though the items that these FOKs referred to remained unrecalled. Analyses showed a criterion shift but no differences in sensitivity.     

Are you sure you forgot? Feeling of knowing in directed forgetting.

One significant issue in metamemory is how variables increasing memorability affect metamemory. Previous research has produced inconsistent results. The effect of directed forgetting on the magnitude and accuracy of feeling-of-knowing (FOK) judgments was investigated. Participants were presented with word pairs, some to be remembered and some to be forgotten, and then were asked to recall all target words regardless of initial instructions. For unrecalled items, they were asked to give FOK judgments about performance in a future memory task: a cued stem-completion task (Experiment 1) or a recognition test (Experiment 2). This encoding manipulation increased both the memory performance and the magnitude of FOK judgments. However, no such effect on the accuracy of FOK judgments was observed.     

Effects of caffeine on performance of low intensity tasks

31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.     

Memory and metamemory in obsessive-compulsive disorder

Studies on the link between checking and memory problems have produced equivocal results regarding a general memory deficit in patients with obsessive-compulsive disorder and subclinical checkers. However, there is clear and consistent evidence that patients with obsessive-compulsive disorder (OCD) show lack of confidence in their memory performance. The purpose of the present study was to investigate memory and metamemory performance (feeling-of-knowing judgments) for neutral and threat-related material in three groups: OCD patients (OCs), subclinical checkers (SCs), and normal controls (NCs). Participants studied a list of neutral and threat word pairs. After an initial cued-recall test, they provided feeling-of-knowing (FOK) judgments for unrecalled word pairs, followed by a recognition test. The results showed that OCs but not SCs were impaired in both recall and recognition compared to NCs. OCs were also less confident about their future memory performance than the other two groups, as reflected in their lower FOK ratings. Moreover, FOK judgments of the OCs were not reliable predictors of their recognition performance. Finally, neither OCs nor SCs showed any evidence of memory bias for threat-relevant information. The results support the idea of a general memory and a metamemory deficit in OCs.     

An investigation of people's metamemories for naturally occurring events

Three studies investigated the role of event salience in the validity of metamemory reports for naturally occurring events. Two studies investigated metamemory for daily forgetting behaviours as recorded on memory diaries for either 10 days (Study 1) or a month (Study 2). A third study examined metamemory for remembering recent events (consisting of the first day of class, the most recent weekend, and the first experimental session). The results indicated that metamemory validity was higher for the more salient memory events, e. g. rote memory failures and memory of the first day of class.     

Lost in the Sauce: The Effects of Alcohol on Mind Wandering

ABSTRACT— Alcohol consumption alters consciousness in ways that make drinking both alluring and hazardous. Recent advances in the study of consciousness using a mind-wandering paradigm permit a rigorous examination of the effects of alcohol on experiential consciousness and metaconsciousness. Fifty-four male social drinkers consumed alcohol (0.82 g/kg) or a placebo beverage and then performed a mind-wandering reading task. This task indexed both self-caught and probe-caught zone-outs to distinguish between mind wandering inside and outside of awareness. Compared with participants who drank the placebo, those who drank alcohol were significantly more likely to report that they were zoning out when probed. After this increase in mind wandering was accounted for, alcohol also lowered the probability of catching oneself zoning out. The results suggest that alcohol increases mind wandering while simultaneously reducing the likelihood of noticing one's mind wandering. Findings are discussed with regard to theories of alcohol and theories of consciousness.     

No evidence for a role of reconsolidation in updating of paired associates

Reconsolidation theory states that memories are labilized through reactivation, making them prone to change, before being re-consolidated. When information in memory requires updating, reconsolidation theory therefore predicts that reminders of previously learned information should facilitate updating of that information and should thus improve memory for the updated information. In two experiments, we tested this prediction by investigating memory for word pairs over a short time-scale. Participants studied word pairs (A–B), some of which were subsequently updated with word pairs that shared the first word (A–C). Half of the A–C pairs received a pre-study reminder of the first word in the pair so as to reactivate and labilize A–B memory. In a recognition memory test targeting the A–C list, reminders by and large had no effect on memory. Results thus failed to support the predictions of reconsolidation theory.     

Percolating ideas: The effects of caffeine on creative thinking and problem solving

Caffeine is the most widely consumed psychotropic drug in the world, with numerous studies documenting the effects of caffeine on people’s alertness, vigilance, mood, concentration, and attentional focus. The effects of caffeine on creative thinking, however, remain unknown. In a randomized placebo-controlled between-subject double-blind design the present study investigated the effect of moderate caffeine consumption on creative problem solving (i.e., convergent thinking) and creative idea generation (i.e., divergent thinking). We found that participants who consumed 200 mg of caffeine (approximately one 12 oz cup of coffee, n = 44), compared to those in the placebo condition (n = 44), showed significantly enhanced problem-solving abilities. Caffeine had no significant effects on creative generation or on working memory. The effects remained after controlling for participants’ caffeine expectancies, whether they believed they consumed caffeine or a placebo, and changes in mood. Possible mechanisms and future directions are discussed.     

‘Beauty is in the eye of the beer holder’: People who think they are drunk also think they are attractive

This research examines the role of alcohol consumption on self‐perceived attractiveness. Study 1, carried out in a barroom (N= 19), showed that the more alcoholic drinks customers consumed, the more attractive they thought they were. In Study 2, 94 non‐student participants in a bogus taste‐test study were given either an alcoholic beverage (target BAL [blood alcohol level]= 0.10 g/100 ml) or a non‐alcoholic beverage, with half of each group believing they had consumed alcohol and half believing they had not (balanced placebo design). After consuming beverages, they delivered a speech and rated how attractive, bright, original, and funny they thought they were. The speeches were videotaped and rated by 22 independent judges. Results showed that participants who thought they had consumed alcohol gave themselves more positive self‐evaluations. However, ratings from independent judges showed that this boost in self‐evaluation was unrelated to actual performance.     

Single-item memory, associative memory, and the human hippocampus

We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in a mixed order. In Experiment 2 (Separated memory test), participants studied single words and then took a memory test involving studied word and new words. In a separate test, they studied word pairs and then took a memory test involving studied word pairs and recombined word pairs. In both experiments, patients were impaired at memory for single items as well as memory for associations, suggesting that the hippocampus is important for both of these memory functions. In Experiment 1, patients appeared to be more impaired at associative memory than item memory. In Experiment 2, patients were similarly impaired at associative memory and item memory. These different findings are considered, including the fact that in Experiment 1 the results depended on the fact that controls produced unexpectedly low false-alarm rates to recombined pairs. We discuss single-item and associative memory from the perspective that the hippocampus and adjacent cortex work cooperatively to signal recognition and that simple dichotomies do not adequately describe the division of labor within the medial temporal lobe.     

Immediate judgments of learning are insensitive to implicit interference effects at retrieval

We conducted three experiments to determine whether metamemory predictions at encoding, immediate judgments of learning (IJOLs) are sensitive to implicit interference effects that will occur at retrieval. Implicit interference was manipulated by varying the association set size of the cue (Experiments 1 and 2) or the target (Experiment 3). The typical finding is that memory is worse for large-set-size cues and targets, but only when the target is studied alone and later prompted with a related cue (extralist). When the pairs are studied together (intralist), recall is the same regardless of set size; set size effects are eliminated. Metamemory predictions at retrieval, such as delayed JOLs (DJOLs) and feeling-of-knowing (FOK) judgments accurately reflect implicit interference effects (e.g., Eakin & Hertzog, 2006. In all three experiments, we found that DJOLs and FOKs accurately predicted set size effects on retrieval but that IJOLs did not. The findings provide further evidence that metamemory predictions are inferred from information other than direct access to the state of the memory trace, as well as indicate that inferences are based on different sources depending on when in the memory process predictions are made.     

延时间隔和线索类型对遗忘学习判断的影响*

主要探讨不同延时间隔和线索类型对遗忘元认知判断的影响。采用传统的学习判断任务,让被试学习40对无意义配对词,并告知随后进行测试,当呈现第一个词时,被试能够回忆与之配对的后一个词。让被试预测当延迟不同时间（5分钟、1天和1周）进行测试时,他们能够记住（学习判断）或者遗忘（遗忘判断）后一词的可能性。最后,要求被试回忆所有词对。结果发现延时间隔对学习判断和遗忘判断有相似的影响;学习判断的等级和相对准确性均高于遗忘判断,说明人们对记住和遗忘的线索很敏感;相比于学习判断,人们监测自己遗忘能力的信心不足。研究结果表明人们能够利用延时间隔和线索类型来预测未来的测验成绩,对遗忘的监测能力低于对记住的监测。     

Processes leading to confidence and accuracy in sentence recognition: A metamemory approach

We propose that memory confidence is based on the processes and products of the just-completed memory task, along with the participants’ metamemory beliefs about the relation of these processes and products to memory accuracy. We tested this metamemory approach to confidence by having participants carry out a simple recognition memory task with deceptive and nondeceptive items. The deceptive items were sentences that contained a possible synonym substitution, thus allowing errors based on gist memory. For nondeceptive items, high confidence was associated with high accuracy. For deceptive items the relationship reversed; high confidence was associated with low accuracy. A memory process questionnaire was developed that provided more differentiated phenomenal reports than the traditional know/remember distinction. For nondeceptive items, metamemory beliefs tended to be valid indicators of accuracy, but for deceptive items involving unconscious reconstructive memory processes, they tended to be invalid indicators of memory accuracy. The overall results lend strong support for our metamemory approach to memory confidence.     

Contrast effect in evaluating palatability of beverages.

This study aimed to clarify the contextual effect in evaluation of the pleasantness of beverages. Participants were presented a test stimulus and were then asked to rate how much they liked it before and after presentation of a contextual stimulus. Specifically, after participants were exposed to a less palatable beverage, they evaluated the test beverage as being more palatable than when their judgment of a test drink occurred after presentation of a neutral or palatable beverage (a positive contrast effect). This contextual effect can be explained by the reasoning that participants were affectively adapted to the palatability (less palatable) of a less palatable stimulus after repeated exposure; thus, they evaluated the test stimulus as more palatable. This study suggests that the evaluated value of the contextual stimuli affects evaluation of the test stimulus. The authors also suggest that these context effects are probably found in everyday life.     

Judgments of learning reflect encoding fluency: conclusive evidence for the ease-of-processing hypothesis

According to the ease-of-processing hypothesis, judgments of learning (JOLs) rely on the ease with which items are committed to memory during encoding--that is, encoding fluency. Conclusive evidence for this hypothesis does not yet exist because encoding fluency and item difficulty have been confounded in all previous studies. To disentangle the effects of encoding fluency and item difficulty on JOLs, we used a variant of the learner-observer-judge method in which participants observed the study phase of another participant and indicated his or her JOLs. At the same time, the to-be-studied word pairs were concealed by strings of symbols. Our experiment revealed that participants use self-paced study time as a cue for JOLs when they themselves have studied and recalled word pairs before. This metacognitive monitoring of study time provides strong support for the ease-of-processing hypothesis.     

再认条件下元监测判断的影响因素

探讨了再认条件下元监测判断的影响因素。以中文双字词对作为实验材料 ,安排在不同预先呈现时间、有无进行有意识记 ,以及不同识记遍数等条件下进行元监测判断。用计算机随机呈现项目 ,再认之前先让被试做元监测判断 ,判断是否是记过的项目的把握程度 ,再对有意识记过的项目做迫选再认 ,作为标准测验 ,以验证元监测判断的准确性。结果是预先呈现时间长、有意识记过的和识记遍数多的项目 ,对其再认的反应时较短 ,相应的元监测判断等级也较高 ;对只看而未有意记过的项目的判断是呈现时间长的判断等级反而低于呈现时间短的。此结果表明 ,再认条件下 ,元监测判断的等级的高低与识记项目的激活程度有关     

The Effects of Caffeine Consumption on Direct and Indirect Majority and Minority Influence

A study is reported that examines the effect of caffeine consumption on majority and minority influence. In a double blind procedure, 72 participants consumed an orange drink, which either contained caffeine (3.5mg per kilogram of body weight) or did not (placebo). After a 40-minute delay, participants read a counter-attitudinal message (antivoluntary euthanasia) endorsed by either a numerical majority or minority. Both direct (message issue, i.e., voluntary euthanasia) and indirect (message issue-related, i.e., abortion) change was assessed by attitude scales completed before and after exposure to the message. In the placebo condition, the findings replicated the predictions of Moscovici's (1980) conversion theory; namely, majorities leading to compliance (direct influence) and minorities leading to conversion (indirect influence). When participants had consumed caffeine, majorities not only led to more direct influence than in the placebo condition but also to indirect influence. Minorities, by contrast, had no impact on either level of influence. The results suggest that moderate levels of caffeine increase systematic processing of the message but the consequences of this vary for each source. When the source is a majority there was increased indirect influence while for a minority there was decreased indirect influence. The results show the need to understand how contextual factors can affect social influence processes.