Arousal and paired-associate learning

Walker and Tarte (1963) postulate that at short retention intervals high arousal paired-associates are reproduced more poorly than low arousal items. Walker and colleagues believe that this hypothesis is confirmed by their paired-associate learning studies. However, results of these paired-associate learning studies are position confounded artifacts. Better recall of low arousal items at short-term retention is caused by the coincidence of the recency effect and low arousal at the end of the trial. When these position effects are controlled there is no action decrement for the high arousal paired-associates. To test this assumption, the Kleinsmith and Kaplan study (1963) was replicated and two other variations were conducted. In these three studies with 76 subjects, which were tested at two minutes or 1 week, the action decrement occurs only when the two position effects coincide.     

Personality and paired-associate learning1

Eysenck has theorized that introverts are high in arousal and should show the pattern of results which has been displayed in several experiments by subjects confronted with high-arousal stimulus materials: poor performance on short-term and good performance on long-term measures of retention. Extraverts, on the other hand, are thought to be low in arousal and should show the reverse pattern as displayed by subjects confronted with low-arousal stimulus materials. The relevant experiments conducted in Britain confirm these predictions. The relevant United States studies do not. The method used in the present study, in which Americans were subjects, is that of an experiment of Kleinsmith and Kaplan (1964) which found the patterns of retention predicted on the basis of the subjects' exposure to high- or low-arousal stimulus materials. But, as in the other tests of Eysenck's predictions, arousal was measured in terms of introversion and extraversion. The results failed to support Eysenck's formulation.     

Facilitation of retention by white noise.

Second and fifth grade subjects were given three verbal tasks: serial, free recall, or paired-associate learning. Retention tests were administered immediately after the acquisition phase or following a long delay. Half the subjects were exposed to a 2-min period of bursts of white noise (arousal) immediately prior to the retention test. The finding of primary interest was that white noise produced substantial improvement in performance relative to a control condition. This effect may be more pronounced for long-term memory than for short-term memory. Although older children exhibited better long-term memory than younger subjects, no interaction of age with arousal condition was observed.     

Differential effects of emotional arousal in short- and long-term memory in healthy adults

Recent studies demonstrated important differences between short- and long-term memory mechanisms. Besides, the emotional component has a crucial role in memory formation. This study was carried out to answer whether there is a differential influence of emotional arousal in short- and long-term memory in healthy adults. Thirty-one healthy volunteers were divided into two major groups. In the first group long-term memory (LTM) was evaluated, with the testing session one week after training. The second group was tested 1h after training, where short-term memory (STM) was evaluated. Each group was divided in to two subgroups. One half of the volunteers was exposed to an emotionally neutral story, and the other half of each group was exposed to a closely matched but more emotionally arousing story. The testing session consisted of a questionary containing 80 questions of multiple choices. The results were evaluated through percentage of correct answers. Results showed that correct answers were increased, in LTM measures, in the subjects that were given the emotional version of the test. In STM measures, no differences were found between the emotional and neutral version. However, the presentation of emotional story caused an emotional reaction in both groups. The lack of effect of emotional arousal in STM suggests that amygdala is not related to STM mechanisms. Further studies using different approaches are needed to elucidate if STM processes are influenced by emotional arousal.     

Working memory, long-term memory, and medial temporal lobe function

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL.     

Effect of arousal and retention delay on memory: a meta-analysis

Two meta-analyses were conducted to examine the magnitude of the interaction between arousal and retention delay on various types of memory, e.g., verbal, visual, etc., as initially reported by Kleinsmith and Kaplan in 1963 and 1964. Results of the first meta-analysis (29 studies, N = 2,637) indicated that the interaction was robust (d = .779), with low arousal leading to better immediate memory than high arousal, whereas high arousal led to better delayed memory than low arousal. Incorporating additional studies, a subsequent meta-analysis (48 studies, N = 3,143) on the effect of arousal on memory, taking retention delay as a moderator, provided further support. At a 2-min. delay, low arousal led to better immediate memory than high arousal (d = -.459). This difference decreased at a 20-min. delay (d = .106), when directions of high and low arousal effects on memory appeared to reverse. At longer delays than 20 min., high arousal led to better delayed memory than low arousal (ds = .753, .219, and .472, for delays of 45-min., 1-day, and more than 1-day, respectively).     

情绪记忆增强效应的时间依赖性

探讨情绪记忆短时和长时增强效应相对特异性机制以及唤醒度和效价在情绪记忆中的作用。运用不同阶段提取和不同情绪类别相结合的多因素设计方法, 对20位正常年轻成人进行行为学检测。结果显示, 情绪对记忆加工不同阶段(短时和长时)的调节作用(增强效应)具有时间依赖性, 且主要取决于情绪唤醒度, 而无显著正负效价性差异。在短时阶段主要涉及高唤醒度的增强; 而长时阶段涉及不同水平唤醒度的增强, 不同唤醒度的增强效应存在相对分离。     

Extraversion and electrodermal activity: arousability and the inverted-U

The Eysenck hypothesis that extraverts are less aroused or more inhibited than introverts has been subjected to a number of tests in the psychophysiological literature. Research to date suggests the need to clearly differentiate between tests of overall group differences in arousal or inhibition and studies of the differential reactions of the two groups to arousal manipulations. Psychophysiological studies of overall arousal differences in our laboratories and elsewhere have yielded somewhat inconsistent results for SCL, nonspecific response frequency, trials-to-criterion habituation and initial response amplitude, though dishabituation results are consistent with the expectation of higher amplitudes in introverts. Far more consistent are findings testing the inverted-U hypothesis, which suggests that introverts reach a point of optimal arousal at lower levels of stimulus input than do extraverts and hence should show earlier asymptotes and decrements in arousal measures. Using stimulus intensity and caffeine to manipulate arousal, we have found supportive results for SCL and several phasic measures, including the initial, test, and dishabituation responses. Overall, findings suggest that the two personality groups differ more clearly in arousability than in overall arousal level and that this difference is most consistent when conditions induce a rapid breakdown of inhibition and increase in arousal. Further research is needed to better understand the conditional relationship of extraversion to arousability, and arousal-manipulation paradigms would appear to be a fruitful initial approach to carrying out the needed research.     

Mental relaxation improves long-term incidental visual memory

Experimental evidence has linked increased arousal to enhanced memory retention. There is also evidence that procedures reducing arousal, i.e., mental relaxation, might improve memory, but conflicting results have been reported. To clarify this issue, we studied the effects of a single session of relaxation training on incidental visual long-term memory. Thirty-two relaxation-naive subjects viewed 280 slides without being told that there would be subsequent memory testing. Afterwards, subjects listened to a 12 min relaxation tape; 16 subjects relaxed by following the instructions (relaxation group), and the other 16 subjects pressed a button whenever a body part was mentioned (control group). While listening to the relaxation tape, high frequency heart rate variability (HRV) was greater and low frequency HRV was lower in the relaxation group, implying effective relaxation and increasing parasympathetic activation. The relaxation group had superior memory retention 4 weeks later (p = .004), indicating enhancement of long-term memory performance. This effect could not be explained by retroactive interference experienced in the control group because short-term memory performance immediately after the tape was slightly better in the control group. Retention of materials acquired after the relaxation session remained unaffected, suggesting relaxation has retrograde effects on memory consolidation. Our data demonstrate a favorable influence of relaxation on at least this aspect of learning. Our data also extend previous knowledge on the beneficial effects of ascending parasympathetic stimulation on memory retention in that enhanced long-term memory consolidation may also occur in the presence of central and descending parasympathetic activation triggered by willful psychomotor activity.     

Adding fuel to fire: the impact of followers' arousal on ratings of charisma

The authors conducted an experimental laboratory study and a longitudinal field study to investigate the impact of followers' arousal on ratings of charisma. Both studies examined 2 contrasting hypotheses: (a) the misattribution hypothesis, which posits a direct effect of arousal, and (b) the response-facilitation hypothesis, which posits an interactive effect of arousal and leaders' charismatic appeal on ratings of charisma. The overall results from both studies provide support for the response-facilitation hypothesis. In addition, the authors tested the hypothesis that arousal effects are limited to ratings of charisma. As expected, ratings of transactional leadership, in contrast with ratings of charisma, were not influenced by followers' arousal states. The authors discuss the implications of these results and offer suggestions for future research.     

生存优势效应的理论解释

生存优势效应指对学习材料进行“生存加工”,其提取正确率最高。研究者试图用主题加工、一致性效应、情绪加工和自然选择等理论对生存优势效应进行解释。研究发现主题加工、一致性效应和情绪加工不足以说明生存优势现象,自然选择理论似乎可以更好地对此加以解释,但目前自然选择理论尚缺乏直接的实验证据支持。文章结合已有研究具体分析了最近的未来研究应该关注的焦点问题,例如,自然选择理论的直接证明,并对直接证明的方案等进行了尝试性的讨论。     

A Novel Demonstration of Enhanced Memory Associated with Emotional Arousal

The relationship between emotional arousal and long-term memory is addressed in two experiments in which subjects viewed either a relatively emotionally neutral short story (presented as a brief slide show) or a closely matched but more emotionally arousing story and were tested for retention of the story 2 weeks later. Experiment 1 provides essential replication of the results of Heuer and Reisberg (1990) and illustrates the common interpretive problem posed by the use of different stimuli (slides) in the neutral versus emotional stories. In Experiment 2, identical slides (and sequence) were used in both the neutral and arousal stores. Two different stories were created by varying the narration that accompanied each slide. In both experiments, subjects who viewed the arousal story both experienced a greater emotional reaction to the story than did the subjects who viewed the neutral story, and subsequently exhibited enhanced memory for the story. Subjects in Experiment 2 who viewed the arousal story also recalled more slides than did the subjects who viewed the neutral story. This effect was greatest for story phase 2, the phase in which the emotional slide narration occurred. Because this enhanced retention of the story slides cannot be explained by any differences in the slides themselves, the results provide new evidence to support the contention that emotional arousal influences long-term memory in normal human subjects.     

Extraversion and sleep: A psychophysiological study of the arousal hypothesis

In order to examine Eysenck's (1967) hypothesis concerning the relationship between extraversion and arousal, autonomic measures were taken from introverts and extraverts immediately before sleep and during 6 hr of sleep. Introverts and extraverts did not differ in heart rate (HR) or skin-potential response rate (SPR) during the pre-sleep period. A variety of sleep-related measures of arousal provided no strong support for the hypothesis that introverts are more aroused than extraverts. The only consistent autonomic difference between introverts and extraverts during sleep was a tendency for introverts to have higher SPRs in the second 3 hr of the night. The results are discussed in terms of the level of environmental stimulation present in the experimental conditions, and suggestions are made for future sleep studies of the relationship between extraversion and arousal.     

Arousal-reducing effects of chronic stimulant use

A variety of studies withhabitual users of nicotine, caffeine, cocaine, and amphetamines have shown that administration of these stimulants has the paradoxical effect of lowering arousal states. Research on transmarginal inhibition shows that when subjects are presented with a succession of stimuli monotonically increasing in intensity, GSR and related arousal responses increase first and then begin to decline beyond a certain point of stimulus intensity. That is, following repeated exposure to intense stimuli, continued more intense stimulation has the effect of lowering arousal. Since stimulants subjectively heighten stimulus intensity, the transmarginal inhibition data provide a basis for explaining opposing effects of stimulants on arousal, depending on dose and frequency of use. It was hypothesized that when dose levels are low and usage is infrequent, arousal increases with stimulant intake. In contrast, when dose levels are high and frequent, arousal shows decrements with new intakes of stimulant. A new questionnaire measure of characteristic arousal was developed and correlated with subjects' reports of habitual levels of stimulant and sedative intake. Weekly total stimulant use correlated significantly and negatively with characteristic arousal level, providing support for the hypothesis. This lowered arousal of frequent stimulant users was not a confound of, or due to, concomitant frequent sedative use, since total stimulant and sedative use levels were uncorrelated.The author would like to thank Janice Schafrik for running the subjects in this study.     

The effects of word co-occurrence on short-term memory: associative links in long-term memory affect short-term memory performance

In immediate serial recall tasks, high-frequency words are recalled better than low-frequency words. This has been attributed to high-frequency words' being better represented and providing more effective support to a redintegration process at retrieval (C. Hulme et al., 1997). In studies of free recall, there is evidence that frequency of word co-occurrence, rather than word frequency per se, may explain the recall advantage enjoyed by high-frequency words (J. Deese, 1960). The authors present evidence that preexposing pairs of low-frequency words, so as to create associative links between them, has substantial beneficial effects on immediate serial recall performance. These benefits, which are not attributable to simple familiarization with the words per se, do not occur for high-frequency words. These findings indicate that associative links between items in long-term memory have important effects on short-term memory performance and suggest that the effects of word frequency in short-term memory tasks are related to differences in interitem associations in long-term memory.     

Primacy versus recency in a quantitative model: activity is the critical distinction

Behavioral and neurobiological evidence shows that primacy and recency are subserved by memory systems for intermediate- and short-term memory, respectively. A widely accepted explanation of recency is that in short-term memory, new learning overwrites old learning. Primacy is not as well understood, but many hypotheses contend that initial items are better encoded into long-term memory because they have had more opportunity to be rehearsed. A simple, biologically motivated neural network model supports an alternative hypothesis of the distinct processing requirements for primacy and recency given single-trial learning without rehearsal. Simulations of the model exhibit either primacy or recency, but not both simultaneously. The incompatibility of primacy and recency clarifies possible reasons for two neurologically distinct systems. Inhibition, and its control of activity, determines those list items that are acquired and retained. Activity levels that are too low do not provide sufficient connections for learning to occur, while higher activity diminishes capacity. High recurrent inhibition, and progressively diminishing activity, allows acquisition and retention of early items, while later items are never acquired. Conversely, low recurrent inhibition, and the resulting high activity, allows continuous acquisition such that acquisition of later items eventually interferes with the retention of early items.     

Incidental learning as a function of anticipated task difficulty

Three experiments were conducted to demonstrate the effects of motivational arousal, due to anticipated task difficulty, on retention of familiar and unfamiliar incidental materials. Brehm, Wright, Solomon, Silka, and Greenberg (1983) have provided evidence that motivational arousal in immediate anticipation of a task is a nonmonotonic function of task difficulty, with difficult tasks producing a relatively higher level of motivational arousal than easy or impossible tasks. It was predicted that increased motivational arousal would facilitate retention of incidentally presented familiar materials (presumably more easily retained) and interfere with retention of incidentally presented unfamiliar materials (presumably less easily retained). In Study 1, subjects anticipating either an easy or a difficult task were exposed to familiar and unfamiliar first names. The predicted interaction between task difficulty and familiarity on recall of the first names was reliably supported. In Study 2, an impossible task condition was added. The results indicated that an effective impossible condition had not been created. In a third study designed as a procedural modification of Study 2, the predicted nonmonotonic interaction was found. Theoretical implications are discussed.These experiments were ably conducted by Ralph Young, whose help is gratefuly acknowledged. We would like to express our gratitude to Jack Brehm for invaluable suggestions concerning this research.     

Electrophysiological differences in the processing of affective information in words and pictures

It is generally assumed that affective picture viewing is related to higher levels of physiological arousal than is the reading of emotional words. However, this assertion is based mainly on studies in which the processing of either words or pictures has been investigated under heterogenic conditions. Positive, negative, relaxing, neutral, and background (stimulus fragments) words and pictures were presented to subjects in two experiments under equivalent experimental conditions. In Experiment 1, neutral words elicited an enhanced late positive component (LPC) that was associated with an increased difficulty in discriminating neutral from background stimuli. In Experiment 2, high-arousing pictures elicited an enhanced early negativity and LPC that were related to a facilitated processing for these stimuli. Thus, it seems that under some circumstances, the processing of affective information captures attention only with more biologically relevant stimuli. Also, these data might be better interpreted on the basis of those models that postulate a different access to affective information for words and pictures.     

Les capacités d'inhibition : une fonction « frontale » ?

It has been strongly suggested that one important function related to frontal lobes is inhibition. However, a review of the literature on classical tests of inhibition (Stroop test, WCST, and AB-AC learning) suggests that this hypothesis is not well established. We further examined this hypothesis using short-term and long-term directed forgetting tasks (Reed, 1970, Zacks et al., 1996), the Stroop test and the Hayling test (Burgess and Shallice, 1996) in 13 patients with focal frontal lesions. The results revealed short-term and long-term memory deficits and a slowing down, but no inhibition deficit compared with control subjects. These results question the relevance of the hypothesis of the frontal lobe as the unique substrate of inhibitory mechanisms. More generally, they address the issue of executive functions: are these sustained by the frontal cortex or by a cortical and subcortical diffuse neural network?     

The robustness of false memory for emotional pictures

Emotional material is commonly reported to be more accurately recognised; however, there is substantial evidence of increased false alarm rates (FAR) for emotional material and several reports of stronger influences on response bias than accuracy. This pattern is more frequently reported for words than pictures. Research on the mechanisms underlying bias differences has mostly focused on word lists under short retention intervals. This article presents four series of experiments examining recognition memory for emotional pictures while varying arousal and the control over the content of the pictures at two retention intervals, and one study measuring the relatedness of the series picture sets. Under the shorter retention interval, emotion increased false alarms and reduced accuracy. Under the longer retention interval emotion increased hit rates and FAR, resulting in reduced accuracy and/or bias. At both retention intervals, the pattern of valence effects differed based on the arousal associated with the picture sets. Emotional pictures were found to be more related than neutral pictures in each set; however, the influence of relatedness alone does not provide an adequate explanation for all emotional differences. The results demonstrate substantial emotional differences in picture recognition that vary based on valence, arousal and retention interval.