Effect of circadian rhythms on retrieval-induced forgetting

This study investigated the effects of natural circadian rhythms on retrieval-induced forgetting (RIF; Anderson et al. in J Exp Psychol Learn Mem Cogn 20:1063–1087, 1994). Individuals tested at optimal times (i.e., morning persons tested in the morning and evening persons tested in the evening) showed a significantly greater RIF effect than individuals tested at non-optimal times (i.e., morning persons tested in the evening and evening persons tested in the morning). Thus, the limited quantity of resources available to allocate in the inhibitory activity during non-optimal times produced a significant decrement in RIF. These findings are compatible with the inhibitory account of RIF and with the notion of a resource-demanding process underlying this memory phenomenon.     

Sleep enhances memory consolidation in the hippocampus-dependent object-place recognition task in rats

The positive impact of sleep on memory consolidation has been shown for human subjects in numerous studies, but there is still sparse knowledge on this topic in rats, one of the most prominent model species in neuroscience research. Here, we examined the role of sleep in the object-place recognition task, a task closely comparable to tasks typically applied for testing human declarative memory: It is a one-trial task, hippocampus-dependent, not stressful and can be repeated within the same animal. A test session consisted of the Sample trial, followed by a 2-h retention interval and a Test trial, the latter examining the memory the rat had for the places of two objects presented at the Sample trial. In Experiment 1, each rat was tested twice, with the retention interval taking place either in the morning or evening, i.e., in the inactive or active phase, respectively. Rats showed significantly (p<0.01) better memory for object place after the Morning session. To control for confounding circadian factors, in Experiment 2 rats were tested four times, i.e., in the morning or in the evening while sleep was or was not deprived. Sleep during the retention interval was recorded polysomnographically. Rats only showed significant memory for the target object place in the Test trial after the Morning retention interval in the absence of sleep deprivation, and recognition performance in this condition was significantly superior to that in the three other conditions (p<0.05). EEG recordings during spontaneous morning sleep revealed increased slow oscillation (0.85-2.0 Hz) and upper delta (2.0-4.0 Hz), but reduced spindle band (10.5-13.5 Hz) activity, as compared to evening sleep. However, spindle band power was increased in the Morning retention interval in comparison to a Morning Baseline period (p<0.05). We conclude that consolidation of object-place memory depends on sleep, and presumably requires NonREM sleep rich in both slow wave and spindle activity.     

Morningness–eveningness orientation and attitude change: Evidence for greater systematic processing and attitude change at optimal time-of-day

This study examines the relationship between morningness–eveningness orientation and time-of day on attitude change, and tests the hypothesis that people will be more persuaded when tested at their optimal time-of-day (i.e., morning for M-types and evening for E-types) than non-optimal time-of-day (i.e., evening for M-Types and morning for E-types). Two hundred and twenty participants read a message that contained either strong vs. weak quality counter-attitudinal arguments (anti-voluntary euthanasia) in the morning (9.00 a.m.) or in the evening (7.00 p.m.). When tested at their respective optimal time-of-day (for both M- and E-types) there was a reliable difference in attitude change between the strong vs. weak messages (indicating message processing had occurred) while there was no difference between strong vs. weak messages when tested at their non-optimal time-of-day. In addition, the amount of message-congruent thinking mediated the attitude change. The results show that M- and E-types pay greater attention to and elaborate on a persuasive message at their optimal time-of-day, and this leads to increased attitude change, compared to those tested at their non-optimal time-of-day.     

Implicit memory, age, and time of day: paradoxical priming effects

Memory retrieval can occur by at least two routes: a deliberate one, as when one attempts to retrieve an event or fact, and an unintentional one, as when one's behavior is triggered by the past without one's knowledge or awareness. We assessed the efficacy of these retrieval systems as a function of circadian arousal and time of day. Evening-type younger adults and morning-type older adults were tested at either peak (morning for old; evening for young) or off-peak times on implicit and explicit stem completion (Experiment 1) or on implicit category generation (Experiment 2). Results for explicit stem-cued recall replicated better performance for each age group at its peak time. In stark contrast, implicit performance was better at off-peak than at peak times of day, raising the possibility that the processes that serve explicit and implicit retrieval are on different circadian schedules, and highlighting the need to consider individual differences in circadian arousal when assessing either memory system.     

Word-list-learning performance in younger and older adults: intra-individual performance variability and false memory

We investigated the word-list-learning performance of younger and older adults over 4 consecutive days at different times of day to study age-related differences in consistency of performance over time and the influence of circadian variation on performance. Eighteen younger (M age, 23.4 years) and 18 older (M age, 73.3 years) men and women participated. The start time of testing alternated between morning and early evening across the 4 days of testing. On each test day, participants learned a different list of 15 unrelated words over four learning trials. As expected, younger adults performed better than older adults on immediate recall, delayed recall, and recognition. Contrary to our expectations, time of day did not significantly influence recall or recognition performance in either the older or younger adults. Older adults did show a greater incidence of false memory (i.e., previously learned list intrusions in free recall and false alarms in recognition) than younger adults. Older adults also exhibited greater intra-individual performance variability on the measures of false memory across test days. This variability was not related to circadian variation. False memory and variability of performance have both been linked to frontal systems dysfunction. The findings presented here are consistent with the notion that changes in cognition with aging in part reflect age-related decline in frontal lobe function.     

Proactive People Are Morning People1

Proactivity is the willingness and ability to take action to change a situation to one's advantage and has been studied in a wide range of contexts. The role of chronotype on proactivity has not been assessed. Individual differences in circadian rhythms have been widely acknowledged and are accepted as an interesting facet of human personality. Morning people were more proactive than evening types, and people with small differences in rise time between weekdays and free days were also more proactive persons. Sleep length (on weekdays and on free days) and total time spent in weekend oversleep did not show any relationship with proactivity. These results suggest that morning people are more proactive than are evening types.     

Word-List-Learning Performance in Younger and Older Adults: Intra-Individual Performance Variability and False Memory

ABSTRACT

We investigated the word-list-learning performance of younger and older adults over 4 consecutive days at different times of day to study age-related differences in consistency of performance over time and the influence of circadian variation on performance. Eighteen younger (M age, 23.4 years) and 18 older (M age, 73.3 years) men and women participated. The start time of testing alternated between morning and early evening across the 4 days of testing. On each test day, participants learned a different list of 15 unrelated words over four learning trials. As expected, younger adults performed better than older adults on immediate recall, delayed recall, and recognition. Contrary to our expectations, time of day did not significantly influence recall or recognition performance in either the older or younger adults. Older adults did show a greater incidence of false memory (i.e., previously learned list intrusions in free recall and false alarms in recognition) than younger adults. Older adults also exhibited greater intra-individual performance variability on the measures of false memory across test days. This variability was not related to circadian variation. False memory and variability of performance have both been linked to frontal systems dysfunction. The findings presented here are consistent with the notion that changes in cognition with aging in part reflect age-related decline in frontal lobe function.     

An investigation of the effects of self-reported self-control strength on shooting performance

During professional shooting tournaments, which typically last multiple hours, athletes must stay focused at all times in order to perform at their highest levels. Sustaining attention over extended periods of time relies on self-control. Crucially, perceived state self-control strength appears to wane as a function of task duration, which ultimately can impair shooting performance. In the present study, we tested the assumption that the level of self-reported self-control strength decreases over the course of a 1-h shooting task measured twice during a regular training day and separated by a 2-h break. Additionally, we assumed that shooting performance would be linked with fluctuations in self-control. A total of 21 shooters (14 elite and 7 sub-elite) took part in this study and were asked to perform a series of 10 shots at a standardized target, five times in the morning and five times in the afternoon (i.e., 100 shots total). The participants also reported their perceived state self-control strength at the baseline (prior to the start of the morning session as well as the afternoon session) and after a series of 10 shots each in the morning and afternoon (i.e., 12 measurements in total). In line with our hypotheses, we observed that perceived state self-control diminished with the number of shots performed, and that perceived state self-control could explain shooting performance. Additionally, these observations could explain the difference in shooting performance between elite and sub-elite athletes. The results suggest that the perception of self-control strength is highly important for optimal shooting performance. Practical implications are discussed.     

Effects of time of day and medium of presentation on immediate recall of violent and non-violent news

A sample of 103 subjects from a technical training college were randomly assigned to nine groups and presented with a sequence of violent and non-violent news stories either audiovisually (via television), in audio-only, or in print at three different times of day (morning—9.30 am, early afternoon—1.30 pm, and later afternoon—5.30 pm). Subjects were tested for immediate cued recall of story content immediately after presentation. There were significant main effects of presentation modality, time of day and news content. Memory for news was best from print and worst from the audiovisual presentation. Memory performance was best in the morning and worst in the evening. Violent news was recalled better than non-violent news in all media and at all times of day. There were also some interactions. Recall of violent news presented in audiovisual and audio-only modalities deteriorated more from morning to afternoon than did non-violent news recall. Non-violent news recall from these two media declined more rapidly in the second half of the day. With print, recall of both violent and non-violent news dropped off more in the late afternoon than in the morning. Practical implications of the findings for news presentation are discussed.     

Assortative mating in morningness-eveningness

Individuals differ in their morningness-eveningness preference (circadian preference); that is, some prefer morning hours for intellectual and physical activities and others prefer late afternoon or evening hours. This has been viewed as an interesting facet of personality. Assortative mating has been studied in personality research, but assortative mating in circadian preference has rarely been examined. Eighty-four couples participated in this study. They filled in the Composite Scale of Morningness; they also supplied data about rise times and bedtimes as well as information about relationship satisfaction and duration. The results revealed a moderate positive relationship between couple partners in morningness-eveningness which persisted after correcting for age. Similarly, correlations existed between the sleep-wake variables (rise time and bedtime) on weekdays and on the weekends, the association being higher for weekends. There was no significant correlation between length of the relationship and dissimilarity in morningness-eveningness, suggesting that the above-reported correlations reflect an initial assortment rather than convergence effects. Further, no significant correlation was found between dissimilarity in morningness-eveningness and relationship satisfaction. The results suggest that assortative mating in morningness-eveningness is likely and is probably based on an initial assortment. The likelihood to meet and mate may also be linked to chronotype. When differences in circadian preferences exist between possible partners, this reduces the likelihood that these persons meet either by accident or during work and leisure activities. Therefore, two extreme chronotypes are unlikely to meet each other because they have the smallest overlap in their preferred active time during the day due to the circadian rhythmicity.     

Diurnal pattern of luminance discrimination in humans

The visual discrimination threshold can be considered as an image of the resolution power of the visual system. Measured with a psychophysical method, it shows a diurnal pattern with a low threshold in the morning, i.e., high sensitivity and an increase in the afternoon that persists until the early evening.     

Assessing teaching opportunities in a residential treatment facility

Seventeen living units in a residential treatment facility for developmentally disabled persons were assessed to determine the availability of teaching opportunities during the course of a normal day's routine. Teaching opportunities exist when the environment is arranged so that residents can participate in the ongoing activities. The teaching opportunities are identified within components that are recognizable activities that occur routinely and have a functional purpose. An assessment form was constructed as a means for documenting teachng opportunities. Assessments were conducted continuously from early morning through evening activities. The results of the assessments suggested that two approaches to resident care were in operation at the facility: one was characterized by a traditional care/custodial model, the other was characterized by a teaching model. On units where the number of teaching opportunities available was high, there was a smaller percentage of unstructured time, i.e., blocks of time when opportunities to engage in structured activities were not available to the residents.     

“Midnight Confessions”: The Effect of Chronotype Asynchrony on Admissions of Wrongdoing

Confession evidence is highly incriminating in court. We examined the interaction between chronotype and time of day on the confession decisions of 60 participants using an experimental paradigm. Pre-identified morning- and evening-type people were randomly assigned to participate in morning or evening sessions. Results supported an interactional asynchrony hypothesis that individuals are more likely to confess during “off-peak” periods (i.e., evening-types in the morning and morning-types in the evening). This interaction was obtained for both high- and low-seriousness transgressions. These results suggest that chronotype asynchrony constitutes a significant risk factor for false confessions and the wrongful convictions that often follow.     

Noise stress and circadian arousal in self-paced computation

Previous work(Frankenhaeuser & Lundberg, 1977) has shown that unpaced mental arithmetic is performed at slower rates in noise, despite unchanged catecholamine indices of arousal; only male subjects were used, tested early in the day. Since the times of testing entail arousal effects that interact with noise stress, and the sex of subject further modifies these interactions, a new experiment was designed to include these variables. Men and women were tested on the Norinder mental arithmetic task, in quiet or in noise, either in the morning, when arousal was low, or during the early evening, when temperature curves indicate that arousal should be high. Analysis of the number of problems attempted shows a significant drop for men in noise in the morning, but an interaction due to reversal of the noise effect in the evening; there is no main effect of noise when women's scores are included. The results are compatible with interpretations combining motivation and cognition, and they demonstrate the importance of the experimental variables in explaining noise stress effects.The authors are indebted to the late David A. Shipp for his assistance in running subjects.     

Performance of chronotypes on memory tests during the morning and the evening shifts

Memory consists of several phases or processes that can be influenced by many factors, including the individual's circadian rhythm and the time of day at which tests are performed. The present objective was to evaluate the performance on memory tests of different chronotypes during the morning and the evening shifts. Subjects (21 men and 26 women, between the ages of 20 and 35 yr.) were evaluated for memory and metamemory differences in the morning and in the afternoon, using a battery of neuropsychological tests composed of the Word List with Emotional Content, Visual Memory, Scale-Semantic Memory, Digit Span, Word-Pairs Associated, Verbal Fluency Test, and Metamemory questionnaire. In the evening shift, there was a statistical difference among chronotypes on the Word List with Neutral Content and on the Verbal Fluency Test. In the morning, there were no statistically significant differences; however, the morning-type subjects had higher scores on the metamemory tests (p<.01), while the evening-type subjects had higher scores in the afternoon (p<.01). In spite of their perception, on Word-Pairs Associated and Word List with Emotional Content, the subjects, independently of their chronotype, showed better performance by the evening than by the morning shift. These results highlight the importance of controlling the shift of day and chronotype in studies with the objective of exploration of human performance.     

日周期类型与心理健康

个体间表现出的昼夜节律差异现象可以从日周期类型上进行分类, 包括偏爱早睡早起的清晨型, 偏爱晚睡晚起的夜晚型以及处于两者之间的中间型。已有研究表明, 夜晚型与心境障碍、注意缺陷多动障碍和进食障碍等心理疾病有关, 而日周期类型与心理健康的关系可能受到基因、社会时差、人格等因素的影响。未来应改进研究设计和测量方法, 深入考察日周期类型与心理健康的关系及其作用机制, 以及在我国文化背景下推进日周期类型与心理健康的关系研究。     

Hope, pride, and processing during optimal and nonoptimal times of day

We examine the conditions under which the distinct positive emotions of hope versus pride facilitate more or less fluid cognitive processing. Using individuals' naturally occurring time of day preferences (i.e., morning vs. evening hours), we show that specific positive emotions can differentially influence processing resources. We argue that specific positive emotions are more likely to influence processing and behavior during nonoptimal times of day, when association-based processing is more likely. We show in three experiments that hope, pride, and a neutral state differentially influence fluid processing on cognitive tasks. Incidental hope facilitates fluid processing during nonoptimal times of day (compared with pride and neutral), improving performance on tasks requiring fluid intelligence (Experiment 1) and increasing valuation estimates on tasks requiring that preferences be constructed on the spot (Experiments 2 and 3). We also provide evidence that these differences in preference and valuation occur through a process of increased imagination (Experiment 3). We contribute to emotion theory by showing that different positive emotions have different implications for processing during nonoptimal times of day.     

Let there be no mistake! On assessment mode and the transference effect in social perception

We examined the possibility that assessment regulatory mode orientation affects the tendency to exhibit transference effects in social perception. Based on a social cognitive methodological paradigm devised by Andersen and colleagues [e.g., Andersen, Glassman, Chen, & Cole, 1996], we find that the transference effect is more pronounced when individuals’ (chronic) assessment orientation is low (vs. high). These results suggest that transference is more likely to occur when less attention is directed towards the target of perception.     

Interserial and intraserial interference processes in morning recall of mental sleep experience

This study investigated ways in which predictions from interference theory might explain partial or total failure in the morning recall of mental sleep experience (MSE) episodes reported after provoked night awakening. Interference could take place either between the contents of one MSE episode (intraserial interference) or between the contents of different MSE episodes (interserial interference) and would be more likely to affect morning recall where similar (i.e., interrelated) contents in MSEs are involved. If interference were mainly intraserial, in the morning there would be no change in the difficulty of retrieving interrelated contents, whereas, if it were mainly interserial, there would be increased difficulty in the retrieval of such contents. All the possible pairs of reports obtained by awakening 8 subjects four times in REM sleep during each of four experimental nights spaced at weekly intervals were scored for interrelated contents, using Clark's (1970) system of analysis of paired units, which operates by matching linguistic features. Results showed that interrelations in morning report pairs are as frequent as in night report pairs, maintaining the same linguistic characteristics and with little transfer of contents from one MSE to another. Overall these findings are compatible with the hypothesis that interference is primarily intraserial rather than interserial. It is consequently suggested that morning recall failure may be due to temporary blocking of retrieval.     

根据血压昼夜节律选择服药时间控制血压晨峰

根据血压昼夜节律,观察给药时间对血压晨峰的影响。256例原发性高血压患者,经24h动态血压监测分为超杓型（n＝49）、杓型（n＝127）和非杓型（n＝80）3组;各组再分为清晨服药组和晚上服药组。用药6周,比较用药前后血压昼夜节律及血压晨峰的变化,发现在改变血压昼夜节律及降低血压晨峰方面,超杓型组清晨服药优于晚上服药,非杓型组晚上服药优于清晨服药;杓型组清晨服药与晚上服药均能降低晨峰值,提示根据个体血压昼夜节律选择服药时间能更好地控制血压晨峰。