Short-term memory performances during sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome

Both working and immediate memories were assessed every 4h by specific short-term memory tasks over sustained wakefulness in 12 patients with obstructive sleep apnea and hypopnea syndrome (OSAHS) and 10 healthy controls. Results indicated that OSAHS patients exhibited lower working memory performances than controls on both backward digit span and complex Sternberg tasks. Speed and accuracy on Sternberg tasks were affected by memory load in both groups. However, immediate memory was not impaired in OSAHS patients. Diurnal and nocturnal SaO(2) were correlated with speed and accuracy high-speed memory scanning performance on Sternberg tasks in patients. These results suggest specific working memory deficits associated with OSAHS over sustained wakefulness with a possible deficiency in the central executive responsible for the higher information processing, in addition to a potentially insufficient storage capacity. Among OSAHS patients, working memory ability involved in high-speed memory scanning may be impaired by chronic hypoxemia.     

Diagnostic test evaluation of a nasal flow monitor for obstructive sleep apnea detection in sleep apnea research

In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea (OSA), 34 patients referred for polysomnography were studied at home for three consecutive nights with the monitor. The mean age of subjects (+/-SD) was 41.9+/-10.3 years, and their mean apnea-hypopnea index (AHI) was 31.5+/-27.2. The difference between the average AHI from three nights at home on the monitor and the polysomnogram (PSG) result was 1.8+/-17.1. The area under the receiver operating characteristic curve (AUC) for PSG AHI > or = 10 was .96. With a threshold AHI of 18 on the flow monitor, sensitivity was .92, specificity .86, positive predictive value .96, and negative predictive value .75. For detecting severe OSA (AHI > or = 30), the AUC was .85. With knowledge of appropriate thresholds and the pretest risk of OSA, the flow monitor can be used to detect or exclude OSA for sleep-related research, as well as to identify severe cases needing priority for further evaluation.     

The effects of sleep on episodic memory in older and younger adults

Evidence on sleep-dependent benefits for episodic memory remains elusive. Furthermore we know little about age-related changes on the effects of sleep on episodic memory. The study we report is the first to compare the effects of sleep on episodic memories in younger and older adults. Memories of stories and personal events were assessed following a retention interval that included sleep and following an equal duration of wakefulness. Both older and younger adults have superior memory following sleep compared to following wakefulness for both types of material. Amount of forgetting of personal events was less during wakefulness in older adults than in younger adults, possibly due to spontaneous rehearsal. Amount of time spent sleeping correlated highly with sleep benefit in older adults, suggesting that quantity of total sleep, and/or time spent in some stages of sleep, are important contributors to age-related differences in memory consolidation or protection from interference during sleep.     

Obstructive sleep apnea syndrome: autobiographical memory predicts the course of depressive affect after nCPAP therapy

Although nCPAP therapy has proven to be efficient at removing symptoms of obstructive sleep apnea syndrome (OSAS), recovery from depression frequently remains unsatisfactory. Other studies have shown that recall of autobiographical memories (AM) is a psychological vulnerability marker for depression, and also have shown its predictive power for the course of depression. It is therefore hypothesized that AM also predict the course of depressive affect in OSAS patients. Fifty-four consecutively admitted OSAS patients received standard nCPAP therapy. Specificity of AM assessed at the beginning of treatment was used as a predictor in a regression analysis, and the extent of recovery from depression over a follow-up period of between six to nine weeks served as the criterion variable. The results supported the hypothesis that patients who were able to recall more specific AM in response to positively valenced cue words showed a more substantial recovery from depression. This has important treatment implications.     

Psychological morbidity, illness representations, and quality of life in female and male patients with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a sleep-related breathing disorder that affects both women and men. The aim of this study was to characterize and investigate the differences in terms of anxiety, depression, illness perception, and quality of life between female and male OSAS patients from a total of 111 patients (33 women and 78 men) who were recently diagnosed with OSAS in an outpatient clinic of a University Hospital in Portugal. They underwent a standardized protocol that included evaluation to assess of psychological morbidity (anxiety and depression - Hospital Anxiety and Depression Scale), illness representations (Brief Illness Perception Questionnaire), and quality of life (Sleep Apnea Quality of Life Index). The most significant differences between female and male OSAS patients result of apnea/hypopnea index (AHI), after controlling for body mass index (p?相似文献   

The role of episodic and semantic memory in episodic foresight

In this paper we describe a special form of future thinking, termed “episodic foresight” and its relation with episodic and semantic memory. We outline the methodologies that have largely been developed in the last five years to assess this capacity in young children and non-human animals. Drawing on Tulving's definition of episodic and semantic memory, we provide a critical analysis of the role that both types of memory might have on the episodic foresight tasks described in the literature. We conclude by highlighting some unanswered questions and suggesting future directions for research that could further our understanding of how memory is intimately connected to episodic foresight.     

Metamemory and memory efficiency: Implications for student learning

Judgments of learning (JOLs) are metamemory judgments about the likelihood of remembering later an item that we are currently studying. Much research has documented that JOLs are accurate at discriminating easy from difficult items (resolution), but often fail to account for other factors such as the advantages of retrieval practice, overlearning, spacing, and desirable difficulty, thus resulting in poor calibration. This implies that JOLs should not be used to determine how long or in what manner to study, although they can be used to determine what to study. To counter poor calibration, explicit metamemory knowledge can be learned and applied in order for students to become more efficient learners. Our goal is to focus on how metamemory influences decisions about studying, and how we might use metamemory to improve our learning efficiency.     

Retrieval processing and episodic memory

The emergence of brain imaging has had a major impact on research into the cognitive and neural bases of human memory. An area in which this impact has been particularly strong is retrieval processing - the processes engaged when attempting to retrieve information during a memory test. Several different classes of retrieval process - such as 'mode', 'effort' and 'success' - have been invoked to account for findings from neuroimaging studies of episodic retrieval. In this article we discuss how these different kinds of process, along with a fourth kind associated with 'retrieval orientation', can be investigated in brain imaging experiments. We then review studies of retrieval processing, and assess how well their designs match up to our proposed criteria for dissociating the neural correlates of different classes of retrieval process. We conclude that few studies have used designs that permit these different kinds of process to be independently identified, and that presently there is little evidence to indicate which kinds of processing can be fractionated in terms of their neural correlates.     

Vantage point in episodic memory

University undergraduates undertook a series of manual tasks (e.g., shaping objects out of clay) and later recalled the experiences they had while doing so from either afield or anobserver vantage point. In the former case, the subjects mentally reinstated the original task environment as if they were seeing it again through their own eyes; in the latter condition, the original task environment was envisioned from the perspective of a detached spectator. Analysis of the subjects’ recollections revealed marked differences in the contents of field and observer memories. For instance, whereas field memories afforded richer accounts of the affective reactions, physical sensations, and psychological states that the subjects experienced as they performed the tasks, observer memories included more information about how the subjects looked, what they did, or where things were. Discussion focuses on prospects for future research whose aim would be to investigate the forensic and clinical implications of the field/observer distinction.     

Gender differences in episodic memory

The relationship between gender and memory has been largely neglected by research, despite occasional studies reporting gender differences in episodic memory performance. The present study examined potential gender differences in episodic memory, semantic memory, primary memory, and priming. Five hundred thirty women and 470 men, randomly sampled from the city of Umeå, Sweden, 35–80 years of age, participated in the study. There were no differences between men and women with regard to age or education, or on a measure of global intellectual functioning. As has been demonstrated previously, men outperformed women on a visuospatial task and women outperformed men on tests of verbal fluency. In addition, the results demonstrated that women consistently performed at a higher level than did men on the episodic memory tasks, although there were no differences between men and women on the tasks assessing semantic memory, primary memory, or priming. The women’s higher level of performance on the episodic memory tasks could not be fully explained by their higher verbal ability.     

Retrieval-induced forgetting in episodic memory

Participants learned the locations of 12 stimuli that were uniquely colored but could be grouped by shape (4 circles, 4 triangles, 4 crosses). Following the study, a retrieval-practice phase required participants to recall the colors of a subset of the stimuli (i.e., 2 circles, 2 triangles) using shape and location as cues. In a final test, participants recalled the colors of all 12 stimuli. Compared with the control set of stimuli (i.e., 4 crosses), memory was facilitated for practiced items but impaired for related items, which were not practiced but shared the same shape group. Across experiments, retrieval-induced forgetting was observed for different perceptual groupings and for different cuing procedures. The effect, however, required retrieval of information during the interpolated phase. Providing extra presentations did not disrupt memory for related items.     

Temporal clustering and sequencing in short-term memory and episodic memory

A model of short-term memory and episodic memory is presented, with the core assumptions that (a) people parse their continuous experience into episodic clusters and (b) items are clustered together in memory as episodes by binding information within an episode to a common temporal context. Along with the additional assumption that information within a cluster is serially ordered, the model accounts for a number of phenomena from short-term memory (with a focus on serial recall) and episodic memory (with a focus on free recall). The model also accounts for the effects of aging on serial and free recall, apparent temporal isolation effects in short- and long-term memory, and the relation between individual differences in working memory and episodic memory performance.     

Decision making is affected in obstructive sleep apnoea syndrome

We assessed decision making in 20 patients newly diagnosed with obstructive sleep apnoea (OSA) and 20 healthy controls with the Iowa Gambling Task (IGT), which evaluates the ability to learn to sacrifice immediate rewards in favour of long‐term gains. A standard neuropsychological battery was administered. Switching scores tended to be lower in patients. Patients persisted in selecting risky decks throughout the IGT, whereas controls behaved normally. Performance was correlated with hypoxaemia. Brain regions underlying decision making may be affected by OSA‐related hypoxaemia.     

Disjunction and conjunction fallacies in episodic memory

It has recently been found that episodic memory displays analogues of the well-known disjunction and conjunction fallacies of probability judgement. The aim of the present research was, for the first time, to study these memory fallacies together under the same conditions, and test theoretical predictions about the reasons for each. The focus was on predictions about the influence of semantic gist, target versus context recollection, and proactive versus retroactive interference. Disjunction and conjunction fallacies increased in conditions in which subjects were able to form semantic connections among list words. In addition, disjunction fallacies were increased by manipulations that minimised proactive interference, whereas conjunction fallacies were increased by manipulations that minimised retroactive interference. That pattern suggests that disjunction fallacies are more dependent on target recollection, whereas conjunction fallacies are more dependent on context recollection.     

Metamemory in temporal lobe epilepsy: Self-monitoring of memory functions

Temporal lobe seizure patients and control subjects participated in an investigation of metamemory. The two-part study explored the individual's perception of memory abilities for both encoding and retrieval. Experiment I addressed self-monitoring of encoding through a study of prediction of memory span. Experiment II explored self-monitoring of retrieval through a study of "Feeling of Knowing." The results indicate that left and right temporal lobe seizure patients tend to overestimate their memory capacities, in comparison with normal controls, and that self-monitoring tends to be less accurate for material (verbal or nonverbal) mediated by side of lesion. The potential impact of inaccurate memory monitoring on the memory dysfunction observed in seizure patients is discussed.     

Metamemory, memory performance, and causal attributions in gifted and average children

Fifth and seventh graders who had been teacher-selected as high- or average-achieving were tested on the Kognitiver F?higkeits Test, a standardized test of intellectual abilities for German children. Children who met preestablished criteria as gifted or average were then tested on measures of metacognitive knowledge, attributional beliefs, and performance on a sort recall task. Results indicated ability-related differences in metamemory and sort recall performances. Responses to the attributional questionnaires also varied systematically according to ability: gifted children were more likely to attribute their academic successes to high ability than were average children, who showed a stronger belief in the importance of effort in determining task outcomes. Causal modeling analyses illustrated the strength of metacognitive knowledge as a performance predictor on the memory task, especially for average children. Results are discussed in terms of the value of metacognitive theory in understanding individual performance differences.     

Variation in working memory capacity and temporal-contextual retrieval from episodic memory

Unsworth and Engle (2007) recently proposed a model of working memory capacity characterized by, among other things, the ability to conduct a strategic, cue-dependent search of long-term memory. Although this ability has been found to mediate individual variation in a number of higher order cognitive tasks, the component processes involved remain unclear. The current study was designed to investigate individual variation in successfully retrieving information from episodic memory by examining various aspects of the retrieval process. Both high- and low-working memory capacity participants were found to initiate recall in a similar fashion; however, low-working memory capacity participants did not show the classic asymmetry in their conditional-response probabilities that is typically observed. Overall, the retrieval deficits observed in low-working memory capacity individuals appear to be rooted in their inability to use the products of retrieval to further aid their search.     

Metamemory,distinctiveness, and event-related potentials in recognition memory for faces

A neglected topic in metamemory research is the ability of subjects to predict their own recognition performance for faces. We investigated whether subjects can make such judgments of learning (JOL) for unfamiliar faces and whether JOLs relate to facial distinctiveness, a powerful determinant of face recognition. One group of subjects made JOLs, and a second group rated the same faces for distinctiveness; subsequently, both groups tried to recognize these faces among new faces. There was significant prospective metamemory for faces that appeared to be based on facial distinctiveness. Both prospective metamemory and distinctiveness ratings related to long-lasting effects in event-related brain potentials (ERPs), closely resembling an ERP component that predicted face recognition. Therefore, the brain processes underlying JOLs, distinctiveness, and recognition memory for faces appear to be intimately related.     

Relationship quality of persons with obstructive sleep apnoea syndrome

In the field of sleep disorders, the quality of couple relationship is arousing increasing attention, given its implications for quality of life and treatment adherence. The aim of the present study was to evaluate relationship quality in a sample of treated or untreated patients with Obstructive Sleep Apnoea Syndrome. Eighty-seven patients were recruited in a hospital-based Centre for Sleep Medicine. Subjects were administered the Dyadic Adjustment Scale (DAS) to evaluate relationship quality, and the Epworth Sleepiness Scale (ESS). Apnoea-hypopnoea indexes (AHI) were collected through nocturnal polysomnography or home testing with a portable monitoring device. Although the DAS average scores were similar to local normative values, relationship quality was significantly lower in the untreated patients when compared with the ones treated. The ESS scores showed a negative correlation with many DAS scores, whereas no significant correlation emerged for AHI. Such data suggest a significant impact of perceived sleep apnoea symptoms on marital satisfaction, even though in the absence of striking differences between the whole sample and the general population.