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We investigated the factorial structure of the Perceived Stress Questionnaire (PSQ-recent; Levenstein, Prantera, Varvo et al., 1993) in a large (N = 1516; 35-95 years) population-based Swedish sample (Nilsson, Adolfsson, Bäckman et al., 2004; Nilsson, Bäckman, Erngrund et al., 1997). Exploratory principal components analysis (PCA) was conducted on a first, randomly drawn subsample (n = 506). Next, the model based on the PCA was tested in a second sample (n = 505). Finally, a third sample (n = 505) was used to cross-validate the model. Five components were extracted in the PCA (eigenvalue1) and labeled "Demands," "Worries/Tension," "Lack of joy," "Conflict," and "Fatigue," respectively. Twenty-one out of the 30 original PSQ items were retained in a confirmatory factor analysis (CFA) model that included the five (first-order) factors and, additionally, a general (second-order) stress factor, not considered in prior models. The model showed reasonable goodness of fit [χ(2)(184) = 511.2, p0.001; CFI = 0.904; RMSEA = 0.059; and SRMR = 0.063]. Multigroup confirmatory factor analyses supported the validity of the established model. The results are discussed in relation to prior investigations of the factorial structure of the PSQ.

The study adopted CFA to investigate the factorial structure and reduce the number of items of the Cognitive Dysfunction Questionnaire (CDQ; Vestergren, Ronnlund, Nyberg, & Nilsson, 2011). The ...

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on m ...

Increasing evidence suggests a role of the immune system in modulation of cognition, but details on affected memory systems are largely lacking. We therefore aimed to study the relation between selected cytokines and subsets of memory, and the impact of age in these relations. From a random population-based sample (the Betula Prospective Cohort Study), 298 women (age 45-90) were studied in terms of episodic recall and recognition, semantic fluency and knowledge, and prospective memory. Circulating cytokines of relevance for cognition and aging were measured with ELISA. Levels of interleukin (IL)-6 and sIL-2R were significantly and negatively associated with most cognitive variables, while the opposite was true for IL-1β. Age shared substantial variance with both cytokines and memory, and turned most correlations non-significant when controlled for together with education, BMI and presence of disease. Interactions between age and cytokines were further analyzed in multiple regressions. For IL-6, significant negative interactions with age were found for semantic fluency (p

The study reports on the development of a questionnaire for assessment of adult cognitive dysfunction (CDQ). Participants in a population-based sample (65 +/- 15 years, N = 370) responded to a 90-i ...

The factorial structure of the Prospective and Retrospective Memory Questionnaire (PRMQ; Smith et al., 2000) was examined in a Swedish population based sample (N= 540, age range; 35–90 years). Conc ...

A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50-85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age.

The present study aimed at comparing participants with and without self reported musculoskeletal pain in a normal population with regard to performance on a range of tests for episodic memory, semantic memory, and other cognitive functions and to see if expected differences interacted with age. The results showed that participants with pain performed worse on a range of tasks as compared to participants without pain, and that these differences occurred regardless of age. The most robust effects of pain were displayed on tests for vocabulary and construction ability as these were the only effects that remained significant after controlling for years of education and reported depression in separate analyses. When depression and education were controlled for in the same analysis, even these effects were eliminated, suggesting interplay between pain, depressive status, and educational level in the negative effects on cognitive functioning.

This study reports the effect of an affect-focused intervention program, the Affect School, on stress, psychological symptoms, cognitive functioning and neural activity. Fifty employees in social service and education, with high levels of chronic stress, were randomly divided into a treatment (N= 27) and control (N= 23) group. Complete sets of data were available in 20 participants in the treatment group and 17 in the control group. The Perceived Stress Questionnaire assessed stress and the Symptom Check List-90 psychological symptoms before and after treatment. Episodic-memory functioning under focused and divided attention conditions was also assessed. Prior and after the Affect School, seven participants in the treatment group were studied with functional magnetic resonance imaging (fMRI) during episodic memory processing. After the Affect School there was a reduction in stress and psychological symptoms for the treatment group but not in the control group. The controls showed a reduction in episodic memory functioning whereas the performance of the treatment group remained intact. The fMRI scanning indicated a qualitative change in the neural network subserving episodic memory. These preliminary results suggest that the Affect School is effective on individuals with high stress.

Selective age-related differences in source memory relative to item memory, and individual differences in memory performance in relation to anxiety were explored with high- and low-anxious subjects screened from normal young and elderly adults. They were read false facts about the locations of well-known and unknown sights in a male or female voice. Intentional and incidental learning instructions were administered for source memory. Selective age-related deficits in source memory were observed under both encoding conditions. Higher level of anxiety was related to lower memory performance only in the old group; this relation was stronger in source recall. The findings suggest that the presence of such selectivity is unrelated to the tradeoff between item encoding and source encoding. Anxiety affects the variability, and mediates the selectivity of age effects on episodic memory.

Testing one's memory of previously studied information reduces the rate of forgetting, compared to restudy. However, little is known about how this direct testing effect applies to action phrases (e.g., "wash the car") - a learning material relevant to everyday memory. As action phrases consist of two different components, a verb (e.g., "wash") and a noun (e.g., "car"), testing can either be implemented as noun-cued recall of verbs or verb-cued recall of nouns, which may differently affect later memory performance. In the present study, we investigated the effect of testing for these two recall types, using verbally encoded action phrases as learning materials. Results showed that repeated study-test practice, compared to repeated study-restudy practice, decreased the forgetting rate across 1 week to a similar degree for both noun-cued and verb-cued recall types. However, noun-cued recall of verbs initiated more new subsequent learning during the first restudy, compared to verb-cued recall of nouns. The study provides evidence that testing has benefits on both subsequent restudy and long-term retention of action-relevant materials, but that these benefits are differently expressed with testing via noun-cued versus verb-cued recall.

It has been demonstrated experimentally that recognition of novel items is more accurate than recognition of previously familiarized items. Tulving and Kroll (1995) proposed that this effect is due to novelty detectors in the brain giving processing priority to novel information. Recently, Dobbins et al. (1998) suggested that the effect is due to source discrimination problems. In the present two experiments attempts were made to facilitate source discrimination by having different orienting tasks and materials in the familiarization and in the critical presentations. Degree of familiarization was manipulated by varying number of presentations one, two or three times. The results in Experiment 1 showed that the novelty effect increased linearly as a function of presentations in the familiarization phase. In the second experiment the difference between familiar and novel items was even more pronounced. Enactment at encoding was added as a manipulation during familiarization. The results of Experiment 2 showed that the novelty effect did increase linearly for items with nonenacted encoding (in which the familiarization and the critical phase were more similar) but not for enacted encoding. All subjects reported experiencing source discrimination difficulties in both experiments despite the measures taken to diminish them. It seems safe to conclude that source discrimination difficulties are a part of the novelty effect.

The study adopted Confirmatory Factor Analysis (CFA) to investigate the factorial structure and reduce the number of items of the Cognitive Dysfunction Questionnaire (CDQ). The analyses were based on data for a total of 1,115 participants from population based samples (mean age: 63.0 ± 14.5 years, range: 25-95) randomly split into a refinement (N = 569) and a cross-validation (N = 546) sample. Equivalence of the measurement and structural portions of the refined model was demonstrated across the refinement and cross-validation samples. Among competing models the best fitting and parsimonious model had a hierarchical factor structure with five first-order and one second-order general factor. For the final version of the CDQ, 20 items within five domains were selected (Procedural actions, Semantic word knowledge, Face recognition, Temporal orientation, and Spatial navigation). Internal consistency reliabilities were adequate for the total scale and for the subscales. Multigroup CFAs indicated measurement invariance across age and sex up to the scalar level. Finally, higher levels of cognitive dysfunction as reflected by CDQ scores were predicted by advancing age, fewer years of education, and with deficits in general cognitive functioning as reflected by scores on the Mini-Mental State Examination. In conclusion, the CDQ appears to be psychometrically sound and shows the expected relationships with variables known to be associated with cognitive dysfunction and dementia. Future studies should apply it among clinical groups to further test its usefulness.

Four experiments examined the effect of spaced repetition of study words on completion of word fragments with only one solution and word fragments with multiple solutions. Recognition was used as test of explicit memory in the first two experiments. The study words were presented either once or three times. Repetition was found to increase recognition memory substantially, and to affect fragment completion performance only marginally. This was true for both single- and multiple-solution fragments, showing that competition among responses is not critical for the magnitude of the repetition effect in fragment completion. This finding, that the repetition effect is marginal also when the type of cues provides an occasion for repetition effects to show up, suggests that the real effect of repetition on perceptual priming is borderline. It is proposed that memory from the first presentation eliminates necessary processing of items when they are re-exposed, and that the repetition effect thereby is reduced.

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on memory, health and aging. The participants were grouped into two age cohorts, 35-60 and 65-85, and studied over a period of 5 years. Episodic memory tasks concerned recognition and recall, whereas semantic memory tasks concerned knowledge and fluency. The results showed, after controlling for education, some diseases, chronological age and leisure activity as covariates, that there were significant differences between married and single individuals in episodic memory, but not in semantic memory. Married people showed significantly better memory performances than singles in both subsystems of episodic memory, that is, recall and recognition. Also, the rate of decline in episodic memory was significantly larger for singles and widowed than other groups over the 5-year time period in both age groups. The findings demonstrate that the positive relation found between marriage and health can be extended to the relation between marriage and cognitive performance. This effect might be explained by the role played by cognitive stimulation in memory and cognition.

Increasing evidence suggests a role of the immune system in modulation of cognition, but details on affected memory systems are largely lacking. We therefore aimed to study the relation between selected cytokines and subsets of memory, and the impact of age in these relations. From a random population-based sample (the Betula Prospective Cohort Study), 298 women (age 45-90) were studied in terms of episodic recall and recognition, semantic fluency and knowledge, and prospective memory. Circulating cytokines of relevance for cognition and aging were measured with ELISA. Levels of interleukin (IL)-6 and sIL-2R were significantly and negatively associated with most cognitive variables, while the opposite was true for IL-1β. Age shared substantial variance with both cytokines and memory, and turned most correlations non-significant when controlled for together with education, BMI and presence of disease. Interactions between age and cytokines were further analyzed in multiple regressions. For IL-6, significant negative interactions with age were found for semantic fluency (p0.05) and prospective memory (p0.01), and for sIL-2R in predicting semantic knowledge (p0.05), indicating an increased negative impact of these cytokines on memory with increasing age. In conclusion, the study indicates a relation between cytokines and memory that appears to be largely mediated by age, and supports the suggestion that cytokine dysregulation with higher age may interact with cognitive aging.

The study reports on the development of a questionnaire for assessment of adult cognitive dysfunction (CDQ). Participants in a population-based sample (65±15 years, N=370) responded to a 90-item pilot version covering multiple aspects of memory/cognition. Based on exploratory principal components analyses and correlations with criterion measures of cognitive functioning (MMSE, Block Design, semantic/episodic memory), 20 items loading on 6 components were selected for the final version of the questionnaire. Cronbach's α for the total score was 0.90. There was evidence of construct validity as judged by correlations between CDQ scores, objective cognitive measures, and a subjective memory measure (PRMQ). Discriminant validity was demonstrated by a low and non-significant correlation with depressive symptoms. Further evidence of construct validity was provided by correlations with age and educational attainment. In conclusion, the CDQ is promising as a self-rating screening tool for cognitive dysfunction, and will be the subject of further development and validation.

Two experiments addressed the influence of secondary task performance at encoding on recall of different features of subject-performed tasks (SPTs) involving objects (e.g., turn the wallet). In Experiment 1, memory for verbs and colors of objects was assessed, with object names serving as cues. In Experiment 2, object and color memory were assessed, with verbs serving as cues. Results from both experiments indicated a greater deterioration of memory performance under divided attention for verbal features than for colors. In addition, intention to remember did not affect performance for any feature in either experiment. The overall pattern of outcome is discussed relative to the view that encoding of verbal features of SPTs is more attention-demanding than encoding of physical task features, such as color.

Previous research has demonstrated that recall of enacted verbal commands is superior to recall of the same commands without enactment. The experiment reported explored whether the same effect would hold true in a social context as opposed to the non-social context used in previous research. The results demonstrated that this is indeed the case. Enacted verbal commands are better recalled than commands that are encoded verbally and better than commands that are encoded by means of observing them being performed. It was also demonstrated that items rated as having positive emotional value were better recalled than items rated as negative or neutral. This was true for enacted as well as for nonenacted commands. It is concluded that there is no basic difference between memory of commands enacted in the social context and memory of commands enacted in a non-social context. We discuss the data in relation to current theory of memory of actions.

There is a growing concern among health authorities that an increasing number of people in the Western world become overweight and even obese. It is well known that obesity is related to several diseases (e.g., diabetes, stroke, and high blood pressure) and that such diseases related to obesity lead to early death. It has also been discussed whether overweight and obesity in themselves or in relation to such diseases lead to cognitive decline. On the basis of data from a large, population-based, prospective study we examined three cognitive domains: episodic memory, semantic memory, and spatial ability. Two body measures were used to define normal weight and overweight, body-mass index and waist/hip ratio. Although these two body measures reveal quite different prevalence data of overweight, the associations between overweight and cognition are similar. For episodic memory, overweight interacts with age, but when controlling for hypertension, stroke and diabetes, this interaction disappears. For semantic memory, normal weight participants outperform overweight participants even after controlling for these diseases. For spatial ability, the well-established advantage for men holds for young-old and old-old normal-weight participants. For overweight participants, this advantage holds for middle-age participants only. We conclude that there is a weight-cognition relationship even after controlling for obesity-related diseases. The results are discussed in terms of possible biological mechanisms.

Two experiments are reported in which we tested the hypothesis that encoding of verbal features of subject-performed tasks or SPTs (e.g., bounce the ball, lift the spoon) is attention-demanding and effortful, whereas physical features of this memory task (e.g., color, weight) are acquired with little effort, and without deliberate encoding strategies. In Experiment 1, subjects were asked to perform a series of SPTs and were examined on recall of verbal instructions and colors of objects involved under conditions of focused or divided attention. In Experiment 2, performance of a series of SPTs was followed by recall of verbal instructions and recall of weights of objects involved. Results of both experiments indicated that recall of the verbal task component was negatively affected by requirements of dual-task performance, whereas recall of both physical task features was equally good in both encoding conditions. The obtained pattern of outcome is interpreted as supportive of the dual conception hypothesis of the nature of the encoding of action events.

The processing speed account suggests that general slowing of mental processing speed results in an overall decline, especially age-related decline, in other cognitive domains. Support for the speed account comes mainly from cross-sectional studies with participants that vary in age (age-heterogeneous samples). This study investigated how well variations in processing speed predict change of episodic recall in a longitudinal framework and examined with the Narrow Age Cohort (NAC) design. Data were obtained from Betula, a population-based longitudinal study. Both 5-year (n= 490; Time 3 - Time 4) and 10-year follow-up results (n= 608; Time 1 - Time 3) were used. In both samples, which were subjected to prospective dementia screening, we found considerably weaker associations in longitudinal data compared to cross-sectional, and also weaker associations in age-homogeneous than in age-heterogeneous samples. The results provide little support for the speed account.

The factorial structure of the Prospective and Retrospective Memory Questionnaire (PRMQ; Smith et al., 2000) was examined in a Swedish population based sample (N= 540, age range; 35-90 years). Concurrent validity was assessed by relating PRMQ to global ratings of memory. Confirmatory factor analyses of the PRMQ items indicated a superior fit of a three-factor model, with prospective and retrospective memory as orthogonal factors and episodic memory as a common factor. Furthermore, the PRMQ scales correlated with the global ratings of memory, suggesting that each rating contributed with unique variance in predicting PRMQ scores. Given differences in levels of complaints as compared with prior research (Crawford et al., 2003) norms for the Swedish version are provided. In conclusion, the present findings extend earlier work by providing additional support for the construct and concurrent validity of the PRMQ scales.

According to the novelty/encoding hypothesis (NEH; Tulving & Kroll, 1995), efficacy of encoding information into long-term memory depends on the movelty of the information. Recognition accuracy is higher for novel than for previously familiarized material. This novelty effect is not a mirror effect: the superiority of novel over familiar items is not found in the hit rates but only in the false-alarm rates. The main result in the present replication study was that novel hit rates were higher than familiar ones when the most confident responses were examined separately, and thus a mirror effect could be demonstrated for these data, for both the low- and the high-frequency words. Similarly, the word-frequency effect on hits was stronger when a stricter response criterion was applied. It was concluded that the novelty effect and the word-frequency effect are more similar to one another than has hitherto been thought.

Although bilinguality has been reported to confer advantages upon children with respect to various cognitive abilities, much less is known about the relation between memory and bilinguality. In this study, 60 (30 girls and 30 boys) bilingual and 60 (30 girls and 30 boys) monolingual children in three age groups (mean ages 8.5, 10.5 and 12.5 years) were compared on episodic memory and semantic memory tasks. Episodic memory was assessed using subject-performed tasks (with real or imaginary objects) and verbal tasks, with retrieval by both free recall and cued recall. Semantic memory was assessed by word fluency tests. Positive effects of bilingualism were found on both episodic memory and semantic memory at all age levels. These findings suggest that bilingual children integrate and/or organize the information of two languages, and so bilingualism creates advantages in terms of cognitive abilities (including memory). Some sex differences were also found in episodic memory but not in semantic memory. This episodic memory difference was found with younger children.

If a recognition test is followed by a cued recall test then the probability of recognition given recall generally follows the Tulving-Wiseman function. Despite this regularity two types of exceptions have been discovered. Both poor integration and cue overlap causes an observed value of recognition given recall that is higher than predicted. The present study explores the first type of exception by proposing and testing an analytical tool, which emanates from confidence ratings given to recall responses, for relating poor integration directly to variations in the degree of deviation from the function. It is demonstrated that very poor integration produces a deviation above the function, whereas a very good integration produces a deviation below the function. The effect of integration (and cue overlap) is explained by means of a conceptualization cue dependency. Support is also given to the notion that an enhanced variability of goodness of encoding contributes to an enhanced dependence between recall and recognition.

Three experiments are presented to demonstrate a striking empirical phenomenon not previously reported in the literature. This new phenomenon is that of perfect recall performance after incidental learning instruction with one trial only. The means taken to establish this effect was to have subjects generate aspects of each item presented at study and then at test to ask subjects to recall these to-be-remembered items when the selfgenerated aspects were re-presented. The phenomenon was first demonstrated in Experiment 1 and then replicated in Experiments 2 and 3. A few critical controls were also employed in these latter experiments. A tentative, theoretical interpretation of these findings reported was proposed. The core concepts of this interpretation are those of uniqueness and reconstruction.

The purpose of this article is to propose a conceptual frame of reference for memory research on the basis of two recent lines of development. One such key development is that of a functional orientation of memory research focusing on processing and function rather than structure and memory entities. The other line of development concerns information storage as distributed rather than localized. A functionalistic frame of reference involving a notion of distributed storage is proposed. According to this view remembering is seen as an interaction between available cognitive capabilities and demands of the task in which the individual is remembering something. Encoding is conceived of as an interaction between “affordances” of the environment and “functional dispositions” of the individual. Retrieval is seen as a re-activation of functional dispositions. The formation of unique combinations of functional dispositions plays a crucial role in obtaining perfect recall performance. The viability of the overall conceptual framework is demonstrated in three experimental studies. The development of the design and procedure for these experiments was a second purpose of this paper, namely to outline an experimental setting which could serve as a complement to computer simulations in studying notions of distributed storage.

A functional conceptualization of the modality effect is presented, i. e. of the empirical finding showing a superior short-term retention of auditorily as opposed to visually presented verbal information. This theoretical view proposes that memory performance should be regarded as a function of an interaction between specific demands of the memory task and available cognitive capabilities. This notion is contrasted with two existing interpretations of the modality effect stating larger processing or storage capacities for a hypothetical memory system when information is auditorily as opposed to visually presented. Four experiments are reported, which all demonstrate the viability of the present view: The nature of the recall difference between modalities varies as a function of the interaction between task demands and cognitive capabilities and not as a function of certain properties of a hypothetical memory system.

— Three different ways of using the concept of rehearsal were discussed. Examples were presented showing confusions in the literature due to a failure to distinguish these three definitions. A free recall experiment was conducted with the purpose of investigating three problems relating to the concept of rehearsal: (a) an unclear relationship between overt and covert repetition, (b) whether overt repetition excluded other control processes, and (c) whether a shallow repetition produces a permanent memory trace or not. Using a pronounced time pressure it was demonstrated first that overt repetition facilitated recall performance of recency items and that recall of primacy items was facilitated by covert repetition. Secondly, it was shown that overt repetition did not exclude other types of encoding. Finally, a shallow maintaining repetition did not produce a permanent memory trace. The results are interpreted as supporting a level of processing point of view rather than a multistore approach.

This study describes initial and one-year follow-up findings on verbal memory testing of two patients who sustained moderate head injuries. The two main purposes were (a) to capture the specific patterns of memory disorders shown by these two head-trauma patients, and (b) to explore the nature of the recovery of these disorders. Several episodic memory tests and semantic memory tests were employed as well as questions about autobiographical events having occurred prior to and after the trauma, and about various aspects of the accident itself causing the trauma. The main conclusions to be drawn from the study are that the memory disorders demonstrated are based on difficulties in memory organization, and that the two patients differ in the nature of the recovery of the deficits. Language: en

Recall of auditory and visually presented information was studied using three different types of material. Although auditory presentation was superior for all three types of material, the size and pattern of the effect depended upon whether the visual presentation was successive or simultaneous. Successive visual presentation reduced recall performance compared to auditory presentation considerably for real sentences, while smaller effects were obtained for noun sequences and scrambled sentences. The overall supremacy in recall of auditory presented items was reduced further when compared to a simultaneous visual presentation. In the last two experiments, all effects of modality of presentation obtained in immediate recall were replicated, but were eliminated in delayed recall. The finding that this modality effect is eliminated in delayed recall is taken to indicate that semantic aspects of the material to be remembered are by and large unaffected by mode of presentation, while more superficial aspects are the ones influenced.

The effect of exteroceptive contextual cues, presented during the conditioned stimulus (CS) and unconditioned stimulus (US) intervals, upon the later development of conditioned saccharin aversions was studied in two experiments. It was found that the presence of the contextual cues during the CS + US and CS intervals resulted in a greater degree of saccharin aversion; the presence of these cues during the US interval was relatively less important. These findings are discussed in terms of conditioning models and retrieval models derived from animal learning and human information-processing data.

Psychological and physiological aspects of emotional arousal were studied concerning their possible roles in mediating amnesia. Subjects were presented with a series of slides consisting of photographs of faces, with each face accompanied by four verbal descriptors. For half of the subjects emotional arousal was induced by means of a source not related to the stimulus material; these subjects were injected with adrenalin and presented with neutral pictures throughout the series. For the other subjects the source of emotional arousal was associated with the stimulus material. These subjects were unexpectedly presented with traumatic slides in the middle of the series. Measurements of palmar, cardiac, and cortical activity were taken continuously during stimulus presentation. Memory performance was measured by means of a cued recall test of the verbal descriptors accompanying the faces. Physiological data as well as post-experimental ratings by the subjects indicated that at the time of the study subjects under both sets of conditions were equally aroused emotionally. However, memory performance for those subjects presented with traumatic slides was clearly below the level of the subjects who were injected with adrenalin. These data suggest that amnesia is mediated by emotional arousal when the source of arousal is related to the to-be-remembered items rather than to high arousal per se (cf. Walker, 1958, 1967).