Ingegerd Carlsson’s research while affiliated with Lund University and other places

Sleep has been found to have a beneficial effect on memory consolidation. It has furthermore frequently been suggested that sleep does not strengthen all memories equally. The first aim of this review paper was to examine whether sleep selectively strengthens emotional declarative memories more than neutral ones. We examined this first by reviewing the literature focusing on sleep/wake contrasts, and then the literature on whether any specific factors during sleep preferentially benefit emotional memories, with a special focus on the often-suggested claim that rapid eye movement sleep primarily consolidates emotional memories. A second aim was to examine if sleep preferentially benefits memories based on other cues of future relevance such as reward, test-expectancy or different instructions during encoding. Once again, we first focused on studies comparing sleep and wake groups, and then on studies examining the contributions of specific factors during sleep (for each future relevance paradigm, respectively). The review revealed that although some support exists that sleep is more beneficial for certain kinds of memories based on emotion or other cues of future relevance, the majority of studies does not support such an effect. Regarding specific factors during sleep, our review revealed that no sleep variable has reliably been found to be specifically associated with the consolidation of certain kinds of memories over others based on emotion or other cues of future relevance.

The study explored to what extent dreams have been perceived as being helpful in waking life. More specifically, for “important” waking life (conscious) decision-making, the solving of emotional or nonemotional (practical/technical/work-related) problems, forming/changing an attitude about something or somebody, or a conscious behavioral change of the dreamer (N = 667). On a general level, 62,1% of participants indicated that dreams at some point had been of help or good use (regression analysis found a strong association with dream attitude, measured on Dream Attitude Scale [DAS]). Most often mentioned areas of help were creative input (55,8%) and emotional problem-solving (52,9%). There was a positive association between dream attitude (DAS) and emotional problem-solving and creative input. In all, 8.9% of participants reported that a “dream had influenced an important decision” (e.g., leaving a job, moving, buying a house, or leaving the partner). A regression analysis again indicated that a more positive attitude toward dreams (DAS) was associated with dreams influencing important decisions. Higher dream recall was also associated with all mentioned aspects.

Sleep has been found to have a beneficial effect on memory consolidation. It has furthermore frequently been suggested that sleep does not strengthen all memories equally. The aim of this literature review was to examine the studies that have measured whether sleep selectively strengthens certain kinds of declarative memories more than others, depending on such factors as emotion, reward, test-expectancy or different instructions during encoding. The review of this literature revealed that although some support exists that sleep is more beneficial for certain kinds of memories, the majority of studies does not support such an effect. A second aim of this review was to examine which factors during sleep that have been found to selectively benefit certain memories over others, with a special focus on the often-suggested claim that rapid eye movement sleep primarily consolidates emotional memories. The review of this literature revealed that no sleep variable has been reliably found to be specifically associated with the consolidation of certain kinds of memories over others.

Introduction A large body of studies has showed that the ability to learn new information is impaired when we are sleep deprived. Pattern separation (PS), the ability to form distinct memories for events that are highly similar and share overlapping features, has also previously been found to be impaired by sleep deprivation. In the present study, we examined if a daytime nap would increase PS performance. Methods 108 young healthy participants came to the lab in the morning and completed the Mnemonic Similarity Task (MST). This task starts with an encoding phase where participants view images of common everyday objects and are asked to classify them as indoor or outdoor objects. During a subsequent memory test, participants view three different kinds of objects; ‘old’ objects that were also present during the encoding phase, ‘new’ objects that have not been seen before, and ‘lure’ objects that are similar to, but not exactly the same as, objects viewed during encoding. The task of the participants during the re-test is to say if the objects presented are ‘old’, ‘new’ or ‘similar’. This test gives two different outcome measures: General Recognition (GR) - the ability to separate old objects from new ones, and PS - the ability to separate similar objects from old ones. After this task, participants were randomly allocated to either a sleep or a wake group. The sleep group had a two-hour nap opportunity and the wake group spent an equal amount of time resting. After this delay interval, participants completed the MST for a second time with a new set of images. Results Results revealed no support for sleep in increasing either GR or PS ability. Within the sleep group, there were no correlations between changes in PS ability and time spent in any sleep stage. Conclusion Previous studies that have found a role of sleep for PS ability has done so using larger manipulation of sleep. Based on the present study however, just a short daytime nap does not seem to have any effect on PS ability. Support (If Any)

The effect of napping versus wakefulness was studied on primed and repeated Remote Associate Tests (RATs) and on divergent creativity tests. The participants were 42 students from the USA, studying international courses at a Swedish university. The hypotheses for the RATs were (1), when the correct answers were primed before the nap, the RAT should be solved better for those who entered REM sleep, compared to those with no REM sleep or a resting condition; and (2), when retested the RAT should be solved better after a nap than after rest. For the creativity tests, hypothesis (3) was that creativity should be higher after the nap than after rest. Hypothesis 1 and hypothesis 3 were not supported. Hypothesis 2 was supported in an ANOVA. The REM group improved more than the rest group on the repeated RAT. Also, the No-REM and rest groups differed, strengthening the importance of both REM and No-REM sleep for creative problem-solving.

The aim of this study was to examine how a daytime nap affected the consolidation of fear learning. Participants first underwent fear conditioning during which they were exposed to a large and a small circle. One of these was repeatedly paired with an electric shock (making it the CS+), whereas the other circle was never paired with the shock (the CS-). After a delay interval containing either a nap or wake, participants again viewed the CS+ and the CS- intermixed with eight novel circles that varied in size between the two stimuli seen before, as well as a blue triangle that served as a novel stimulus without prior fear relevance. We examined both fear retention (the difference between the CS+ and the CS-) as well as fear generalization (responses to the novel stimuli based on their similarity to the original CS+). Contrary to previous studies, results from the participants who acquired a differentiated fear response during the acquisition phase revealed that the wake group showed significantly larger skin conductance responses to the CS+ compared to the CS-, whereas no such difference was present in the sleep group. These results were not driven by differences in explicit memory or by differences in general reactivity. Analyzing responses to the novel stimuli revealed a tendency towards a more generalized response in the sleep group, with no differences between the CS+ and any other stimulus, whereas the wake group showed increased responses to the stimuli depending on their similarity to the original CS+. This effect was however only present when controlling for baseline differences in worry.

This study investigates the impact of an intervention of playful improvisational theater on organizational creativity. Teams from nine participating organizations (N = 93) completed pre- and post-test measures of adult playfulness, workplace playfulness, individual creativity, group creativity, and psychological safety. Group creativity was assessed with the newly developed test Distributed Creativity in Organizational Groups. The intervention group (n = 50) participated in improvisation training, whereas the control group (n = 43) did not. After the intervention, the intervention group reported higher scores of workplace playfulness, individual creativity, and group creativity compared to the control group. Individual creativity was positively correlated with adult playfulness. No differences were found for psychological safety. The findings suggest that organizational playfulness can be increased with brief interventions and that play is a promising enhancer of organizational creativity.

The aim of this study was to examine how the memory of fear conditioning is affected by a daytime nap. We examined both the retention of the actual fear learning as well as how participants reacted to other novel stimuli, not seen before, depending on their similarity to the original CS+. This was examined using the Lissek paradigm for measuring generalization of fear learning. Participants first underwent cued fear conditioning during which they were exposed to a large and a small circle where one of these was repeatedly paired with an electric shock (CS+) whereas the other circle was never paired with the shock (CS-). At a re-test after a delay interval containing either a nap or wake, participants once again viewed the CS+ and the CS-. They were additionally presented with eight novel circles that varied in size between the two stimuli seen before, as well as a blue triangle that served as a novel stimulus without prior fear relevance. Contrary to previous studies, results from the participants who acquired a differentiated fear response during conditioning revealed preserved fear memory after wake, with higher SCRs to the CS+ compared to the CS-, whereas such a difference was no longer present in the sleep group after the delay interval. Analyzing responses to the stimuli not seen before revealed a trend towards a more generalized response in the sleep group, with no differences between the CS+ and any other stimulus, whereas the wake group showed increased responses to the stimuli depending on their similarity to the original CS+. This was not driven by differences in explicit veridical memory, as evident by the lack of differences in the subjective ratings, or by differences in general physiological reactivity.

The study investigated subjective theories of dream function (why do we dream)-measured as level of agreement with selected prescientific and contemporary views of science (N = 667) and thus explored differences in dream attitude with respect to age, educational level, and sex. A factor analysis revealed 3 factors. One can be described as seeing dreams as meaningful information processing (memory consolidation, sorting inputs, and solving problems), a 2nd included prescientific dream theory (dreams as messages from outside and/or from deceased, or dreams as prophecies). A 3rd factor included viewing dreams as insignificant products of the brain (random chemical signal interpretation and garbage products of the brain). Factor 1 was highly related to dream attitude-the more generally approving of dreams and dreaming, the more participants would regard dreams as meaningful information processing. Factor 2 was related to sex (women being more approving) and negatively related to level of education. Factor 3 was negatively related to the dream attitude scale but positively related to dream recall, which seemed counterintuitive. This could be seen as a way of explaining the often irrational content of dreams that participants were then able to recall. Women had a more supportive attitude toward dreams and dreaming. (PsycINFO Database Record