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| 2. |
- Davidson, Per, et al.
(författare)
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Sleep and the generalization of fear learning
- 2016
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Ingår i: Journal of Sleep Research. - : Wiley-Blackwell. - 0962-1105 .- 1365-2869. ; 25:1, s. 88-95
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Tidskriftsartikel (refereegranskat)abstract
- Fear conditioning is an important survival mechanism, as is the ability to generalize learned fear responses to stimuli that are similar to the original conditioned stimulus. Overgeneralization of fear learning, prominent in many anxiety disorders, is however highly maladaptive. Because sleep is involved in the consolidation of fear learning, and in active processing of information, the present study explored the effect of sleep on generalization of fear learning. Participants watched a random sequence of pictures of a small and a big circle, one of them coupled with an aversive sound. Then, after a delay period containing either a nap or wake, generalization was examined as participants watched the two circles again, together with eight novel circles that gradually varied in size between the former two. Results showed that the fear response increased as a function of similarity to the conditioned response. However, there was no difference in the degree of generalization between the sleep and the wake group.
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| 3. |
- Johansson, Eva M., 1956-
(författare)
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Det motsägelsefulla bedömningsuppdraget : En etnografisk studie om bedömning i förskolekontext
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study examines the assessment practices and discourses in Swedish preschool in times of changing principles for state control and steering. These practices and discourses are analyzed in relation to theories about state control, and about cultural and social reproduction in education. The study was conducted with an ethnographic approach in two preschools located in areas that differ in terms of socio-economic status and ethnic diversity. The results show that pre-school teachers express ambivalence towards assessment as an aspect of their work. An increased focus on children's learning and on mastery of specific assessment formats and discourses are on the one hand constructed as signs of being professional – and thus function to increase their professional status. On the other hand, by their association with school, the same features seem to conflict with the values and discourses that constitute preschool teachers' professional identity. In their talk about assessments, the preschool teachers tend to focus on how assessments should be expressed (form) rather than what they are targeting (content). Furthermore, the assessments tend to concern social and behavioral aspects rather than the children's learning. As much as promoting institutional development and children's learning, the assessment practice can thus be seen as a sort of assessment game. Finally, the results suggest that the norms and focus of assessments to some extent both indicate and reinforce the institutional culture of different preschools, thereby exposing children to different socializing messages. This is problematized in regard to the role of education to promote justice and equality.
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| 4. |
- Davidson, Per, et al.
(författare)
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A daytime nap does not increase pattern separation ability
- 2019
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Ingår i: Sleep. - 0161-8105 .- 1550-9109. ; 42:1, s. 42-42
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionA 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.Methods108 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.ResultsResults 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.ConclusionPrevious 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.
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| 5. |
- Davidson, Per, et al.
(författare)
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A daytime nap does not increase pattern separation ability
- 2019
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Ingår i: Sleep. - : Oxford University Press. - 0161-8105 .- 1550-9109. ; 42:1, s. 42-42
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Davidson, Per, et al.
(författare)
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A more generalized fear response after a daytime nap
- 2018
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Ingår i: Neurobiology of Learning and Memory. - : Elsevier. - 1074-7427 .- 1095-9564. ; 151, s. 18-27
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
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| 8. |
- Davidson, Per, et al.
(författare)
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A more generalized fear response after a daytime nap
- 2018
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Ingår i: Neurobiology of Learning and Memory. - : Elsevier BV. - 1074-7427 .- 1095-9564. ; 151, s. 18-27
-
Tidskriftsartikel (refereegranskat)abstract
- 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−) and 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.
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