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- Badinlou, Farzaneh, 1984-
(författare)
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The power of action and knowledge in episodic memory for school-aged children
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Developmental and cognitive research suggests that there are age-related differ-ences in children’s episodic memory across school ages due to the development of knowledge, which in turn affects memory strategy use and information pro-cessing over time. However, there are controversial findings related to devel-opmental patterns and factors involved in children’s episodic memory function.This dissertation studies action memory, a form of episodic memory, across school ages to explore developmental differences and children’s memory per-formance as related to different encoding conditions, retrieval modes, materi-als, and events. In study I, the effects of different encoding conditions (i.e., verbal tasks, VTs; experimenter-performed tasks, EPTs; and subject-performed tasks, SPTs) and memory tests (i.e., recall and recognition) were examined across school ages. This study found that the developmental pattern of action memory was more pronounced for enacted encoding than verbal encoding, the most pronounced in recall test than in recognition test. In study II, the recall period of enactment effects and the effects of task difficulty were investigated as functions of age and encoding conditions in school-aged children. The results revealed that enacted encoding not only outperformed verbal encoding but also that the response speed increased over the recall period, the effect being more noticeable in older than younger children. Moreover, the level of task difficulty can be regarded as an important factor affecting the pattern of memory output among school-aged children. Study III explored the effect of children’s declarative knowledge on memory performance by presenting knowledge-based cues such as objects and semantic integration items. Providing cues related to children’s prior knowledge in the encoding and test phases improved memory performance, especially in older children. The overall results indicated clear-cut developmental differences in episodic memory across school ages. Episodic memory functions differed as functions of age, encoding, testing instructions, and type of event. SPTs and EPTs can improve memory function, this improvement was more pronounced in SPTs than in EPTs. The positive impact of action memory on memory performance is discussed in terms of the cognitive mechanism, memory strategies, and information processing involved.
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| 2. |
- Herlitz, Agneta, 1962-
(författare)
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Remembering in Alzheimer's disease : utilization of cognitive support
- 1991
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present doctoral thesis was to investigate the ability of patients with Alzheimer's disease (AD) to utilize cognitive support in order to improve episodic remembering. A review of previous research indicated that most studies have failed to find beneficial effects of encoding support on memory in AD patients. The ability to utilize cognitive support (i.e., motoric activities, semantic organization, and semantic knowledge) for episodic remembering was investigated in five studies (Bäckman & Herlitz, 1990; Herlitz, Adolfsson, Bäckman, & Nilsson, in press; Herlitz & Bäckman, 1990; Herlitz & Viitanen, in press; Karlsson et al., 1989). Patients with mild, moderate, or severe AD, and normal older adults participated in the studies. On the basis of the results from these studies and the review of the literature, it was concluded that (a) AD patients, irrespective of dementia severity, perform at a lower level than normal older adults in episodic memory tasks; (b) provided that support is supplied at retrieval, AD patients may be sensitive to manipulations at encoding; (c) the strength of the encoding manipulation determines the size of the memory improvement in AD patients; and (d) depending on dementia severity, the type of encoding support also determines the magnitude of memory improvement obtained.
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| 3. |
- Nordin, Kristin
(författare)
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Aging Along the Hippocampal Axis : Structure, Function and Whole-brain Connections in Association with Memory
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hippocampus-dependent functions display marked reductions in older age, an observation that has led to the extensive study of age effects on hippocampal properties. Even though research indicates that the hippocampus is structurally and functionally heterogeneous along its longitudinal axis, its anterior and posterior regions differentially supporting episodic and spatial memory representations, few studies explicitly consider age effects in relation to axis. Relatedly, as men and women commonly differ in episodic and spatial memory performance, and sometimes also in rates of age-related hippocampal atrophy, sex could be a potential modifier of age effects. The aim of this thesis was therefore to assess age effects on the hippocampus and its role in episodic and spatial memory across young (20-35 years), middle-aged (40-50 years) and older (60-70 years) adults, adopting a longitudinal-axis approach while considering interactions with sex. Study I evaluated hippocampal volume and activation in relation to associative memory across middle-aged and older adults. Age differences in associative memory were largest in men and paralleled by smaller volumes and less activation in the anterior hippocampus. Study II assessed hippocampus-dependent network-like organization of gray matter by measures of structural whole-brain covariance. The anterior and posterior hippocampus showed shared and distinct patterns of covariance, which were qualitatively comparable across age groups. However, participants’ expression of these patterns decreased as a function of age, comparably for men and women, and showed significant associations with episodic memory. Study III investigated age effects on resting-state functional connectivity and demonstrated that both the anterior and posterior hippocampus decreased in connectivity with several brain regions across middle-aged and older adults. Memory was only associated with age-related connectivity of the posterior hippocampus: episodic memory negatively with connectivity increasing as a function of age, and spatial memory positively with connectivity that decreased. These studies demonstrate distinct effects of age on the anterior and posterior hippocampus, and show that age-related decline of these regions differentially relates to episodic and spatial memory. Overall, findings highlight the importance of explicitly considering the heterogeneity of the hippocampal axis in the assessment of its role in age-related memory decline.
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| 4. |
- Rehnman, Jenny, 1971-
(författare)
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The role of gender in face recognition
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Faces constitute one of the most important stimuli for humans. Studies show that women recognize more faces than men, and that females are particularly able to recognize female faces, thus exhibiting an own-sex bias. In the present thesis, three empirical studies investigated the generality of sex differences in face recognition and the female own-sex bias. Study I explored men’s and women’s face recognition performance for Bangladeshi and Swedish female and male faces of adults and children. Result showed sex differences, favoring women, for all face categories. Study II assessed boys’ and girls’ ability to recognize female and male faces from two age- and ethnic groups. The result demonstrated that girls recognize more faces than boys do, but that no sex differences were present for Swedish male faces. The results from Study I and II consistently demonstrate that females show reliable own-sex biases independent of whether the female faces were young, old, or of Bangladeshi or Swedish origin. In an attempt to explain the mechanisms of sex differences in face recognition and the female own-sex bias, Study III investigated men’s and women’s recognition performance for androgynous faces, either labeled “men”, “women”, or “faces”. The result showed that women told to remember “women” recognized more faces than women told to remember faces labeled “men” or “faces”, and that sex differences were present for androgynous faces, regardless of the label. Based on these findings, it is suggested that females’ attention is in particular directed towards other females, resulting in an own-sex bias. It is also suggested that there may be a difference in females’ and males’ orientation toward other individuals. This difference can have a biological base, which together with socialization may result in sex differences in face recognition.
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