Selective sex differences in declarative memory

Sex invariance of a six-factor, higher order model of declarative memory (two second-order factors: episodic and semantic memory; and four first-order factors: recall, recognition, fluency, and knowledge) was established for 1,796 participants (35-85 years). Metric invariance of first- and second-order factor loadings across sex was demonstrated. At the second-order level, a female advantage was observed for both episodic and semantic memory. At the first-order level, sex differences in episodic memory were apparent for both recall and recognition, whereas the differences in semantic memory were driven by a female superiority in fluency. Additional tests of sex differences in three age groups (35-50, 55-65, and 70-85 years of age) indicated that the female superiority in declarative memory diminished with advancing age. The factor-specific sex differences are discussed in relation to sex differences in hippocampal function.     

Effects of age and anxiety on episodic memory: selectivity and variability

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.     

Memory bias for faces that are perceived as hostile by crime victims with acute post-traumatic stress disorder

The present study tested, and found support for, the hypotheses that crime victims with acute post-traumatic stress disorder have: (i) a general memory impairment for faces; and (ii) a memory bias for faces that they perceive as hostile, even when these faces are not arranged to show any hostile face expressions. It is suggested that crime victims with acute post-traumatic stress disorder perform worse on recognition memory due to impaired concentration, and that they allocate their limited attentional resources to the detection of hostility in others in order to avoid being victimized again. This produces a memory bias for perceived hostility even in relatively innocuous everyday interactions with others, which contributes to maintaining the sense of serious current threat that characterizes post-traumatic stress disorder.     

Sex differences in cognition are stable over a 10-year period in adulthood and old age

Sex differences in declarative memory and visuospatial ability are robust in cross-sectional studies. The present longitudinal study examined whether sex differences in cognition were present over a 10-year period, and whether age modified the magnitude of sex differences. Tests assessing episodic and semantic memory, and visuospatial ability were administered to 625 nondemented adults (initially aged 35-80 years), participating in the population-based Betula study at two follow-up occasions. There was stability of sex differences across five age groups and over a 10-year period. Women performed at a higher level than men on episodic recall, face and verbal recognition, and semantic fluency, whereas men performed better than women on a task-assessing, visuospatial ability. Sex differences in cognitive functions are stable over a 10-year period and from 35 to 90 years of age.     

Verified hormone therapy improves episodic memory performance in healthy postmenopausal women

Studies of hormone therapy (HT) and cognition have yielded conflicting results. The aim of this observational study was to examine the effect of estradiol, via serum verified HT (estradiol, estriol, progesterone) and endogenous estradiol, on 108 healthy postmenopausal women's cognitive performance. The results demonstrated that the 43 HT-users performed at a significantly higher level than non-users on episodic memory tasks and on a verbal fluency task, whereas HT-users and non-users did not differ on tasks assessing semantic memory and spatial visualization. In addition, there was a positive relationship between serum estradiol level and episodic memory performance, indicating that postmenopausal HT is associated with enhanced episodic memory and verbal fluency, independent of age and education. These observational results suggest that HT use may be sufficient to exert small, yet positive effects on female sensitive cognitive tasks. Hormone therapy compliance and formulation is discussed as confounding factors in previous research.     

Mathematical constraints and the tulving-wiseman law: A Rejoinder

Abstract

Hintzman (1991; 1992) has claimed that the reason data points approximate the recognition failure function discovered by Tulving and Wiseman (1975) is that they are mathematically constrained to do so, and the reason that a few data points do not approximate the function, but are exceptions to it, is that these data points are less subject to mathematical constraints. He has additionally argued that such exceptions are more likely with low levels of recall and strong underlying sources of positive covariance. We provide empirical evidence relevant to this mathematical model using 301 observations from a database of all relevant experimental conditions published between 1973 and 1992 (Nilsson & Gardiner, 1993). We conclude that mathematical constraints have only a minor influence on the function, not the causal role assigned to them in Hintzman's (1992) model. By our account, both the function and exceptions to it reflect a single psychological principle, the functional effectiveness of contextual cues.     

Sex Differences in Cognition are Stable Over a 10-Year Period in Adulthood and Old Age

ABSTRACT

Sex differences in declarative memory and visuospatial ability are robust in cross-sectional studies. The present longitudinal study examined whether sex differences in cognition were present over a 10-year period, and whether age modified the magnitude of sex differences. Tests assessing episodic and semantic memory, and visuospatial ability were administered to 625 nondemented adults (initially aged 35–80 years), participating in the population-based Betula study at two follow-up occasions. There was stability of sex differences across five age groups and over a 10-year period. Women performed at a higher level than men on episodic recall, face and verbal recognition, and semantic fluency, whereas men performed better than women on a task-assessing, visuospatial ability. Sex differences in cognitive functions are stable over a 10-year period and from 35 to 90 years of age.     

Recall of Subject-Performed Tasks,Verbal Tasks,and Cognitive Activities Across the Adult Life Span: Parallel Age-Related Deficits

Motor activity during encoding of verbal information has been suggested to reduce age differences in episodic memory. Here we examined memory for sentences encoded with enactment (SPTs, subject-performed tasks) or without enactment (VTs, verbal tasks) in a population-based sample consisting of 10 groups ranging in age from 35 to 80 years (N = 1000). Memory performance was assessed by immediate free- and category-cued recall. Degree of clustering was measured by the adjusted ratio of clustering score. Recall of cognitive activities served as a complementary measure of memory for performed tasks. Sentence recall showed a gradual decline across age, of about the same magnitude for SPTs and VTs, in both free and cued recall. Clustering in free recall was higher for SPTs than for VTs, but there were no age differences in clustering. A pattern of gradual decline from age 35 was observed also in activity recall, regardless of whether the activities involved motor activity or not. Across the memory measures, differences in education accounted for all of the age-related variance in performance among the younger (35-55 years) but not the older groups (60-80 years), suggesting that genuine aging effects in these measures are more prominent in old age. Together, the results indicate that age differences in episodic memory, in line with most, if not all, types of encoding support, generalize across the performed/non-performed distinction.     

Clinical Validation of the Swedish Version of the Quality of Life Inventory in Crime Victims with Posttraumatic Stress Disorder and a Nonclinical Sample

The Swedish version of the Quality of Life Inventory (QOLI) was cross-culturally validated with a crime victim sample (N = 53) with posttraumatic stress disorder (PTSD) and a nonclinical group (N = 100) with no lifetime and current psychiatric disorder from the general population in the Stockholm county of Sweden. The QOLI showed excellent internal consistencies in the clinical and the nonclinical sample. In addition, PTSD participants displayed a significantly lower self-perceived quality of life in 13 out of 16 domains of life than the nonclinical individuals. Furthermore, the QOLI was inversely correlated with interview and self-report measures of PTSD symptoms, depression, and anxiety. Overall, the results support the utility of the Swedish QOLI version as a potentially useful measure of self-perceived quality of life in Swedish clinical and nonclinical samples. The results are discussed in relation to the Swedish cross-cultural validation of the QOLI, methodological limitations and future directions.     

Examination of the processing speed account in a population-based longitudinal study with narrow age cohort design

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.