Both odor identification and ApoE-ε4 contribute to normative cognitive aging

Research indicates that apoliprotein E (ApoE) plays a role in the development of Alzheimer's disease (AD) and possibly in the cognitive decline associated with normative aging. More recently, researchers have shown that ApoE is expressed in olfactory brain structures, and a relationship among ApoE, AD, and olfactory function has been proposed. In the current analyses, we investigated the contribution of ApoE and odor identification in decline trajectories associated with normative cognitive aging in various domains, using longitudinal data on cognitive performance available from the Swedish Adoption/Twin Study of Aging. Data on both ApoE status and olfactory functioning were available from 455 individuals ranging in age from 50 to 88 years at the first measurement occasion. Odor identification was measured via a mailed survey. Cognitive performance was assessed in up to 5 waves of in-person testing covering a period of 16 years. Latent growth curve analyses incorporating odor identification and ApoE status indicated a main effect of odor identification on the performance level in three cognitive domains: verbal, memory, and speed. A main effect of ApoE on rates of decline after age 65 was found for verbal, spatial, and speed factors. The consistency of results across cognitive domains provides support for theories that posit central nervous system-wide origins of the olfaction-cognition-ApoE relationship; however, olfactory errors and APOE ε4 show unique and differential effects on cognitive trajectory features.     

Incidental sounds of locomotion in animal cognition

The highly synchronized formations that characterize schooling in fish and the flight of certain bird groups have frequently been explained as reducing energy expenditure. I present an alternative, or complimentary, hypothesis that synchronization of group movements may improve hearing perception. Although incidental sounds produced as a by-product of locomotion (ISOL) will be an almost constant presence to most animals, the impact on perception and cognition has been little discussed. A consequence of ISOL may be masking of critical sound signals in the surroundings. Birds in flight may generate significant noise; some produce wing beats that are readily heard on the ground at some distance from the source. Synchronization of group movements might reduce auditory masking through periods of relative silence and facilitate auditory grouping processes. Respiratory locomotor coupling and intermittent flight may be other means of reducing masking and improving hearing perception. A distinct border between ISOL and communicative signals is difficult to delineate. ISOL seems to be used by schooling fish as an aid to staying in formation and avoiding collisions. Bird and bat flocks may use ISOL in an analogous way. ISOL and interaction with animal perception, cognition, and synchronized behavior provide an interesting area for future study.     

Women and Natural Hierarchy in Aristotle

In this paper, I examine the frame of reference in Aristotle's Politics within which he makes claims about women and their place in his conception of politics.     

INTROMISSION FREQUENCY AND INTROMISSION DURATION IN THE MALE RAT MATING BEHAVIOR

C arlsson , S. G. & L arsson , K. Intromission frequency and intromission duration in the male rat mating behavior. Scand, J. Psychol ., 1962, 3 , 189–191.—The male rat attains ejaculation after repeatedly mounting and penetrating the receptive female. By artificially prolonging the intervals of rest separating the intromissions the male is made to ejaculate after fewer intromissions than occurs when he copulates ad libitum . It was found that the reduction in intromission frequency was accompanied by an increase in intromission duration.     

Fixation identification in centroid versus start-point modes using eye-tracking data

Fixation-identification algorithms, needed for analyses of eye movements, may typically be separated into three categories, viz. (i) velocity-based algorithms, (ii) area-based algorithms, and (iii) dispersion-based algorithms. Dispersion-based algorithms are commonly used but this application introduces some difficulties, one being optimization. Basically, there are two modes to reach this goal of optimization, viz., the start-point mode and the centroid mode. The aim of the present study was to compare and evaluate these two dispersion-based algorithms. Manual inspections were made of 1,400 fixations in each mode. Odds ratios showed that by using the centroid mode for fixation detection, a valid fixation is 2.86 times more likely to be identified than by using the start-point mode. Moreover, the algorithm based on centroid mode dispersion showed a good interpretation speed, accuracy, robustness, and ease of implementation, as well as adequate parameter settings.     

Prevalence, course, incidence, and 1-year prediction of deliberate self-harm and suicide attempts in early Norwegian school adolescents

In this survey of early Norwegian school adolescents, the prevalence, course, and incidence of self-harm behavior with or without suicide intent were examined, in addition to predictors of self-harm for a 1-year follow-up period. Lifetime prevalence rates of self-harm without suicide intent and suicide attempts were 2.9% and 3.0%, respectively, while 1-year incidence rates were 3.6% and 1.7%, respectively. In multivariate analysis, five predictors significantly differentiated self-harmers from non-self-harming adolescents. Early school adolescents having frequent or intense suicidal ideation over an extended time period and attempting self-harm repeatedly with or without suicide intent should be identified and offered treatment.     

The Developmental Leadership Questionnaire (DLQ): some psychometric properties

The development leadership model (Larsson et al., 2003), designed to introduce refinements to the transformational leadership model, has been adopted for use in the Swedish Armed Forces. The Developmental Leadership Questionnaire (DLQ) was constructed to measure important parts of the model. The main aim of the study was to evaluate some psychometric properties of the DLQ. Most analyses are based on two subsets of individuals from a sample mostly consisting of male Swedish, military officers, each of whom has rated a given leader (n = 450 and 449 respectively). A second sample consisted of Swedish military cadets (n = 141). The dimensionality was assessed with a confirmatory factor analysis. Most DLQ scales were reasonably well reproduced and showed high or acceptable internal consistency. When related to perceived results of leadership (self-rated by leaders and rated by subordinates), results from multiple regression analyses supported what could be predicted by the theoretical model. It was concluded that the DLQ has acceptable psychometric properties and that the theoretical refinements introduced to the developmental leadership model were empirically supported.     

Recollective experience in odor recognition: Influences of adult age and familiarity

We examined recollective experience in odor memory as a function of age, intention to learn, and familiarity. Young and older adults studied a set of familiar and unfamiliar odors with incidental or intentional encoding instructions. At recognition, participants indicated whether their response was based on explicit recollection (remembering), a feeling of familiarity (knowing), or guessing. The results indicated no age-related differences in the distribution of experiential responses for unfamiliar odors. By contrast, for familiar odors the young demonstrated more explicit recollection than the older adults, who produced more know and guess responses. Intention to learn was unrelated to recollective experience. In addition, the observed age differences in remember responses for familiar odors were eliminated when odor naming was statistically controlled. This suggests that age-related deficits in activating specific odor knowledge (i.e., odor names) play an important role for age differences in recollective experience of olfactory information.