Psychosocial stress and HPA functioning: no evidence for a reduced resilience in healthy elderly men

In order to investigate if HPA functioning is altered with age, the present study was conducted. Fifteen healthy elderly men (60-76 years; mean age 66.5 +/- 1.48 yrs.) and 12 younger adults (20-29 years; mean age 25.6 +/- 0.77 yrs.) collected salivary free cortisol profiles after awakening for basal HPA activity. Then, all subjects were exposed to the "Trier Social Stress Test" (TSST). This psychosocial stress protocol consists of a free speech and a mental arithmetic task of 13 minutes duration performed in front of an audience. Beside the assessment of endocrine and cardiovascular responses to the stressful task ratings of depression, mood and perceived stressfulness were obtained. Results show that younger and elderly men had similar morning cortisol profiles after awakening with both groups showing the expected rise after awakening (P=0.004). The TSST induced significant increases in ACTH, total plasma cortisol, saliva free cortisol, and heart rates (all P<0.0001). Regardless of age, both age groups showed comparable endocrine response patterns when confronted with the stressor. However, cardiovascular responses were significantly higher in younger men compared to elderly men (P=0.03). Catecholamine data revealed significant norepinephrine and epinephrine increases due to the stressor (both P<0.0001) with a trend toward elevated norepinephrine levels in elderly men (P=0.058). In sum, the investigated basal and response parameters of HPA functioning neither support the idea of a reduced resilience in healthy aged humans nor do they appear to strengthen assumptions derived from the so called "glucocorticoid cascade hypothesis".     

The interplay of memory and judgment processes in effects of aging on hindsight bias

Hindsight bias is the phenomenon that after people are presented with the correct answer to a question, their judgment regarding their own past answer to this question is biased toward the correct answer. In three experiments, younger and older adults gave numerical responses to general-knowledge questions and later attempted to recall their responses. For some questions, the correct answer was provided during recall (Experiment 1) or before recall (Experiments 2 and 3). Multinomial model-based analyses show age differences in both recollection bias and reconstruction bias when the correct judgment was in working memory during the recall phase. The authors discuss implications for theories of cognitive aging and theories of hindsight bias.     

Who Are the People Reluctant to Participate in Research? Personality Correlates of Four Different Types of Nonresponse as Inferred from Self‐ and Observer Ratings

This article outlines a typology of nonresponse biases that may occur in research based on voluntary participation and presents empirical evidence on the relationships between nonresponse and personality traits. We describe four different types of nonresponse occurring at the recruitment stage, during data collection, and at the stage of recruitment for further research. Personality correlates of all types of nonresponse were investigated using data from an online survey e-mailed to owners of personal Web sites, and observer ratings on the targets' personality were obtained. After reviewing the target persons' Web sites, observers judged complete nonrespondents as less agreeable and less open to experience than respondents. Furthermore, higher extraversion, higher openness to experience, and higher narcissism differentiated volunteers for follow-up research from nonvolunteers in both self- and observer ratings. We found only weak evidence of personality correlates of careless and selective item nonresponse. Findings show that nonresponse biases may have significant implications for representativeness in surveys and personality test norms.     

Positive affectivity and lifestyle in adulthood: do you do what you feel?

There is much evidence for the adaptive value of positive affect. Empirical work examining different facets of positive affect and their consequences for psychological adaptation remains sparse, however. This study (young, middle-aged, and older adults; N = 293) investigated the links between two dimensions of positive affect (positive involvement and pleasant affect) and two lifestyles (hedonic and growth related), each indicated by general value orientations, self-reported everyday activities, and activity aspirations. Structural equation models showed that pleasant affect and positive involvement constitute distinct dimensions evincing different age trends and relating differentially to hedonic and growth-related lifestyles. Specifically, pleasant affect, but not positive involvement, was related to a hedonic lifestyle, whereas positive involvement, and not pleasant affect, was associated with a growth-related lifestyle. These findings underline the importance of considering two dimensions of positive affect--pleasant feelings and positive involvement--separately when studying the link between affect and lifestyle.     

Adult age differences in distinctive processing: the modality effect on false recall

Age differences in distinctive processing were investigated by examining the effects of study presentation modality on false recall in younger and older adults using the Deese/Roediger and McDermott paradigm. Participants were presented with study words either visually or auditorily. Older adults did not show the typical reduction in false recall after visual, compared to auditory, study presentation (R.E. Smith & R.R. Hunt, 1998). The authors interpret these results as evidence of reduced distinctive processing on the part of older adults.     

Age differences in emotional reactivity: the sample case of sadness

Past studies have suggested that the intensity of subjective reactions to emotion-arousing stimuli remains stable, whereas the magnitude of autonomic reactions declines with age. The goal of the present studies was to investigate whether this evidence will generalize to newly edited films dealing with age-relevant themes such as the loss of loved ones. In Study 1, greater self-reported sadness was found in older than in younger adults in response to all films. Findings of Study 2, which were based on an independent sample, replicated those of Study 1. In addition, 6 indicators of autonomic nervous system activity were assessed. Young and old adults did not differ in their autonomic reactions to the films. This evidence suggests that when older people are exposed to stimuli featuring themes that are relevant to their age group, they show greater subjective and physiological reactions than would be expected on the basis of past research.     

A multinomial model of event-based prospective memory

Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory processes. The model was validated in 4 experiments. Manipulations of instructions to place importance on either the prospective memory task or the background task (Experiments 1 and 2) and manipulations of distinctiveness of prospective memory targets (Experiment 2) had expected effects on model parameters, as did a manipulation of the difficulty of prospective memory target encoding (Experiments 3 and 4). An alternative model was also evaluated.     

The dynamical foundations of motion pattern formation: stability,selective adaptation,and perceptual continuity

A dynamical model is used to show that global motion pattern formation for several different apparent motion stimuli can be embodied in the stable distribution of activation over a population of concurrently activated, directionally selective motion detectors. The model, which is based on motion detectors being interactive, noisy, and self-stabilizing, accounts for such phenomena as bistability, spontaneous switching, hysteresis, and selective adaptation. Simulations show that dynamical solutions to the motion correspondence problem for a bistable stimulus (two qualitatively different patterns are formed) apply as well to the solution for a monostable stimulus (only one pattern is formed) and highlight the role of interactions among sequentially stimulated detectors in establishing the state dependence and, thereby, the temporal persistence of percepts.