Age-related changes in grip force and dynamics of hand movement

The authors investigated whether older adults (n = 16; mean age = 65 years) increased grip force to compensate for load force fluctuations during up and down movements more than young adults did (n = 16; mean age = 24 years) and whether older and young adults exhibited similar adaptation of grip force to alterations in friction associated with changes in object surface texture. As previously reported, older adults used a higher level of grip force than young adults during static holding. Increased grip force was observed in the older group during movement. The increase was appropriate to the lower coefficient of friction estimated for the older group. In both groups, grip force was greater with a smooth than with a rough surface (the latter having the higher coefficient of friction) during static holding and during movement. Moreover, grip force modulation was equally well synchronized with load force fluctuation during movement in the two groups. The authors concluded that changes in organization of grip force with age are well adapted to change in hand-object interface properties. Elevated grip force in older adults does not necessarily signify a fundamental change in synchronizing grip force modulation with load force fluctuation.     

A review of the déjà vu experience

For more than a century, the déjà vu experience has been examined through retrospective surveys, prospective surveys, and case studies. About 60% of the population has experienced déjà vu, and its frequency decreases with age. Déjà vu appears to be associated with stress and fatigue, and it shows a positive relationship with socioeconomic level and education. Scientific explanations of déjà vu fall into 4 categories: dual processing (2 cognitive processes momentarily out of synchrony), neurological (seizure, disruption in neuronal transmission), memory (implicit familiarity of unrecognized stimuli),and attentional (unattended perception followed by attended perception). Systematic research is needed on the prevalence and etiology of this culturally familiar cognitive experience, and several laboratory models may help clarify this illusion of recognition.     

Idealization and psychoanalytic learning

Idealization is an intrinsic part of psychological maturation, but it is also a potential barrier to psychoanalytic learning, and must to some degree be outgrown if an analyst is to develop a natural authority and individual style. Unrecognized idealizations stifle analysts' engagement in the transferences of their patients, and so compromise the ability to freely experience and analyze them. Attention to real life and the lessons it teaches counterbalances the tendency to idealize and encourages lifelong psychoanalytic growth.     

Visual masking during the attentional blink: tests of the object substitution hypothesis

When 2 masked targets are presented in a rapid sequence, correct identification of the 1st hinders identification of the 2nd. Visual masking of the 2nd target plays a critical role during this 2nd-target deficit, or "attentional blink" (AB). The object substitution hypothesis (B. Giesbrecht & V. Di Lollo, 1998) predicts that late-stage visual processes involved in object substitution mediate masking of the 2nd target during AB, whereby stronger masking should produce a more severe deficit. Six experiments are presented, together testing this hypothesis. Although masking by object substitution was observed, it did not interact with the AB. An alternative hypothesis is proposed stating that mostly early-stage visual processes mediate the masking effects that are critical to the AB.     

The effects of aging and divided attention on memory for item and associative information

The present study examined how aging and divided attention influence memory for item and associative information. Older adults and younger adults working under full-attention conditions and younger adults working under divided-attention conditions studied unrelated word pairs. Memory for item information was measured by later recognition of the 2nd word in the pair, and associative information was measured by recognition of the entire pair. Both older adults in the full-attention condition and younger adults in the divided-attention condition performed more poorly than younger adults in the full-attention condition, with the deficit in associative information being greater than the deficit in item information. In addition, a differentially greater associative decrement was found for the older adults, as shown by their heightened tendency to make false-alarm responses to re-paired (conjunction) distractors. The results are discussed in terms of an age-related reduction in processing resources compounded by an age-related increase in older adults' reliance on familiarity in associative recognition memory.     

Early maternal availability and prefrontal correlates of reward-related memory

Early emotional experiences affect developing brain systems that subsequently mediate adult learning and memory in rodents. Here we test for similar effects in squirrel monkeys (Saimiri sciureus) four years after disruptions in early maternal availability. These conditions were previously shown to generate differences in emotional behavior, hypothalamic-pituitary-adrenal stress physiology, and right ventral medial prefrontal volumes determined in adulthood by magnetic resonance imaging. This report identifies in the same monkeys variability in reward-related memory on tests with a spatial reversal. Adult monkeys that more often selected locations repeatedly rewarded before each reversal had larger right ventral medial prefrontal volumes, but not hippocampal nor dorsolateral prefrontal volumes on the left or right brain side. Differences in performance were also discerned after each spatial reversal. These findings indicate that maternal availability alters developing ventral medial prefrontal brain regions involved in reward-related memory.     

Hormones and Cognition: Current Concepts and Issues in Neuropsychology

This article provides an extensive and comprehensive review of the effects of hormones on cognition. Studies detailing specific neurocognitive functions affected by variation in hormone levels across the life span are presented. Dysregulation of hormone levels is considered from models of both normal and diseased functioning. Patterns of cognitive dysfunction are described for a range of syndromes involving the neuroendocrine system, and evidence of specific neurophysiological mechanisms that can account for these findings is outlined. This review includes discussion of treatment outcomes and the permanency of endocrine-related cognitive dysfunction. The authors present a set of guidelines for clinical neuropsychologists to use for assessment of patients with neuroendocrine system dysfunction. Clinical and methodological issues in research and treatment settings are discussed.     

Inequalities in Health and Intergenerational Equity

In the popular folklore three-score-years-and-ten is treated as a fair innings for people, and thereby serves as an informal reference point for judgements about distributive justice within a community. But length of life alone is an insufficient basis for such judgements - a person's health-related quality-of-life also needs to be taken into account. If one of the objectives of public policy is to reduce inequalities in lifetime health, it will be demonstrated that this is very likely to require systematic discrimination against the older members of a community. The notion of community solidatity will also be tested, because a decision will need to be made as to whether the same fair innings applies to all members of the community, or whether some are entitled to more than others. The strength of the fair innings principle is that it brings these issues to the fore in a systematic way which should ais their resolition in a practical context.     

Perceived area and the luminosity threshold

Observers made forced-choice opaque/luminous responses to targets of varying luminance and varying size presented (1) on the wall of a laboratory, (2) as a disk within an annulus, and (3) embedded within a Mondrian array presented within a vision tunnel. Lightness matches were also made for nearby opaque surfaces. The results show that the threshold luminance value at which a target begins to appear self-luminous increases with its size, defined as perceived size, not retinal size. More generally, the larger the target, the more an increase in its luminance induces grayness/blackness into the surround and the less it induces luminosity into the target, and vice versa. Corresponding to this luminosity/grayness tradeoff, there appears to be an invariant: Across a wide variety of conditions, a target begins to appear luminous when its luminance is about 1.7 times that of a surface that would appear white in the same illumination. These results show that the luminosity threshold behaves like a surface lightness value—the maximum lightness value, in fact—and is subject to the same laws of anchoring (such as the area rule proposed by Li & Gilchrist, 1999) as surface lightness.