Computerized cognitive training during physical inactivity improves executive functioning in older adults

The hippocampus is closely tied to spatial navigation, a central component in cognitive functioning, and critically involved in age-associated cognitive decline and dementia. This study evaluated a novel, cognitive computerized spatial navigation training (CSNT) program targeting the hippocampus, with expectation of mitigating possible cognitive decline with bed rest (BR). During a 14-day BR study with 16 healthy, older men (mean age = 60 ± 3, range = 55–65 years), half received CSNT for 12 days in 50-min sessions and half were controls (watching documentaries). This design uniquely controlled diet, sleep, and other personal and environmental activities. Although there were no cognitive declines in controls post-BR, CSNT participants demonstrated significant increases in executive/attention ability and processing speed, and continued spatial navigation testing showed improvement to 400 days post-BR. This intervention may prove useful to mitigate cognitive declines known to occur in long periods of immobilization and could have broader implications in protecting against age-related cognitive decline.     

The Ant and the Grasshopper: Adolescents’ Time Perspective,Satisfaction with Life and the Mediating Role of Hope

The present study examined the predictive role played by the three time perspective’s dimensions (Present-Hedonistic, Present-Fatalistic and Future) on the satisfaction with life and the mediational role of hope in adolescence, using cross-sectional data. Participants were 675 adolescents (333 males and 342 females), with a mean age of 17.4 years (SD = .84). Adolescents lived in Rome and its surroundings regions and attended the 3th or the 4th year of high school. A structural equation modeling was used. The results shown that Present-Hedonistic predicts directly and indirectly (through agency) the life satisfaction; Future and Present-Fatalistic predicts indirectly (through agency) the life satisfaction; the Present-Hedonistic and Future predicted the pathway, but it does not seem to play a role of mediator. This model is the same for males and females. These results offers new useful guidance to adolescents’ counsellors and educators that should endeavor to increase the hope of both Present and Future oriented adolescents.     

Uterus Transplantation: The Ethics of Using Deceased Versus Living Donors

Research teams have made considerable progress in treating absolute uterine factor infertility through uterus transplantation, though studies have differed on the choice of either deceased or living donors. While researchers continue to analyze the medical feasibility of both approaches, little attention has been paid to the ethics of using deceased versus living donors as well as the protections that must be in place for each. Both types of uterus donation also pose unique regulatory challenges, including how to allocate donated organs; whether the donor / donor's family has any rights to the uterus and resulting child; how to manage contact between the donor / donor's family, recipient, and resulting child; and how to track outcomes moving forward.     

Stress-induced salivary cortisol secretion during hypobaric hypoxia challenge and in vivo urinary thromboxane production in healthy male subjects

Few studies have assessed the effects of stress on in vivo platelet activation. In the present study, hypobaric hypoxia induced by rapid decompression during high-altitude simulated flight in a hypobaric chamber was used to evaluate the effects of environmental stress on salivary cortisol and urinary thromboxane metabolite (TXM) excretion, a noninvasive marker of in vivo platelet function. Twenty-one male aviators (mean ± SD age = 36 ± 7 years) experiencing hypoxia by removing their oxygen mask for 4-5 min during a simulated flight to 25,000 ft (7,620 m; pO(2) = 59.17 mmHg) and a matched control group of thirteen flying instructors wearing oxygen masks during the challenge, were studied. Hypobaric hypoxia induced a transient significant increase (P < 0.001) in the aviators' salivary cortisol concentration; the overall pattern of diurnal cortisol fluctuation was maintained in both groups. Urinary TXM showed a significant ～30% reduction (P < 0.01) after the chamber session in aviators exposed to hypobaric hypoxia, but not in controls. A significant inverse correlation was found between salivary cortisol and urinary TXM in aviators (r = - 0.64, P = 0.0015). Salivary cortisol was a significant predictor (P < 0.001) for urinary TXM concentrations in aviators. In conclusion, here we observed that an acute stress-induced salivary cortisol increase was associated with reduced urinary thromboxane biosynthesis, providing the first indirect evidence for an inhibitory effect of acute stress on in vivo platelet function.     

Prospective Memory Impairment in Mild Cognitive Impairment: An Analytical Review

Mild cognitive impairment (MCI) is a heterogeneous condition characterized by the presence in an otherwise healthy elderly individual of cognitive deficits involving specific domains in the absence of significant functional impairments. Reports indicate that prospective memory (PM), that is, the ability to remember to execute delayed intentions, is impaired in individuals with MCI. The present review discusses the current debate in the literature on PM functioning in MCI by focusing on the relationship between prospective retrieval and retrospective memory functioning. Analysis of the reported evidence revealed that both the prospective component and the retrospective component of PM can be impaired in MCI. Declarative memory dysfunction may account for the retrospective memory impairment, while either reduced executive abilities or a deficit of reflexive mechanisms could explain the prospective component impairment.     

Pupillary Stroop effects

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with pupillary diameter recordings: relative to non-color words, pupil diameters increased for color distractors that differed from color responses, while they reduced for color distractors that were identical to color responses. Analyses of the time courses of pupil responses revealed further differences between color-congruent and color-incongruent distractors, with the latter inducing a steep increase of pupil size and the former a relatively lower increase. Consistent with previous findings that have demonstrated that pupil size increases as task demands rise, the present results indicate that pupillometry is a robust measure of Stroop interference, and it represents a valuable addition to the cognitive scientist’s toolbox.     

Holistic processing impairment can be restricted to faces in acquired prosopagnosia: Evidence from the global/local Navon effect

Previous studies have shown that acquired prosopagnosia is characterized by impairment at holistic/configural processing. However, this view is essentially supported by studies performed with patients whose face recognition difficulties are part of a more general visual (integrative) agnosia. Here, we tested the patient PS, a case of acquired prosopagnosia whose face‐specific recognition difficulties have been related to the inability to process individual faces holistically (absence of inversion, composite, and whole–part effects with faces). Here, we show that in contrast to this impairment, the patient presents with an entirely normal response profile in a Navon hierarchical letter task: she was as fast as normal controls, faster to identify global than local letters, and her sensitivity to global interference during identification of local letters was at least as large as normal observers. These observations indicate that holistic processing as measured with global/local interference in the Navon paradigm is functionally distinct from the ability to perceive an individual face holistically.     

Compensation for subliminal timing perturbations in perceptual-motor synchronization

 It is sometimes assumed that limits of temporal discrimination established in psychophysical tasks constrain the timing information available for the control of action. Results from the five perceptual-motor synchronization experiments presented here argue against this assumption. Experiment 1 demonstrates that subliminal (0.8–2%) local changes in interval duration in an otherwise isochronous auditory sequence are rapidly compensated for in the timing of synchronized finger tapping. If this compensation is based on perception of the highly variable synchronization error (SE) rather than of the local change in stimulus period, then it could be based solely on SEs that exceed the temporal order threshold. However, that hypothesis is ruled out by additional analyses of Exp. 1 and the results of Exp. 2, a combined synchronization and temporal order judgment task. Experiments 3–5 further show that three factors that affect the detectability of local deviations from stimulus isochrony do not inhibit effective compensation for such deviations in synchronized tapping. Experiment 5, a combined synchronization and detection task, shows directly that compensation for timing perturbations does not depend on explicit detection. Overall, the results suggest that the automatic processes involved in the temporal control of action have access to more accurate timing information than do the conscious decision processes of auditory temporal judgment. Received: 19 November 1998 / Accepted: 18 March 1999