The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge because it is influenced by the upstream drainage network, the surrounding land, the riparian zone, and - in the case of migrating aquatic fauna - downstream reaches. Such prerequisites are hardly ever met. Immediate action is needed where opportunities exist to set aside intact lake and river ecosystems within large protected areas. For most of the global land surface, trade-offs between conservation of freshwater biodiversity and human use of ecosystem goods and services are necessary. We advocate continuing attempts to check species loss but, in many situations, urge adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods in order to provide a viable long-term basis for freshwater conservation. Recognition of this need will require adoption of a new paradigm for biodiversity protection and freshwater ecosystem management - one that has been appropriately termed 'reconciliation ecology'.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/96AA265E3D88C95FB802E7A73CCB4332/S1464793105006950a.pdf/div-class-title-freshwater-biodiversity-importance-threats-status-and-conservation-challenges-div.pdf

Freshwater biodiversity: importance, threats, status and conservation challenges

Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

http://download.neurosky.com/docs/papers/bcq/Klimesch_1999_EEG_alpha_and_theta_oscillations_reflect_cognitive_and_memory_performance.pdf

EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis

In the 20 years since zebra mussels (Dreissena polymorpha) first appeared in North America, they have become one of our most widespread and abundant freshwater animals, and have fundamentally transformed freshwater food webs and biogeochemistry. Indeed, few human impacts on North American fresh waters have been greater or more far-reaching than the arrival of this single species. Nevertheless, ecological research has been uneven, and important research questions remain unanswered, especially concerning the long-term, large-scale effects of the invasion. Economic impacts have also been incompletely estimated, although they already exceed $100 million. We know little about the extent to which large outreach programs about zebra mussels have changed public knowledge, attitudes, or behaviors, and there are still substantial gaps in policies to curb the establishment, spread, and impacts of species like zebra mussels. Scientific, educational, and policy responses to the zebra mussel invasion highlight our successes and limitations concerning alien species in general.

https://www.jstor.org/stable/pdfplus/25595088.pdf

Twenty years of zebra mussels: lessons from the mollusk that made headlines

Approximately 50% of streamwater dissolved organic C (DOC) disappeared from interstitial water moving along a hyporheic flowpath below a gravel bar. Concurrent decreases in oxygen and increases in dissolved inorganic C (DIC) indicate metabolism of streamwater-derived DOC by hyporheic microbes. Loss of - 100 PM DOC would account for 24-39% of the oxygen depletion and DIC accumulation. Sediments were incubated with DOC collected from the stream channel and two wells along the flowpath to examine whether streamwater and hyporheic DOC could support growth of sedimentary bacteria. Streamwater and hyporheic DOC collected from the upstream end of the flowpath stimulated higher bacterial growth rates and supported higher biomass than hyporheic DOC collected from the downstream end. The supply of streamwater-derived DOC is a significant source of C for hyporheic sediment microorganisms, and these organisms are capable of using about half the DOC contained in streamwater.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1993.38.7.1493

Metabolism of streamwater dissolved organic carbon in the shallow hyporheic zone

Only a small proportion of exotic species invasions give rise to hyper-successful nuisance species, but those that do have dramatic negative impacts on ecosystems, such as the displacement of native species and disruption of native food webs. For a native predator, such changes may mean a major transformation in its resource base and a decline in its fitness. However, native predators may adapt to become more effective at feeding on exotic prey, either rapidly, via existing phenotypic plasticity, or more slowly, via natural selection. Despite a rapidly growing number of publications on the importance of species invasions as a driver of contemporary evolution in both invading and native species, we know little about how the arrival of exotic prey affects native predators. We propose that native predators could be important in regulating the long-term dynamics of invading species and, consequently, that the overexploitation of predators could facilitate biological invasions.

/pdf/native-predators-and-exotic-prey-an-acquired-taste-2af9r6qsx3.pdf

Native predators and exotic prey –an acquired taste?

Theory suggests that driving should be impaired for any motorist who is concurrently talking on a cell phone. But is everybody impaired by this dual-task combination? We tested 200 participants in a high-fidelity driving simulator in both single- and dual-task conditions. The dual task involved driving while performing a demanding auditory version of the operation span (OSPAN) task. Whereas the vast majority of participants showed significant performance decrements in dual-task conditions (compared with single-task conditions for either driving or OSPAN tasks), 2.5% of the sample showed absolutely no performance decrements with respect to performing single and dual tasks. In single-task conditions, these "supertaskers" scored in the top quartile on all dependent measures associated with driving and OSPAN tasks, and Monte Carlo simulations indicated that the frequency of supertaskers was significantly greater than chance. These individual differences help to sharpen our theoretical understanding of attention and cognitive control in naturalistic settings.

/pdf/supertaskers-profiles-in-extraordinary-multitasking-ability-55wzus5ch3.pdf

Supertaskers: Profiles in extraordinary multitasking ability.

Adults and children are spending more time interacting with media and technology and less time participating in activities in nature. This life-style change clearly has ramifications for our physical well-being, but what impact does this change have on cognition? Higher order cognitive functions including selective attention, problem solving, inhibition, and multi-tasking are all heavily utilized in our modern technology-rich society. Attention Restoration Theory (ART) suggests that exposure to nature can restore prefrontal cortex-mediated executive processes such as these. Consistent with ART, research indicates that exposure to natural settings seems to replenish some, lower-level modules of the executive attentional system. However, the impact of nature on higher-level tasks such as creative problem solving has not been explored. Here we show that four days of immersion in nature, and the corresponding disconnection from multi-media and technology, increases performance on a creativity, problem-solving task by a full 50% in a group of naive hikers. Our results demonstrate that there is a cognitive advantage to be realized if we spend time immersed in a natural setting. We anticipate that this advantage comes from an increase in exposure to natural stimuli that are both emotionally positive and low-arousing and a corresponding decrease in exposure to attention demanding technology, which regularly requires that we attend to sudden events, switch amongst tasks, maintain task goals, and inhibit irrelevant actions or cognitions. A limitation of the current research is the inability to determine if the effects are due to an increased exposure to nature, a decreased exposure to technology, or to other factors associated with spending three days immersed in nature.

/pdf/creativity-in-the-wild-improving-creative-reasoning-through-5czhhz21hi.pdf

David L. Strayer

Papers

Twenty years of zebra mussels: lessons from the mollusk that made headlines

Metabolism of streamwater dissolved organic carbon in the shallow hyporheic zone

Native predators and exotic prey –an acquired taste?

Supertaskers: Profiles in extraordinary multitasking ability.

Creativity in the Wild: Improving Creative Reasoning through Immersion in Natural Settings