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

It is well documented that the ability to effectively scan a visual scene is modulated by the perceptual and cognitive demands of the observer’s search task, with increases in visual workload effecting changes to both overt attention, the eye movements made in searching the environment, and covert attention, the processing which occurs within the span of a single fixation of the eye (see Crundall, et al, 1998, for review) More poorly understood are the effects of non-visual workload on search and representation of the visual environment Experimental data as well as everyday experience indicate that multiple-task performance is generally facilitated when input and output channels are distributed across perceptual modalities and response effectors (Wickens & Holland, 2000) Nonetheless, evidence demonstrates that cognitive interference can impair multiple-task performance even when structural interference—that is, competition for sensory mechanisms and response effectors (Kahneman, 1973)—is eliminated With the burgeoning popularity of in-vehicle technology, and in particular the growing use of cellular phones on the road, the consequences of cross-modal and cognitive interference for visual performance have become of increasing concern Intuition, manifest in legislation banning only the use of hand-held cellular phones in vehicles, suggests that the effects of such technology on drivers’ performance will be largely structural Accumulating data, however, demonstrate that conversation alone, absent the demand to hold or manipulate any apparatus, can impair driver performance, delaying responses to sudden events, for example, and disrupting manual control (eg, Strayer & Johnston, in press; Alm & Nilsson, 1995) Other studies provide indirect evidence that visual scanning of the environment may likewise suffer interference from the cognitive workload imposed by conversation Recartes and Nunes (2000), for example, found changes in drivers’ on-the-road saccadic behavior as a consequence of various secondary cognitive tasks, noting, among other effects, a decrease in fixation durations during performance of a verbal (word generation) task The aim of the present experiment was to examine the effects of naturalistic conversation on observers’ scanning and consequent representation of visual scenes Toward this end, observers were asked to perform a change detection task Events in the visual environment commonly produce local transient signals that attract attention and ensure that meaningful changes to an observer’s surroundings are perceived When the transient produced by an event, however, is masked—for example by saccadic suppression (Grimes, 1996) or an occluder (Simons & Levin, 1998)—the event itself may go unattended and undetected Changes within a scene can thus fail to reach awareness even when they occur seemingly in full view of an observer, a phenomenon known as change blindness (Simons & Levin, 1997) To avoid such perceptual failure and maintain situation awareness in a dynamic and complex environment, an observer must rely on attentive scanning, actively encoding objects and noting changes to them (Rensink, et al, 1997) An observer’s ability to detect changes unaccompanied by attention-capturing transients therefore provides a functional measure of attentional scanning performance Here, observers were asked to search for changes within complex traffic scenes, either while concurrently maintaining a conversation or under single-task control conditions Of interest were the effects of conversation on observers’ accuracy and speed of detection, and on saccadic behavior during search; past research, as described above, suggests that visual scanning may be disrupted by the workload imposed by conversation, and that change detection may concomitantly be impaired Because previous studies have found that elderly subjects tend to suffer greater multiple-task interference than do younger subjects (eg, Alm & Nilsson, 1995; Kramer et al, 1999), two age groups, one of relatively young observers and the other of older observers, were run

Conversation Disrupts Visual Scanning of Traffic Scenes

The present study used brain imaging to determine the neural basis of individual differences in multitasking, the ability to successfully perform at least two attention-demanding tasks at once. Multitasking is mentally taxing and, therefore, should recruit the prefrontal cortex to maintain task goals when coordinating attentional control and managing the cognitive load. To investigate this possibility, we used functional neuroimaging to assess neural activity in both extraordinary multitaskers (Supertaskers) and control subjects who were matched on working memory capacity. Participants performed a challenging dual N-back task in which auditory and visual stimuli were presented simultaneously, requiring independent and continuous maintenance, updating, and verification of the contents of verbal and spatial working memory. With the task requirements and considerable cognitive load that accompanied increasing N-back, relative to the controls, the multitasking of Supertaskers was characterized by more efficient recruitment of anterior cingulate and posterior frontopolar prefrontal cortices. Results are interpreted using neuropsychological and evolutionary perspectives on individual differences in multitasking ability and the neural correlates of attentional control.

On supertaskers and the neural basis of efficient multitasking.

In 1955–1965, the streams and rivers of the upper Susquehanna River basin in New York were surveyed for unionid mussels. We resurveyed unionid populations at the same sites in 1996–1997 to determine whether populations had declined and whether declines could be correlated with inputs of sediments and nutrients from agriculture, which have been thought to be major threats to imperiled unionid populations in North America. Despite widespread evidence of high nutrient and sediment loading from agriculture and other human activities in the upper Susquehanna basin since at least 1965, we found little change in unionid populations between the two time periods. The range of Alasmidonta varicosa contracted while that of Lampsilis cariosa expanded. Overall species richness and the ranges of the other nine species were unchanged. Six species in the basin were formerly listed as Category 2 species or are now considered “Species at Risk” by the United States Fish and Wildlife Service. Of these, Alasmidonta u...

Changes in the Distribution of Freshwater Mussels (Unionidae) in the Upper Susquehanna River Basin, 1955–1965 to 1996–1997

The introduction of semi-automated driving systems is expected to mitigate the safety consequences of human error. Observational findings suggest that relinquishing control of vehicle operational c...

80 MPH and out-of-the-loop: Effects of real-world semi-automated driving on driver workload and arousal:

Diacyclops dimorphus, new species, was collected from clean sand sediments of the Blackwater River, State of Florida, USA. The new species differs from congeners in that the female has all rami of the swimming legs biarticulate, but the male has most rami biarticulate and the leg 4 exopodite triarticulate. Only two other species of Diacyclops show comparable extreme reduction of the swimming legs. These are Diacyclops virginianus and Diacyclops trajani (a new name proposed for Speocyclops minutissimus sensu Petkovski 1954). The swimming leg articulation patterns of all species of Diacyclops are reviewed. This is the first report of consistent sexual dimorphism in swimming leg articulation in Diacyclops. Sexual dimorphism in the swimming legs rarely occurs in the subfamily Cyclopinae. We suggest that preferential reduction in endopodites of posterior legs of smaller cyclopines allows the female genital double somite to remain relatively large. Many interstitial cyclopine copepods possess distinctive morpho...

David L. Strayer

Papers

Conversation Disrupts Visual Scanning of Traffic Scenes

On supertaskers and the neural basis of efficient multitasking.

Changes in the Distribution of Freshwater Mussels (Unionidae) in the Upper Susquehanna River Basin, 1955–1965 to 1996–1997

80 MPH and out-of-the-loop: Effects of real-world semi-automated driving on driver workload and arousal:

Diacyclops dimorphus, a New Species of Copepod from Florida, with Comments on Morphology of Interstitial Cyclopine Cyclopoids