Human behavior measurements

Animal models of fear and anxiety have primarily used the rat, the mouse and, to a lesser extent, nonhuman primates. It is not particularly difficult to evoke or measure anxiety in these species. However, difficulties arise when one attempts to define exactly how a stimulus and resultant behavioral response are related to human behavior, i.e. when a mouse exhibits freezing behavior to an unfamiliar and threatening cue, what is the human equivalent Or, similarly, what stimulus could one present to a rat to best model the anxiety-inducing-experience of... 

Numerous behavioral measures have been evaluated for their usefulness in providing a sensitive index of exposure to ionizing radiation. Radiation-related mental retardation is the most likely type of behavioral abnormality in humans sensitivity peaked between 8 and 15 weeks of conception... 

A PDE10A inhibitor may also have the potential to treat the cognitive symptoms of schizophrenia. The principal evidence for this claim is papaverine reversal of a PCP-induced deficit in the EDID-set shifting assay in rats [35]. This assay translates into human behavior in the form of the Wisconsin Card Sorting Test (WCST). EDID-set shifting is a test of executive function, a measure in which schizophrenics have a robust deficit. It has also been shown recently that papaverine is efficacious in the Novel Object Recognition cognition assay [36]. 

The inference of past human behavior from measurements of light and heavy isotopes in material remains has been termed isotope archaeology (e.g.,... 

Reproductive success measured where there is effective contraception is, of course, of limited value in assessing the evolutionary utility of a given human behavior. Under these modem conditions it may be better to measure mate value, i.e., sexual attractiveness, as a proxy for reproductive success (e.g., Dong et al., 1996 Weisfeld et al., 1992). Sexual attractiveness, of course, refers to an emotion and as such is a proximate cause of ultimate biological success. 

Finally, the MOS should also take into account the uncertainties in the estimated exposure. For predicted exposure estimates, this requires an uncertainty analysis (Section 8.2.3) involving the determination of the uncertainty in the model output value, based on the collective uncertainty of the model input parameters. General sources of variability and uncertainty in exposure assessments are measurement errors, sampling errors, variability in natural systems and human behavior, limitations in model description, limitations in generic or indirect data, and professional judgment. 

Based on effects caused in monkeys and rats, the following are expected in humans 20,000 ppm for 60 minutes, coma and possibly death 10,000 ppm for 30 minutes, marked incoordination 2000ppm for 5 minutes, disturbance of equilibrium. Human subjects exposed to 900-1000ppm for 20 minutes experienced light-headedness, incoordination, and impaired equilibrium transient eye irritation has also been reported at similar concentrations. Impairments in psychomotor task performance such as reaction time, perceptual speed, and manual dexterity have been demonstrated at levels around 350ppm. Other studies at similar exposure levels have failed to show any impairment, but the type of task chosen to test behavioral effects and the times at which behavioral measures were sampled during the course of exposure may explain the variations from study to study." ... 

Kelly, T.H., Foltin, R.W., and Fischman, M.W., The effects of repeated amphetamine exposure on multiple measures of human behavior, Pharmacol. Biochem. Behav., 38, 417, 1991. 

Another important consideration in the selection of an impairment testing system is whether norm-based decision criteria will be used to evaluate readiness to perform an assignment and, if so, whether such norms are currently available. It is important that such norms address both decrements and improvements in performance, as improved performance may also signal the influence of a risk factor. For example, stimulant medications may have minimal effect on performance of most tasks, but under test conditions requiring sustained attention, enhanced performance may be noted.14 These same doses of stimulant medication may have important implications for more complex dimensions of human behavior,15 16 so the detection of enhanced performance may signal an increased risk for detrimental effects on other more complex behaviors that are not directly measured during testing. 

The primary approach currently used to detect and characterize potential neurotoxicants involves the use of animal models, particularly rodents. Behavioral and neurophysiological tests, often similar to the ones used in humans, are typically administered. The sensitivity of these measures to neurotoxicant exposure is widely accepted. Although it is often not possible to test toxicant effects on some higher behavioral functions in animals (e.g., verbal ability, cognitive flexibility), there are other neurobehavioral outcomes such as memory loss, motivational defects, somatosensory deficits, and motor dysfunction that can be successfully modeled in rodents. These behaviors are based on the ability of the nervous system to integrate multiple inputs and outputs, thus they cannot be modeled adequately in vitro. Although the bulk of neurotoxicity data has been collected in rodents, birds and primates are also used to model human behavioral outcomes. 

Once a stable chronic model has been established,the affected primates exhibit a typical Parkinsonian syndrome, for which a variety of behavioral measures have been developed. These include neurological descriptions of symptoms typical of human PD including action and resting tremor, cogwheel rigidity, postural impairments, hypokinesia and... 

Once there is a measure of the concentration of the pesticide in the exposure medium (air, water, food, etc.) in contact with the body or the actual concentration that comes into contact with the body, a daily dose metric can be calculated (e.g. maximum, average, geometric mean, etc.). This typically involves developing a mathematical equation that expresses dose as a function of pesticide concentration and other important parameters referred to as human exposure factors (USEPA, 1999a). In the context of this discussion, the term human exposure factor refers specifically to (a) human characteristics, such as body weight, surface area, life expectancy, inhalation rates for air and consumption rates for food, drinking water and soil (b) human behaviors, such as activity patterns, occupational and residential mobility and consumer product use, which are used by exposure assessors to calculate potential dose. 

The test batteries commonly used in human studies have come primarily from the field of clinical neuropsychology, in which human testing has predominated. Behavioral measures such as are utilized... 

Enrollees were asked to submit to a series of performance and health effects measures. Tests included the Global Assessment System for Humans/ Behavioral Assessment and Research System (GASH/BARS), the Postural Sway Test, the Eye Blink Conditioned Response Test and the Electroretino-gram (ERG). Subjects were also asked complete an electronically administered questionnaire. Medical records were reviewed for pertinent health events occurring during the preceding year. 

Unfortunately, for the development of the human brain, this question can be addressed only indirectly—from animal experiments and by deduction. But even animal experiments are problematic because it s not always clear how measurements of animal behavior have any serious meaning for measurements of human behavior. An animal, even a chimpanzee, is not just a simplified human being exhibiting simplified human behavior. Deduction, on the other hand, gives us a clearer answer It stands to reason that clinical observations of the effects of brain-development aberrations are the proverbial tip of the iceberg—with an entire universe of subclinical differences, variations, and developmental aberrations that we have no means yet to measure. 

Does this mean that gloves are necessarily always safer than bare hands Not if an employee performs an adequate handwash with an effective antimicrobial product, but it does suggest that such handwashes commonly did not occur. Hence, corrective measures that must be implemented by the food service industry are behavioral. And human behavior depends upon motivation, which depends upon values and meaning—both cultural (shared) and individual. 

Numerous behavioral measures have been evaluated for their usefulness in providing a sensitive index of exposure to ionizing radiation. Radiation-related mental retardation is the most likely type of behavioral abnormality in humans sensitivity peaked between 8 and 15 weeks of conception and doses >0.4 Gy. No specific mechanism for the production of mental retardation has been established, although proposed mechanisms include the loss of cells, migration of neurons, and failure of synapto-genesis. In studies with rats, operant responses decreased (maintained by positive reinforcement such as food or water) at sublethal radiation doses (3.0-6.75 Gy) under various schedules of reinforcement. Dismpted operant responses under shock avoidance at >LD100 levels are reported in pigs and rhesus monkeys. 

While performance relates more to what a system can do (i.e., a challenge or maximal stress is implied), behavior measurements are used to characterize what a system does naturally. Thus a given variable such as movement speed can relate to both performance and behavior depending on whether the system (e.g., human subsystem) was maximally challenged to respond as fast as possible (performance) or simply observed in the course of operation (behavior). It is also possible to observe a system that it is behaving at one or more of its performance capacities (e.g., at the maximum speed possible, etc.) (see Table 73.1). 

Considering the number of studies using psychophysiological measures and the potential of the application, a more concrete conceptual fiamework is required to integrate past studies, differentiate more precisely between insufficient measurement qualities and nonsignificant, but true, results, and obtain a more exhaustive etqjlanation of human behavior. Only a multidisciplinary effort promises progress in this direction. 

The results focus on the success rate of finding a safe evacuation route rather than on overall route optimization. This is due to the fact that, for measuring the improvement comparison between virtual evacuations, time using ERAM and real evacuation time is required. In order to obtain the real one, sophisticated human behavior simulation is needed. 

Parameters of human behavior are also frequently acquired, often to help understand an individual s response to a therapy or new circumstance (e.g., obtaining a new wheelchair or prosthetic device). Behavioral parameters reflect what the subject does normally and are typically recorded over longer time periods (e.g., hours or days) compared with that required for a performance capacity measurement under conditions that are more representative of the subject s natural habitat (i.e., less laboratory like). The general approach involves identifying the behavior (i.e., an event such as head flexion, keystrokes, steps, repositionings, etc.) and at least one parametric attribute of it. Frequency, with units of events per unit time, and time spent in a given behavioral or activity state (Ganapathy and Kondraske, 1990) are the most commonly employed behavioral metrics. States may be detected with... 

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