Attentional performance tests

Cognitive effects Human nonsmokers Administration of nicotine to tobacco nonusers produces small cognitive enhancements. Studies in tobacco nonusers have primarily measured attention, information processing speed, and memory. Nicotine improves perceptual speed, choice reaction time, and digit recall (Stough et al. 1995 Le Houezec et al. 1994 Foulds et al. 1996). Improvements also occur in digit symbol substitution and continuous performance tests without reducing accuracy (Petrie and Deary 1989 Levin et al. 1998). 

Manor, I., Tyano, S., Eisenberg, J., Bachner-Melman, R., Kotler, M., and Ebstein, R. P. (2002) The short DRD4 repeats confer risk to attention deficit hyperactivity disorder in a family-based design and impair performance on a continuous performance test (TOVA). Mol. Psychiatry. 7, 790-794. 

Because the respiratory tract is an initial target of any air pollutant challenge, it usually receives primary attention in tests to determine irritant effects of exposure. Other aspects of interest include hematology, blood enzyme biochemistry, eye irritation, and p chomotor performance. Constriction of the large airways, maldistribution of ventilation due to narrowing in some small airways, constriction of peripheral lung units, and mechanical or gas diffusion impairment due to edema are possible effects of insult by pollutants. A variety of pulmonary tests is required to examine the possibilities. 

A later study supported the findings that methylphenidate s benefits are most apparent in sleep-deprived/sleep-restricted volunteers. Roehrs et al. (52) compared the effects of 09 00 doses of 10 mg methylphenidate to placebo on sleepiness (Multiple Sleep Latency Test, MSLT), Profile of Mood States (POMS) ratings, and divided-attention performance after either 4 or 8 hr of sleep. After these test days, the 4- and 8-hr sleep conditions were repeated, but this time subjects were given their choice of drug or placebo. Results indicated that performance was improved by methylphenidate, most notably after the 4-hr condition. Methylphenidate also improved sleep latency and mood, but only after restricted sleep. During the choice phase of the study, subjects showed a preference for methylphenidate after 4 hr sleep (in 88% of opportunities), but not after 8 hr sleep (in only 29% of opportunities), suggesting that the preference for methylphenidate depended on the perceived sleepiness level of the individual. 

Influence/effects not apparent or obvious Behavior nearly normal by ordinary observation Impairment detectable by special tests Mild euphoria, sociability, talkativeness Increased self-confidence decreased inhibitions Diminution of attention, judgment, and control Some sensory-motor impairment Slowed information processing Loss of efficiency in finer performance tests Emotion instability loss of critical judgment Impairment of perception, memory, and comprehension... 

Schmidt and Sommer 1993 65 (15 m/50f) neurotic depression or brief depressive reaction (HAMD 15-20) [ICD-9 300.4, 309.0] Jarsin (LI 160) 3 x 300 mg 6 weeks A all randomized patients (Hyp 32, Pic 33) R HAMD response rate (decrease in total score >50% or total score <10) 66.6% (placebo 26.7%) Cognitive performance tests (Vienna determination device and Test d2 acc. to Brickenkamp no impairment of attention and choice reaction time due to Hypericum treatment... 

Information on specific production methods can be found in the literature [Pinna 1998]. Impregnated catalysts are mainly produced batchwise with discontinuous process steps. Therefore, continuous quality control of the individual catalyst batches is vital (e.g., testing of mechanical strength, performance tests in screening reactors). The process developer must pay special attention to transferring the laboratory recipe to industrial catalyst production. Test production should be carried out relatively early... 

In comparison to single-task performance test situations, in which the attention processor may not be working at capacity, the additional demand is designed to change (compared to a single-task baseline) and sometimes maximizes the stress on attention performance resources. Performance on both primary and secondary tasks, compared to levels attained when each task is independently performed, can provide an indirect measure of capacity associated with attention [Parasuraman and Davies, 1984]. This approach... 

Manor I., Corbex M., Eisenberg J., Gritsenkso I., Bachner-Mehnan R., Tyano S. and Ebstein R. P. 2004. Association of the dopamine D5 receptor with attention deficit hyperactivity disorder (ADHD) and scores on a continuous performance test (TOVA). Am. J. Med. Genet. B Neuropsychiatr. Genet. 127 73-77... 

Heavy metals and arsenic Heavy metals are routinely determined, often with one or other form of sulfide precipitation. These compendial tests are performed from the viewpoint of safety and the general limits (l-30pgml g ) are now more often related to the dose. For metals such as mercury, lead, cadmium, or nickel, atomic absorption spectrometry or other instrumental methods are often prescribed. Copper and other transition metals can act as catalysts in certain degradation reactions and thus require special attention. Arsenic tests that were important at the beginning of the previous century are now being phased out. 

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