Digit span

Scopolamine produces dose-dependent impairments of attention and slows the speed of information processing (Ebert et al. 1998 Vitiello et al. 1997). It causes psychomotor slowing when it is administered to the elderly, and to young adults at higher doses (Flicker et al. 1992). Digit span is not affected by scopolamine in young volunteers, but more omis-... 

More recent studies have not only challenged the early conclusion that the cholinergic system has no relation to attention, but these studies have brought into question the notion that the cholinergic system is not associated with short-term or immediate memory (Kopelman and Corn 1988 Rusted 1988 Rusted and Warburton 1988, 1989). Former studies had used only simple ( mechanic ) short-term retention tasks such as the digit-span for-... 

Auditory memory Wechsler Digit Span Test Recall digits in series forwards and backwards immediately after hearing them. 

Working memory Forward and Backward Digit Span Word Digit Memory Task Digit Comparison Task Oral PCP 5 vs. 10 mg 18, controlled l on all tests Bakker and Amini (1961)... 

Digit span 0.4 mg/kg, IV V4 doses were repeated every 15 min 11, crossover J. for forward digit span but not backward Harris et al. (1975)... 

Rescue and safety workers have also been studied. Nishiwaki et al. (2001) studied 27 male rescue team staff and 30 police officers, 3-45 months after the event. The study subjects showed decreased performance on the digit span test however, no effects on stabilometry and vibration perception threshold were found. Li et al. (2004) followed 27 male firefighters and 25 male police officers three years after the attack for genotoxic effects. They found an elevated frequency of sister chromatid exchanges in lymphocytes of the victims which were related to the percentage of ChE inhibition observed just after the attack. 

Memory dysfunction has been a frequent complaint in populations of workers exposed to various neurotoxicants and is tapped by several different tests used in a human testing context. One of the most widely used for this purpose is the digit span that constitutes one of the WAIS subtests. As indicated earlier, this test requires the subject to recall a series of digits, and the length of the list is successively increased contingent upon the subject correctly recalling the members of the list. In some cases, words or letters are utilized instead of digits. As is the case with experimental animal studies, more complex versions of these tests have been devised and... 

Decreases in performance on tests that measured intelligence (a similarities test) and memory (digit span and visual reproduction tests) were observed in chloralkali workers exposed for an average of 16.9 years to low levels of mercury when compared to an age-matched control group (Piikivi et al. 1984). 

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