Subject cognitive effect

Interestingly enough, most of the studies reporting positive effects of caffeine in information-processing tasks have used primarily or exclusively male subjects.39 42 43 45 48 59 In fact the only study that found positive cognitive effects of caffeine on females employed fatigued females, whose baseline arousal levels may have been lower.41... 

Limited data are available on the pharmacokinetics of arecoline. Intravenously administered arecoline in subjects with Alzheimer s disease shows variation in the optimal dose (between 4 and 16 mg/day) due to differing plasma kinetics (Asthana et al. 1996). The mean plasma half-lives for these doses were 0.95 0.54 and 9.3 4.5 minutes, respectively. However, the mean plasma concentrations that optimized cognitive effects were 0.31 0.14 ng/ml. Drug clearance was 13.6 5.8 L/min and the volume of distribution was 205 170 L. 

Cognitive effects The effects of LI 160 on cognitive performance of subjects being treated for depression were examined. A significant antidepressant effect was seen and with low incidence of side effects, but no adverse cognitive effects were found on measures of attention, concentration, or reaction time (Schmidt and Sommer 1993). 

Opioids are sedating and cause a reduction in processing speed in clinical populations (e.g.. Digit Symbol Substitution Test) (Wood et al. 1998). However, a study in healthy subjects did not confirm these effects on digit substitution (Walker and Zacny 1998). Improvements are seen in choice reaction time after morphine administration (Hanks et al. 1995). Deficits have been reported in early-stage visual processing (O Neill et al. 1995 Hanks et al. 1995). By comparison, morphine s cognitive effects are lesser than those of lorazepam, but milder than hydromorphone (Rapp et al. 1996 Hanks et al. 1995). 

A few studies have been performed with event-related potentials (ERP) to examine the cognitive effects of THC. In subjects viewing emotionally valenced words (neutral, negative, or positive), THC produced a behavioral decrease in recognition rate (Leweke et al. 1998). The ERPs showed the typical difference between old and new words (enhanced positivity for old words beginning 250 milliseconds poststimulus), and THC enhanced the positivity in response to old words. This counterintuitive dissociation between ERPs and behavioral indices was interpreted as a reflection of implicit memory processes underlying the ERP effect. 

Shiftman S, Paty JA, Gnys M, Kassel JD, Elash C. (1995). Nicotine withdrawal in chippers and regular smokers subjective and cognitive effects. Health Psychol. 14(4) 301-9. 

Nathan, P.J., Baker, A., Carr, E., et ah Cholinergic modulation of cognitive function in healthy subjects acute effects of donepezil, a cholinesterase inhibitor. Hum. Ptychopharmacol. 16, 481-483, 2001. 

One study evaluated only the cognitive effects of single doses of 0.125-mg triazolam ( 324). Although the others assessed hypnotic efficacy, in all but one of these, study duration was 2 to 14 nights. In the remaining study, with a duration of 3 to 9 weeks, five of 22 elderly subjects (23%) were taken off triazolam between the third and fifth weeks because of serious adverse effects ( 323). The researchers reported, At week 3 significantly more triazolam patients were rated as more restless during the day (p < 0.05) and they also appeared more hostile, less relaxed, more irritable, and more anxious. After withdrawal of triazolam, these adverse reports... 

Possible central, cognitive, effects that are important in subjective audio quality assessment are ... 

In a 3-week, double-blind study of the cognitive effects of lithium (serum concentration about 0.8 mmol/1 n = 15) versus placebo (n = 15) in healthy subjects, lithium did not impair implicit recall, ability to process two tasks concurrently and simultaneously, short-term memory, or selective attention, but caused impaired learning during repeated administration of memory tests (226). Since neuropsychological testing could not distinguish lithium treatment from pre- and post-treatment in the lithium group, any lithium effects must be considered subtle at best. 

Tagawa M, Kano M, Okamura N, Higuchi M, Matsuda M, Mizuki Y, Arai H, Fujii T, Komemushi S, Itoh M, Sasaki H, Watanabe T, Yanai K. Differential cognitive effects of ebastine and (+)-chlorpheniramine in healthy subjects correlation between cognitive impairment and plasma drug concentration. Br J Clin Pharmacol 2002 53(3) 296-304. 

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