Arousal and performance

Parrott AC and Hindmarch I (1975). Arousal and performance - the ubiquitous inverted U relationship. Comparison of changes in response latency and arousal level in normal subjects induced by CNS stimulants, sedatives and tranquillizers. IRCS Medical Science, Clinical Pharmacology and Therapeutics, Psychiatry and Clinical Psychology, 3, 176. 

Dinges DF. Probing the limits of functional capability the effects of sleep loss on short-duration tasks. In Broughton RJ, Ogilvie R, eds. Sleep, Arousal and Performance. Cambridge MA Birkhauser-Boston, 1992 176-188. 

Folkard S, Akerstedt T. A three-process model of the regulation of alertness-sleepiness. In Broughton RJ, Ogilvie RD, eds. Sleep, Arousal, and Performance. Boston Birkhauser, 1992 11-26. 

Psychogenic dysfunction occurs if a patient does not respond to psychic arousal. It occurs in up to 30% of all cases of ED. Common causes include performance anxiety, strained relationships, lack of sexual arousability, and overt psychiatric disorders such as depression and schizophrenia.5 It is postulated that the anxious or nervous man will have excessive stimulation of the sympathetic system, leading to smooth muscle contraction of arterioles and vascular spaces within erectile tissue.6 O Many patients may initially have organic dysfunction, but develop a psychogenic component as they try to cope with their inability to achieve an erection. It has been estimated that up to 80% of ED cases have an organic cause, with many having a psychogenic component as well.1... 

The results of these two studies and others provide further support for the theoretical inverted U-shaped arousal function. In the first case,93 high doses of caffeine pushed subjects over the top of the curve and hence impaired vigilance performance. As time passed and the subject became more accustomed to the experimental situation, arousal returned to more optimal levels and performance improved. In the second study,94 caffeine combined with moderately high intensity situational stimulation (white noise) to drive arousal up beyond the point of transmarginal inhibition and, again, decrease performance. 

The inconsistent effects of caffeine in cognitively mediated performance tasks may result from differences in age groups, dosage levels, and environmental factors.124-125 The latter have been shown to substantially affect arousal126-127 in both adults128-129 and children.130-131 Office noise is effective in increasing self-reported arousal,132 as are white noise in the laboratory,94 exercise,133 and stress.134 Such environmental factors are sources of arousal and can interact with stimulants like caffeine.135... 

There does, however, appear to be a ceiling on the acute dosage of caffeine that will enhance reaction time. At relatively low doses given prior to simple tasks or highly practiced complex tasks, the drug does enhance RT.41 104-117-143-144 However, these results may not apply to more complex tasks that have not been extensively practiced. For example, Lieberman79 found that 64 mg of caffeine decreased RT on a simple visual task in which the subject had to identify an object. However, the same dose of caffeine had no effect on RT when the subject had to choose objects in a more complex task. In fact, caffeine has been found to have detrimental effects on reaction times in some complex tasks.51 104 145 Again, there appears to be an inverted-U relationship between overall arousal — induced by the combination of caffeine and other arousal factors — and performance on reaction time tasks. 

Davidson, R., Smith, B., Tamny, T. and Fedio, P., Emotional arousal in temporal lobectomy autonomic and performance effects of success and failure feedback. Journal of Clinical and Experimental Neuropsychology 1995. 

Sawyer, D. A., Julia, H. L., Turin, A. C., Caffeine and human behavior Arousal, anxiety, and performance effects. Journal of Behavioral Medicine 5(4), 415-439, 1982. 

Hindmarch I, Parrott AC and Lanza M (1979). The effects of ergot alkaloid derivative (Hydergine) on aspects of psychomotor performance, arousal, and cognitive processing ability. Journal of Clinical Pharmacology, 19, 726-732. 

Rodent models thus provide opportunities to explore the relationship between dopaminergic function, attention and consciousness. Based upon the well designed study of Granon et al. (2000) showing a clear improvement of attentional performance after the infusion of a D1 agonist into the prefrontal cortex, further study of cortical arousal and variability of reaction times in these models may provide important information. The preliminary data indicating that D2 receptor antagonists may increase cortical arousal (Sebban et al., 1999) is contrary to expectation and requires confirmation... 

Methaqualone also affects involuntary body functions that are controlled by the autonomic nervous system, lowering blood pressure, breathing rate, and pulse and bringing about a state of deep relaxation. Though thought to be an aphrodisiac because it lowers inhibitions, methaqualone, as a CNS depressant, usually impairs sexual performance, inhibiting arousal and climax. 

Fig. 6. The Yerkes-Dodson principle based on the inverted U-shaped function describing the relationship between arousal and efficiency. A similar relationship holds for the relationship between DA activity (e.g. within the mesocortical DA system) and performance efficiency. Note that the optimal level of performance may also be a function of the nature of the task in the classical formulation, easy tasks being best performed at higher levels of arousal than hard or difficult tasks.

The subjective and behavioral effects of triazolam were investigated in 20 healthy women, who took oral triazolam 0.25 mg or placebo at the follicular, periovulatory, and luteal phases of their menstrual cycle in a within-subject design (12). After triazolam most of them reported the expected increases in fatigue and decreases in arousal and psychomotor performance. Neither plasma concentrations of triazolam nor mood and performance differed across the three phases. This study shows that the effects of triazolam are highly stable across the menstrual cycle. 

Source Adapted with permission from a table in Sawyer, 0. A., Julia, H. L, and Turin. A. C. (1982). Caffeine and human behavior Arousal, anxiety, and performance effects. Journal of Behavioral Medicine, 5, pp. 41 439 (Plenum Press) and in Kenny, M.. and Darragh, A. (1985), Central effeas of caffeine in man. in S. D. Iverson (ed.). Fsychopharmacology Recent Advances and Future Prospects, pp, 278-288 (Oxford University Press). Also adapted from information in Barone and Roberts (1996), Clementz and Dailey (1988). and Greden and Walters (1992). Up ted 2006. 

F Pharmacologically, alcohol impairs sexual performance, particularly when BACs reach 0.05% and higher. However, people may perceive that the use of alcohol is associated with greater sexual arousal and better sexual performance. 

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