Methods for recording behavioral drug effects

In the following paragraphs the emphasis has consequently been laid on studies using a variety of performance tests. There are many ways to classify such methods, e.g. by the specific mental function a task is thought to tap or simply by test duration. Similar to a classification used by Deutsch Lezak (1995) for neuropsychological tests, we will distinguish the following areas of mental performance  

There are no sharp borderlines between some of these areas of mental performance (elements of attention, perception and some motor function are involved in all forms of performance), and allocation to a specific area is debatable for man tests. When studies are planned in practice this will be considered by compiling a battery of tests containing some redundancy while still retaining parameters from various areas of performance. 

The term perception designates physiological and mental processes that serve to absorb and classify information from our internal and external environments. Speed, extent and quality of perception not only depend on the condition of the sensory organs but they are also a function of such factors as wakefulness, attentiveness or concentration, emotional and motivational state 

Only a small proportion of the methods available, mainly for diagnostic purposes (Lezak, 1995, p. 385), have been used in drug experiments. Special mention should be made of the determination of criticalflicker fusion frequency (CFF) and of tachistoscopic trials, Le. of methods directed at the characteristics of visual perception. In contrast, drug effects on hearing have rarely, and those influencing senses of touch, smell and taste have hardly ever, been investigated (Turner, 1971). 

Tachistoscopic trials serve to record speed and extent of perception. In the course of such experiments visual stimuli are shown for a very short time and the subject has to name the items presented as far as he has recognized them. Tests with simple configurations of stimuli (colors, single letters or objects) primarily record speed of perception, whereas experiments with more varied content also investigate elements of short-term memory. Tachistoscopic experiments are nowadays hardly used in pharmacopsychology, presumably because of their low sensitivity to the effects of substances. 

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