Psychometric function

Levocetirizine had no deleterious effect on cognitive and psychometric functions compared with placebo, as assessed by a comprehensive battery of psychometric tests in healthy men. 

In 201 patients scheduled for day-case surgery, those who received remifentanil had significantly fewer responses to surgical stimulation and had better psychomotor and psychometric function during the recovery period, although there was no significant difference in time to recovery room or hospital discharge (594). 

Orbaek P, Nise G. 1989. Neurasthenic complaints and psychometric function of toluene-exposed rotogravure printers. Am J Ind Med 16 67-77. 

Researchers summarize FC results by plotting proportion correct versus concentration. Urban [36] called this a psychometric function (Fig. 7). The function ranges from chance, or no ability to choose the correct sample, e.g., 0.50 for 2-AFC or 0.33 for 3-AFC, to perfect ability to choose (1.00 for all tasks). Fitted functions (typically sigmoid, or S-shaped) help researchers estimate the concentration that corresponds to a criterion proportion correct (usually halfway between chance and perfect). 

Figure 7 A hypothetical psychometric function for a two-altemative forced-choice (2-AFC) task. Experimenters typically define threshold as halfway between chance and perfect performance (for 2-AFC, 75% correct). Since functions rarely include a point that has a y value of exactly 0.75, experimenters often interpolate by fitting S-shaped functions. Others have described various functions used and procedures for fitting them to empirical date (e.g., [131-133]). The solid curve in the figure represents a cumulative Gaussian, which has the longest history [134]. Using the fitted function, we find that threshold equals 5 log units.

Method of constant stimuli has an important advantage it yields an entire psychometric function. The shape and slope of the function can... 

Much less is known about individual variation in chemesthetic sensitivity. Using CO2 as an intranasal chemesthetic stimulus, individual psychometric functions for sensitivity can be generated two such functions are contained... 

Figure 19 Psychometric functions for detecting the irritation from carbon dioxide (CO2) in the nose obtained from two individuals. Horizontal bars at 0.75 indicate the 95% confidence interval at the localization threshold. These two individuals are significantly different from each other. Across many individuals, there are broad differences in sensitivity to CO2.

DM Green, RD Luce. Parallel psychometric functions from a set of independent detectors. Psychol Rev 82 483 486, 1975. 

JL Hall. Hybrid adaptive procedure for estimation of psychometric functions. J Acoust Soc Am 69 1763-1769, 1981. 

GB Wetherill, H Levitt. Sequential estimation of points on a psychometric function. Br J Math Psychol 18 1-10, 1965. 

B Treutwein, H Strasburger. Fitting the psychometric function. Percept Psychophys 61 87-106, 1999. 

Research work into clinical conditions such as attention deficit disorder has investigated performance of tasks such as serial and choice reaction time tests, and the relation of these to other areas of psychometric functioning. Information from tests to assess the effects of mild head trauma and other brain disorders, and tests and investigations used in demyelinating conditions, could also be studied to see what information they provide on the relationship of known functional deficit to test results. 

Rasmussen K, Jeppesen HJ, Sabroe S. 1993c. Psychometric tests for assessment of brain function after solvent exposure. Am J Ind Med 24 553-565. 

The Delta system contains many of the same tests contained in the APTS system, including those that monitor motor function, reaction time, attention and working memory, learning and memory, spatial perception and reasoning, mathematical calculation, and language (Table 6.1). More complete descriptions of the psychometric and validity studies supporting the utility of this testing system are available elsewhere.61,62... 

Austin EJ, Deary IJ. Effects of repeated hypoglycemia on cognitive function a psychometrically validated reanalysis of the Diabetes Control and Complications Trial data. Diabetes Care 1999 22(8) 1273-7. 

S, Gandon HM, Bouhours P. Effects of risperidone on psychometric and cognitive functions. 

The term psychometrics signifies the most objective recording possible concerning mental functions and personality features with the aid of a variety of test procedures. 

The acute or acute recurrent form can be equated with the manifestation of portosystemic encephalopathy in chronic liver disease. It is also known as acute episodic form . Discrete psychometric disorders usually precede the manifest picture as a latent stage. Manifestation includes stages I-IV and hence covers a wide spectrum of clinical, neurological and psychopathological symptoms. Once the liver function is stabilized and the trigger factors are eliminated, all the symptoms of this form are as a rule reversible. 

Given the varied functional disturbances in the brain (s. tabs. 10.1, 10.3), psychometrics should not rely on one test only. 

Stage State of consciousness Intellectual function Elements of consciousness and behaviour Neuromuscular function Psychometric tests EEG... 

Disorders of cerebral functions on the one hand and of the water and electrolyte balance on the other hand are the earliest and most reliable hints of the onset of decompensation in severe liver disease, especially cirrhosis. In clinical terms, they can be easily diagnosed as latent hepatic encephalopathy (by carrying out psychometric tests) and/or latent oedema (by recording the increase in body weight). For this reason, these examination methods are also of fundamental importance in the follow-up of chronic liver disease, (s. fig. 15.3)... 

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