A discrimination box containing two levers with a light above each was used to train eight rats to press beneath the brighter light for a milk reinforcer. The brighter light was held constant and the comparison light was varied to produce 12 brightness differences. The animals were run under two experimental methods: the block method in which each brightness level comparison was presented for a block of 11 contiguous trials, and the staircase method in which the sequence of brightness comparisons was determined by the correctness of the response on the preceding comparison. The block method produced a smaller differential brightness threshold and a larger change in discrimination performance for stimulus magnitude changes than did the staircase method.

Animals↗

PubMed1966

Timetable for orthodontic therapy.

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Dentistry↗

PubMed1963

"Cystic" tuberculosis of bone.

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Adult↗

PubMedDate not supplied

Issues in drug-related performance impairment.

Performance impairment associated with alcohol, drugs, and medical disorders is of increasing concern to clinicians. Understanding and assessing performance impairment associated with a particular drug or condition is complex and requires careful, critical evaluation of the literature. Awareness of the issues involved enhances the ability of the clinician to assess risks for a given patient and of a given medical therapy. Important study variables are described that should be considered when evaluating the literature pertaining to performance impairment. The clinical relevance of the results of performance studies is also discussed.

Drug-Related Side Effects and Adverse Reactions↗

PubMedDate not supplied

[The concept of acidity].

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Acids↗