Twitmyer, E. B. (1902/1974). A study of the knee jerk. Journal of Experimental Psychology, 103(6), 1047-1066.

Knee-jerks to the sound of a bell were obtained from 6 college students after 150-238 trials, during which the 2 patellar tendons were struck 0.5 sec after the sound of the bell. These knee- jerks to the bell alone were not the result of S’s voluntary effort, and attempts to inhibit the kicks were wholly unsuccessful. With increased numbers of paired stimulations, the regularity of responding to the bell alone was greatly increased, and the pattern of the knee-jerks was exactly the same as that of knee-jerks resulting from blows to the patellar tendon. The knee-jerks to the bell can be explained only in terms of reflex action, wherein repeated association of the functioning of the motor cells of the lumbar segment of the spinal cord with excitation of centers of the medulla resulting from the sound of the bell resulted in the development of an unusual reflex arc. (PsycINFO Database Record (c) 2000 APA, all rights reserved)(unassigned) Record 2 of 3 in PsycINFO 1887-1966

Courts, F. A. (1943). Modifications of the knee-jerk resulting from continued stimulation. Journal of Experimental Psychology, 33, 333-336.

Habituatory response decrement in the knee-jerk was studied in male undergraduates in three experimental sessions within the same week. “Records of the amplitude of the knee-jerk measured in terms of muscle thickening were obtained on all three days from 26 Ss and on the first two days from 25 others.” The mean amplitude of deflection of the recording stylus for successive responses reveals “a substantial decrement in amplitude, the change being greatest on the first day. Although there is partial recovery from the end of one day to the beginning of the next, a relatively large portion of the decrement persists, in that the amplitude is less at the beginning of the second and third days than it was at the beginning of the first and second respectively.” Intrasubject variability was found to be less on the first than on the second and third days. (PsycINFO Database Record (c) 2000 APA, all rights reserved)(unassigned)

Green, J. T., & Woodruff Pak, D. S. (2000). Eyeblink classical conditioning: Hippocampal formation is for neutral stimulus associations as cerebellum is for association- response. Psychological Bulletin, 126(1), 138-158.

Extensive evidence has been amassed that the cerebellum, hippocampus, and associated circuitry are activated during classical conditioning of the nictitating membrane/eyeblink response. In this article, the authors argue that the cerebellum is essential to all eyeblink classical conditioning paradigms. In addition, the septohippocampal system plays a critical role when the classical conditioning paradigm requires the formation of associations in addition to the simple association between the conditioned and unconditioned stimuli. When only a simple conditioned stimulus-unconditioned stimulus association is needed, the septohippocampal system has a more limited, modulatory role. The neutral stimulus association versus simple association-response distinction is one of the ways in which declarative or relational memory can be separated from nondeclarative or nonrelational memory in classical conditioning paradigms. (PsycINFO Database Record (c) 2000 APA, all rights reserved)(journal abstract) Record 11 of 19 in PsycINFO 1999-2000/12