The age factor in multiple-discrimination learning by white rats.

1953 ◽  
Vol 46 (5) ◽  
pp. 387-389 ◽  
Author(s):  
Paul E. Fields
Keyword(s):  
Discrimination Learning ◽  
White Rats ◽  
Age Factor

scholarly journals DIET AND TISSUE GROWTH

1927 ◽  
Vol 46 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Theodore S. Moise ◽  
Arthur H. Smith
Keyword(s):  
High Protein Diet ◽  
Experimental Period ◽  
Tissue Growth ◽  
High Protein ◽  
Standard Diet ◽  
Focal Lesions ◽  
Renal Lesions ◽  
White Rats ◽  
Age Factor ◽  
Standard Ration

The effects of the ingestion of diets containing different concentrations of protein on the remaining kidney in adult white rats after a unilateral nephrectomy has been studied. In the animals on the high protein diet (85 per cent casein), actual glomerular and tubular lesions were observed in the kidneys of animals maintained for 90, 120 and 150 days after nephrectomy. In the animals on the standard ration, 18 per cent casein, no significant renal lesions were observed within the experimental period. Spontaneous focal lesions in the kidneys of rats maintained on Sherman's diets "A" and "B" were inconspicuous at the age of 350 days but became progressively more frequent and were commonly observed after 500 days. The animals on the high protein and standard rations were all under 350 days old at the completion of the experiment. It is suggested that the age factor is of importance in that young animals may have greater powers of adaptation in withstanding the injurious effect of high protein rations. The animals on the high protein ration excreted definitely larger quantities of protein in the urine, and showed a higher incidence of casts in periods roughly corresponding to those in which anatomic lesions were observed than did the rats on the standard diet.

Distinctive Phonetic Features as Relevant and Irrelevant Stimulus Dimensions in Speech-Sound Discrimination Learning

1974 ◽  
Vol 17 (3) ◽  
pp. 417-425
Author(s):  
Stuart I. Ritterman ◽  
Nancy C. Freeman
Keyword(s):  
College Students ◽  
Discrimination Learning ◽  
Irrelevant Dimension ◽  
Speech Sound ◽  
Irrelevant Stimulus ◽  
Relevant Dimension ◽  
Phonetic Features ◽  
Sound Discrimination ◽  
Nonsense Syllables

Thirty-two college students were required to learn the relevant dimension in each of two randomized lists of auditorily presented stimuli. The stimuli consisted of seven pairs of CV nonsense syllables differing by two relevant dimension units and from zero to seven irrelevant dimension units. Stimulus dimensions were determined according to Saporta’s units of difference. No significant differences in performance as a function of number of the irrelevant dimensions nor characteristics of the relevant dimension were observed.

Cognitive Development Meets Discrimination Learning

1996 ◽  
Vol 41 (11) ◽  
pp. 1109-1110
Author(s):  
Deborah G. Kemler Nelson
Keyword(s):  
Cognitive Development ◽  
Discrimination Learning
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