No abstract

Complexes of DL-ethionine, CH~CHZSCHZCHZCH( NH2)COOH (ethH), and S-methyl-L-cysteine, CH3SCHzCH ( KHz)-COOH (SmcH), have been prepared with manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), palladium(II), platinum(II), cadmium(II), and mercury(I1). The infrared spectra of the amino acids and of the metal complexes were measured in the range 4000-200 cm-l. The diffuse reflectance spectra of the cobqlt, nickel, and copper complexes were measured in the range 25,000-7000 cm+. Spectral and magnetic data indicate that the complexes are of four types, as follows. (a) ML2 (L = eth, Smc; M = Mn, Co, Ni, CU, Zn, Cd) complexes are polymeric in the solid state with carboxyl bridges. The metal atom is six-coordinate and the amino acid is bound to one metal atom via the nitrogen and one oxygen and t o another metal atom via the second oxygen. M(LH)Xz (M = Pd, P t ; X = C1, Br) complexes in which the amino acid is bound to the four-coordinate metal atom via the nitrogen and sulfur atoms only. (c) [Hg(ethH)~] (C104)z* HzO in which ethionine is possibly bound via the nitrogen only.[ A~C U ( S~C )~] N O~ in which the amino acid residue is coordinated to the copper via nitrogen and oxygen and to silver via the sulfur atom.(b) (d)

Eleven healthy male volunteers were infused with MSH/ACTH 4-10 and a control solution in a completely crossed and balanced procedure. Perception, attention and memory were tested as were heart rate and cephalic pulse amplitude in response to changes in the environment. Treatment of subjects with MSH/ACTH 4-10 raised their perceptual threshold for detection of simple stimuli and facilitated perceptual integration of patterned information. Administration of the heptapeptide improved the subjects' ability to discriminate tests of relevant from irrelevant information and augmented the heart-rate deceleratory response during presentation of novel stimuli. It was speculated that MSH/ACTH 4-10 has a predominant influence on attentional processes and that it may be uniquely coded for attentional/perceptual functioning.

In Experiment I, SO schizophrenic Ss were trained under one of three discrimination learning conditions: reversal (R) shift, extradimensional (ED) shift, or control. Half of the Ss in each shift condition received overtraining on the preshift discrimination. Performances of nonovertrained Ss on the R and ED shifts were very similar to performances of schizophrenic 5s tested by Nolan, Newman-Keuls analyses indicated that in Experiment I, overtraining facilitated the R shift relative to the ED shift. The result was a significant overall effect due to shift type. Experiment II was a replication of Experiment I, but with 60 college student Ss. In Experiment II, R shifts were learned faster than ED shifts, but overtraining had no discernable effect. Results were compared with those reported by Nolan and were discussed in terms of a two-stage attention model of discrimination learning.

The hypothesis that reorganizing written material while taking notes would aid free recall was evaluated in two experiments with high school juniors. Eighty-two subjects read a passage on anthropology organized either by society or by topic. They were then instructed to take notes either (a) in the same order as the material was presented or (b) by reorganizing the information according to specified categories. Free recall was higher for subjects who reorganized the material. In a second experiment with 146 subjects, the effect persisted when the categories were given to subjects in all conditions. Subjects of average verbal aptitude benefited from reorganizing to a greater extent than did subjects of higher verbal aptitude. The results were discussed in terms of the encoding variability hypothesis.