The effects of experimentally induced changes in self-concept on associative learning

It has been hypothesized that self-concept influences ability to learn. This experiment systematically manipulated the self-concepts of learners regarding their abilities to learn a foreign language and measured their subsequent learning of a synthetic foreign language vocabulary list. Eleven Ss were randomly assigned to each of three groups: self-concept raised, self-concept lowered, control. Ss were college freshman who were not enrolled in a foreign language course or had not previously taken more than one semester of a foreign language. Self-concepts were measured as self-description of ability to learn a foreign language. Self-concepts were raised or lowered by providing false scores on a foreign language aptitude test. Learning was measured as performance on a paired-associates task utilizing random shapes and CVCs. Ss with lowered self-concepts learned more slowly than control Ss or Ss with raised self-concepts.

Fluorescence différée et émissions photostimulées du carbazole et de la diphénylamine dans une matrice rigide d'éther à 77 °K

The isothermal delayed fluorescence along with the visible (6000 Å) photostimulated fluorescence and phosphorescence emissions have been recorded and analyzed in the following systems: diphénylamine (DPA) – ether rigid glass and carbazole (C) – ether rigid glass at 77°K. The electron–cation recombination after visible light stimulation has been analyzed in terms of a kinetic model already described (10). The triplet quantum yields of the DPA and C molecules are calculated and compared to the existing experimental values. The rate constant ratio (β) of populating the first triplet (T1) relative to populating the first excited singlet (S1) after the recombination event has taken place, is equal to about 2 in both systems investigated here. A value of 4.4 was obtained for indole and tryptophan in the same matrix. This difference can only be explained in terms of various singlet state energies for these molecules and also in terms of the stimulating energies used in these experiments.

Isothermal and Photostimulated Emissions of Indole and Tryptophan in Two Polar Matrices at 77 °K

The isothermal delayed fluorescence along with the visible photostimulated fluorescence and phosphorescence emissions have been recorded and studied for the following systems: a 10−3 M solution of indole in an ether glassy matrix, a 10−3 M solution of indole in an ethylene glycol–water glassy matrix (EG–W) (70–30 by volume), a 10−3M solution of tryptophan in an EG–W glassy matrix (70–30 by volume). All these experiments have been performed at the temperature of liquid nitrogen. It has also become possible to record the action spectra of the photostimulated emissions which give us information about the entities playing an active part in the recombination processes. The electron–cation recombination after visible light stimulation has been analyzed in terms of a kinetic model based on the assumption that upon neutralization an intermediate state is formed from which the molecule decides what its spin multiplicity will be. It was found that in an EG–W glass at 77 °K about 80% of the recombination events lack the energy necessary to reach the first excited singlet state of the amines studied. In an ether glass this percentage decreases to about 28%. This result is qualitatively in accord with the fact that the photostimulated electrons are more stabilized in an EG–W glass by an amount of energy equal to 1.5 eV.

Stimulus identifiability and perceptual ability in paired-associate learning of retardates

The paired-associate learning by educable mental retardates as a function of perceptual ability (Bender-Gestalt) and stimulus identifiability was examined. Ss of high and low perceptual ability learned a paired-associate task employing stimuli which were hard and easy to identify. Control groups were CA-matched normals and MA-matched normals. The results suggest that performances of retardates of high and low perceptual ability do not differ when easily identified stimuli are used but do when stimuli are difficult to identify.