Processing sets of letters for order: Evidence from reaction time experiments

In two experiments, subjects were required to impose different levels of organization on randomly ordered letters. In a between-subject design, the subject was to identify the letter in the set coming first in the alphabet or to reorganize the set into an alphabetic sequence. In a within-subject design, presentation of the letters was followed by an instruction to carry out the identification or reorganization task or to recite the letters in left-to-right order. Reaction time varied systematically with level of required organization, size of the presented set, and position and spacing of the letter set in the alphabet. The results are discussed in terms of two simple models.     

Partial reinforcement effects in instrumental escape conditioning

In Experiment I acquisition and extinction of instrumental escape conditioning with rats (N = 64) were studied as a function of reinforcement magnitude under conditions of partial and continuous reinforcement. In Experiment II the effects of partial and continuous reinforcement were studied in rats (N = 96) during acquisition followed by small, medium, and large reductions in reinforcement magnitude. A water-tank escape apparatus was used with temperature as the relevant variable. It was found that (1) with large reinforcement magnitude a continuously reinforced group was superior in acquisition to one that was partially reinforced; there were no differences with small reinforcement; (2) disruptive effects of a nonreinforced trial (a) appear early in learning, (b) are quite strong after each nonreinforced trial, and (c) persist through several succeeding reinforced trials; (3) major competing behaviors persist throughout acquisition for small reinforcement magnitude regardless of schedule, decline with large reinforcement (more so with continuous than with partial), and return to a high level in extinction for all conditions; (4) the partial reinforcement extinction effect occurs after large reinforcement but not after small, and it appears only with large reductions in reinforcement magnitude which approach extinction conditions. Only the first part of the last finding appears to be consistent with the appetitive conditioning literature.     

The effect of insstructions on judgment of the Müller-Lyer illusion with normal and haptically mediated visual inspection

An experiment with the Müller-Lyer figure is reported in which variation in instructions resulted in a change in the magnitude of the visual illusion under normal viewing conditions. Variation in instructions did not, however, have a differential effect on the magnitude of the illusion when Ss inspected the figure by means of a point source of light attached to one fingertip. These results are equivalent to differences found between the effect of instructions on visual and haptic illusions using the same illusion figure and support the view that variation in inspection patterns rather than differences in higher processingof sensory input might account for differences between the two modalities.     

Mood induction effects upon goal setting and performance in young children

The purpose of the present investigation was to demonstrate that goal setting varies with happy/sad mood-induced states in young children. In turn, on the basis of current Goal Setting Theory, it was predicted that goal level mediates the child's subsequent performance. Young children were assigned randomly to either happy or sad mood induction states, were asked to set their own goals, and then performed the task. In light of the findings, mood state was manipulated effectively in the children, with the following result: A happy mood state produced a significantly higher goal and superior performance than a sad mood state. However, no strong evidence was provided for the notion that goal setting mediated the impact of mood induction upon performance. The developmental implication of these findings are discussed.     

Daily and major life events: A test of an integrative model of psychosocial stress

The hypothesis that negative daily events mediate the relationship between major negative events and psychological symptomatology was tested using a three-wave, three-variable panel design. Measures of major and daily life events and psychological symptomatology were administered to 58 older adolescents at three time points during the transition from high school to college. The results indicated that the pathways from major life events to daily events and from daily events to psychological symptomatology were significant at each of the time points, but that the direct pathways from major events to psychological symptomatology were not significant at any time point. Thus, the hypothesis was fully supported. The findings are discussed in light of their implications for an integrative theory of the process by which major and daily events have an effect on psychological symptomatology.     

Preserved learning of novel information in amnesia: Evidence for multiple memory systems

Four of five patients with marked global amnesia, and others with new learning impairments, showed normal processing facilitation for novel stimuli (nonwords) and/or for familiar stimuli (words) on a word/nonword (lexical) decision task. The data are interpreted as a reflection of the learning capabilities of in-line neural processing stages with multiple, distinct, informational codes. These in-line learning processes are separate from the recognition/recall memory impaired by amygdalohippocampal/dosomedial thalamic damage, but probably supplement such memory in some tasks in normal individuals. Preserved learning of novel information seems incompatible with explanations of spared learning in amnesia that are based on the episodic/semantic or memory/habit distinctions, but is consistent with the procedural/declarative hypothesis.