Hemispheric interference: A dual-task investigation of youngsters who stutter

Hemispheric interference was studied in this investigation by requiring 24 right-handed grade-school children who stutter to tap a button, as rapidly as possible, in five randomized conditions. Hand order was counterbalanced in the single-task silent control condition and in the four increasingly demanding dual-task conditions. In three of the experimental conditions tapping and speech occured concurrently. In the fourth dual-task condition the subjects were to vocalize the sound of a siren (in an irregularly patterned way) as they tapped the button. Analysis of the tapping rates in this two-by-five factorial study revealed statistically significant differences among hands and conditions. The tapping rate was faster with the right than with the left hand and the rate decreased as the demands of the dual-task conditions increased. Interaction was not evidenced; the interference pattern was similar in both hands across the conditions. Since interference was significantly present in both the speech and vocalic conditions, the data are not consistent with a laterality model. This finding and the increase in interference with increased attentional demand, however, are consistent with a capacity framework.     

Children's decision strategies and their adaptation to task characteristics

Recent research has established decision making as an important type of strategic problem solving. From this perspective, the present paper examines strategic decision behavior in children and, in particular, the ability to adapt decision strategies to task characteristics. Twelve-year-olds' strategies were identified through analyses of information search patterns with different-sized matrices of information. Using a similar procedure, Payne (1976, Organizational Behavior and Human Performance, 16, 366–387) found that adults shifted to more efficient (but less “optimal”) strategies as task complexity increased. The present study indicates that, by 12 years of age, children understand many of the basic concepts of strategic decision making, such as compensation and elimination, and, like adults, they modify their strategies appropriately in response to complexity. However, their behavior differs from that reported for adults in that the distinctions among specific decision strategies are not clear cut, and there is frequent use of less demanding, cost-cutting strategies even with smaller decision tasks. Memory capacity and topic interest also affect decision strategy. The results support the feasibility of further developmental study of decision strategies. Analytical techniques developed here for use with children may profitably be applied in studies with adults as well.     

Measuring the importance of cues in judgment for individuals: Subjective theories of IQ as a function of heredity and environment

To measure the relative subjective importance attached to heredity and environment, undergraduates, graduate students, and faculty were asked to predict the IQ scores of hypothetical adopted children based on the IQs of the biological mother and father, the IQs of the adoptive parents, and the socioeconomic status of the adoptive parents. Intuitive predictions of IQ were inconsistent with additive, multiple regression models. Rather, the data for individual subjects were consistent with a configural-weight averaging model. Weights derived from this model were correlated with ratings of the relative importance of cues. Judges who rated the environment more important not only had greater weights for the environmental variables, but also placed greater weight on high rather than low scores. The judges who rated heredity more important than environment had greater estimated weights for heredity information and for lower-valued information. Results were thus consistent with the hypothesis that model-derived relative weights and individuals ratings of the relative importance of cues are both measures of the importance that individuals attach to these cues.     

Enabling,facilitating, and precipitating factors associated with women's career orientation

Women who had completed a career/life survey 13 to 21 years after enrolling as freshmen in college were classified as career (N = 372) or homemaker (N = 797) oriented on the basis of their actual work experiences. Statistically significant differences between the groups were found on 90% of the variables within the enabling conditions (i.e., family characteristics), 60% of the variables within the facilitating conditions (i.e., educational and vocational characteristics), and 88% of the variables within the precipitating conditions (i.e., attitudinal factors). The proportion of variance accounted for in career orientation by these variables varied from 0 to 32%. The variables which best differentiated between the two groups were categorized within the enabling conditions. The results are discussed in terms of previous theory, research, and practical application.     

A reinforcement plus interruption method of eliminating behavioral stereotypy of profoundly retarded persons

Stereotyped responses have been shown to be eliminated by an overcorrection-reinforcement program. The present study evaluated response-interruption as an alternative to the overcorrection component with seven profoundly retarded adults. During the baseline praise condition, stereotypy occurred during 66% of the observations for the seven profoundly retarded adults but decreased to less than one response per half hour in a mean of two sessions of individual training. In the subsequent class situation, stereotypy was reduced to less than 5% on the first day of class, to less than 1% by the fourth day and less than one stereotypy per hour after the third day. The interruption method seems preferable to postural overcorrection because of its apparent and relative nonaversiveness.     

Acquisition and retention of control of instrumental behavior by a cue-signaling airblast: How specific are conditioned anticipations?

The conditioned state evoked by a CS that had been paired with an aversive airblast was assessed by superimposing the CS on baselines of instrumental responding. The first experiment used a shock avoidance baseline; CS-airblast pairings were administered on the baseline, with the shock avoidance schedule in effect. The CS that signaled airblast came, over trails, to accelerate shock avoidance responding. As further CS-airblast trials were administered, however, the acceleratory effect of the CS decreased, producing an inverted-U-shaped acquisition curve. A second experiment used off-baseline CS-airblast conditioning, and the CS was tested on both shock avoidance and water reinforcement baselines. After 20 CS-airblast pairings the CS accelerated shock avoidance and suppressed water-reinforced responding. After 10o pairings, however, the acceleratory effect on shock avoidance was much attenuated, although the suppressions of the water-reinforced behavior did not differ between 20- and 100-trial groups. Two further experiments examined retention, over a 45-day interval, of the attenuation of the CS's effects on shock avoidance. Over the retention interval, this attenuation disappeared. It was, however, reinstated by giving the animals “reminder” presentations of the airblast. These results are interpreted as representing systematic changes in the specificity of the conditioned state evoked by a Pavlovian CS.     

Probe similarity and recognition of set membership: A parallel-processing serial-feature-matching model

A model for memory scanning is proposed in which the encoded representation of a probe is compared in parallel with encoded representations of each item in the positive set. The within item matches are serial feature by feature comparisons that terminate when either a positive or negative criterion is reached. This model is shown to predict the results of a probe similarity experiment. The serial location of a similarity within an item affects negative reaction times, but the number of items in the positive set to which the probe is similar has no main effect. The model is also shown to yield predictions consonant with existing data on the relation between reaction times and set size and speed-accuracy trade offs.