On-line brain stimulation: Measurement of threshold of reinforcement

This program and interface for a small computer (PDP8/e) performs the following operations: generates and delivers constant current stimulation to the brain of an animal, monitors electrical resistance at the stimulating electrode, and calculates the threshold of reinforcement based upon the frequency of characteristic pauses in the animal’s responding.     

Children’s orientation judgments: Retinally or environmentally determined?

Attention, Perception, & Psychophysics - Children between the ages of 3 and 9 years judged the uprightness of pictures of realistic figures under three conditions: tilt of the visual surround,...     

Auditory generalization gradients for response latency in the monkey

Two monkeys were trained to press and hold a response key in the presence of a light and to release it at the onset of a pure tone. Initially, all responses with latencies shorter than 1 sec were reinforced without regard to the frequency of the pure tone, and the intensity of the pure tone that resulted in equal latencies at each frequency was determined. The second stage of the experiment consisted of discrimination training, during which releases to one pure-tone frequency (positive stimulus) were reinforced and releases to a second frequency (negative stimulus) were extinguished. Median latencies to the negative stimulus slowly increased as did the variability of the latency distribution for the negative stimulus. There was no evidence of a concurrent decrease in latencies to the positive stimulus indicative of behavioral contrast. The third part of the experiment consisted of determining maintained generalization gradients by increasing the number of nonreinforcement stimuli. The gradients that eventually resulted showed approximately equal latencies to all frequencies of the negative stimulus and shorter latencies to the positive stimulus frequency.     

Operant control of response latency in monkeys: evidence for a central explanation

Two monkeys (M. mulatta) were trained to press a telegraph key after onset of a tone and release it quickly in response to a subsequent light or click stimulus occurring after a variable interval. After training first with a fixed time limit on response latency for key release and then with a continuously adjusting limit, reaction time to click was 160 msec and to light, about 200 msec. Temporal contingencies or "payoff bands" were then introduced which reinforced only responses with latencies which fell between two limits 50 msec apart. Feedback was given as to whether each latency was too slow, within the band, or too fast. A trained monkey could precisely center its latency distribution on any 50 msec-wide payoff band located from 200 to 600 msec after the stimulus, with from 60 to 80% of its responses achieving reinforcement. Distribution statistics were comparable to those of trained human subjects. Because such precise timing might be accomplished by a peripheral adjustment, such as changing the manner of holding the key, latency of electromyographic activation was measured in participating arm muscles in one monkey. Electromyographic activation preceded key release by a constant interval, regardless of response latency, indicating a more central mechanism for timing of brief intervals.     

Context effects in sentence comprehension: A study of the subjective lexicon

These studies explore the role of context in determining what information about the meanings of words is activated in memory at the time a word is encountered in a sentence. Using a color-naming paradigm, it was shown that both meanings of a word that has two distinct meanings are activated in memory at the time the word is heard in a sentence. This activation occurs even when there is sufficient contextual information to indicate which meaning was intended by the speaker. These results support the hypothesis that there exists in memory an isolable subjective lexicon. They suggest that context which is effective in disambiguating lexical ambiguities in the language has its effect only at a relatively late stage in the cognitive processing involved in language comprehension.     

Help Wanted: People With Disabilities and Recruitment Advertising

People with disabilities rely heavily on specialist agencies to find suitable employment. This research examines how agency consultants use recruitment ads in their work with clients. The authors analyzed the ads collected by consultants and learned that the ads were dominated by organization and job attributes. The ads contained less information about preferred applicant characteristics and selection procedures. Consultants used the ads to facilitate immediate matches between clients and employers, but they also used the ads to nudge clients in new career directions. The results reflect challenges consultants experience in balancing the long‐term needs of clients against the short‐term demands of employers.     

The Influence of Religion and Ethnicity on Family Planning Approval: A Case for Women in Rural Western Kenya

The role of sociocultural factors such as religion and ethnicity in aiding or hampering family planning (FP) uptake in rural Western Kenya, a region with persistently high fertility rates, is not well established. We explored whether attitudes towards FP can be attributed to religious affiliation and/or ethnicity among women in the region. Findings show that religion and ethnicity have no impact; the most significant factors are level of education and knowledge about the benefits of FP for the mother. FP interventions ought to include strategies aimed at enhancing women’s knowledge about the positive impacts of family planning.     

Parenting Behaviors and Child Externalizing: A Short-Term Investigation of Directionality

Children (N = 404) provided data during 3rd and 4th grades concerning their mothers’ use of punitive discipline and yielding to coercion. Teachers provided data regarding their perceptions of children’s externalizing behaviors at school. We tested a cross-lagged model examining parental disciplinary behaviors as predictors of child externalizing behavior, as well as child externalizing behaviors as a predictor of parental disciplinary behaviors. For boys and for girls, there was over-time stability in all three variables of interest. For boys only, more externalizing behaviors in Grade 3 predicted greater use of punitive discipline by parents and more parental yielding to coercion in Grade 4, over and above Grade 3 levels of these parenting variables. The reverse direction of effects was not observed.     

Career and work attitudes of blue-collar workers,and the impact of a natural disaster chance event on the relationships between intention to quit and actual quit behaviour

Despite being part of a highly visible and important occupational group, blue-collar workers have, to date, been under-represented in careers research. We explore the relevance and applicability of new career concepts to blue-collar employees, specifically, bus drivers. Based on a survey of 112 bus drivers, we test a model specifying the relationship between career attitude, perceived organizational support, psychological contract, and job satisfaction, as well as intention to quit. Employing a two-phase data collection process, we also test relationships between intentions and actual quit behaviour. Our results support the validity of career theories for blue-collar workers but with notable exceptions, such as lack of relationships between protean career and intention to quit. Contrary to intention-behaviour theory we find that actual quit behaviour was not related to intention to quit, which we attribute to a significant external chance event, a devastating earthquake, which took place during the study period. In addition, we identify relationships that appear to be unique to blue-collar workers.