Rats in a Pavlovian situation were trained under three different reward schedules, at either a 30 s or a 90 s intertrial interval (ITI): Consistent reward (C), 50% irregular reward (I), and single alternation of reward and nonrewarded trials (SA). Activity was recorded to the conditioned stimulus (CS) and in all 10 s bins in each ITI except the…

The renewal of extinguished conditioned behaviour appears to reflect context-dependent learning. The present research used a conditioned suppression task with humans to examine whether instructions concerning the context could influence renewal. Pairings of a conditional stimulus (CS) and unconditional stimulus (US) were made in one context,…

Pigeons were trained in three experiments with a two-key, concurrent-chains choice procedure. The initial links were equal variable-interval schedules, and the terminal links were random-time schedules with equal average interreinforcement intervals. Across the three experiments, the pigeons either stayed in a terminal link until a reinforcer was…

This article provides the first demonstration of a reliable second-order conditioning (SOC) effect in human causal learning tasks. It demonstrates the human ability to infer relationships between a cause and an effect that were never paired together during training. Experiments 1a and 1b showed a clear and reliable SOC effect, while Experiments 2a…

Three experiments examined the effects of physical context changes and multiple extinction contexts on the renewal of conditioned suppression in humans. A conditioned suppression task used an undesirable event as the unconditional stimulus (US). One conditional stimulus (CS+) predicted the occurrence of the US and another (CS-) predicted US…

This study examines frequency, overlap, and genetic and environmental influences on sleep difficulties, which are understudied in school-aged children. The Sleep Self Report and the Children's Sleep Habits Questionnaire were completed by 300 twin pairs (aged 8 years) and their parents. Child report suggested more frequent sleep problems than…

Discusses current learning theories, indicating that though many psychologists and ethologists now agree on using a mechanistic approach, some linguists doubt its adequacy. Implications of research on the mollusk "Aplasia" to understand the learning process are included. (JN)

Discusses three themes important for the future progress of developmental psychology: (1) a focus on not only individuals, but also individuals in networks of relationships; (2) description as the first, but not the only, stage in the analysis of developmental processes; and (3) a multidisciplinary approach. (BC)

Infant temperament is theorized to have a strong genetic basis. Yet, studies of the stability of temperament and molecular genetics research on temperament have revealed inconsistent findings. One reason may be because research has not taken into account the influence of early social experiences. We review research on aspects of infant…

Although millions of young children spend much of their lives in classrooms, research rarely provides guidance to teachers organizing classrooms for play activities. Psychological literature on social play and pretend play illustrates the absence of clear guidance. Whereas early research posited a progression through levels of social play (i.e.,…