Two components of responding in Pavlovian lick suppression

The present research examined the temporal distribution of responding in a lick suppression paradigm. In Experiment 1, rats were trained with either a 30- or a 120-s conditioned stimulus (CS), which was followed either by a footshock (unconditioned stimulus [US]) or nothing. Licking during the CS was suppressed only in the former condition. Suppression was more pronounced early in the CS. In Experiment 2, rats were exposed to two 30-s or two 120-s CSs, with delivery of the shock being contingent on CS1 for half of the animals and on CS2 for the other half. For both the paired and the unpaired conditions, suppression at the beginning of CS1 was observed for all the groups. By discounting the possibility of generalization between CS1 and CS2, it appears that this initial suppression was not a conditioned response to the CS, but an unconditioned one due to mere exposure to the shock US.     

Some determinants of second-order conditioning

In a Pavlovian conditioning situation, an initially neutral stimulus may be made excitatory by nonreinforced presentations in compound with an established conditioned excitor [i.e., second-order conditioning (SOC)]. The established excitor may be either a punctate cue or the training context. In four conditioned suppression experiments using rats, we investigated whether SOC phenomena parallel other cue interaction effects. In Experiment 1, we found that the response potential of a target stimulus was directly related to the intertrial interval when SOC was mediated by a punctate cue, and inversely related to the intertrial interval when SOC was mediated by the training context. Experiment 2 demonstrated that punctate- and context-mediated SOC are oppositely affected by posttraining context extinction, and Experiments 3 and 4 demonstrated that context- and punctate-mediated SOC are differentially affected by conditioned stimulus (Experiment 3) and unconditioned stimulus (Experiment 4) preexposure treatments. These findings parallel phenomena in conditioned inhibition and cue competition situations.     

FIRST YEAR IMPLEMENTATION OF A PROJECT-BASED LEARNING APPROACH: THE NEED FOR ADDRESSING TEACHERS�� ORIENTATIONS IN THE ERA OF REFORM

The purpose of this study was to examine the extent to which three teachers’ professional experience and existing orientations toward teaching and learning mathematics and science influenced their implementation of a project-based curriculum (i.e. project-based learning (PBL)). Data sources included interviews, videotapes of classroom activity, and a teaching philosophy questionnaire. Data analysis was conducted using an iterative coding technique. We found coherency between the teachers’ perceived orientations and their emergent ideas about PBL, their sense of PBL as being compatible with their goals, and the specific challenges with which they struggled. All the teachers wanted their students to be successful; however, different definitions of success led to quite different approaches toward teaching, and for the most part, these differences appeared to have occurred because of existing orientations the teachers held for teaching their discipline. Implications for professional development taking into account teachers’ orientations and thus their professional experience are discussed, as well as disciplinary challenges to using PBL.     

A Dual Identity Approach for Conceptualizing and Measuring Children's Gender Identity

The goal was to test a new dual identity perspective on gender identity by asking children (n = 467) in three grades (M_age = 5.7, 7.6, 9.5) to consider the relation of the self to both boys and girls. This change shifted the conceptualization of gender identity from one to two dimensions, provided insights into the meaning and measurement of gender identity, and allowed for revisiting ideas about the roles of gender identity in adjustment. Using a graphical measure to allow assessment of identity in young children and cluster analyses to determine types of identity, it was found that individual and developmental differences in how similar children feel to both genders, and these variations matter for many important personal and social outcomes.     

The effects of child maltreatment on language development

The separate effects of child neglect, abuse, and their interaction upon language development as measured by the Preschool Language Scale were examined in four groups of children (n = 79) in a quasi-experimental design. There were three groups of maltreated subjects, all drawn from a treatment center: an abused only group (n = 13), a neglected only group (n = 7), and an abused and neglected group (n = 31); a non-maltreated group (n = 28) was drawn from a day care center. Abuse, neglect, and their interaction were used to predict both auditory comprehension and verbal ability as separate criteria in two stepwise multiple regression equations, where the variance attributable to gender and mother's status on Aid to Dependent Children had been removed. Child neglect was found to predict significantly both auditory comprehension and verbal ability. Neither child abuse nor the interaction between abuse and neglect significantly predicted either dependent variable. These findings suggest that child neglect may be the critical type of maltreatment associated with language delay.