Conditioned fear and startle magnitude: effects of different footshock or backshock intensities used in training

In Experiment 1 four groups of rats received 30 light-shock pairings using footshock intensities of either .2, .4, .8, or 1.6 mA. One day later all rats were tested for startle by presenting tones in the presence or absence of the light CS. Potentiated startle (the difference between startle on light-tone vs tone-alone trials) was nonmonotonically related to the shock intensity used in training, with the greatest potentiation at intermediate shock levels. Experiment 3 demonstrated a similar relationship when backshocks instead of footshocks were used. In Experiment 2 rats were trained with either a moderate or high shock and then given an extended extinction-test session 1 day later. The moderate-shock group showed a gradual decline in potentiated startle over extinction. The high-shock group showed a nonmonotonic extinction curve where potentiation progressively increased toward the middle of extinction and dissipated thereafter. The results suggest that acoustic startle bears an inverted U-shaped relationship to fear and are discussed in relation to other studies concerned with this issue.     

A method of restraining goldfish during conditioning of electric-shock-induced suppression of breathing movements

An efficient method of holding individual fish in position for delivery of visual conditioned stimuli and electrical unconditioned stimuli, and for registration of breathing movements with a thermistor, is described. The holder restrains the fish gently and is readily opened and closed. In addition, a “mechanical fish” signal generator, for assessing thermistor performance in detecting breathing movements, and a safe constant-current electrical shock stimulus generator are described.     

Father-child relationships from the preschool years through mid-adolescence

In this study, we examined variations in fathering and father-child relationships from the children's preschool years through mid-adolescence. One hundred seventy-seven fathers with first-born children ages 4, 8, 12, and 16 years responded to five sets of questionnaires tapping four domains of childrearing: practices, attitudes, parental role involvement, and role satisfaction. A multivariate analysis of variance identified significant variability among the four age groups in fathers' use of acceptance in childrearing practices, role involvement (frequency and task sharing), satisfaction with paternal role performance, and attitudes about the modifiability of child behavior. The results contribute new information about the nature of fathering throughout the childhood years and adolescence and provide additional support for the view of parenting as dynamic and responsive to the developmental level and gender-related characteristics of the child.     

Emotional Empathy in a Courtroom Simulation: A Person-Situation Interaction1

A pair of experiments were conducted using a simulated courtroom trial of a criminal case. In Experiment I subject-jurors were asked by defense counsel either to imagine themselves as the defendant (empathy-inducing appeal) or to pay close attention to evidence (nonempathy appeal). Later the judge delivered only general instructions or, in addition, charged jurors to give consideration only to the facts presented. When there was no Fact-focused judge's charge, juror-subjects who heard the empathy-inducing appeal rated the defendant's actions as more lawful and attributed less of the cause for the incident to his personality than did their counterparts in the nonempathy condition. Experiment II included individual differences in the tendency to empathize as an additional mediating variable. The original pattern of effects found for the manipulated variables in Experiment I appeared again, but were overshadowed by the stronger effects of the individual difference variable and of subject sex. Subject-jurors who scored high on the empathy individual difference measure rated the defendant less guilty, assigned less cause to him, and showed corresponding mood shifts when they heard the empathy-inducing appeal. In addition, male subjects empathized more strongly with the male defendant and viewed him more favorably.     

Transection of direct anterior thalamic afferents from the hippocampus: effects on activity and active avoidance in rats

This investigation demonstrates the importance of the direct hippocampo-anterior thalamic component of the postcommissural fornix in the control of general locomotion and active avoidance. Transection of anterior thalamic afferents from the hippocampal formation (subicular cortex), at the point where they exit from the fornix posterior to the septum, is sufficient to enhance bidirectional active avoidance acquisition and increase general activity. This transection may also interrupt fibers to or from other thalamic nuclei and the anterior septum. However, destruction of connections of the anterior septum with the hippocampus, habenula, and thalamus by transection in the coronal plane anterior to the descending fornix columns, without damage to the subiculothalamic fibers, increases general activity levels without damage to the subiculothalamic fibers, increases general activity levels without affecting active avoidance behavior. The activity increase in this case resembles that seen after septal lesions rather than that seen after hippocampal lesions. Thus, destruction of a single fornix component contributing afferents to the anterior thalamic nuclei reproduces at least part of the hippocampal syndrome. This suggests that these fibers contribute significantly to the control of these behaviors and may mediate active avoidance changes resulting from hippocampal and fornix damage.