Parameters affecting the maintenance of negatively reinforced key pecking

Three negative reinforcement experiments employing a key-peck response are described. In Experiment I, pigeons shocked on the average of twice per minute (imposed condition) could produce, by pecking a key, an alternate condition with correlated stimuli. Delayed shocks were added, across sessions, to the alternate condition until pecking stopped. Two of three pigeons continued to peck despite a 100% increase in shock frequency. In Experiment II, pigeons were shocked in the imposed condition four times per minute. The postresponse delay to shock was held constant by delivering, in the alternate condition, the next shock, or the next two, three, or four shocks from the imposed-condition shock schedule. All three subjects continued to peck with no change in delay to the first two postresponse shocks but with a 75% reduction in shock frequency. In Experiment III, a response produced an immediate shock followed by a shock-free period. Three of four subjects continued to respond despite reduced delay to shock. Delay-to-shock or shock-frequency reduction was sufficient to maintain key pecking, but neither was necessary. The conditions that negatively reinforce the pigeon's key peck were similar to conditions that negatively reinforce the rat's bar press.     

Development of sensitivity to information for impending collision

Infants were tested in three experiments to study the development of sensitivity to information for impending collision and to investigate the hypothesis that postural changes of very young infants in response to an approaching object are of a tracking rather than of a defensive nature. Experiment 1 involved the presentation of three types of shadow projection displays, specifying (1) collision, (2) noncollision, and (3) a nonexpanding rising contour, to infants from 1 to 9 months of age. Avoidance of collision appears to be absent in 1- to 2-month-olds, begins to develop in 4- to 6-month-olds, and is present in 8- to 9-month-old infants. In Experiment 2, 1- to 2-month-old infants were presented with optical expansion patterns which specified collision and noncollision. The top contour of these displays stayed at eye level. No significant difference was observed between reaction to the collision and the noncollision displays, suggesting that the young infants were tracking the displays and not attempting to avoid collision. Experiment 3 was designed to determine whether an approaching real object might elicit an avoidance response in infants not sensitive to an optical display specifying collision. No evidence of avoidance behavior was observed in the 1- to 2-month-olds; however, avoidance, as indexed by blinking, does appear to be present at 4 months of age.     

Generalization of a tactile stimulus in horses.

Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain dispenser. The experimenters secured a tactile-stimulus belt to the horse's back. The stimulus belt was constructed by mounting seven solenoids along a piece of burlap in a manner that allowed each to provide the delivery of a tactile stimulus, a repetitive light tapping, at different locations (spaced 10.0 cm apart) along the horse's back. Two preliminary steps were necessary before generalization testing: training a measurable response (lip pressing) and training on several reinforcement schedules in the presence of a training stimulus (tapping by one of the solenoids). We then gave each horse two generalization test sessions. Results indicated that the horses' behavior was effectively controlled by the training stimulus. Horses made the greatest number of responses to the training stimulus, and the tendency to respond to the other test stimuli diminished as the stimuli became farther away from the training stimulus. These findings are discussed in the context of behavioral principles and their relevance to the training of horses.     

Relations between nutrition and cognitive performance in Egyptian toddlers

Two relatively unexplored questions--which specific components of chronic mild child malnutrition are associated with specific behavioral and cognitive deficits and do psychosocial child rearing factors moderate the nutrition-development relationship?--were investigated in a longitudinal study involving 153 toddlers from the Egyptian village of Kalama. Beginning at study entry at age 18 months and continuing until 30 months, food intake information was obtained for 2 consecutive days each month. During the same period, researchers visited the homes twice a month to observe both toddler behavior and caregiver styles. Finally, standardized infant development tests were administered at 24 months and 30 minutes and the capacity for exploratory, symbolic play was assessed. Specific components of nutritional intake at 18-23 months of age were confirmed to be uniquely related to specific developmental outcomes at 24 months of age. Changes in toddler intake from 18-30 months also predicted 30-month cognitive performance. At 24 months, general mental competence was associated positively with fat intake, total kilocalories, and total protein intake while symbolic play capacity was related only to total protein intake. Significant increases in predictive variance occurred when the model was expanded to encompass caregiver behaviors as well as nutritional factors. For example, when nonverbal response to child vocalizations was used as the environmental measure, there was evidence of both coactive and synergistic interactions for comparisons involving cognitive development indicators. For symbolic play, an increase in predictive variance was found when the model included the multiplicative interaction of animal kilocalories by nonverbal response to vocalizations. Also observed was a buffering effect against poor psychosocial rearing conditions given the presence of adequate nutritional intake. These findings suggest the feasibility of multidimensional risk profiles, the provision of specific nutrients targeted at specific deficits, and multidisciplinary interventions.     

A validational note on the revised Socialization Scale of the California Psychological Inventory

The revised (1987) Socialization Scale of the California Psychological Inventory was studied in a sample of 121 delinquent and nondelinquent males to determine if the revised scale, compared to the original version of the scale (1957), could differentiate among a group of nonoffenders and a comprehensive typology of offenders. Results of an ANOVA and product-moment correlations provided significant and considerable support for the discriminability of the revised So Scale. Obtained results indicate that the revised instrument can differentiate offenders from nonoffenders to about the same, or a greater, degree than the original scale.     

Beyond Babel: An Anglican perspective in Bradford the eighth lambeth interfaith lecture

Bradford represents a unique vantage point from which to chart the attempts by a British city to respond to the social fact of religious and cultural diversity. A town famous for its textile industry, it has attracted migrant labour for over one hundred and fifty years: the Irish Catholic migration in the mid-nineteenth century anticipates in many particulars the Muslim experience a hundred years later. After thirty years the sizeable South Asian Muslim presence has begun to participate in the political, economic, institutional and cultural life of the city. The Church's role in both creating and supporting institutions where Christian and Muslim can work together, and using its own institutional influence to accommodate Muslim needs has been considerable. The trust and respect in which the local Bishop was held in the city enabled him to facilitate and maintain a dialogue between Muslims and civic and political leaders at a time when communities were threatening to polarize into mutual incomprehension, in the wake of The Satanic Verses affair. The Church's role was also to affect the temper and challenge the terms in which issues were discussed, not least the dismissal of Muslims as 'fundamentalists', which obscured the diversity and debate within the Muslim communities in the city.     

Thirty years of teaching psychotherapy skills

The author outlines a basic model for teaching psychotherapeutic skills that includes five modules relating to (1) the dynamics of exploration, designed to encourage the patient's affective expression; (2) relationship structure, considering patterns of patient-therapist interaction along a closeness/separateness continuum; (3) affect, empathy, and distance regulation, emphasizing the crucial significance of identifying correctly and responding empathically to patients' affective messages; (4) basic cognitive interventions, focused on techniques for facilitating the patient's narrative flow and capacity to analyze experiences, and for formulating the patient's psychopathology; and (5) the therapist's use of self. The author concludes by examining why systematic psychotherapy training is particularly important at this time, in light of such pressures as managed health care, neuroscientific advances and psychopharmacologic breakthroughs, and the wave of self-help organizations.     

MMPI correlates of Exner's Egocentricity Index in an adolescent psychiatric population

This research examined the relationship between Exner's Egocentricity Index (EI) and Minnesota Multiphasic Personality Inventory (MMPI) Scales 2, 4, and 9 in an adolescent psychiatric population. Subjects with a low EI had significantly higher MMPI Depression (D) scale elevations compared to those with a high EI. Furthermore, of the adolescents who had Scale 2 scores in the clinical range, 68% also had an EI in the bottom half of the distribution. There was no relationship between the EI and MMPI scales 4 and 9. These findings are discussed in light of the generally poor correlations between MMPI and Rorschach variables.     

Elicited responding in chain schedules.

An omission procedure was employed to study elicited pecking in the first component of a two-component chain schedule. Both components were fixed-interval schedules correlated with colored keylights. The first response following the initial-link schedule produced a second fixed-interval schedule. We studied several fixed-interval lengths in two conditions: a standard response-dependent condition and an omission-contingent condition. The omission-contingent condition differed from the response-dependent condition in that responses during the initial fixed interval terminated the trial (omitting the terminal component and grain). If the terminal component was not omitted, a response following the terminal link's requirement produced 4-s access to grain. Pigeons responded during more than 70% of the initial links in the omission-contingent condition and responded during more than 90% of the initial links in the response-dependent condition. In general, rates of responding were consistent with the percentage data. The responding in the omission condition suggests that there may be elicited pecking, in chain schedules using pigeons, that is not the result of contingent conditioned reinforcement.     

Informal Drunk Driving Intervention: Psychosocial Correlates Among Young Adult Women and Men1

Based on experimental research on helping and survey findings on drunk driving intervention, we selected 28 variables for study that might relate to informal intervention in a drunk driving situation. We tested six hypotheses by categorizing the 28 variables into personal (12), relationship (4), situational (5), and individual response (7) aspects. Bivariate correlations and multivariate logistic regression analyses were performed between these 28 predictor variables and intervention for 303 college students (192 females and 111 males). Three personal, one relationship, three situational, and four individual responses in situation variables were correlated significantly with intervention. Four significant predictors emerged in the stepwise logistic regression equation: knowing the driver well; having a conversation that encouraged the respondent to intervene; perceiving the driver as needing help; and the respondent's feeling able to intervene. All hypotheses received at least some confirmation in these results, but noteworthy discrepancies from expectations emphasize the need to appreciate differences between studies of helping behavior in the laboratory and this natural form of helping behavior.