Timing the second response in two-response avoidance.

Rats were trained on a free-operant avoidance task requiring two lever presses within R seconds, with the opportunity for each response distinguished by differing stimuli. Response latencies at a variety of response-shock intervals were found to be proportional to the time available for the response. These results are shown to be consonant with a scalar expectancy model of timing behavior.     

Interview with Dr. Peter Rutter,author ofSex in the Forbidden Zone,July 27, 1990

Articles

Interview with Dr. Peter Rutter, author ofSex in the Forbidden Zone, July 27, 1990     

The effects of parental alcoholism on perception of control and imposter phenomenon

The present study examined the differences in internal and external locus of control and imposter phenomenon among persons with alcoholic and non-alcoholic parents. The subjects were 48 college students and 21 members of local Adult Children of Alcoholic groups. The students were further divided into those with alcoholic parents and non-alcoholic parents. The subjects were administered the following three instruments: the Nowicki-Strickland Internal-External Control Scale for Adults (Nowicki & Duke, 1973), the Imposter Test (Chance & O’Toole, 1987), and a family history survey. Analysis of locus of control scores revealed a highly significant (p<.01) difference for externality, with Adult Children being most external and students with non-alcoholic parents least external. Similarly, internality scores differed significantly (p<.0001), with Adult Children being least, and the non-alcoholic group being most internally oriented. Analysis of variance for imposter phenomenon revealed a significant (p<.05) difference among the three groups, with the Adult Children of Alcoholics group having the highest scores and students with non-alcoholic parents having the lowest. These findings are consistent with the idea that parental alcoholism interferes with nurturing and consistent reinforcement, and with the development of personal adaptability.     

Quality of life and affect in older persons: Hope, time frames, and training effects

This is a preliminary report of a project designed to increase hope and quality of life (QOL) in older persons through a series of five training sessions. The training sessions for the experimental groups are based on research on happiness, goal imagery, and time management. Data indicates that the training is effective in increasing expected QOL. Several measures of affect and stress are examined as a function of three time frames of self-reported QOL. Daily uplifts are significantly related to present and future QOL while measures of stress and major life changes are not. Correlations of affective measures with QOL tend to increase from time frames of the past five years through the present to the next five years, indicating the relevance of hope for older persons. Training for increased hope works with older persons. Data obtained in the process is used to address theoretical models of QOL in older persons. This project was supported by a grant from the American Association of Retired Persons Andrus Foundation.     

Midlife divorce initiation: From crisis to developmental transition

The midlife phase in the marital relationship is a complicated transition period, challenging the flexibility and coping skills of every couple. Separation-Divorce Initiation (S/DI) at this time can serve a special function in the change process required in this stage. A comprehensive therapeutic model for S/DI couples is described. It includes (1) assessment of the relationship's stamina and the function of the S/DI; (2) treating symptoms and reactions to the traumatic event in an emergency intervention mode; (3) steps and techniques to help the couple overcome the traumatic effects of the SD/I and to rebuild their relationship on a more appropriate basis.     

Sensory superstition on multiple interval schedules.

Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food.     

The acquisition of observing.

Pigeons were exposed to stimuli correlated with the presence or absence of a variable-interval 60-second schedule of reinforcement only while they depressed a crossbar or "perch." In the first experiment, the stimuli were different tilts of a line displayed on the key. When the difference in brightness between the line and the background (salience) was maximal, seven of eight birds acquired the discrimination, but when the difference was reduced by 50%, only one succeeded. In the second experiment, wavelength of chamber illumination served as the relevant dimension. Neither experiment showed a large effect attributable to the magnitude of the difference (disparity) between the positive and the negative stimulus. Individual differences in time spent observing were positively correlated with level of discrimination in the presence of the stimuli. All birds produced the positive stimulus for a greater proportion of the available time than they did the negative stimulus. This may be the mechanism that provides selective reinforcement of observing. Finally, the formation of a discrimination was analyzed in terms of changes in the proportion of time spent in contact with the discriminative stimuli.     

Stimulus discriminability in free-operant and discrete-trial detection procedures.

Six pigeons were trained to discriminate different light intensities in four experimental procedures. Experiment 1 compared stimulus discriminability in a yes-no signal-detection task with discriminability measures obtained from two free-operant procedures. Discriminability estimates were significantly lower in the detection procedure. Experiment 2 showed this lowered discriminability to be a function of the delay between stimulus presentation and the availability of the choice-response keys in the standard detection task. In addition, reinforcement sensitivity was lowest when correct choice responses were intermittently, rather than continuously, reinforced.     

Recognizing faces in and out of context

Two experiments are reported which examined the influence of context on face recognition accuracy for novel and familiar faces respectively. Context was manipulated by varying the physical background against which the faces appeared. In Experiment I, 80 student subjects observed 18 faces before attempting to recognize them in a sequence of 36 alternatives. For half the subjects, the backgrounds changed from study to test, while for the remainder they stayed the same. In addition, for half the subjects, both the pose and expression of the face also changed, while for the others it remained constant. Changes in pose plus expression and context significantly reduced recognition accuracy for the target faces. Experiment II used an identical design, except that the faces of celebrities replaced the novel faces. The influence of context was eliminated but the effects of pose and expression were maintained. However, when only faces which were actually identified by subjects were considered, the effects of pose and expression, too, were eliminated. The significance of these findings for theories of contextual memory are discussed.     

Effects of cocaine and d-amphetamine on the repeated acquisition and performance of conditional discriminations.

The acute and chronic effects of cocaine and d-amphetamine on food-reinforced behavior were investigated in pigeons responding on a two-component multiple schedule. In one component, the behavioral task consisted of the same chain of conditional discriminations each session (performance). In the other component, the chain of conditional discriminations was changed from session to session (learning). In comparison to control sessions, both acute cocaine and d-amphetamine increased errors in each component of the multiple schedule. Responding in the learning component, however, was generally disrupted at lower doses than those that affected responding in the performance component. At high doses, both drugs produced pauses in responding in each component in three of the four subjects. Pausing engendered by d-amphetamine was approximately twice as long as that under cocaine. Upon chronic administration, both the pausing and error-increasing effects of each drug diminished. Drug-induced changes in timeout responding, however, did not decrease during chronic administration. Redeterminations of the d-amphetamine dose-effect curves following chronic cocaine administration suggested the existence of cross-tolerance between cocaine and d-amphetamine. Both the acute and chronic data are consistent with the view that conditions of stimulus control may modulate the behavioral effects of drugs.