The genetic context of perceptual imprinting: Canalization by stimulus preference

Recent data from various sources converge in pointing to constitutional constraints and genetic influences in behavioral development. What are the mechanisms that mediate such constraints and influences? Are they expressed through mechanisms of behavior acquisition and learning? Or are they expressed through genetically determined perceptual capacities and response propensities that guide behavior along species-typical and ontogenetically adaptive developmental trajectories? These alternatives are examined in the context of genetically and environmentally manipulated stimulus preferences and perceptual imprinting in Japanese quail chicks (Coturnix coturnix japonica). Data indicate that the genotype is a source of variation in unconditional stimulus preferences and that there are inhibitory and facilitative interactions between different unconditional preferences and also between unconditional and acquired preferences. Variations in stimulus-specific and stimulus-general learning may guide behavioral development in ways that are genetically preadapted, yet individually variable, and ontogenetically adaptive. Interpretation of data favors a synthesis of earlier psychological and biological concepts of canalization.     

Reciprocal heuristics: A discussion of the relationship of the study of learned behavior in laboratory and field

At the turn of the century, the initiators of laboratory study of animal learning advocated two very different approaches to the subject matter. Willard Small favored the investigation of learning in ecological settings appropriate to individual species. E. L. Thorndike treated the process of association formation in animals as a general one, best studied in situations distant from those to which subject species were adapted. The latter view dominated laboratory study of animal learning for 80 years. The consequent absence of ecological content from laboratory investigations of animal learning, together with recent expansion in knowledge of the behavior of free-living animals, has created opportunities for ecologically sound investigations of animal learning of the type first advocated by Small. Studies of taste-aversion learning, although introducing evolutionary issues into the study of animal learning, do not exemplify such an approach. Integration of field and laboratory studies of behavioral plasticity in animals requires a change in the methods used to select phenomena for analysis. Such integration does not often lead to identification of the behavioral processes underlying the development of particular behaviors observed in nature. Rather, its results are an increase in the variety of learning processes investigated in laboratory settings and enhanced understanding of the behavioral capacities of subject species.     

Stimulus configuration and valence-enhanced pecking by neonatal chicks

Valence-enhanced pecking occurs when hatchling chicks preferentially peck at releasing stimuli that have been assigned increased releasing power or valence. Enhanced valence is assigned by another releasing stimulus—here a “pecking” arrow. Pecking movements by the arrow have two separate effects: the stimulation or release of pecking by chicks and releasing valence enhancement, that is, pecking directed to particular stimuli. Exposure of chicks to the moving arrow yields pecking significantly increased over that accruing to a stationary arrow. A distinctive stimulus placed on the floor at the tip of the arrow, or, most effective, attached to the tip of the moving arrow, produces enhanced valence: pecking by observing chicks that is selectively increased to matching stimuli.     

The eyes have it: Young children's discrimination of age in masked and unmasked facial photographs

The ability of preschool children to discriminate age, and their use of information from different facial areas in this task, was investigated. Most 4-year-olds were able to rank sets of seven facial photographs into age order successfully. Subsequently, they were presented with facial stimuli in which different regions of the face were masked out. Masking of the eyes produced a marked performance decrement, and masking of the nose and cheeks a slight decrement, relative to masking of either the mouth and chin, or of the hair and neck. Possible explanations of the results are discussed, together with the verbal comments of the children on the cues they were aware of using.     

Managerial career stage and facets of job satisfaction

The purpose of the present study was to assess the relationship between a three-stage model of careers (establishment, advancement, and maintenance) and facets of managers' job satisfaction. Four hundred eighty-three managers responded to a questionnaire regarding the length of time they had been in their occupation and their satisfaction with various aspects of work. The results indicated that career stage moderated managers' satisfaction with all facets of work. Specifically, managers in the establishment stage were significantly more satisfied than those in the advancement and maintenance stages with five of the six facets studied. Further analyses indicated that the first year in the occupation accounted for the differences in satisfaction obtained in the three-stage model. The results are discussed in terms of the implications for the study of managerial careers and the need for consistency in the operational definition of career stages.     

Recognition and discrimination of emotional faces and pictures

In order to learn whether patients with right-hemisphere disease (RHD) had a deficit in their ability to discriminate and comprehend emotional faces and pictures, we studied nine patients with RHD, nine patients with left-hemisphere disease (LHD), and nine controls. The subjects were presented with six picture tests that comprised either emotional faces or emotional scenes. Their task was either to denote (name or choose) an emotion or to discriminate (same, different) between two faces or emotions. Patients with RHD performed significantly worse than subjects with LHD when asked to discriminate between faces, to discriminate between emotional faces, and to name emotional scenes. There was also a trend for the RHD group to be more impaired than the LHD group when asked to name the emotional face or choose the emotional face. Except for the facial and emotional discrimination tests, the LHD patients also performed worse than controls.     

Extinction of morphine analgesic tolerance

It has been suggested that the analgesic effect of morphine becomes attenuated over the course of successive administrations by a conditional, compensatory, hyperalgesic response elicited by the administration procedure, thus accounting (in part) for analgesic tolerance. On the basis of this associative model of tolerance, it would be predicted that established tolerance would be extinguished by placebo sessions. In experiments of apparently similar design (but conducted by different experimenters in different laboratories), data both confirming and refuting this prediction have previously been published. The present experiment, conducted jointly by the experimenters who reported the divergent findings, was designed to determine the reasons for the different results. It was found that placebo sessions do consistently attenuate morphine analgesic tolerance. Such extinction is not limited to the experimenter, drug preparation, rat strain, or apparatus used in the original, successful demonstration of the phenomenon, but rather is also demonstrable under conditions similar to those used in subsequent experiments which failed to demonstrate extinction of tolerance. Results of the present experiment suggest that the failures to demonstrate extinction of tolerance were attributable to insufficient extinction training.     

An investigation of various performance-based treatments with acrophobics

Five different performance-based treatments (participant modeling, participant modeling without therapist physical contact, modeling plus exposure, therapist-controlled exposure in vivo and rationale only) were compared to evaluate their relative effectiveness in the treatment of acrophobia. Ten subjects were assigned to each of the five groups. Avoidance behavior was assessed using a behavior test, self-report fear measures, heart-rate and self-efficacy expectation measures. Subjects were first submitted to two behavioral approach tests. These two pre-tests were administered 1 week apart, and no significant differences occurred between the evaluations. Analyses of variance for repeated measures at pre-test. post-test and follow-up revealed a significant improvement on all main outcome measures for the five groups. No significant differences among groups were observed. The total treatment time, which was also used as a dependent measure, did not yield any significant differences among treatment conditions. These findings have many implications. For instance, the need for induction aids, such as physical contact with the therapist and modeling, is questioned. Also, exposure per se whether therapist or self-controlled is shown to be effective in reducing avoidance behavior. Finally, the theoretical and clinical implications of these results are discussed.     

Cognitive restructuring treatment: A controlled trial with anxious patients

Cognitive restructuring, modified systematic desensitization and a combined treatment (cognitive behaviour modification) were compared with a no-treatment control group, using a simple randomized design. Twenty seven general anxiety out-patients selected from the hospital waiting list were used as subjects. Assessments were made at the beginning and end of treatment, and at follow-up 1 month later. The assessments included two subjective anxiety measures, the Zung self-rating anxiety scale and fear thermometer scores, a behavioural anxiety measure, a measure of cognitive anxiety as estimated by a diary recording of thinking time, fear survey schedule scores and I/E scores.Cognitive behaviour modification was found to be a superior form of treatment, relative to the no-treatment control and the other active treatment groups as assessed by FSS intensity score. The cognitive behaviour modification group showed greater improvement than the cognitive restructuring group on the diary anxiety scores. The results also demonstrated a relationship between outcome and initial severity of condition. The higher the subjects' initial scores on neurotic symptoms and subjective anxiety level, the greater the degree of positive change after treatment. Moreover, subjects with high levels of internal control prior to treatment responded most to therapy.