Incompatability between the pigeons' unconditioned response to shock and the conditioned key-peck response

High-speed photography was used to compare the pigeon's response to unsignalled shock with the pigeon's key-peck response. During shock, pigeons flex their neck (i.e., the distance between their eyes and shoulders decreases). Following shock, the neck is extended. During key pecking, the neck remains extended and the head moves toward the key in a slight arc as though attached to a fixed fulcrum. Response topography during pecking and shock appear to be incompatible, and it is concluded that the difficulty in key-peck training pigeons to escape electric shock is due to interference from the unconditioned flexion response. This conclusion supports the species-specific defense theory of escape and avoidance behavior.

Clinical correlates of body-size distortion

Body-size distortion has been considered a central symptom of eating disorders. We studied 35 female eating-disordered patients and 85 controls using a computer-based body-size estimation technique. We have found almost identical linear relationships between body-size distortion and weight:height ratios in both groups. In the clinical group, distortion scores were not correlated with scores on the Eating Attitudes Test or Beck Depression Inventory but were negatively correlated with body dissatisfaction as measured on the Eating Disorder Inventory. These results raise further questions about the role of body-size distortion both as a diagnostic criterion and as a complicating phenomenon in eating disorders.

Body-image distortion among male and female American and Costa Rican students and female Japanese students

395 American male and female high school and college students, 286 Costa Rican male and female high school students, and 127 Japanese female college students were tested for body-image distortion using a computer-based body-image distortion task. A reliable negative relationship between stature and body-image distortion was observed. No reliable differences in body-image distortion were observed between different sex or cultural groups.

Body-image dissatisfaction among American male and female college students: a computer-based graphical approach

College students (56 women and 43 men) attending state colleges in the southwestern United States were tested for body-image dissatisfaction using a computer-based graphical body-image task. A reliable relationship between desired stature and desired body-image was observed for the women. Women of large stature showed a greater discrepancy between verbally reported desired stature and redrawn images of desired stature than women of average or smaller than average stature. No reliable discrepancy between desired body-image and verbally reported desired stature was shown by the men.

Increased risk of profound weight loss among women exposed to diethylstilbestrol in utero

We surveyed 1711 women exposed to diethylstilbestrol in utero, and 919 women not exposed, concerning lifetime weight loss histories. The prevalence of a history of unexplained profoundly low body weight (weight less than or equal to 80% of expected weight for age, sex, and height) was 18.7 per 1000 in the exposed group compared to 3.3 per 1000 in the unexposed group; a 5.72 to 1 ratio of increased risk.

Body-image distortion among male and female college and high school students, and eating-disordered patients

For 179 male and female college and high school students, and 26 female eating-disordered patients body-image distortion was measured using a computer-based image-analysis of redrawn images of standardized human figures. Statistical analysis indicated that body-image distortion was the same for all groups. Body-image distortion was significantly and negatively related to weight:height ratio as a function of a simple polynomial. These results suggest this evaluation of distortion of body-image yields a quantitative measure reliably related to weight status but also suggests the technique, and possibly measurement of body-image distortion in general, may not be a valid discriminator between eating-disordered and normal persons.

Coyote control and taste aversion

Studies in which conditioned taste aversion was used as a non-lethal method to suppress coyote predation are reviewed in light of the controversy that surrounds such research. It is concluded that the negative results obtained to date may have been due to theoretical and methodological problems in the studies. Uncritical acceptance of those results has slowed progress on an effective and inexpensive method of coyote management.

Taste-Aversion Conditioning of Crows to Control Predation on Eggs

Free-ranging crows (Corvus brachyrhynchos) that ate chicken eggs that were painted green and contained a nonlethal toxin subsequently avoided green eggs at various locations, whether or not they contained toxin. The crows also continued to eat unpainted and nontoxic chicken eggs. Illness-induced aversions among predators in nature may be a powerful determiner of the evolution of Batesian mimicry and, in human hands, serve as a practical tool for wildlife ecologists.

Coyote Predation Control by Aversive Conditioning

Conditioned aversions were induced in coyotes by producing lithium chloride illness in them following a meal, and the effects upon eating and attack behavior were observed. One trial with a given meat and lithium is sufficient to establish a strong aversion which inhibits eating the flesh of that prey. One or two trials with a given flesh (lamb or rabbit) specifically suppresses the attack upon the averted prey but leaves the coyote free to attack the alternative prey. A method of saving both prey and predator is discussed.