ELOPTA: A novel microcontroller-based operant device

Operant devices have been used for many years in animal behavior research, yet such devices a regenerally highly specialized and quite expensive. Although commercial models are somewhat adaptable and resilient, they are also extremely expensive and are controlled by difficult to learn proprietary software. As an alternative to commercial devices, we have designed and produced a fully functional, programmable operant device, using a PICmicro microcontroller (Microchip Technology, Inc.). The electronic operant testing apparatus (ELOPTA) is designed to deliver food when a study animal, in this case a bird, successfully depresses the correct sequence of illuminated keys. The device logs each keypress and can detect and log whenever a test animal i spositioned at the device. Data can be easily transferred to a computer and imported into any statistical analysis software. At about 3% the cost of a commercial device, ELOPTA will advance behavioral sciences, including behavioral ecology, animal learning and cognition, and ethology.     

Divergent effects of healthy ageing on semantic knowledge and control: Evidence from novel comparisons with semantically impaired patients

Effective use of semantic knowledge requires a set of conceptual representations and control processes which ensure that currently relevant aspects of this knowledge are retrieved and selected. It is well-established that levels of semantic knowledge increase across the lifespan. However, the effects of ageing on semantic control processes have not been assessed. I addressed this issue by comparing the performance profiles of young and older people on a verbal comprehension test. Two sets of variables were used to predict accuracy and RT in each group: (1) the psycholinguistic properties of words probed in each trial and (2) the performance on each trial by two groups of semantically impaired neuropsychological patients. Young people demonstrated poor performance for low-frequency and abstract words, suggesting that they had difficulty processing words with intrinsically weak semantic representations. Indeed, performance in this group was strongly predicted by the performance of patients with semantic dementia, who suffer from degradation of semantic knowledge. In contrast, older adults performed poorly on trials where the target semantic relationship was weak and distractor relationships strong – conditions which require high levels of controlled processing. Their performance was not predicted by the performance of semantic dementia patients, but was predicted by the performance of patients with semantic control deficits. These findings indicate that the effects of ageing on semantic cognition are more complex than has previously been assumed. While older people have larger stores of knowledge than young people, they appear to be less skilled at exercising control over the activation of this knowledge.     

When Is Seeking Safety Functional? Taking a Pragmatic Approach to Distinguishing Coping From Safety

Currently, most exposure-based treatments call for clinicians to assess for and remove all safety behaviors during exposure tasks. However, the notion that safety behaviors are detrimental across all scenarios has recently been challenged, and research regarding the effects of safety behaviors on exposure outcomes is limited and inconsistent. In clinical practice, classifying a strategy as a safety behavior can be a complex and challenging endeavor, particularly when distinguishing between harmful safety behaviors and helpful coping behaviors. We outline an approach that emphasizes the pragmatic truth criterion and uses functional outcomes to classify behaviors as serving either safety or coping functions. Our focus on doing what “works” simplifies decision-making for clinicians and maintains the focus of treatment on enhancing functioning. We propose a model for using functional outcomes to distinguish between safety and coping behaviors and illustrate our approach through case examples.     

How does the ecological foraging behavior of desert kangaroo rats (Dipodomys deserti) relate to their behavior on radial mazes?

Experiment 1 showed that laboratory-reared desert kangaroo rats, like domestic Norway rats, efficiently search for food on a radial arm maze (RAM) by avoiding revisiting arms within a trial. By placing an RAM on the floor so the animals could approach food from any direction, Experiment 2 tested whether efficient search by kangaroo rats was based on tactics of distance minimizing, central-place foraging, trail following, or meandering. In contrast to the dominant trail-following tactic of domestic Norway rats (Hoffman, Timberlake, Leffel, & Gont, 1999), kangaroo rats tended to distance minimize, whether maze arms were present or not. Experiment 3 indicated that kangaroo rats treated a floor configuration of eight food cups as two patches of four, based on beeline travel between patches and meandering within them. We conclude that similar performance in an elevated RAM by different species can be based on different tactics, and we suggest that a laboratory apparatus can be used to cast light on niche-related mechanisms.     

Mothers' ambivalence with their babies and toddlers: manifestations of conflicts with aggression

In this paper the author continues his study of conflicts over aggression in women, discussing the implications for contemporary theories of feminine psychology of observations of mothers in parent/child groups with their infants and toddlers. Many mothers experience conflicts over aggression (both in themselves and in their children) and become intolerant of their ambivalence toward their children. The author suggests that this observation provides an avenue that allows an integration of psychoanalytic ideas about maternity and childrearing with psychoanalytic understandings of women's conflicts about achievement in the social realm outside the home. In both roles, difficulties mastering conflicts with aggression may cause women to struggle profoundly, and to experience problems, in successfully negotiating their important life goals, whether the goals refer to their roles as effective mothers or their roles as effective individuals in the social sphere outside the home. Some women may demonstrate these difficulties in one sphere or the other, some in both, and others in neither. The author suggests on the one hand that we need to eliminate the concept of normality when considering the activities of women, and on the other hand that we need to normalize the omnipresence of ambivalence in the psychology of women.     

Parsing silhouettes: the short-cut rule.

Many researchers have proposed that, for the purpose of recognition, human vision parses shapes into component parts. Precisely how is not yet known. The minima rule for silhouettes (Hoffman & Richards, 1984) defines boundary points at which to parse but does not tell how to use these points to cut silhouettes and, therefore, does not tell what the parts are. In this paper, we propose the short-cut rule, which states that, other things being equal, human vision prefers to use the shortest possible cuts to parse silhouettes. We motivate this rule, and the well-known Petter's rule for modal completion, by the principle of transversality. We present five psychophysical experiments that test the short-cut rule, show that it successfully predicts part cuts that connect boundary points given by the minima rule, and show that it can also create new boundary points.     

Women's characteristics and gender role attitudes: support for father involvement with children

Women's (N = 364) personal characteristics and gender role attitudes were examined in relation to their support for father involvement with children. The respondents completed measures of trust, attitudes toward women, hostility, self-esteem, and father involvement. Nontraditional gender role attitudes, positive ratings of their own interpersonal trust, and low hostility toward men were predictive of the respondents' support for father involvement. Participant demographics (including age, marital status, and number of children) were unrelated to their views of father involvement. Results indicate the importance of considering the characteristics and attitudes women bring to the co-parental relationship in the examination of factors influencing father involvement with children. Findings are discussed within the context of mothers' primary child-care and gatekeeping roles.     

Parsing silhouettes: The short-cut rule

Many researchers have proposed that, for the purpose of recognition, human vision parses shapes into component parts. Precisely how is not yet known. The minima rule for silhouettes (Hoffman & Richards, 1984) defines boundary points at which to parse but does not tell how to use these points to cut silhouettes and, therefore, does not tell what the parts are. In this paper, we propose the short-cut rule, which states that, other things being equal, human vision prefers to use the shortest possible cuts to parse silhouettes. We motivate this rule, and the well-known Petter’s rule for modal completion, by the principle of transversality. We present five psychophysical experiments that test the short-cut rule, show that it successfully predicts part cuts that connect boundary points given by the minima rule, and show that it can also create new boundary points.     

Early sexual experiences among pregnant and parenting adolescents.

One hundred sixty-six pregnant or parenting adolescent females completed a survey regarding early sexual experiences (wanted and unwanted), family dysfunction and violence, and health-risky behaviors occurring prior to age 18. Fifty-three percent had at least one unwanted sexual experience. Younger age at first unwanted sexual experience was associated with younger age at first wanted sexual experience. Adolescent females with an unwanted sexual experience, as compared to those without, were more likely to be victims of physical violence, to have run away, to be substance abusers, and to have family members with drug or alcohol problems. Four factors explained 39% of the variance in age at first pregnancy: presence of a family member with a drinking problem, age first got hit with a belt or other object by a family member, age first got drunk, and age at first wanted sexual experience. It was concluded that the prevention of teenage pregnancy entails a multifaceted approach that addresses family life, early sexual experiences, and health-risky behaviors.