Basal ganglia, dopamine and temporal processing: performance on three timing tasks on and off medication in Parkinson's disease

A pervasive hypothesis in the timing literature is that temporal processing in the milliseconds and seconds range engages the basal ganglia and is modulated by dopamine. This hypothesis was investigated by testing 12 patients with Parkinson's disease (PD), both 'on' and 'off' dopaminergic medication, and 20 healthy controls on three timing tasks. In a seconds range (30-120 s) time production task, patients tested 'on' medication showed a significantly different accuracy profile compared to controls and when tested 'off' medication. However, no group or on vs off medication differences in accuracy were found on a time reproduction task and a warned reaction time task requiring temporal processing within the 250-2000 ms range. Variability was measured using the coefficient of variation, with the performance of the patient group on the time reproduction task violating the scalar property, suggesting atypical temporal processing mechanisms. The data suggest that the integrity of the basal ganglia is necessary for 'typical' time production in the seconds range as well as for time reproduction at shorter intervals. Exploratory factor analysis suggested that the time production task uses neural mechanisms distinct from those used in the other two timing tasks. The dissociation of the effects of dopaminergic medication and nature of task on performance in PD raises interesting questions about the pharmacological mediation and task-specificity of deficits in temporal processing.     

The social endocrinology of dominance: basal testosterone predicts cortisol changes and behavior following victory and defeat

Past research suggests that individuals high in basal testosterone are motivated to gain high status. The present research extends previous work by examining endocrinological and behavioral consequences of high and low status as a function of basal testosterone. The outcome of a competition--victory versus defeat--was used as a marker of status. In Study 1, high testosterone men who lost in a dog agility competition rose in cortisol, whereas high testosterone men who won dropped in cortisol. Low testosterone men's cortisol changes did not depend on whether they had won or lost. Study 2 replicated this pattern of cortisol changes in women who participated in an experimental laboratory competition, and Study 2 extended the cortisol findings to behavior. Specifically, high testosterone winners chose to repeat the competitive task, whereas high testosterone losers chose to avoid it. In contrast, low testosterone winners and losers did not differ in their task preferences. These results provide novel evidence in humans that basal testosterone predicts cortisol reactivity and behavior following changes in social status. Implications for the social endocrinology of dominance are discussed.     

Reinforcer control by comparison-stimulus color and location in a delayed matching-to-sample task

Six pigeons were trained in a delayed matching-to-sample task involving bright- and dim-yellow samples on a central key, a five-peck response requirement to either sample, a constant 1.5-s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green-key responses were occasionally reinforced following the dimmer-yellow sample, and red-key responses were occasionally reinforced following the brighter-yellow sample. Reinforcer delivery was controlled such that the distribution of reinforcers across both comparison-stimulus color and comparison-stimulus location could be varied systematically and independently across conditions. Matching accuracy was high throughout. The ratio of left to right side-key responses increased as the ratio of left to right reinforcers increased, the ratio of red to green responses increased as the ratio of red to green reinforcers increased, and there was no interaction between these variables. However, side-key biases were more sensitive to the distribution of reinforcers across key location than were comparison-color biases to the distribution of reinforcers across key color. An extension of Davison and Tustin's (1978) model of DMTS performance fit the data well, but the results were also consistent with an alternative theory of conditional discrimination performance (Jones, 2003) that calls for a conceptually distinct quantitative model.     

The role of femininity and averageness of voice pitch in aesthetic judgments of women's voices

Although averageness is preferred in auditory stimuli (eg music) and non-face objects (eg wristwatches), exaggerated feminine characteristics are preferred to averageness in female faces. To establish whether or not men prefer femininity in female voices to average characteristics, we conducted a correlational study (study 1) to assess the relationship between voice pitch and attractiveness ratings. We found a positive linear relationship between voice pitch and attractiveness ratings. In study 2 we manipulated pitch in women's voices with low (lower than average), average, and high (higher than average) starting pitches and gauged men's preferences. Men preferred women's voices with raised pitch for all levels of starting pitch. These findings suggest that men prefer high voice pitch to average voice pitch in women's voices.     

Commitment to Work, Care Giving and Seniority: The Case of Nursing

The current study examined whether differences in commitment to paid employment or different levels of private sphere responsibility between women and men could explain the gender segmentation of the paid work force. A survey of a composite sample (N?=?380) of Australian nurses showed that there were no significant differences between women and men in terms of commitment to paid employment although commitment was a predictor of seniority. Primary care-giving status also predicted seniority and women were more likely than men to have care-giving responsibility for dependents. Multiple logistic regression showed that, independent of gender, primary responsibility for care-giving to dependents, rather than commitment to paid employment, explained more of the differing chances for women and men of being in senior positions.     

Computer simulations of developmental change: the contributions of working memory capacity and long-term knowledge

Increasing working memory (WM) capacity is often cited as a major influence on children's development and yet WM capacity is difficult to examine independently of long-term knowledge. A computational model of children's nonword repetition (NWR) performance is presented that independently manipulates long-term knowledge and WM capacity to determine the relative contributions of each in explaining the developmental data. The simulations show that (a) both mechanisms independently cause the same overall developmental changes in NWR performance, (b) increase in long-term knowledge provides the better fit to the child data, and (c) varying both long-term knowledge and WM capacity adds no significant gains over varying long-term knowledge alone. Given that increases in long-term knowledge must occur during development, the results indicate that increases in WM capacity may not be required to explain developmental differences. An increase in WM capacity should only be cited as a mechanism of developmental change when there are clear empirical reasons for doing so.     

EVIDENCE AND FALSIFICATION: CHALLENGES TO GREGORY PETERSON

In this reply to Gregory Peterson's essay “Maintaining Respectability,” which itself is a response to my “Is Theology Respectable as Metaphysics?” I elaborate upon my claims that theology treats God's existence as an absolute certainty immune to refutation and that modern science constitutes the canons of respectable reasoning for metaphysical disciplines. I conclude with some comments on Peterson's “In Praise of Folly? Theology and the University.”     

“Words with Power” for Social Transformation: An Anatomy of Biblical Criticism for Theological Education

Abstract. The proliferation of methods of literary criticism in biblical studies raises the question of how to introduce students to the field. This article argues that the work of Northrop Frye is useful for teaching the existential meaning and social impact of the Bible. The first section introduces relevant aspects of Frye's literary theory. The second presents the author's teaching as a case study. The third section concludes with implications for a philosophy of theological education.     

Heritability of antisocial behaviour at 9: do callous‐unemotional traits matter?

A previous finding from our group indicated that teacher-rated antisocial behaviour (AB) among 7-year-olds is particularly heritable in the presence of callous-unemotional (CU) traits. Using a sample of 1865 same-sex twin pairs, we employed DeFries-Fulker extremes analysis to investigate whether teacher-rated AB with/without CU traits also shows aetiological differences among 9-year-olds. Furthermore, we assessed whether the differences in the magnitude of heritability would be evident even when hyperactive symptoms were controlled for in the statistical analysis. AB among 9-year-olds was more heritable with than without concomitant CU. The heritability difference was even more pronounced in magnitude when hyperactive symptoms were controlled. CU traits thus appear to index one valid way of sub-typing children with early-onset AB.