PET studies of language: An assessment of the reliability of the technique

In order to understand the basis of language in the brain, we must be able to describe the neurological systems that are used in language comprehension and production. In this paper, one technique for functional neuroimaging is discussed: measurement of blood flow change using positron emission tomography (PET). Two experiments were carried out investigating the usefulness of this method. One experiment examined the intrinsic time limitations of blood flow change as a measure of cognitive activity. A second issue considered is the replicability of the results obtained using this method. A comparison of two experiments containing the same conditions suggests that the results are replicable, when the experiments and method are similar. One case is discussed where the experiments differ; it is suggested that this is due to a difference in the materials used in the experiments, and that the difference has a principled basis.     

Why P rather than Q? The curiosities of fact and foil

Conclusion Of the various proposals regarding the fact/foil relationship discussed above my own most closely resembles that of Lipton: a largely similar type of causal history is indeed required for true P and false Q to generate a contrastive why question. What I add is the requirement that P and Q be culminating events of a single type of natural causal process.While my immediate aim has been to describe the nature of the fact/foil relationship, the greater significance of this project lies in an improved understanding of the nature of contrastive explanation. Temple proposes in his (1988) article that to explain why P rather than Q is ultimately just to explain why P and not Q — but on this account (in the absence of an account of contrast itself) it ought to be possible to explain why Bush won the election rather than life never having arisen in the universe by simply conjoining the explanation of Bush's victory with the explanation of the origin of life. But insofar as one may not sensibly say that Bush won the election rather than life never having originated it ought not to be possible to explain this later fact: our account of explanation should prohibit explanations where there are, in principle, none to be found. Lipton's own theory of contrastive explanation is that one explains why P rather than Q by citing some cause of P that is not matched by a corresponding cause of the same type for Q; but again, this by itself would allow explanations of insensible contrastive phenomena (a cause of Bush's victory would certainly not be matched by a corresponding cause of the same type of life's not coming into existence — should we then allow some cause of the Bush victory to explain why Bush won rather than life never having arisen?) That Garfinkel, Lipton, Sober and Temple make serious efforts to understand the fact/foil relationship indicates that they each accept the premise of this paper: our account of contrastive explanation will remain incomplete until we understand the nature of contrastive phenomena.For comments and criticism on one or another version of the present paper I am grateful to Paul Humphreys, Peter Lipton, Elliott Sober, Dennis Temple, and Bas van Fraassen.     

Time Past and Time Present: ;Linearities, Circularities and Life

In 1979 this journal published 'Psychodynamic and structural approaches to work with families', a paper reflecting my preoccupation at that time with the move from a psychodynamic model to a model that was not only systemic, but based on developmental principles of family life and family evolution. This paper considers some of the effects of social context, past and present, which relate to the social construction of myself as a woman therapist, and my relationship to changes in professional and gendered issues since 1979.     

Gender and the self-presentation of academic achievement

Two experiments were conducted in which first-year male and female subjects (75% white; 25% minorities) at a highly selective liberal arts college predicted their first-semester grade point averages (GPAs). The first experiment varied whether predictions were given publicly or privately when an incentive for accuracy was either present or absent. Whereas the actual GPAs obtained by women did not differ from those obtained by men, women predicted that they would receive lower GPAs than men predicted, but only in the public condition. Whether incentive was present or absent did not affect predictions. The second experiment varied whether predictions were given publicly or privately as well as the perceived achievement of the experimenter. Once again, women's actual GPAs did not differ from men's. However, women predicted that they would receive lower GPAs than men predicted, but only when their estimates were given publicly to a low-ability experimenter. Although previous research has concluded that gender differences on performance estimates is attributable to a lack of confidence among women, these results suggest that the gender difference may be (at least partly) attributable to self-presentational style. It appears that women in this study adopted a modest self-presentational style that was motivated by attempts to protect the self-esteem of the experimenter.We are especially grateful to Rob Abel, David McGill, and Melinda Varn for their help in data collection.     

Treating emotionally disturbed youth: A comparison of home-based and outpatient interventions

The purpose of this study was to compare home-based and outpatient treatment for families with an emotionally disturbed child. Following treatment, both groups reported improvement in child and family functioning. Guidelines are offered to therapists working with families-at-risk of having a child removed from the home.John J. Zarski, PhD, is coordinator of the Marriage and Family Therapy Training Program and Leslie Barnes Fluharty, MS, is a doctoral student in counseling psychology at the University of Akron, Akron, OH.     

A transfer of functions through derived arbitrary and nonarbitrary stimulus relations

During Experiments 1 and 2, subjects were trained in a series of related conditional discriminations in a matching-to-sample format (A1-B1, A1-C1 and A2-B2, A2-C2). A low-rate performance was then explicitly trained in the presence of B1, and a high-rate performance was explicitly trained in the presence of B2. The two types of schedule performance transferred to the C stimuli for all subjects in both experiments, in the absence of explicit reinforcement through equivalence (i.e., C1 = low rate and C2 = high rate). In Experiment 2, it was also shown that these discriminative functions transferred from the C1-C2 stimuli to two novel stimuli that were physically similar to the C stimuli (SC1 and SC2, respectively). For both these experiments, subjects demonstrated the predicted equivalence responding during matching-to-sample equivalence tests. In Experiments 3 and 4, the conditional discrimination training from the first two experiments was modified in that two further conditional discrimination tasks were trained (C1-D1 and C2-D2). However, for these tasks the D stimuli served only as positive comparisons, and ND1 and ND2 stimuli served as negative comparisons (i.e., C1 × ND1 and C2 × ND2). Subsequent to training, the negatively related stimuli (ND1 and ND2) did not become discriminative for the schedule performances explicitly trained in the presence of B1 and B2, respectively. Instead, the ND1 stimulus became discriminative for the schedule performance trained in the presence of B2, and ND2 became discriminative for the schedule performance trained in the presence of B1. All subjects from Experiment 4 showed that the novel stimulus SND1, which was physically similar to ND1, became discriminative for the same response pattern as that controlled by ND1. Similarly, SND2, which was physically similar to ND2, became discriminative for the same response pattern as that controlled by ND2. Subjects from both Experiments 3 and 4 also produced equivalence responding on matching-to-sample equivalence tests that corresponded perfectly to the derived performances shown on the transfer of discriminative control tests.     

Social Categorization and Stimulus Equivalence

Northern Irish Protestant subjects, Northern Irish Catholic subjects, and English Protestant subjects were taught a series of conditional discriminations using a matching-to-sample procedure. In the presence of Northern Irish Catholic names, subjects were trained to select three-letter nonsense syllables, and in the presence of the nonsense syllables subjects were trained to select Northern Irish Protestant symbols. Subjects were then tested to determine whether the Protestant symbols and Catholic names had become related through symmetry and transitivity. A generalization test was employed to allow for a preliminary investigation of the transfer of experimentally generated equivalence responding to untrained, socially loaded names. Preliminary findings suggest that prior social learning might interfere with equivalence responding. The relevance of these results to the theoretical interpretation of the equivalence phenomenon and to social attitude measurement in general is discussed.

     

Relationship between first-grade marks and the high school dropout problem

Academic records were obtained for students from two towns in southwestern Ontario who attended their town's major public elementary school from first through eighth grade and then completed their secondary education in each town's only public high school between 1982 and 1986. The evidence showed that students who experienced the most difficulty in mastering the two main areas of the first-grade curriculum (reading and arithmetic) had a much higher probability of leaving high school without graduating and of experiencing serious academic problems while in high school than students who received B to A + marks in first grade.     

Posture and gaze in early mother–infant communication: synchronization of developmental trajectories

Weekly laboratory observations of free play for 13 middle-income mother–infant dyads, from 1 to 6 months of age, were used to study the synchronization of developmental trajectories between infant postural position and gaze direction. Mothers sat in a straight-backed chair while holding infants on their laps and were free to adjust the infant’s posture. Postural position was coded as upright (supported sitting or standing on the mother’s lap) or other (lying, cradling, or being held close to mother). Gaze was coded as either at mother’s face or away. The age of onset of visually guided reaching was also assessed. Results show that there were longer durations of gazing away when the infant was in an upright position. Over the 5 month period of observation, the dyads began with a pattern of non-upright positions accompanied by gaze at mother. Contrary to previous predictions, the developmental shift in the first 6 months from exclusive gazing at mother’s face to gazing away from mother was not synchronized with the development of reaching, but rather with changes in the infant’s posture to more upright positions. The possible role of postural position in fostering positive emotional communication is discussed.