Development of cerebral dominance: dichotic listening asymmetry in normal and learning-disabled children

The magnitude of the dichotic right-ear advantage was assessed in 48 normal and 48 learning-disabled children representing an age range of approximately 5 years. All subjects were matched according to age, sex, and handedness. An analysis of results indicated a significant right-ear advantage in both the normal and learning-disabled children, but revealed no developmental trends for either group. Differences observed in the performance of the learning-disabled and normal children may reflect variability in selective attention rather than differences in the degree of cerebral lateralization. These results suggest a need for a reconceptualization of the causative factors affecting children with learning disorders and lend support to the notion that cerebral lateralization is not a developmental phenomenon.     

Dual effects of response blocking following avoidance learning

It was shown that either enhanced or decreased avoidance responding by rats could be produced by the same response blocking procedure occurring after avoidance training. The particular result produced depended on (1) the duration of the blocking trial and (2) when during the retention interval the blocking trial occurred. Results were interpreted in terms of a memory reactivation explanation and implications for the therapeutic uses of extinction were discussed.     

Severe Withdrawal (and Recovery)

The problem of how to remove information from an agent's stock of beliefs is of paramount concern in the belief change literature. An inquiring agent may remove beliefs for a variety of reasons: a belief may be called into doubt or the agent may simply wish to entertain other possibilities. In the prominent AGM framework for belief change, upon which the work here is based, one of the three central operations, contraction, addresses this concern (the other two deal with the incorporation of new information). Makinson has generalised this work by introducing the notion of a withdrawal operation. Underlying the account proffered by AGM is the idea of rational belief change. A belief change operation should be guided by certain principles or integrity constraints in order to characterise change by a rational agent. One of the most noted principles within the context of AGM is the Principle of Informational Economy. However, adoption of this principle in its purest form has been rejected by AGM leading to a more relaxed interpretation. In this paper, we argue that this weakening of the Principle of Informational Economy suggests that it is only one of a number of principles which should be taken into account. Furthermore, this weakening points toward a Principle of Indifference. This motivates the introduction of a belief removal operation that we call severe withdrawal. We provide rationality postulates for severe withdrawal and explore its relationship with AGM contraction. Moreover, we furnish possible worlds and epistemic entrenchment semantics for severe withdrawals.     

The Image of God of Neurotheology: Reflections of Culturally Based Religious Commitments or Evolutionarily Based Neuroscientific Theories?

In Augustinian fashion, James B. Ashbrook and Carol Rausch Albright develop a neurotheology that finds evolutionarily based correlations between the functions of the human mind-brain and the roles God plays in human life. I argue that their assumptions of anthropomorphism , that the human mind-brain must conceptualize its environment in human terms, and realism , that anthropomorphism is correct, are evolutionarily unlikely. I conclude that the image of God ( imago dei ) the authors find reflected in the human mind-brain appears to derive from their Christian religious commitments rather than from evolutionary theory.     

Does God Play Dice? A Response to Niels H. Gregersen, “The Idea of Creation and the Theory of Autopoietic Processes”

The idea that the Creator has a plan for creation is deeply rooted in the Christian notion of Providence. This notion seems to suggest that the history of creation must be the execution of the providential plan of God. Such an understanding of divine providence expects science to confirm that cosmic history is under supernatural guidance, that evolution is therefore oriented toward a goal—to bring forth human beings, for example. The problem is, however, that science finds evidence for neither supernatural guidance nor teleology in nature. To address this problem, I understand Niels H. Gregersen to suggest that God is involved in the creative process. The reason science cannot demonstrate God's supernatural guidance of evolution is that the Creator structures the process from within. Gregersen argues that God is involved in the process of creation by changing the overall probability pattern of evolving systems.
In my view, such a model of how God interacts with creation is supported neither by orthodox Christianity nor by modern science. After a critique of Gregersen's argument and a brief history of the relationship between Christianity and science, I shall suggest an alternative. It is that the freedom of creation to create itself is implicit in the fundamental dogma of Christianity that God is love.     

Expertise, Evaluative Motivation, and the Structure of Citizens' Ideological Commitments

Political psychologists have typically argued that ideological commitments are structured in a bipolar fashion, where a positive evaluation of conservative objects implies a negative evaluation of liberal objects (and vice versa). Individual differences in conformity to this pattern are usually attributed to an ability-related variable, i.e., political expertise . Departing from this strict focus on ability, this study examines the hypotheses that an important motivational variable—the need to evaluate , or the desire to form opinions of objects as "good" or "bad"—would (1) predict deviations from ideological bipolarity, even controlling for expertise; and (2) moderate the relationship between expertise and deviations from bipolarity. Data from two national surveys provided evidence for these hypotheses and indicated that the results extended to deviations from bipolarity in evaluations of presidential candidates and political parties.     

On the limits of the matching concept in monkeys (Cebus apella).

Two cebus monkeys, with many years of experience matching a variety of static visual stimuli (forms and colors) within a standard matching-to-sample paradigm, were trained to press a left lever when a pair of displayed static stimuli were the same and to press a right lever when they were different. After learning the same/different task, the monkeys were tested for transfer to dynamic visual stimuli (flashing versus steady green disks), with which they had no previous experience. Both failed to transfer to the dynamic stimuli. A third monkey, also with massive past experience matching static visual stimuli, was tested for transfer to the dynamic stimuli within our standard matching paradigm, and it, too, failed. All 3 subjects were unable to reach a moderate acquisition criterion despite as many as 52 sessions of training with the dynamic stimuli. These results provide further evidence that, in monkeys, the matching (or identity) concept has a very limited reach; they consequently do not support the view held by some theorists that an abstract matching concept based on physical similarity is a general endowment of animals.     

Functional classes and equivalence relations

Three adult subjects were taught a set of two-choice simultaneous discriminations, with three positive and three negative stimuli; all possible combinations of positive and negative stimuli yielded nine different pairs. The discriminations were repeatedly reversed and rereversed, the former positive stimuli becoming negative and the former negative stimuli becoming positive. With all subjects, a reversal of the contingencies for one pair of stimuli became sufficient to change their responses to all of the other pairs. The reversals had produced functional stimulus classes. Then, all subjects showed conditional discriminations emerging between members of a functional class; given a sample from one class and comparisons from both classes, they selected the comparison that was in the same class as the sample. Next, 2 of the subjects showed that the within-class conditional relations possessed the symmetric and transitive properties of equivalence relations; after having been taught to relate new stimuli to existing class members, the subjects then matched other class members to the new stimuli. Subsequent tests of two-choice discriminations showed that the conditional discriminations had transferred functional class membership to the new stimuli. The 3rd subject, who did not show equivalence relations among functional class members, was also found to have lost the within-class conditional relations after the equivalence tests.     

Stimulus context and infant orientation discrimination

In three experiments, the effect of additional "contextual" elements on the discrimination of the orientation of linear and curvilinear segments was investigated with 4-month-old infants. In Experiment 1, paired visual matrices (one which contained some irregularity in orientation of internal elements, vs one which contained no irregularities) were presented. Infants detected irregular matrices significantly better than chance, but such detection was not aided by contextual elements. Discrimination of orientation in Experiment 2 was assessed with a paired-comparison familiarization-novelty paradigm. It was found that the addition of elements here significantly aided discrimination of linear segment orientation, but not curvilinear segment orientation. Experiment 3 investigated why this effect was not found for curvilinear segments; after equating the curvilinear stimuli to linear ones used in Experiment 2 with respect to the closedness of figure, discrimination of curvilinear orientation was observed.     

Development of differences in response latencies to right and left visual fields

Robust lateralization developed in right-handed adults who were asked to judge letter pairs as "same" or "different" during 4608 trials. By the end of the first two blocks (768 trials) "same" responses were favored when presented in the RVF (transmitted directly to the left hemisphere) and "different" responses were favored when presented in the LVF (transmitted direction to the right hemisphere). This gradually reversed over sessions with "same" responses becoming faster for letters presented in the LVF, and "different" responses becoming faster for stimuli presented in the RVF. The laterality acquired under these conditions was cumulative and reproducible, appeared in all 16 subjects, and was preserved between sessions a week apart. The data suggest that laterality is a flexible and reversible characteristic of the human brain even when stimulus and task remain constant.