Characterization of state transitions in spatially distributed,chaotic, nonlinear,dynamical systems in cerebral cortex

The neurons of cerebral cortex are largely autonomous and generate activity that is manifested in trains of microscopic axonal action potentials. The neurons interact by sparse but numerous synaptic connections to generate macroscopic dendritic activity patterns that are observed in electroencephalographic (EEG) waves. The macroscopic patterns are constructed by the populations and they shape the output of cortical neurons in parallel arrays. Sensory cortexes receive sensory information in the form of microscopic action potentials, which induce state transitions in population dynamics. Each state transition transforms sensory information to perceptual meaning. The EEG reflects both kinds of activity. The sensory input is accessed by time ensemble averaging, whereas the perceptual output is found by spatial ensemble averaging. Spatial phase gradients in the EEG are useful for identifying EEG segments in a sequence of state transitions in response to sensory input. The rapidity and flexibility with which they take place give strong reason to postulate that the mechanism for the construction of these sequences of patterns is a dynamical system operating in a chaotic domain.     

Contrary-to-duty obligations

We investigate under what conditions contrary-to-duty (CTD) structures lacking temporal and action elements can be given a coherent reading. We argue, contrary to some recent proposals, that CTD is not an instance of defeasible reasoning, and that methods of nonmonotonic logics are inadequate since they are unable to distinguish between defeasibility and violation of primary obligations. We propose a semantic framework based on the idea that primary and CTD obligations are obligations of different kinds: a CTD obligation pertains to, or pre-supposes, a certain context in which a primary obligation is already violated. This framework is presented initially as an extension of Standard Deontic Logic (SDL), a normal modal logic of type KD, and is illustrated by application to a series of examples. The concluding section is concerned with some resemblances between CTD and defeasible reasoning. We show first that the SDL-based framework contains a flaw and must be adjusted. A discussion of possible adjustments, including an alternative treatment in terms of a preference-based semantics, reveals difficulties that are reminiscent of problems in defeasible reasoning and intensional accounts of defeasible conditionals.     

Preparing the Way: A Qualitative Study of High-Achieving African American Males and the Role of the Family

Employed qualitative methods to examine the role of the family in the academic success of very high-achieving African American males. Findings revealed a complex tapestry of family processes and contexts involved in each youth's journey to outstanding academic achievement. Specifically, the combined importance of parental-determined academic engagement, strict discipline, nurturance, and community connectedness appeared to counteract potentially negative contextual influences of neighborhood, peers, schools, and society. The qualitative findings tell a multifaceted, rich, and compelling story of the pathways to academic success for Black males, and highlight the need for culture-specific and ecologically based conceptualization, research, and intervention approaches.     

Consider the source: One step in assessing premise acceptability

Premise acceptability is conceptually connected to presumption. To say that a premise is acceptable just when there is a presumption in its favor is to give a first approximation to this connection. A number of popular principles of presumption suggest that whether there is a presumption for a premise, belief, or claim depends on the sources which vouch for it. Sources consist of internal belief-generating mechanisms and external testimony. Alvin Plantinga's notion of warrant lays down four conditions upon a source for the belief which it generates to be warranted. We argue that there is a presumption for a premise, belief, or claim if and only if there is a presumption of warrant for that premise,belief or claim. This amounts to the thesis that there is a presumption for a belief from a challenger's point of view if and only if there is a presumption from that person's point of view that her cognitive faculties which have generated the belief have been functioning properly, in an appropriate cognitive environment, in accord with a segment of her design plan aimed at the truth, and that these faculties are reliable. In light of our argument for this thesis, we may legitimately claim that one way to determine that there is a presumption for a belief is to determine that there is a presumption of warrant for that belief, and thus that in determining whether there is a presumption for a belief or premise, we may consider the source.     

What shall we do with Norman? An experiment in communal discernment.

We were a group of Christian friends searching for affirmations that lay at the heart of our faith and reached to the limits of our existence and moral authority. As we have reflected on our role in deciding whether and to what extent we could assist in allowing our terminally ill friend, seventy-nine-year-old, Norman to die, we were deeply troubled by the moral ambiguity of our involvement. Through a careful process of authority through communal discernment, our responsibility for Norman became clear: we were to assist him in living the life he embraced in baptism -- a life which included a destiny that was conformed to the crucified and risen one. That was not the destiny we chose for Norman; it was the destiny he owned. We recognized with Norman that our lives are not our own to be guided by autonomy and liberty, but rather to be lived for the glory of Jesus the Christ.     

The psychologist's role in assessing and facilitating patients' knowledge of advance directives in medical settings: A preliminary investigation

In a time of budgetary shortfalls in the medical industry, an aging population, and an increased emphasis on health care choices, psychologists are being called upon to administer advance medical directive programs to patients. This study reports preliminary findings from a program to assess and facilitate patients' knowledge of advance directives (ADs) by the Psychology Service at the Ann Arbor VA Medical Center. The participant pool included 243 male veteran patients admitted to medical and surgical wards at the hospital. The intervention included the use of a computer-generated prompt for consultation, which was sent to the psychology staff in response to a patient inquiry regarding ADs. It also involved an increased emphasis on the delivery of written material on ADs by the admissions clerks. The intervention appeared to result in a modest increase in patients' knowledge of advance directives. Suggestions are offered for areas that should be emphasized in future attempts to increase patients' knowledge and utilization of advance directives.     

Chlorpromazine and serial reaction performance

The effect of 25 mg or 75 mg of chlorpromazine on the serial reaction performance of 12 male human subjects was studied. Speed or number of correct responses was reduced by the high dose of chlorpromazine and errors of commission and omission were increased. The adverse effect of the drug upon speed appeared only at the end of the half-hour test. By contrast the adverse effect upon gaps and errors was apparent throughout the test and there was no interaction with test duration.     

Progressive changes in articulatory patterns in verbal apraxia: A longitudinal case study

This research reports findings in a 10-year study of an apraxic adult, who was one of five subjects described by Shankweiler and Harris, (Cortex, ,2 277–292, 1966). Confusion matrices and feature analysis were used to compare 1965 and 1975 performances. Results indicate that over the 10-year period, errors of place, manner, and omission were markedly reduced. Voicing errors, however, while reduced in total number, still constituted a significant percentage of the patient's residual errors. Implications of these findings are discussed.     

Infant search tasks reveal early concepts of containment and canonical usage of objects

It is difficult to gain unambiguous evidence on the use of concepts by infants. Many results can be accounted for in terms of action-based strategies. The evidence reported here fulfils the minimal criteria for the operation of working concepts in infants. Search tasks are used with a filled interval which forces memory-search, and the object is hidden in containers which fulfil their customary job or violate it. Infants treat an upright cup as a more reliable location marker than an inverted one. A series of experiments probes the phenomenon. The results indicate that the infants have a working concept of containment which can be triggered by the provision of containers in their canonical orientation. Even “object permanence tasks” lead infants to access their knowledge of the relationships into which things typically enter in the world outside the laboratory.     

Children's knowledge of the separation of variables concept

Children 8, 10, and 13 years of age were either given prior experience constructing seriations or matrices with two-dimensional stimuli, or no prior experience. Knowledge of the separation of variables concept was then assessed by examining children's use of controlled tests of a problem variable's effect (probe questions), and recognition of the inadequacy of confounded variable tests (negative counter-suggestion questions). Although many children either passed both questions or failed both questions, a significant number of children correctly used controlled variable tests, and yet failed to recognize the inadequacy of a confounded test. These results suggest that although a preliminary form of the separation of variables concept is characterized by use of controlled variable tests, subsequent refinement of the concept includes recognition of the inadequacy of confounded tests. Relative to seriation, prior experience constructing matrices facilitated recognition of a confounded test's inadequacy. Constructing matrices may have focused attention on the simultaneous variation of problem elements on multiple dimensions and thus facilitated recognition of the necessary role of both variation of stimuli on test dimensions and equality of stimuli on nontest dimensions, e.g., a controlled test.