You Can't Lose What you Ain't Never Had: A Reply to Marquis on Abortion

Philosophical Studies -     

The Representation of Knowledge in Minds and Machines

Human knowledge can be represented as a propositional network in which the meaning of a node is defined by its position in the network. That is, the relationship between a node and its neighbours determines how this node is used in language understanding and production, i.e., its meaning. The propositions that make up such a network are predicate-argument structures with time and location slots. Schemas, frames, and production rules can be expressed in the same formalism. Implications for this contextual view of meaning are discussed. Since the construction of such a propositional network depends on hand coding and is therefore impractical, an alternative automatic statistical procedure is explored that yields a high-dimensional semantic space. Vectors in this space correspond to nodes in the propositional network, in that the meaning of a vector in the Latent Semantic Analysis space is given by its neighbouring vectors in that space.     

Personal constructs, performance schemata, and “folk theories” of subordinate effectiveness: Explorations in an army officer sample

This research employs personal construct theory (Kelly, 1955)to explore the content of categories or schemata that may be used in making work performance judgments. Twenty-five experienced U.S. Army officers, focusing on the job of noncommissioned officer (NCO; first-line supervisor), generated independently a total of 189 personal work constructs that they believe differentiate between effective and ineffective NCOs. The officer subjects numerically defined each of their own 6–10 constructs by rating the similarity between each of these constructs and each of 49 reference performance, ability, and personal characteristics concepts. Correlations were computed between the subject-provided similarity ratings for the constructs, and the 189 × 189 matrix was factor analyzed. Six interpretable content factors were identified (e.g., Technical Proficiency, Organization), with 123 of the 189 constructs from 23 of the 25 subjects loading substantially on these factors. Findings here suggest that a core set of concepts is widely employed by these officers as personal work constructs, but that different officers emphasize different combinations of this core set. The personal constructs elicited from officer subjects are likened to performance schemata and “folk theories” of job performance.     

Kinetic attraction during bimanual coordination

Two experiments examined the effects of independent variations in kinetic and kinematic requirements on interlimb coupling during a bimanual task. The goal of the investigation was to provide preliminary evidence regarding one general class of physical variables that constrains discrete bimanual movements. Subjects attempted to execute a smooth unidirectional movement with the left arm, along with a three-segment reversal movement with the right arm. The first experiment manipulated the torque required to produce the reversal action, while movement duration and average angular velocity were held constant for both limbs. Several indications of increased interlimb coupling, due to the kinetic variation, were evident. The converse manipulation was used in the second experiment, with movement time and kinematics (velocity, acceleration) changed independently of joint torque requirements for the reversal limb. No clear effect of kinematics on coupling strength was noted. The results suggest that one variable influencing interlimb attraction toward common spatiotemporal trajectories may be kinetic in nature.     

Relationship between neuropsychological data and response to behavioral treatment in a case of carbon monoxide toxicity and dementia

The ability of learning measures to predict a behavioral treatment response was of interest in this study. A severely impaired and behaviorally disturbed female neuropsychiatric patient was unable to demonstrate any learning on "direct" tests involving multiple free recall trials or cued paired associate recall. However, she performed normally on an "indirect" test involving implicit learning of new associations. To assess whether direct or indirect measures tapped the kind of learning required by a positive reinforcement-based treatment approach, a token program was carried out. There was a 72.5% reduction in maladaptive behavior relative to baseline, indicating a positive treatment response. The results are discussed in terms of the potential treatment utility and predictive validity of indirect measures of learning and memory and the relation of neuropsychological data to intervention issues in general.     

Protection Motivation Theory: Prediction of Intentions to Engage in Anti-Nuclear War Behaviors1

The present study examined potential mediators of intentions to engage in behaviors related to the prevention of nuclear war. Protection motivation theory (Rogers, 1975, 1983) suggested that perceived severity of the consequences of nuclear war, perceived likelihood of occurrence of nuclear war, perceived efficacy of responses designed to prevent nuclear war, and perceived capability of engaging in those responses would combine additively and interactively to predict behavioral intentions. The theory further suggested that the effects of a fear-arousing communication on behavioral intentions would be mediated indirectly by changes in the predictor variables. Thus, a second purpose of the study was to evaluate the effects of the program “The Day After”, which dramatically depicted a nuclear holocaust, on viewers' affect (fear-arousal) and cognitions. Surprisingly, the program had no effects on viewers that we could document. We were, however, able to predict behavioral intentions, for both viewers and nonviewers (n= 282), from subjects' affect and cognitions, providing support for protection motivation theory in a new domain.