Maps between some different kinds of contraction function: The finite case

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.     

Self-Control: Essence and Development

The paper surveys practical knowledge about the act of self-control, particularly how to cultivate it. The discussion is organized around four totally interrelated components: awareness, intervention, sense of self, and sense of will.

     

Interparent agreement on the Personality Inventory for Children: Are substantial correlations sufficient?

Mothers' and fathers' responses on the Personality Inventory for Children (PIC) were compared for 360 clinic-referred children and adolescents. Interparent agreement was measured by several different indices. Correlations between parental pairs of scale T-scores derived from each parent averaged .66 for 13 of the profile scales; 9 of the scales exceeded this value. In contrast, mothers and fathers agreed in the classification of the presence of clinical significance an average of 77% of the time across these 13 scales, and pairs of parental PIC profiles contained an average of 3 scales in disagreement. The type of index used to measure interparent agreement was found to affect the results. The discussion examines the nature of interparent disagreement and addresses the implications regarding the use of fathers as informants on this instrument.This article is based on Thomas A. Hulbert's master's thesis. The authors extend their appreciation to James Orisell and Dena Mussaff for their assistance in data preparation and analysis.     

Integration of noxious stimulation across separate somatosensory communications systems: a functional theory of pain

Functional measurement analyses and psychophysical techniques were used to assess how separate, cross-modal, aversive events are integrated in judgements of pain. Subjects made magnitude estimations of noxious stimuli produced by a 6 X 6 factorial design of electric shocks and loud tones. Group data and most of the individual results were consistent with a model of linear pain summation: The estimates of pain approximated the linear sum of the pain estimates of the individual electrocutaneous and auditory components. The relation between painful sensation and current intensity could be described by a mildly expansive power function with an exponent of about 1.1. Auditorily produced painful sensation related to sound pressure level by a mildly compressive power function with an exponent of about 0.90 as a representative figure. Results are interpreted in terms of a functional theory of pain. Noxious events are first transformed to psychological scale values via stimulus-specific psychophysical transfer functions. The outputs of these functions are then combined with other pain-related internal representations of either sensory or cognitive origin, according to simple algebraic models.     

Iconic memory, location information, and partial report

It has been suggested that the systematic decline of partial report as the delay of the partial-report cue increases is due to a time-related loss of location information. Moreover, the backward masking effect is said to be precipitated by the disruption of location information before and after identification. Results from three experiments do not support these claims when new indices of location information and of item information are used. Instead, it was found that the systematic decline in partial report was due to a time-related loss of item information, and location information was affected neither by the delay of the partial-report cue nor by the delay of backward masking. Subjects adopted the "select-then-identify" mode of processing.     

Perceptual interactions in two-word displays: familiarity and similarity effects

Previous studies have demonstrated the existence of perceptual interactions in the processing of two-word displays such as SAND LANE. When postcued to report one of the two words, subjects often make migration errors, in that the report of the specified word includes a letter of the other word (e.g., LAND or SANE instead of SAND). We find that migrations depend on the abstract, structural similarity of the strings, but not on the physical similarity; on whether the strings are words; and on whether the possible migration responses are words. We also rule out an interpretation of migration errors that attributes them to a guessing strategy. Our findings are interpreted in terms of models in which both strings simultaneously access high-level structural knowledge, that is, knowledge about what sequences of letters fit together to form familiar wholes.     

Fluctuations and phase symmetry in coordinated rhythmic movements

Pendular, clocking movements typify mammalian terrestrial locomotion. They can be investigated with a procedure in which people swing hand-held pendulums at the wrists, comfortably and rhythmically. Pendular, clocking behavior was examined for in-phase and out-of-phase coordinations. The periodic timing and powering of rhythmic movements in the comfort state follow from different laws (Kugler & Turvey, 1986). One law guides the assembling of the reference frame for "clocking." Another law guides the assembling of the muscular, escapement processes determining the cycle energy. Wing and Kristofferson's (1973) method for parsing periodic-timing variance into independent "clock" and "motor" sources was applied. Mean periodicity was unaffected by phase. "Clock" fluctuations, however, were larger out of phase than in phase. "Motor" fluctuations were indifferent to phase but reflected the departures of individual wrist-pendulum systems from their preferred periods. It appears that an intended phase relation is realized as a constraint on "clock" states. These states are more stable under the in-phase constraint than under the out-of-phase constraint.