The role of neuroimaging in the discovery of processing stages a review

In this contribution we show how neuroimaging methods can augment behavioural methods to discover processing stages. Event Related Brain Potentials (ERPs), Brain Electrical Source Analysis (BESA) and regional changes in cerebral blood flow (rCBF) do not necessarily require behavioural responses. With the aid of rCBF we are able to discover several cortical and subcortical brain systems (processors) active in selective attention and memory search tasks. BESA describes cortical activity with high temporal resolution in terms of a limited number of neural generators within these brain systems. The combination of behavioural methods and neuroimaging provides a picture of the functional architecture of the brain. The review is organized around three processors: the Visual, Cognitive and Manual Motor Processors.     

Decision-making incapacity among nursing home residents: results from the 1987 NMES survey. National Medical Expenditure Survey

Recent legislative and regulatory developments have focused attention on older adults' capacity for involvement in health care decision-making. The Omnibus Budget Reconciliation Act of 1987 (OBRA 87) focused attention on the rights of nursing home residents to be involved in health care decision-making to the fullest extent possible. This article uses data from the 1987 National Medical Expenditure Survey (NMES) to examine rates of incapacity for health care decision-making among nursing home residents. Elements of the Oklahoma statute were used to operationalize decision-making incapacity: disability or disorder, difficulty in decision-making or communicating decisions, and functional disability. Fifty-three percent of nursing home residents had a combination of either physical or mental impairment and an impairment in either self-care or money management. The discussion focuses on the policy and practice implications of significant rates of incapacity among nursing home residents.     

Self-Deceptive Coping: Adaptive Only in Ambiguous Contexts

ABSTRACT Two experiments investigated claims for the efficacy of self-deceptive coping (e.g., Sackeim, 1983, 1988). In Study I the performance of self-deceivers on solvable anagrams was found to he remarkably poor relative to that of non-self-deceivers after both groups were exposed to unsolvable problems. The starkly unambiguous failure experience may have precluded self-deception. Therefore, in Study 2 participants were exposed to unsolvable problems either with or without an excuse. Self-deceivers who encountered failure with an excuse subsequently performed much better on the solvable tasks than those without an excuse. These findings suggest that the use of self-deception following threat is constrained by the availability of contextual ambiguity (e.g., excuses). The effect of the excuse was not related to participants' mood or attributions for performance.     

Resistance to reinforcement change in multiple and concurrent schedules assessed in transition and at steady state

Behavioral momentum theory relates resistance to change of responding in a multiple-schedule component to the total reinforcement obtained in that component, regardless of how the reinforcers are produced. Four pigeons responded in a series of multiple-schedule conditions in which a variable-interval 40-s schedule arranged reinforcers for pecking in one component and a variable-interval 360-s schedule arranged them in the other. In addition, responses on a second key were reinforced according to variable-interval schedules that were equal in the two components. In different parts of the experiment, responding was disrupted by changing the rate of reinforcement on the second key or by delivering response-independent food during a blackout separating the two components. Consistent with momentum theory, responding on the first key in Part 1 changed more in the component with the lower reinforcement total when it was disrupted by changes in the rate of reinforcement on the second key. However, responding on the second key changed more in the component with the higher reinforcement total. In Parts 2 and 3, responding was disrupted with free food presented during intercomponent blackouts, with extinction (Part 2) or variable-interval 80-s reinforcement (Part 3) arranged on the second key. Here, resistance to change was greater for the component with greater overall reinforcement. Failures of momentum theory to predict short-term differences in resistance to change occurred with disruptors that caused greater change between steady states for the richer component. Consistency of effects across disruptors may yet be found if short-term effects of disruptors are assessed relative to the extent of change observed after prolonged exposure.     

Biasing the pacemaker in the behavioral theory of timing

In the behavioral theory of timing, pacemaker rate is determined by overall rate of reinforcement. A two-alternative free-operant psychophysical procedure was employed to investigate whether pacemaker period was also sensitive to the differential rate of reinforcement. Responding on a left key during the first 25 s and on a right key during the second 25 s of a 50-s trial was reinforced at variable intervals, and variable-interval schedule values during the two halves of the trials were varied systematically. Responding on the right key during the first 25 s and on the left key during the second 25 s was not reinforced. Estimates of pacemaker period were derived from fits of a function predicted by the behavioral theory of timing to right-key response proportions in consecutive 5-s bins of the 50-s trial. Estimates of pacemaker period were shortest when the differential reinforcer rate most strongly favored right-key responses, and were longest when the differential reinforcer rate most strongly favored left-key responses. The results were consistent with the conclusion that pacemaker rate is influenced by relative reinforcer rate.     

Are All Hostility Scales Alike? Factor Structure and Covariation Among Measures of Hostility1

Few studies have examined the correlational and structural relationships between measures of hostility that may predict coronary heart disease. Using data from a population-based study (N= 2,682), we examined the factor structure among the five subscales from Siegel's (1986) Multi-dimensional Anger Inventory, the three subscales from Spielberger et al.'s (1985) anger expression scales, a Cook-Medley (Cook & Madley, 1954) hostility subscale that measures cynicism, and items measuring hostility from four scales that assess Type A behavior. Eight separate factors were identified: hostile anger expression, perceived control over the expression of one's anger, frequency of anger, ease of anger provocation, brooding, hostile outlook, cynicism, and sullenness. These results suggest that the structure of hostility measures is more complex than previous factor analyses have suggested. Our findings point to the dangers in assuming that a factor structure can be generalized beyond the data on which it is based to provide theoretical statements about psychological structure. The new scales appear to be valid because they correlate with demographic variables and indicators of social support in the expected directions.     

Controlling the Ground Reaction Force During Lifting

The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.5 years) repeatedly lifted a barbell. A biomechanical analysis that used a linked segment model revealed that the summed rotations of body segments during lifting yielded a specific rate of change of the angular momentum of the entire body. This equaled the external moment provided by Fsubg; relative to CoG. This implies that multisegment movements involve control of the angular momentum of the entire body through an appropriately directed Fsubg;. Thus, in dynamic tasks Fsubg; is pointed away from rather than lined up with the CoG, as is the case in static tasks.