• The effects of early experience on the hippocampus.

      Wilson, Lynn Allison.; Nadel, Lynn; Figueredo, A.J.; Wenk, Gary (The University of Arizona., 1993)
      Some experiences occurring early in life affect structure and function of the nervous system. Handling and isolation of infant rats produce physiological and behavioral changes that persist throughout life. These changes may result from interference with the maturation of late developing systems, such as the hippocampus. The research reported here used handling and isolation alone, and in combination, and measured activity, cognitive ability and plasma CORT levels in adult rats. Handling resulted in increased activity, decreased CORT levels, and impaired spatial learning ability. Isolation failed to alter activity levels, impaired spatial ability, and increased CORT levels in females, and reduced them in males. Combining the two manipulations produced no changes in behavior or CORT levels. The results are discussed in terms of altering the manner in which the animals respond to environmental challenges.
    • Exploring the nature of recency discrimination deficits in frontal lobe patients.

      Kaszniak, Alfred W.; Butters, Meryl Ann.; Glisky, Elizabeth L.; Rubens, Alan B.; Nadel, Lynn (The University of Arizona., 1991)
      Damage to the frontal lobes appears to result in a deficit in the temporal organization of memory. McAndrews and Milner (1991) recently found that subject performed tasks (SPTs) with objects allowed frontal lobe-damaged patients to circumvent this deficit and perform normally on recency judgments. The present study was an attempt to investigate the critical properties of SPTs, by comparing the performance of frontal lobe-damaged patients and healthy control subjects on recency judgments under five different encoding conditions: SPT, naming, visual imagery, visual observation, and verbal elaboration. Results revealed a significant group-by-condition interaction, indicating that patients' performance varied across encoding conditions, while controls did not. Post-hoc comparisons confirmed that patients performed significantly poorer than normal controls across all encoding tasks, except SPT. In the SPT condition, there was no significant difference between the groups. The present findings serve as a replication of McAndrews and Milner's results. Further, they help elucidate the nature of both SPTs and memory for temporal order. The fact that patients' performance in the SPT condition was superior to all other conditions, suggests that performing an action served as more than an elaborative encoding technique. It is concluded that activating and executing motor programs was the critical feature responsible for the observed SPT effect. It is further concluded that SPTs, rely on automatic processes. The use of an automatic method for item encoding may have allowed frontal lobe patients to devote available cognitive resources to encoding temporal order. Thus, SPTs compensated for frontal lobe patients' deficits in effortful processing, and hence improved their recency judgments.
    • The influence of psychosocial factors on heart transplantation.

      Geller, Stacie Ellyn.; Connolly, Terry; Beach, Lee; Scott, Anne; Burns, Lawton R.; Copeland, Jack (The University of Arizona., 1994)
      This research addresses the role that psychosocial factors currently play in selection of candidates for heart transplantation, and the predictive validity of these factors to selection decisions and patient outcomes. The initial focus of this research was on what psychosocial factors are considered and how much impact they have individually and collectively on selection decisions. This investigation examined how individual members of a cardiac transplant team (University Medical Center, Tucson, Arizona) arrive at these decisions and how these individual judgments are combined into a consensual team decision. Further, in an effort to usefully standardize the psychosocial information used in patient assessments, we developed a consensus weighting formula for the whole transplant team. Our findings from the initial phase of the research indicate general agreement among team members that psychosocial factors are of some importance in screening transplant candidates. Most team members give primary attention to medical factors, though all were attentive to the influence of psychosocial factors on patient eligibility for transplant and on post-transplant adjustment. We next examined the relationship between what the team believes they are doing in selecting candidates for transplantation against empirical data from the cases the team has evaluated. However, when belief was tested against empirical evidence we find some disparity between what the team reported as important to their decision making and the actual decisions the team had made. Our results showed that team members use some, but not all, psychosocial factors in their transplant eligibility decisions. Lastly, we investigated the relationship between psychosocial factors and various patient outcomes. We investigated the extent to which outcome measures: mortality, morbidity, functional status, quality of life, patient management, and patient compliance, can be predicted by measures, including psychosocial measures, available at the time of initial evaluation. Our results indicate an association between pre-transplantation psychosocial evaluation and certain behavior aspects of transplant outcome, patient management and compliance. However, no relationship was found between psychosocial factors and medical and functional outcomes. The findings from this empirical prediction model should add to the information available to the team at the time of the pre-transplant screening decision.