Role of the area postrema in three putative measures of motion sickness in the rat

After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.     

Does spreading activation summate?

Summary Network models of semantic memory assume implicitly or explicitly that the degree of activation of a node is a monotonic function of the total amount of excitation reaching that node from all sources. For example, the activation level of the node representing apple should be greater if it is receiving excitation due to the activation of the nodes for fruit and pear than if only one of these neighboring nodes is activated. This notion was tested by presenting semantic primes 80 ms or 320 ms before a letter string (e.g., apple or ipple) requiring a lexical decision. The prime stimuli consisted of a pair of simultaneous items that were identical in the single prime condition (e.g., fruit/fruit or pear/pear) or different in the double prime condition (e.g., fruit/pear or pear/fruit), and were either related (target = apple) or unrelated (target = copper) to the target, or neutral. As predicted by the summation of semantic activation assumption of network models there was a larger priming effect (in the 320 ms SOA condition) following the simultaneous activation of two related nodes than following the activation of only one node.This research was supported by grants to the first author from the Natural Sciences and Engineering Research Council of Canada.     

Retroactive interference in the retention of prose: A reconsideration and new evidence

The sensitivity of naturalistic prose material to retroactive interference (RI) was investigated in three experiments, with due consideration given to the conditions known to produce RI in non-prose material. In experiment 1, unrelated, related, and nearly identical (parapharase) prose passage conditions yielded a pattern of results very similar to those obtained with non-prose material, with only the related condition associated with significant amounts of RI. Based upon these results and a few simple assumptions, a classificatory scheme was developed within which predictions were made regarding RI in related prose material. Several such predictions were tested and confirmed in Experiments 2 and 3. It was concluded that the many previous failures to detect RI in the retention of prose may be attributed to factors other than any inherent insensitivity of the material itself, and that RI may be just as predictable in prose as it is non-prose material.     

Learning from lectures: The effect of varying the detail in lecture handouts on note-taking and recall

Previous research on the effect of lecture handouts on student learning indicates that students who are given skeletal handouts usually perform better in course examinations than students who take all their own notes. The present study investigates whether the amount of detail in the handout is a critical factor in this. A randomized groups experiment was conducted in the context of a course on dental surgery. Four lecture handout conditions (headings and full text; headings and key points; headings only; no supplementary materials) were compared on tests 2 days and 2 weeks after the lecture. The significant differences between conditions were: ‘headings only’ better than ‘headings and key points’ on the first test; ‘headings only’ better than ‘no supplementary materials’ on the second test; and ‘headings and full text’ better than ‘no supplementary materials’ on the second test. These results indicate that the amount of detail is a critical factor in handout effectiveness.     

Self-help and child abuse: Victims,victimizers, and the development of self-control

Study of child abusers reveals that many victimizers were once victims and that the behaviors underlying the perspectives of victims and victimizers are related. Three groups of abusing parents using directed self-help were studied at Parents Anonymous by participant observation methodology for two and-a-half years. Four of the 52 participating parents read and commented on a draft of the research. Their violence appeared to be an attempt to gain a sense of control or to deal with the frustration of not feeling in control. Suggestions are made for developing social services that enhance individuals' sense of control.Paper presented at the Groves Conference on Marriage and the Family, London, England, July, 1986.     

Mass media treatment of violence in sports and its effects

There appears to be a strong relationship between mass media portrayals of violence and real-life violence itself. This article reviews the available literature on the effects of media treatment of sports violence; analyzes the theoretical explanations for this treatment; and makes proposals on how the problems of both sports violence and its media coverage may be remedied, with a particular focus on amateur hockey in Canada.     

Relaxation therapy for tension headache in the elderly: a prospective study

We evaluated the effects of an 8-week progressive muscle-relaxation therapy regimen on the headache activity of 10 elderly tension-headache subjects. Posttreatment assessment at 3 months revealed significant decreases in overall headache activity (50% or greater) in 7 subjects. Significant clinical or statistical prepost differences, or both, were also found for the number of headache-free days, peak headache activity, and medication index. This is the first prospective study of tension headache in an elderly population, and, unlike previous retrospective studies, it suggests that relaxation therapy may be an effective intervention in the treatment of such headaches.     

Leadership behavior,group climate and outcome in group psychotherapy: A study of outpatient psychotherapy groups

A recent clinical study of outpatient psychotherapy groups in a community mental health center explored the linkage between group leadership variables, group climate, and outcome. The study involved nine outpatient therapy groups, over 50 group clients, and several group therapists. A repeated measures design involving assessment of clients' outcome and level of functioning, group leadership style, and group climate was used to assess changes over a 6-month period. The findings suggest: 1) a reduction in symptoms and improved functioning for clients; 2) a similarity of perceptions by members and leaders of perceived leadership behaviors and group climate; 3) the presence of direct and indirect influences of group climate and leadership behavior on clients' outcome; and 4) a linkage between leadership behavior and group climate with the theoretical orientation of the group. The findings of the research are discussed in relation to the understanding of specific effects in group psychotherapy and the implications for construction of group psychotherapy theory.The authors would like to thank Robert Dies, Ph.D., for his helpful suggestions in the early phase of this study; Roy MacKenzie, M.D., for permission to use the Group Climate Questionnaire; Diane DePalma, Ph.D., for permission to use the Global Leadership Behavior Index; Chris Boltwood, B.A., for her untiring efforts in administering the instruments and coding and entering the data; and most importantly, the psychotherapy group members and the group therapists for their cooperation in this endeavor—without their help, this clinical study would not have been possible.A version of this paper was presented at the Annual Meeting of the American Group Psychotherapy Association, 1987, New Orleans, Louisiana. Lenore Phipps, R.N., M.S., C.S., was formerly Director, Group Psychotherapy Program at Park Ridge Mental Health Center, Rochester, now in private practice at Guild Medical Center, Norwood, MA 02062.