This thesis is an investigation of the proximate mechanisms and ultimate functions of memory for emotional events. The theoretical basis of this Thesis is that in order to reach a full understanding of a biological phenomenon, it is important that both proximate and ultimate (functional) explanations for that phenomenon are explored. Chapters 2 and 3 present an examination of the proximate mechanisms involved in memory consolidation of emotional events. In Chapter 2, three experiments are presented each testing the hypothesis that stress hormone activation immediately following viewing an emotional event enhances memory for that event. Each of the three experiments failed to find an enhancing effect of stress hormone activation on memory consolidation. Chapter 3 describes an investigation into whether the reduced feedback from the body to the brain, which occurs as a result of total spinal cord transection, diminishes the intensity of emotional experience and therefore impairs memory for emotional events. The results of this investigation revealed no differences between spinal cord transection patients and matched control participants in emotional expressivity, emotional awareness and in memory for emotional material. Chapters 4 and 5 explore how memory and emotion may interact differently for males and females and in manner that facilitates their survival and reproduction. Evolutionary theory argues that males should be more concerned than females about threats to their social status, whereas females should be more concerned about threats to their physical appearance and sexual reputation. Chapter 4 describes two experiments testing whether a) males have enhanced emotional arousal and memory for words implying they are of low social status; b) females have enhanced emotional arousal and memory for words implying they are physically unattractive and sexually untrustworthy. The results of these experiments showed that females had enhanced memory for words relating to physical appearance, and partial evidence that males have 2 enhanced memory for words relating to social status. Chapter 5 tests the evolutionary theory that males should be more emotionally aroused and thus have greater memory for cues relating to sexual infidelity (the thought of their partner having sex with another man), whereas females should be more emotionally aroused and have greater memory for cues to emotional infidelity (the thought of their partner forming a close emotional attachment with another woman). It also examines whether relationship status affects emotional arousal and memory for these cues. The results did not find any support for these hypothesised sex difference in memory. However, those ‘currently in a relationship’ did show enhanced emotional arousal to cues to sexual infidelity compared to those ‘currently not in a relationship’. Chapter 6 presents an investigation concerning the evolutionary hypothesis that individuals tend to have enhanced recognition memory for the faces of deceivers or ‘liars’. This chapter describes a study in which participants viewed a series of short video clips of individuals, half of whom were lying, half telling the truth. Participants’ memory for the individuals that appeared in the video clips was tested but there was no evidence of enhanced memory for the faces of ‘liars’. Chapter 7 provides a general discussion of the findings of this thesis. The failure to find an enhancing effect of post learning stress hormone activation on memory for emotional material, and the failure to find an impairment in memory for emotional material in people with total spinal cord transection contradict two established views on the proximate mechanisms involved in emotion, and emotions effect of the brain. How these findings relate to the established mainstream views on emotion and memory are discussed. The findings of studies concerning the functional interaction of memory and emotion presented in this thesis are also discussed in relation to previous research.

The ability to learn spatiotemporal characteristics of biologically significant events is advantageous for an animal and is known as time-place learning (TPL). Gallistel (1990) proposed an influential theory positing that whenever a biologically significant event occurred, a memory code was automatically formed, encoding the nature of the event, and the time and place in which it occurred. When the animal is later faced with a biological need it could consult these memory codes and determine when and where that need had been met in the past. This information could be used to guide current behaviour. Importantly, Gallistel theorized that the encoding of the spatiotemporal characteristics of an event into a tripartite code was an automatic process. Despite the appealing power and simplicity of Gallistel's theory, I have provided arguments suggesting that it has serious limitations. Perhaps the most damaging evidence against this theory is the reluctance of rats to demonstrate daily TPL (i.e., events that vary in location depending on time of day). Widman, Gordon, and Timberlake (2000) argue that for TPL to occur the response cost for incorrect decisions must be high. While this hypothesis is unable to explain the inconsistencies in TPL, it does highlight the fact that animals do not automatically store time-place-event information as a tripartite code. If they did, it would not make sense for them to ignore such information in some tasks. I have provided an alternative hypothesis that states that whenever a biologically significant event occurs two bipartite memory codes (time-event and place-event) are automatically formed. Only under some conditions, perhaps those with high response cost, do animals form tripartite codes. For this reason, rats often have difficulty learning a TPL task; although rats easily learn a place preference for those places that provide reinforcement (place-event), and easily learn a go/no-go discrimination (time-event). This thesis provides data from both the daily and interval TPL realms supporting the proposed theory of bipartite codes. Although rats do not readily learn daily TPL tasks, they do demonstrate knowledge of interval TPL under a variety of conditions designed to enhance the ecological validity of the task. The properties of interval TPL are discussed. / Arts, Faculty of / Psychology, Department of / Graduate

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent conditions among school children. Executive function deficits representing difficulties in maintaining an appropriate problem set for the attainment of future goals are reported to be the major deficit in ADHD populations. There is a high rate of co-morbidity of learning disabilities and ADHD, with empirical evidence indicating an association with math and reading difficulties, but there is little research on the written expression of this population. There is a body of emergent research indicating that written expression is mediated by executive function. Written expression is a complex task that is affected by motivation, working memory, cognitive processes and long term memory, factors which are reported to be compromised in ADHD populations. This study evaluated the working memory and fluid reasoning in children with (combined and predominantly inattentive types) and without ADHD. Second, it explored the relationship between working memory and fluid reasoning on written expression in children with and without ADHD. Finally, the possible link between the executive functions of working memory and fluid reasoning, with written expression of children with and without ADHD was examined. The findings of this study indicate that children with the combined type of ADHD had lower written expression and working memory scores compared to children with the inattentive type of ADHD. The results of this study also indicated an association between disinhibition and working memory deficits on written expression performance. This research will serve to contribute to an understanding of the functional impact of ADHD on academic performance. Findings from this study could potentially help with interventions for deficits in written expression among school children.

The purposes of the present study were to investigate the relationship between short-term memory and reading in learning disabled and average learners, and to determine whether this relationship is different between ages 8 to 10 and ages 11 to 13 in these two populations. Studies have shown that children with learning disabilities tend to perform poorer on short-term memory tasks compared to children with no disabilities. The present study was conducted because the short-term memory component in the Stanford-Binet Intelligence Scale is new and it was felt that information regarding this test's usefulness with learning disabled students would be beneficial for individuals in the field of educational assessment. A total of 80 children, 39 average and 41 learning disabled were selected from the five public elementary schools that have learning disabilities classes in the Langley School District. For each group of learning disabled children selected from the learning disabilities class, an equal number of average learners was chosen from the same school. The children were divided into two age groups: 8- to 10-year-olds and 11- to 13-year-olds and then further divided into their two learning categories. Four short-term memory subtests of the Stanford-Binet Intelligence Scale: Fourth Edition: Bead Memory, Memory for Sentences, Memory for Digits and Memory for Objects and three reading comprehension subtests, from B.C. QUick Individual Educational Test, Peabody Individual Achievement Test and Test of Reading Comprehension respectively, were administered to all groups to measure short-term memory and reading. The Multivariate Analysis of Variance and the Pearson Product-Moment Correlation were used to analyse the data. Results showed that the average learners scored significantly higher than the learning disabled group in both short-term memory and reading. There was no interaction effect of learning group and age on reading or short-term memory. Significant relationships were found between short-term mmeory and reading for the average learning group but none was found for the learning disabled group. / Education, Faculty of / Graduate