Investigating proximate mechanisms and ultimate functions of memory for emotional events

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

Investigating proximate mechanisms and ultimate functions of memory for emotional events

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.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Sex-Role Orientation in Men Is Related to Salivary Testosterone Levels

Previous research has implicated the involvement of androgens in sex-role orientation in males, from studies of 2 nd to 4 th digit ratio (a purported marker of prenatal testosterone). The present pilot study investigates the relationship between salivary testosterone levels and sex-role orientation using Bem Sex Role Inventory (BSRI) scores in adult males. Twenty-one males (aged 18 -24) completed the BSRI and provided saliva samples for assay. BSRI Femininity scores were significantly negatively correlated with testosterone levels; the higher the Femininity scores, the lower the testos-terone levels. There was no relation of BSRI Masculinity scores with testosterone levels. Our preliminary results add to the research suggesting that sex-role orientation in males may be partially related to underlying hormone levels

Sex-role orientation in men is related to salivary testosterone levels

Previous research has implicated the involvement of androgens in sex-role orientation in males, from studies of 2nd to 4th digit ratio (a purported marker of prenatal testosterone). The present pilot study investigates the relationship between salivary testosterone levels and sex-role orientation using Bem Sex Role Inventory (BSRI) scores in adult males. Twenty-one males (aged 18-24) completed the BSRI and provided saliva samples for assay. BSRI Femininity scores were significantly negatively correlated with testosterone levels; the higher the Femininity scores, the lower the testosterone levels. There was no relation of BSRI Masculinity scores with testosterone levels. Our preliminary results add to the research suggesting that sex-role orientation in males may be partially related to underlying hormone levels.Publisher PDFPeer reviewe

Examining the effect of spinal cord injury on emotional awareness, expressivity and memory for emotional material

The prevailing view on the effects of spinal cord injury (SCI) on emotion is that it dampens emotional experience due to a loss of peripheral bodily feedback, with the higher the lesion on the spinal cord the greater the reduction in the intensity of emotional experience. This view persists despite many studies showing an absence of such an emotional impairment in people with SCI. This study specifically aimed to investigate whether total cervical-6 spinal cord transection (i) reduces emotional expressivity and emotional awareness (ii) impairs memory for emotional material. The study contained 3 groups: 24 patients with SCI, 20 control patients with orthopaedic injury (OIC) and 20 young adult controls. A mixed factor design was employed to examine between group and within subject differences. Participants completed the Levels of Emotional Awareness Scale (LEAS), the Berkeley Expressivity Questionnaire (BEQ), and viewed an emotionally arousing slide presentation. Thirty minutes post viewing, participants completed memory tests for the presentation. SCI patients reported greater present levels of emotional expressivity compared with perceived levels prior to their injury. SCI and OIC groups did not differ on any of the emotional awareness variables. There was also no evidence that SCI leads to impairment in memory for emotional events. This study’s findings contradict the mainstream view in the cognitive neuroscience of emotion that SCI dampens emotional experience

Maternal tendencies in women are associated with estrogen levels and facial femininity

Previous studies have shown that women with higher maternal tendencies are shorter and have lower testosterone levels than those with lower maternal tendencies. Here we report two studies that investigated the relationships between maternal tendencies and two further measures of physical masculinization/feminization; urinary estrogen metabolite (estrone-3-glucuronide: E1-3G) levels (Study 1) and rated facial femininity (Study 2). In Study 1, nulliparous women reported both their ideal number of children and ideal own age at first child and also provided urine samples. There was a significant positive correlation between measured late-follicular estrogen levels and reported ideal number of children. In Study 2, analyses of facial cues in two independent samples of women showed that the average facial characteristics of women who reported desiring many children were rated as more feminine than those desiring fewer children. Collectively, these results support the proposal that maternal tendencies are related to physical feminization and that this effect may, at least in part, reflect the influence of the hormone estrogen