Recent Submissions

  • Executive and Retrospective Memory Processes in Preschoolers’ Prospective Memory Development

    Fuke, Taissa; Department of Psychology
    Prospective memory (PM), the ability to remember to carry out future intentions, is critical for children’s daily functioning. The Executive Framework of PM Development predicts that executive function should drive young children’s PM development once a sufficient level of retrospective memory has developed. In two studies, we investigated the predictors of PM development in 3- to 6-year-old children using behavioural and parent-reported measures. Neither retrospective memory nor executive function predicted children’s behavioural PM in Study 1. Retrospective memory significantly predicted parent-reported PM in Study 2. Across both studies, executive function consistently predicted parent-reported PM regardless of the method of measurement. Parent-report and behavioural measures may tap into different aspects of PM, but both retrospective memory and executive processes are important to PM development in early childhood.
  • Linkage Behaviours and Outcomes for Serial Sexual Offenders

    Batinic, Mirna; Department of Psychology
    The purpose of the present study was three-fold; 1) to describe the behaviours exhibited by serial sexual offenders, including their criminal histories, 2) to gain a better understanding of the information that is used when linking (potential) serial sexual offences, and 3) to explore linkage outcomes and potential investigative barriers. Previous research on serial offenders has focused on how to link offenders to their multiple offences using a process known as linkage analysis. Through this process, trained analysts review case information and assess for potential links to other cases. Linking offences together allows investigators to focus their resources on investigating one offender that is responsible for multiple offences, rather than investigating each offence separately. Further, the linkage process facilitates communication between law enforcement agencies. This can help protect the public by aiding in the identification of offenders and potentially reducing victimization. There is a gap in the literature with respect to the information that is being used to link and confirm offences in practice. The current study aimed to address these limitations by reviewing a sample of 78 potential linkages (57 male sexual offenders) made by trained analysts from the Violent Crime Linkage Analysis System (ViCLAS) centre to examine the information and offence behaviours that were used to link serial sexual offenders to their offences. Further, this study described the current status of the linkages and potential investigative barriers. Overall, the information used to make linkages was consistent with previous research in that both consistent and distinctive offence behaviours were used. Regarding linkage outcomes, at the time of writing, the majority of linkages remain as potential (i.e., neither confirmed nor rejected) due to potential investigative barriers. As investigations continue, these may be updated and confirmed in the future. Implications and future directions are discussed.
  • The Association Between Puberty, Emotional Difficulties, and Sleep Problems

    Shahid, Hamnah; Department of Psychology
    Puberty is a period of developmental maturation that is often characterized by difficulties with sleep and emotion. However, the nature of the relation, if any, between pubertal development and emotional difficulties and sleep problems is unclear. The current three-year longitudinal study aimed to investigate whether adolescents’ pubertal status, level of sleep problems, and level of emotional difficulties at Time 1 predict subsequent changes in the developmental trajectories of sleep problems and emotional difficulties. Participants (N = 1284) aged 7-14 years completed a survey measuring their demographics, pubertal status, emotional difficulties, and sleep problems. The results showed that for both boys and girls, puberty was not associated with increases in emotional difficulties over time. Meanwhile, pubertal development was related to increases in sleep problems over time for girls, but not boys. Thus, the latter stages of puberty may be a time of onset for sleep problems in girls.
  • Examining the Role of Physiological Arousal in Laboratory Risk-Taking in Social and Non-Social Contexts

    Resch, Chelsie; Department of Psychology
    Current theoretical models attribute the rise in risk-taking during adolescence to heightened activity in reward processing brain regions when in the presence of social and non-social rewarding stimuli. However, non-rewarding, but very salient stimuli, have also been shown to increase activity in reward processing brain regions and could, in theory, also increase risk taking propensity in adolescents. To examine this, we had participants complete a risk-taking task under “standard” conditions as well as under one of three experimental conditions: virtual peer observer with positive social feedback (positive social), virtual peer observer with neutral social feedback (negative social), and with triple the potential rewards (non-social positive). The study’s sample consisted of 59 mainly young adult participants (Mage = 20.69, SD = 5.08), where 22 identified as men and 37 identified as women. A multi-level model revealed no overall effect of exposure to the experimental context on risk-taking. Greater skin conductance was, unexpectedly, associated with less risk-taking. When examining each context in separate models, exposure to the non-social showed associations with increased risk-taking, whereas the positive social context did not. Negative social contexts showed a pattern of means suggesting that exposure to such contexts may be associated with increased risk-taking, but our models may have been underpowered and were unable to detect this effect. These findings suggest that the salience of a context may be an important factor to consider when exploring what drives adolescent risk-taking.
  • He Said, She Said: The Role of Self and Peer Rated Attractiveness in the Personality-Victimization Relationship

    McDowell, Hannah; Department of Psychology
    Our own and others' perceptions of our attractiveness are impressively salient. Such perceptions have the power to influence not only the respect and attention we receive from others but also how we are treated in platonic and romantic relationships. This association is found to be particularly relevant for children and adolescents' victimization. I hypothesized that the relationship between attractiveness and victimization is influenced by personality. Victimization outcomes are thought to differ in shy and attractive adolescents compared to outgoing and attractive adolescents. In the current study, links between personality, attractiveness, and victimization were explored. Participants (N = 539, M = 11.82) completed self-report questionnaires to assess personality (via HEXACO Personality Inventory), self-perceptions of attractiveness and victimization. Peer nominations were used to assess students' perceptions of their peers' level of attractiveness and victimization. Significant negative associations were found between Openness and peer nominations of attractiveness and Honesty-Humility and self-reported attractiveness. Furthermore, a significant positive relationship was found between self-reported attractiveness and self-reported indirect victimization. In contrast, significant negative relationships were found between peer-nominated attractiveness and all measures of peer nominated victimization. Mediation analyses resulted in different paths when comparing self-reported and peer nominated victimization. Lastly, contrasting results were found when direct effects were assessed for gender differences. A positive relationship between Emotionality and peer nominated attractiveness was found for girls, while a negative relationship was found for boys. Furthermore, a positive relationship between self-reported attractiveness and self-reported direct victimization was found exclusively in boys. Results have the potential to expand bullying interventions to include not only those who are customarily regarded as victims but all students
  • First impressions of child faces: Facial trustworthiness influences adults’ interpretations of children’s behaviour in ambiguous situations

    Thierry, Sophia; Department of Psychology
    Despite the profound behavioural consequences that first impressions of trustworthiness have on adult populations, few studies have examined how adults’ first impressions of trustworthiness influence behavioural outcomes for children. Using a novel task design, we examined adults’ perceptions of children’s behaviour in ambiguous situations. After a brief presentation of a child’s face (high or low trust), participants viewed the child’s face embedded within an ambiguous scene involving two children (Scene Task) or read a vignette about a misbehaviour done by that child (Misbehaviour Task). In the Scene Task, participants described what they believed to be happening in each scene; in the Misbehaviour Task, participants indicated whether the behaviour was done on purpose or by accident. In both tasks, participants also rated the behaviour of the target child and indicated whether that child would be a good friend. In Experiment 1, young (n=61) and older (n=57) adults viewed unaltered face images. Ambiguous scenes and misbehaviours were interpreted more positively when the target child had a high- versus low-trust face, with comparable patterns of results for the two age groups. In Experiment 2, young adults (N=59) completed the same tasks while viewing images of child faces morphed towards high- and low-trust averages. The pattern of results mirrored that of Experiment 1. Collectively, our results demonstrate that a child’s facial trustworthiness biases how adults interpret children’s behaviour—a heuristic that may have lasting behavioural consequences for children through a self-fulfilling prophecy.
  • Dimensions Underlying First Impressions of Older Adult Faces by Young and Older Adult Perceivers

    Twele, Anita; Department of Psychology
    First Impressions (FIs) based on facial cues have significant consequences in real-world contexts and have the potential to influence how older adults (OAs), a vulnerable population, are treated by others. The present study used a data-driven approach to examine dimensions underlying FIs of OAs and whether those dimensions vary by perceiver age. In Experiment 1, young adult (YA) and OA participants provided unconstrained, written descriptions in response to OA faces. From these descriptors, 18 trait categories were identified that were similar, but not identical, across age groups. In Experiment 2, YA and OA participants rated OA faces on the trait words identified for their age group in Experiment 1. In separate principal components analyses, two dimensions of sternness and confidence emerged for OA faces for both YA and OA participant ratings. Our results suggest that there are no significant differences in perceiver age when forming first impressions of OA faces.
  • Psychopathy and Fear Enjoyment: The Role of Invincibility

    Wattam, Tori; Department of Psychology
    Previous research has found a significant positive relationship between psychopathic traits and fear enjoyment (Book et al., 2020; Hosker-Field et al., 2016a). Because enjoyment of fear may be contingent on not feeling like one is actually in danger (Hitchcock, 1949), the current study investigated whether a sense of invincibility could explain the relationship between psychopathy and fear enjoyment. Participants included two online samples, one from two universities, and one from MTURK (Total N = 825). Participants viewed exciting and fear-inducing videos and completed affective appraisals for each video. As expected, psychopathic traits were associated with less negative and more positive responses to the fear-inducing video. Also as expected, invincibility partially explained the relationship between psychopathy and fear enjoyment. Mediation analyses confirmed a significant indirect effect for negative (but not positive) ratings of the fear-inducing video. The results of the current study supply further support for the Fear Enjoyment Hypothesis (Hosker-Field et al., 2016a) and support invincibility as one possible mechanism of the relationship between psychopathy and fear enjoyment.
  • Adults' perceptions of forgetful children: The impact of child age, domain, and memory type

    Moeller, Samantha; Department of Psychology
    Prospective memory (PM) tasks have been described as social in nature because carrying out one’s intentions often has an impact on others. Despite the claim that PM errors (compared to retrospective memory [RM] errors) are perceived as character flaws, little empirical work has tested this assertion. In particular, no study has examined how adults perceive children’s PM errors. Thus, the aim of the current studies was to examine adults’ perceptions of children’s forgetfulness depending on child age (4 vs. 10-year-olds), domain of the memory error (academic vs. social), and memory type (PM vs. RM). In Study 1, adult participants rated children’s PM errors on seven traits. Findings showed that social errors were rated more negatively than academic errors, and age and domain interacted such that 10-year-olds were rated more negatively than 4-year-olds for making social errors but not academic errors. Study 2 examined the impact of child age, domain, and memory type on perceptions of forgetful children to specifically test differences between PM and RM errors. Results showed a larger difference between ratings of 10-year-olds for their academic and social memory errors compared to 4-year-olds, but only for RM errors.
  • Investigating the Relationship Between MHI, Cognitive Fatigue, and EDA

    LaRiviere, Blake; Department of Psychology
    Mild head injury (MHI) has been associated with various debilitating effects leading to impairments in many individuals which can be long-lasting. Some of the effects can be explained by disruption to the brain as a result of acceleration, deceleration and rotational forces which lead to axonal stretching and tearing. The ventromedial prefrontal cortex (VMPFC) is particularly vulnerable following MHI and has been associated with attenuated autonomic arousal as indicated by electrodermal activity (EDA). These neural disruptions and its associated physiological underarousal may explain some of the consequences of MHI. Cognitive fatigue is a known consequence of MHI and is defined as an increase in mental exhaustion due to prolonged mental effort and a lack of cognitive resources to sustain mental activity and performance. Increases in autonomic physiological arousal have been found to contribute to sustained performance and attention, but eventually can lead to cognitive fatigue. As such, those who have sustained a MHI and live with attenuated arousal may be disadvantaged when engaging in cognitive tasks. This study investigates the effects of cognitive fatigue, EDA, and task performance following MHI in university students. Forty-two university students (38% MHI) completed self-report questionnaires on general, and cognitive, fatigue and completed a series of simple, but increasingly demanding, cognitive tasks. Physiological arousal was measured by EDA throughout. Individuals with MHI reported significantly greater levels of cognitive fatigue relative to their no-MHI cohort at baseline. Interestingly, participants with MHI also reported greater capacity for recovery from cognitive fatigue which may imply an inability to self-monitor. Even so, while both groups demonstrated initial heightened EDA activation that significantly declines over the course of completing the cognitive tasks, there were no observable performance differences between the groups in terms of accuracy (which declined across tasks), response time (which increased across tasks), or self-reported cognitive fatigue at completion of testing. Future research will focus on establishing improved measures for assessing acute cognitive fatigue across tasks, as well as challenging cognitive tasks that induce measurable cognitive effort independent of cognitive capability.
  • Under Scrutiny: Comparing the Effects of Virtual Peer Ratings on Risk-Taking

    Rothwell, Valerie; Department of Psychology
    Adolescents, compared to other age groups, disproportionately choose to engage in behaviours that endanger them or others, especially in the presence of peers. The dual-systems model attributes this heightened risk-taking to a rapidly developing reward system that overpowers a slower-maturing cognitive control system in situations where excitement is high. The current study uses a new virtual peer paradigm to compare the effects of positive evaluation, negative evaluation, and heightened non-social rewards on risk-taking. Participants (n = 73, ages 12-30, 65.75% women) were randomly assigned to conditions and completed a risk-taking task in two contexts: under low arousal (alone), and under high arousal (watched by a virtual peer). Participants who received a negative evaluation evinced significantly greater risk-taking than those who received a positive evaluation when watched. This effect was not observed when participants completed the task alone. Results suggest, preliminarily, that negative social evaluative contexts may be more likely to lead to increased risk-taking than positive ones.
  • Devaluation of Sucrose Caused by Social Instability Stress in Adolescent Male Long-Evans Rats in the Presence of an Unfamiliar Peer

    Herlehy, Racheal; Department of Psychology
    Rats that undergo the Social Instability Stress procedure during adolescence (SS: daily 1-hour isolation + re-pairing with an unfamiliar cage partner for 16 days) display changes in reward-related behaviour. Specifically, SS rats spend less time in social interaction but more time in social approach compared to controls, indicative of an altered social repertoire; SS males also show increased aggression when competing for access to sweet substances. To investigate to what extent SS influences choice behaviour when social and sweet rewards are presented simultaneously, a Social Discounting test was conducted. The SS procedure was administered during either adolescence or adulthood to both male and female rats to investigate sex differences and to determine if SS effects were specific to administration during adolescence. Results showed that increasing concentrations of sucrose (0%, 2%, 5%, 10%) had no influence on time spent near a novel peer during the Social Discounting choice test, but rats drank less of 5% sucrose when in a social condition relative to when drinking alone. The only stress effect to emerge was in adolescent-stressed males tested immediately after the stress procedure; SS adolescent males spent significantly less time drinking sucrose overall compared to controls, indicative of a stress-induced anhedonia. The stress-induced devaluation of sucrose was not long-lasting as it was not found in adolescent males tested after a delay. Thus, Social Instability stress produces short-lasting behavioural changes in reward processing only in adolescent male rats.
  • Victimization by bullying and non-bullying aggression: An evolutionary psychological perspective

    Prabaharan, Nivetha; Department of Psychology
    Using an evolutionary psychological perspective, I investigated the correlates of two kinds of peer victimization with differential power relations between the perpetrator and victim. Bullying is goal-directed aggression towards an individual with less power than the perpetrator. In contrast, non-bullying aggression is aimed towards an individual of equal or greater power than the perpetrator. Specifically, I examined the relation between psychosocial vulnerability and evolutionary advantages with both types of victimization. A total of 627 adolescents aged 9-14 years (M = 11.93; SD = 1.40) completed self-report and peer nomination measures. Indicators of psychosocial vulnerability included emotional problems and fewer close friendships. Evolutionary advantages were assessed by measuring peer-nominated physical attractiveness, dating popularity, perceived popularity, and respect by others. Victimization by bullying was not related to psychosocial vulnerability, but was negatively associated with physical attractiveness, perceived popularity, and respect. As predicted, victimization by non-bullying aggression was positively associated with all four evolutionary advantages. The results demonstrate the importance of measuring the power relation between the perpetrator and victim when studying peer victimization. Adolescents victimized by those with greater power may be targeted due to the vulnerability of having fewer evolutionary advantages. In contrast, adolescents victimized by those of equal or less power may be targeted due to competition and rivalry, insofar as they possess greater evolutionary advantages than their peers, which mark them as rivals.
  • My life compared to others: Examining the impact of better or worse off comparisons on young adults’ beliefs about how their life satisfaction is unfolding over time

    DeGagne, Brock; Department of Psychology
    Many individuals perceive their lives as becoming increasingly satisfying over time. Drawing on social comparison theory and research based on the better/worse-than-average effects, the present research investigated comparisons to the average other as a potential cause of how individuals evaluate their past, current, and anticipated future life satisfaction, as well as their affective reactions and motivation to achieve their future goals. In two studies, participants were randomly assigned to describe their current life (Study 1; N = 382; M age = 30.01 years; 43% female) or their life as unfolding over time (Study 2; N = 451; M age = 30.89; 54% female) in a manner that is either better (better-than-average) or worse (worse-than-average) than the average person their age and gender, or a third ‘no comparison’ group (control) that provided no description (Study 1) or a description without reference to others (Study 2). Dependent measures for both studies included ratings of recollected past, current, and anticipated future life satisfaction, positive and negative affect, and motivation for the future (commitment, confidence). In addition, self-esteem was assessed as an exploratory moderator. In both studies, participants in the better-than-average conditions (vs. the other two conditions) reported greater perceived improvement in life satisfaction over time (from the past to the future), as well as higher positive and lower negative affect. Participants in the worse-than-average conditions (vs. controls) reported less perceived improvement in life satisfaction over time, as well as lower positive and higher negative affect. Additionally, participants in the better (vs. worse) than average conditions reported greater (vs. lesser) commitment and confidence to achieve future goals. There was little evidence for the moderating role of self-esteem. Thus, present findings suggest that comparison involving individuals’ current lives or their progress in life relative to others influences how they view their lives as unfolding over time, as well as their affective reactions and motivation. Specifically, viewing one’s current life or one’s progress in life over time as better (vs. worse) than average results in more favourable life evaluations, affective responses, and motivation.
  • Alpha suppression as a neural marker of task demands in voluntary vs involuntary retrieval in older and younger adults

    Henderson, Sarah Elizabeth; Department of Psychology
    Voluntary episodic memory relies on intentionally controlled retrieval, while involuntary episodic memory comes to mind automatically. Consistent with findings of reduced cognitive control with age, recent work suggests that voluntary memory declines with age while involuntary memory is relatively preserved. However, the neurophysiology underlying these age differences has yet to be established. The current study used EEG to test 31 young and 35 older adults during voluntary vs. involuntary retrieval (manipulated between-subjects). Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later retrospectively reported which sounds brought the paired picture to mind during the sound task. Older adults said they remembered as many pictures as young adults, but their objective memory was lower on a final cued recall test. For the EEG analysis, older adults showed greater alpha event-related desynchronization (ERD; a neural marker of memory reactivation) for paired than unpaired sounds at occipital sites, possibly reflecting visual reactivation of the associated pictures. Young adults did not show memory-related alpha ERD effects. However, young adults did show greater alpha ERD during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD (indicative of effortful retrieval) regardless of condition. These data suggest that alpha ERD can be used as a neural marker of memory in older adults; however, a more naturalistic paradigm may be required to study true involuntary memory with age.
  • The Relation Between Young Children's Memory and Metacognition

    Lavis, Lydia; Department of Psychology
    Prospective memory, the ability to remember to carry out future intentions (PM; Einstein & McDaniel, 1990) is a critical skill in children’s daily lives. Despite this, little is known about children’s awareness of their own PM ability and how this might be affected by the difficulty of a PM task. The current study sought to examine the effect of task difficulty on children’s predictions, postdictions, and actual PM performance. Four-to 6-year-old children (N = 132) completed an easy or difficult PM task and made predictions and postdictions before and after the task. Results showed that: (1) children’s PM increased with age and was worse in the difficult condition, (2) PM predictions and postdictions did not vary with age but PM postdictions were more accurate than PM predictions, and (3) PM postdictions were affected by difficulty of the PM task with children reporting having remembered to carry out their intention fewer times in the difficult compared to the easy condition. Overall, children’s PM postdictions were more accurate than their predictions, and difficulty of a PM task only affected children’s reflections (and not predictions) of their PM performance.
  • Implicit associative memory remains intact with age and extends to target-distractor pairs

    Davis, Emily; Department of Psychology
    Past research has shown that older adults’ reduced inhibitory control causes them to hyper-bind, or form erroneous associations between task-relevant and -irrelevant information. In the current study, we aimed to extend hyper-binding to a novel, implicit memory paradigm. In two experiments, participants viewed pictures of objects superimposed with text and their task was to make speeded categorization judgments about the objects. The encoding phase contained three blocks that varied the potential for binding: no-binding, some-binding, and full-binding. During the no/some-binding blocks, participants decided if the pictured object alone could fit inside a common desk drawer while ignoring the superimposed text. In the no-binding block, the text was a nonword; in the some-binding block, it was an object word. During the full-binding block, participants attended to both the picture and word and decided if both items could fit inside a drawer together. After a delay, participants completed the test phase during which they viewed intact and rearranged pairs from the three encoding blocks and decided if both items could fit in a drawer together. In both experiments, older adults responded faster to intact than rearranged pairs from both the some- and full-binding blocks, suggesting that they had learned both target-target and target-distractor pairs. Young adults showed no difference in RTs to pairs from either block. These findings suggest that the binding mechanism itself is spared with age; what declines instead is inhibitory control, which serves to limit attention, and ergo binding, to task-relevant information.
  • Sleep and Emotion Processing in Individuals with Insomnia Symptoms and Good Sleepers

    Howlett, Reuben; Department of Psychology
    Despite complaints of deficits in waking socioemotional functioning by individuals with insomnia, only a few studies have investigated waking emotion processing performance in this group. Additionally, the role of sleep in socioemotional processing has not been investigated using quantitative measures of sleep. The thesis investigated sleep and behavioural processing of emotionally expressive faces in individuals with insomnia symptoms (n=14) compared to healthy, good sleepers (n=15). The primary aim was to investigate the degree to which sleep predicted emotion processing. Participants completed two nights of at-home polysomnography-recorded sleep, and sleep diaries, which was followed by an afternoon of in-lab performance testing on tasks measuring processing of emotional facial expressions with an emotional Stroop task and a face categorization and intensity rating task. The insomnia group reported less total sleep time on their diary but no other differences in subjective or objective sleep were observed. No behavioural differences in emotion processing were observed overall. Post-hoc analysis of the individuals with insomnia symptoms that had a poor night of sleep on the night prior to performance assessment (n=8) revealed that a poor night of sleep in insomnia was associated with reduced time in Stage 2, REM and NREM sleep, and, there was trending support for elevated Sigma and Beta activity throughout the night as well as performance deficits for identifying emotional face expressions. For individuals with insomnia symptoms, greater levels of Beta EEG activity throughout sleep was associated with greater intensity ratings of happy, fearful, and sad faces. In conclusion, the thesis identified that the hyperarousal phenomenon in insomnia was related to altered waking salience assessments and gives promise for a new stream of research that investigates the relationship between hyperarousal in sleep and waking emotion functioning in insomnia.
  • Generalized Anxiety Disorder Following Mild Head Injury: An Investigation into the Relationship Between Physiological Underarousal and Symptoms of Anxiety

    Murray, Laura; Department of Psychology
    Mild head injury (MHI; concussion) is a major health concern worldwide as thousands of people each year suffer from an impact to the head or body sufficient to cause concussion. Acceleration/deceleration and rotational forces cause axons to stretch and tear, particularly in the area of the ventromedial prefrontal cortices (vmPFC), which in turn can attenuate physiological autonomic arousal and disrupt emotional regulation (Bechara, Damasio, & Damasio, 2000; Fisher, Rushby, McDonald, Parks, & Piguet, 2015; Pardini, Krueger, Raymont, & Grafman, 2010). Diminished levels of visceral feedback leaves one at a disadvantage for predicting, anticipating and reacting to environmental events. Therefore, individuals with MHI are described as experiencing heightened or exaggerated reactions to situations as they are not psychologically, or physiologically, prepared for stressful events. Some of these overreactions may be viewed as aggressive, others may be viewed as symptoms of anxiety; and in fact, many studies indicate these to be common complications following head injury. Diagnoses of Generalized Anxiety Disorder (GAD) are particularly frequent in a head injury population, however its characteristics may not capture the symptoms individuals with MHI experience. Whereas worry or maladaptive anticipation of adverse outcomes are the cardinal features of GAD and, reportedly, serve to control the physiological reactions that accompany uncertainty (Behar, DiMarco, Hekler, Mohlman, & Staples, 2009; Roemer & Borkovec, 1993) an absence of hypervigilance and lessened alertness is more likely in persons with MHI. To examine these variances in symptom characteristics, 84 participants (39% with MHI) completed self-report measures of aggression, dimensions of anxiety (cognitive, affective, somatic), worry, and somatization. Electrodermal activation (EDA) was measured as an indicator of autonomic physiological arousal across 4 phases of a stress manipulation (Initial Baseline, Anticipatory, Scare, Final Baseline). Having a history of MHI was not associated with significant expressive/reactive aggression; those with a GAD diagnoses endorsed the most number of aggressive symptoms. Similarly, individuals with GAD reported the highest levels of anxiety across all anxiety measures and subtypes. However, in line with our predictions, students with MHI reported the highest levels of somatic anxiety symptoms relative to affective and cognitive symptoms, and somatic anxiety was positively correlated with severity of the injury (i.e., the more severe the injury, the higher levels of somatic anxiety reported). Further, as expected, whereas the GAD group reported the highest level of worry-related symptoms, neither a history of MHI, nor injury severity, was correlated with worry. While no significant difference between EDA levels was noted in the baseline or experimental conditions, the pattern of results across the manipulation was as anticipated with the MHI group displaying the lowest level at baseline and anticipation, and the largest reaction to the scare phase. The GAD group did not demonstrate the expected reduction in autonomic responsivity. However, EDA levels for the MHI group alone had a significant negative correlation to the Anticipatory phase and trending towards a significant positive correlation in the Scare phase. Together, these findings indicate a fundamental difference in types of anxiety and vigilance symptoms found in persons with GAD versus MHI. A dampened baseline and anticipatory physiological response can result in a decreased ability to predict outcomes, and exaggerated reactions, especially in times of uncertainty (Bechara et al., 2000; Damasio & Bishop, 1996). Frequent and ongoing behavioural outbursts are observed in persons with TBI (traumatic brain injury), but may reflect autonomic, as opposed to affective, underlying neural mechanisms. Acknowledging and understanding these subtle differences in symptom description can provide insight into more effective treatment paradigms.
  • The effect of stereotype-threat on memory and cortisol in older adults

    Ryan, Ashley Dawn; Department of Psychology
    Stereotype-threat is characterized by underperformance on a task after exposure to a negative, self-relevant stereotype. In the case of older adults, there is a widely-held stereotype that older adults have poor memory function. It has been suggested that reminding older individuals of this stereotype results in poorer memory performance on effortful, but not automatic memory tasks. Further, testing older adults under certain conditions may increase cortisol levels, a biomarker associated with stress. The present study investigated whether stereotype-threat affects implicit and explicit memory, and cortisol levels in older adults. We gave older adults (n = 62) an incidental encoding task wherein they rated a list of common words for pleasantness. Participants were randomly assigned to threat-activated or threat-eased groups, with each group reading a newspaper article designed to either induce or ease the salience of stereotype-threat. Memory was tested implicitly, via word stem completion task, and explicitly, via free recall task and forced choice recognition. Saliva samples were taken before encoding and after memory testing to assess changes in cortisol. Stereotype threat had no effect on implicit or explicit memory, or the change in cortisol levels over time. However, there was a negative relationship between salivary cortisol levels and free recall in older men. We suggest that this finding may be explained by sex differences in reactivity and resilience to psychosocial stressors. Further, we discuss the difficulties involved with measuring stereotype-threat in older adults, who are often tested in youth-favouring settings.

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