Psychology

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Motivated Resistance to Counterattitudinal Arguments: The effects of affirmation, argument strength and attitude importance
(University of Waterloo, 2000) Correll, Joshua
In this study we explored some of the factors associated with biased processing of attitude-relevant information. We were particularly interested in the possibility that a self-affirmation, by reducing self-evaluative concerns, might increase participants' willingness to impartially evaluate information that conflicts with their current views. We examined students' reactions to arguments about increasing tuition as a function of four factors: attitude importance, argument strength, the congruence of arguments with existing attitudes, and our experimental manipulation of affirmation. We found that affirmation reduced biased evaluation only for participants who rated the issue as important. We also found that affirmation dramatically impacted the perception of argument strength. Stronger counterattitudinal arguments were rejected by non-affirmed participants, who did not distinguish them from weak arguments, presumably because of the esteem threat posed by a strong ideological challenge. Affirmed participants, though, evaluated strong counterattitudinal arguments more positively.
Witnessing-condition Heterogeneity and Witnesses’ Versus Investigators’ Confidence in the Accuracy of Witnesses’ Identification Decisions
(APA, 2000-06) Lindsay, D. Stephen; Nilsen, Elizabeth S.; Read, J. Don
Undergraduate participants were tested in 144 pairs, with one member of each pair randomly assigned to a “witness” role and the other to an “:investigator” role. Each witness viewed a target person on video under good or poor witnessing conditions and was then interviewed by an investigator, who administered a photo lineup and rated his or her confidence in the witness. Witnesses also (separately) rated their own confidence. Investigators discriminated between accurate and inaccurate witnesses, but did so less well than witnesses' own confidence ratings and were biased toward accepting witnesses' decisions. Moreover, investigators' confidence made no unique contribution to the prediction of witnesses' accuracy. Witnesses' confidence and accuracy were affected in the same direction by witnessing conditions, and there was a substantial confidence–accuracy correlation when data were collapsed across witnessing conditions. Confidence can be strongly indicative of accuracy when witnessing conditions vary widely, and witnesses' confidence may be a better indicator than investigators'
Reading aloud is not automatic: Processing capacity is required to generate a phonological code from print
(University of Waterloo, 2005) Chan-Reynolds, Michael G.
The process of generating a phonological code from print is widely described as automatic. This claim is tested in Chapter 1 by assessing whether phonological recoding uses central attention in the context of the Psychological Refractory Period (PRP) paradigm. Task 1 was a tone discrimination task and Task 2 was reading aloud. Nonword letter length and grapheme-phoneme complexity yielded additive effects with SOA in Experiments 1 and 2 suggesting that assembled phonology uses central attention. Neighborhood density (N) yielded additive effects with SOA in Experiments 3 and 4, suggesting that one form of lexical contribution to phonological recoding also uses central attention. Taken together, the results of these experiments are inconsistent with the widespread claim that phonological codes are computed automatically. Chapter 2 begins by reconsidering the utility of ?automaticity? as an explanatory framework. It is argued that automaticity should be replaced by accounts that make more specific claims about how processing unfolds. Experiment 5 yielded underadditivity of long-lag word repetition priming with decreasing SOA, suggesting that an early component of the lexical contribution to phonology does not use central attention. There was no evidence of Task 1 slowing with decreasing SOA in Experiments 6 and 7, suggesting that phonological recoding processes are postponed until central attention becomes available. Theoretical development in this field (and others) will be facilitated by abandoning the idea that skilled performance inevitably means that all the underlying processes are automatic.
Means-end Search for Hidden Objects by 6.5-month-old Infants: Examination of an Experiential Limitation Hypothesis
(University of Waterloo, 2005) Menard, Karen
Three experiments were conducted to investigate the hypothesis that young infants? failures to search for occluded objects arises, not from deficiencies in their object representations, but from limitations in experience with the physical world. Successful means-end search is typically found at 8 months of age and is traditionally taken as the hallmark of object permanence. However, recent evidence suggests that infants much younger than 8 months of age are able to represent and reason about objects that are no longer visible. In Experiment 1, successful means-end search was found for 8. 5-, but not 6. 5-month-old infants in a traditional task, but younger infants showed successful search ability when the task was made familiar to them in Experiment 2 (i. e. , when the toy and occluder are first presented as a single composite object), and when they were given the opportunity to watch a demonstration of the solution to the task in Experiment 3. These results are taken as evidence for the ?experiential limitation? hypothesis and suggest that young infants are more apt at solving manual search tasks than previously acknowledged.
Human smoking behaviour, cigarette testing protocols, and constituent yields
(University of Waterloo, 2005) Hammond, David
The issue of how to test and ultimately regulate tobacco products represents a critical challenge for the public health community. Although the current international testing regime for conventional cigarettes is widely acknowledged to be seriously flawed, there is a lack of data to guide potential alternatives, particularly in the area of human puffing behaviour. The current study sought to: 1) collect naturalistic measures of smoking behaviour, 2) examine the extent to which levels of tar, nicotine, and carbon monoxide from each of five testing protocols were associated with measures of nicotine uptake among smokers, and 3) examine the validity of self-report measures of smoking behaviour. These questions were examined through two different studies. First, a field study of smoking behaviour was conducted with 59 adult smokers, who used a portable device to measure smoking topography over the course of 3 one-week trials. Participants were asked to smoke their usual ?regular-yield? brand through the device for Trial 1 and again, 6 weeks later, at Trial 2. Half the subjects were then randomly assigned to smoke a ?low-yield? brand for Trial 3. The smoke intake and constituent yield of each brand was then tested under five testing protocols: ISO, Massachusetts, Canadian, a Compensatory protocol, and a Human Mimic regime. Participants also completed self-report measures of puffing behaviour at recruitment and immediately following each of the three one-week smoking trials. Several of these self-report measures were subsequently included in the Waves 2 and 3 of the International Tobacco Control Policy Evaluation (ITC) Survey?an international cohort survey of adult smokers from Canada, Australia, the US, and the UK.

The results of the field study indicate a high degree of stability in puffing behaviour within the same smoker over time, but considerable variability between smokers, including those smoking the same brand. Puffing behaviour was strongly associated with cotinine levels, particularly when included in an interaction term with cigarettes per day (Part r = . 50, p<. 001). Smokers who were switched to a ?low-yield? cigarette increased their total smoke intake per cigarette by 40% (p=. 007), with no significant change in their in salivary cotinine levels.

The results indicate systematic differences between human puffing behaviour and the puffing regimes used by machine testing protocols. The puffing behaviour observed among participants during the one-week smoking trials was significantly more intense than the puffing parameters of the ISO and Compensatory testing regimes. When cigarette brands were machine tested using participants? actual puffing behaviour, the results suggest that participants ingested two to four times the level of tar, nicotine, and carbon monoxide indicated by the ISO regime, and twice the amounts generated by the Compensatory regime for ?regular-yield? brands. The Canadian and Massachusetts regimes produced yields much closer to the ?Human Mimic? yields, although nowhere near a maximum or intense standard, as they were designed to do. Only the nicotine yields from the Human Mimic regime were correlated with measures of nicotine uptake among smokers, and only moderately so (Part r = . 31, p=. 02).

Self-report measures of puffing behaviour collected during the field study were moderately correlated with physiological measures of puffing and exposure. Self-report measures of puff depth and puff number showed some promise as predictors of salivary cotinine, although the results are characterized by inconsistencies across models. The self-report measures included in the ITC survey were only weakly associated with age and cigarettes per day, with modest between-country differences.

Overall, this research highlights the importance of puffing behaviour as a determinant of smoke exposure, and provides strong evidence of compensatory smoking for ?low-yield? brands. The findings also highlight the variability in human smoking behaviour and the limitations associated with machine testing protocols. Perhaps most important, the findings underscore the immediate need to revise the ISO protocol, which systematically underestimates smoking behaviour among humans and exaggerates differences between cigarette brands.
Auditory target identification in a visual search task
(University of Waterloo, 2005) Lochner, Martin Jewell
Previous research has shown that simultaneous auditory identification of the target in a visual search task can lead to more efficient (i. e. ?flatter?) search functions (Spivey et al. , 2001). Experiment 1 replicates the paradigm of Spivey et al. , providing subjects with auditory identification of the search target either before (Consecutive condition) or simultaneously with (Concurrent condition) the onset of the search task. RT x Set Size slopes in the Concurrent condition are approximately 1/2 as steep as those in the Consecutive condition. Experiment 2 employs a distractor ratio manipulation to test the notion that subjects are using the simultaneous auditory target identification to ?parse? the search set by colour, thus reducing the search set by 1/2. The results of Experiment 2 do not support the notion that subjects are parsing the search set by colour. Experiment 3 addresses the same question as Experiment 2, but obtains the desired distractor ratios by holding the amount of relevantly-coloured items constant while letting overall set size vary. Unlike Experiment 2, Experiment 3 supports the interpretation that subjects are using the auditory target identification to parse the search set.
SOCIAL IDENTITY AND MEMORIES OF INJUSTICES INVOLVING INGROUP: WHAT DO WE REMEMBER AND WHY?
(University of Waterloo, 2006) Sahdra, Baljinder
Motivational changes due to individual differences and situational variations in ingroup identification can influence accessibility of memories of ingroup violence, victimization and glories. In Study 1, high identifiers recalled fewer incidents of ingroup violence and hatred than of ingroup suffering. As well, they recalled fewer incidents of ingroup violence and hatred than did low identifiers. In Study 2, a manipulation of ingroup identity produced shifts in memory. Relative to those in the low identity condition, participants in the high identity condition recalled fewer incidents of violence and hatred and more good deeds by members of their group. Participants in a control condition recalled more positive than negative group actions; this bias was exaggerated in the high identity condition and eliminated in the low identity condition. With respect to memories of ingroup tragedies, Studies 3 and 4 demonstrated that experimental reminders of ingroup suffering enhanced participants' sense of connectedness to the ingroup. The findings suggest that memories of ingroup aggressions threaten ingroup identity whereas memories of ingroup suffering enhance ingroup identity. Societal implications of the findings are discussed. The present research informs the literature on reconstructive memory by extending previous findings on the flexibility of personal memories to historical memory.
Age-related changes in the neural and cognitive processes relating to memory retrieval under conditions of full and divided attention.
(University of Waterloo, 2006) Skinner, Erin I.
We examined the neural and cognitive processes engaged during auditory verbal recognition performance under full attention (FA) and divided attention (DA) conditions in younger and older adults. Recognition was disrupted by a word (DA-word), but not digit-based (DA-digit) distracting task, performed concurrently with retrieval. In Study 1, a multivariate functional magnetic resonance imaging analysis technique, Partial Least Squares (PLS) was used to identify distributed patterns of brain activity most related to the different conditions and behaviours. We found that similar retrieval networks were recruited during the FA and DA-digit, but not DA-word, condition in both age groups, mirroring behavioural performance. There was, however, an age-related change in the brain regions that predicted successful memory performance. In addition, we found that a neural network relating to hippocampal activity predicted memory success during the FA and DA-digit, but not DA-word, condition in younger, but not older, adults. In study 2, we used a Remember-Know paradigm to examine how manipulations of DA affect recollective and familiarity-based retrieval processes. Younger and older adults showed an increase in false Remember responses during both DA conditions and decreased accuracy in Know responses only during the word-based DA condition. In addition, aging was associated with decreased accuracy in Remember, but not Know, responses, in both DA conditions. In a follow-up experiment, we showed that these results cannot be accounted for by differences in difficulty level of the chosen distracting tasks. Results suggest that recollective processes rely on attentional resources during retrieval. Together these studies show that declines in available attentional resources, common with advancing age, affect both the neural networks used during retrieval, and the qualitative nature of the memories that are retrieved. Results also suggest that familiarity processes rely on the reactivation of content-specific representations, mediated by a neural network relating to hippocampal activity in younger, but not older, adults.
A Stimulus-Response Account of Stroop and Reverse Stroop Effects
(University of Waterloo, 2006) Blais, Chris
This thesis concerns selective attention in the context of the Stroop task (identify the colour) and Reverse Stroop task (identify the word). When a person is asked to select and identify one dimension of a bidimensional stimulus (e. g. , the word RED printed in green) the typical finding is that the word influences colour identification (i. e. , the Stroop effect) but the colour does not influence word identification (i. e. , no Reverse Stroop effect). A major account of performance in these tasks posits that one dimension interferes with the other only when a translation occurs (e. g. , Roelofs, Psychological Review, 2003; Sugg & McDonald, Journal of Experimental Psychology: Human Perception & Performance, 1994; Virzi & Egeth, Memory & Cognition, 1985). This translation assumption is implicit in virtually all work in the field. The first part of this thesis completely undermines the translation assumption. In a series of four experiments (two unique paradigms), I demonstrate that interference from the colour in a Reverse Stroop task occurs in the absence of a translation. The second part of this thesis contains two additional experiments designed to discriminate between translation effects and response conflict effects. The results of these experiments confirm that a translation was not required because no stimulus conflict effect, the most likely locus of a translation effect, was observed. However, response conflict effects were observed. The third part of this thesis implements a computational model based on the principle that the strength of association (Cohen, Dunbar, & McClelland, Psychological Review, 1990) between a specific stimulus and its response (Logan, Psychological Review, 1988) is important in determining the influence of the irrelevant dimension. This model has no translation mechanism. A final experiment was conducted to test this model; the model accounted for over 98% of the variance in RTs and 92% of the variance in interference and facilitation scores in both the Stroop and Reverse Stroop tasks independent of whether a translation was required.
SIBLING RELATIONSHIPS AND FAMILY DYNAMICS IN FAMILIES WITH A CHILD WITH TOURETTE SYNDROME
(University of Waterloo, 2006) Maleki-Tehrani, Marjan
This study investigated the association between the severity of Tourette Syndrome (TS) and comorbid tendencies (Attention Deficit Hyperactivity Disorder (ADHD), Obsessive-Compulsive Disorder (OCD), and rage), maternal differential treatment, fairness evaluation of maternal differential treatment, and communication with both sibling and family relationships. Fifty-five mothers and healthy siblings of individuals with Tourette Syndrome participated in the study. The parents provided information regarding family demographics and the severity of Tourette Syndrome and comorbid tendencies, and the healthy siblings completed the sibling and family relationship questionnaires. The questionnaires were posted on a secure website, where the parents and healthy siblings could complete the online measures via internet connections.

The study revealed several important findings. The results showed significant associations between the severity of Tourette Syndrome and comorbid OCD, ADHD and rage tendencies thus suggesting that studying Tourette Syndrome without considering comorbidity would be unrealistic. Additionally, communication regarding Tourette Syndrome between the healthy siblings and their parents played an important role with respect to sibling and family relationships. Communication between the healthy siblings and their parents predicted more warmth between the healthy siblings and their sibling with Tourette Syndrome as well as more family cohesion and adaptability as reported by the healthy siblings. Communication had a significant moderating effect on both severity of Tourette Syndrome and healthy siblings' fairness evaluation of maternal differential treatment in predicting family relationships. When the sibling had less severe Tourette Syndrome, the healthy siblings reported more family adaptability when they had more communication with their parents, and reported less family adaptability when they had less communication with their parents. The results also indicated that when healthy siblings perceived their maternal differential treatment to be unfair, they reported more family cohesion when they had more communication with their parents, and reported less family cohesion when they had less communication with their parents. The study did not support the negative impact of maternal differential treatment on sibling relationships; however, the results confirmed the previous findings regarding the moderating effect of fairness evaluation on maternal differential treatment in predicting sibling relationships. When the sibling with Tourette Syndrome was favored, the healthy siblings reported more sibling warmth when they perceived the favouritism (maternal differential treatment) to be fair. Furthermore, the results showed that healthy siblings' perceptions of maternal differential treatment could predict cohesion and adaptability in the family. The more the healthy siblings reported being treated differently by their mothers, the less cohesion and adaptability they reported in their families.

The present study supported previous studies in finding that sibling conflict decreased with age. The results also highlighted the role of age in moderating the effects of communication and maternal differential treatment in predicting sibling conflict. When healthy siblings had more communication with their parents they reported more conflict with their sibling with Tourette Syndrome when they were younger, and reported less sibling conflict with their sibling with Tourette Syndrome when they were older. Furthermore, when healthy siblings were favored by their mothers, they reported more conflict with their sibling with Tourette Syndrome when they were younger than when they were older, thereby emphasizing the importance of developmental differences in dynamics between the siblings. The significant contributions of the study include underlining the importance of communication, the relationship between Tourette Syndrome and comorbid conditions, and healthy siblings' perceptions of sibling and family relationships.
Collaboration During Visual Search
(University of Waterloo, 2006) Malcolmson, Kelly
Three experiments examine how collaboration influences visual search performance. Working with a partner or on their own, participants reported whether a target was present or absent in briefly presented search displays. The search performance of individuals working together (collaborative pairs) was compared to the pooled responses of the individuals working alone (nominal pairs). Collaborative pairs were less likely than nominal pairs to correctly detect a target and they were less likely to make false alarms. Signal detection analyses revealed that collaborative pairs were more sensitive to the presence of the target and had a more conservative response bias than the nominal pairs. This pattern was observed when the search difficulty was increased and when the presence of another individual was matched across pairs. The results are discussed in the context of task sharing, social loafing and current theories of visual search.
Developing Knowledge of Polysemous Vocabulary
(University of Waterloo, 2007-01-08T18:20:40Z) Sullivan, Jennifer
This study investigated the development of knowledge of vocabulary including multiple meanings of words during the school years. Twenty children from each of Grades 2, 5, 8, and 11 were tested for their knowledge of all the meanings of a large random sample of words from an unabridged dictionary (Webster's Third, 1981). Approximately 47% of the words had more than one meaning. Total average estimated vocabulary increased from 17,970 words in Grade 2 to 83,871 words in Grade 11. The estimated number of known derived words increased at the greatest rate throughout the school years. There was evidence that participants may have used morphological problem solving to figure out at least one meaning for 45% of their total vocabulary. Not only did the number of words known increase dramatically through the school years but the total average estimated number of different word meanings known increased also from 28,797 word meanings in Grade 2 to 185,990 word meanings in Grade 11. Three types of meanings were identified according to their relation to their principal meaning (known by the most children): homonyms (share no semantic relationship); conversions (different grammatical part of speech); and metaphorical extensions (share some other semantic relationship). When children demonstrated knowledge of more than one meaning, they were asked to attempt to explain the relation between those two meanings. Even the youngest children in Grade 2 knew a large number of multiple meanings but the ability to express knowledge of a relation between those meanings was uncommon until the later school years. This developing ability can be explained in part by the children’s increasing metalinguistic awareness and general linguistic expressiveness but also by an increasing ability to understand and express metaphorical similarities between lexical concepts, which are common to the metaphorically extended meanings.
Rationalization and Regret among Smokers in Thailand and Malaysia
(University of Waterloo, 2007-01-11T15:15:31Z) Lee, Wonkyong Beth
The current study examines two psychological experiences—rationalization and regret—among smokers from Thailand and Malaysia and the behavioural impact of rationalization and regret—intentions to quit. More specifically, the goals of the study were not only to examine differences between the two countries in rationalization, regret, and intentions to quit, but also to explain country differences by using the psychological constructs of social norms and the cultural psychological construct of collectivism (via mediation and moderation analyses). The data were from the International Tobacco Control (ITC) Policy Evaluation Southeast Asia Survey, a cohort survey of representative samples of adult smokers in Thailand (N = 2,000) and Malaysia (N = 2,006). The ITC Southeast Asia Survey was conducted January-March 2005. Participants were asked to complete a 40-minute in-person survey. Thai smokers were more likely to have intentions to quit smoking than Malaysian smokers and this country difference in quit intentions were, in part, explained by differences between the two countries in rationalization and regret, and that those variables, in turn, were significant predictors of quit intentions. Next, the psychological constructs of social norms and the cultural psychology construct of collectivism were used to explain the country differences in rationalization and regret. Thai smokers were more traditional and family oriented (high in vertical collectivism) and thus, they are more sensitive about their social norm and familial rejections about smoking. This, in part, contributed the fact that Thai smokers, compared to Malaysian smokers, were less likely to rationalize and more likely to regret smoking. Finally, the predictive models of rationalization and regret for Thailand and Malaysia were mirror images. The current study points to the importance of understanding smokers’ rationalization and regret. Rationalization and regret are negatively related and have an important implication for future behaviour. Different social norms against smoking, which are shaped by different regulatory environments and cultural values, contribute to the country differences in rationalization and regret. This study has demonstrated the benefits/value of psychological constructs in understanding smoking in a cultural context.
Hostility in the context of depression: Testing the relevance of perceived social ranking
(University of Waterloo, 2007-01-29T14:55:48Z) Law, Ada Kwan-Wing
Theoretical positions (Sloman & Gilbert, 2000), current research (Robbins & Tanck, 1997) and clinical observations (APA, 1994) have generally concluded that depressed populations tend to demonstrate an elevated level of hostility. Based on the premises of the Social Rank Theory (SRT; Sloman & Gilbert, 2000), the current study explores the purported etiological underpinnings of the co-occurrence between depression and hostility. The SRT regards depression as a state of inferiority resulting from a drop in social rank and hostility as stemming from a sense of injustice over this inferiority. To test this idea, measures of perceived social rank, depression, trait anger, anger expression and perceived injustice were administered to 97 university students at two time points, one month apart. Long-term rank change was measured retrospectively at Time 1 and short-term rank change was measured prospectively by sampling at Time 1 and Time 2. Three hypotheses were advanced: 1) social rank would be negatively associated with depression; 2) unfavourable rank change would predict greater levels of depression; and 3) unfavourable rank change from an initially superior rank would predict greater levels of anger and perceived injustice. Results were partially supportive of the hypotheses. As expected, social rank was negatively associated with depression. As well, a long-term change in social rank predicted greater levels of anger suppression. Results were discussed with respect to their consistency with the SRT. Potential weaknesses of the methodology and future directions of this line of inquiry were also presented.
The Influence of Implicit Norms on Cognition and Behaviour
(University of Waterloo, 2007-02-09T19:17:49Z) Yoshida, Emiko
Recent development of implicit measures has enabled researchers to investigate the relation between implicit attitudes and automatic behaviours. Among these measures, the implicit association test (IAT: Greenwald, McGhee Schwartz, 1998) is one of the most widely used measures of implicit attitudes. However, recently, Olson and Fazio (2004) demonstrated that the IAT is contaminated by “extrapersonal associations” and suggested that the personalized version of the IAT is less influenced by these associations. In this paper, we demonstrated that the extrapersonal associations reflect cultural norms and predict meaningful behaviour. In Study 1, we found that the traditional IAT is predicted by both the personalized IAT and our cultural norm IAT. In Study 2, we found the cross-cultural differences in the implicit cultural norms. Finally, in Study 3, we demonstrated that the personalized IAT and normative IAT both predict behaviours among European-Canadians and Asian-Canadians. Thus, our studies provide evidence of predictive validity for the cultural norm IAT.
Subtle Effects of Sleepiness on Electrocortical Indices of Attentional Resources and Performance Monitoring
(University of Waterloo, 2007-02-19T16:37:57Z) Murphy, Timothy Ian
In this dissertation, the effect of mild sleep deprivation on attentional allocation and performance monitoring was investigated using a variety of event-related potential (ERP) paradigms with ecologically realistic periods of sleep deprivation. Seventeen female young adults completed several tasks under alert and sleepy conditions, after 3 and 20 hours of wakefulness, respectively. Objective behavioural measures of response times and error rates indicated virtually no decrements that could be attributed exclusively to sleepiness; however, there were consistent alterations in the ERPs indicative of subtly reduced attentional resources and performance monitoring. The first study (Chapter 2) examined the effect of distraction on the P300, an ERP component related to attention and stimulus processing. Participants performed an auditory oddball task with and without a secondary visual working memory task. Response times (RTs) and P300 amplitudes were affected by the addition of the secondary working memory task. However, an interaction showed that the P300 latency was significantly increased by the secondary task only in the sleepy condition, indicating that processing speed is impaired by a secondary task only when the participant is sleepy. The next study (Chapter 3) used a Go/NoGo contingent negative variation (CNV) task. The CNV is reflective of sustained attention, and is known to be associated with frontal lobe functioning. This task was performed twice, with and without a financial incentive for fast responses, to assess the effect of motivation. The P300 amplitude to the first stimulus and CNV prior to the second were clearly larger to Go stimuli for both levels of alertness when the participant was motivated by the financial incentive. However, with no incentive in the sleepy condition, there was reduced differentiation of the two types of stimuli, indicating a reduced ability to discriminate between important and less important information. In chapters 4 and 5, performance monitoring was examined using two tasks, the Eriksen Flanker task and the Anti-Saccade task, producing an ERP related to errors with two basic components: the error-negativity (Ne/ERN) and error-positivity (Pe), thought to be related to error recognition and error evaluation, respectively. In both data sets, the amplitude of the Ne/ERN was not significantly reduced by sleep deprivation, but the amplitude of the Pe was. In addition, smaller anti-saccade errors produced reduced Ne/ERN amplitudes compared to larger anti-saccade errors. Another marker of performance monitoring is post-error slowing, which was present in the flanker task only during the alert condition. These results indicate that error detection or recognition (Ne/ERN) appears to be relatively preserved during sleep deprivation, but further error evaluation (Pe) and compensation (post-error slowing) are impaired. Taken together, the findings demonstrate that even mild sleep deprivation has a subtle but reliable effect on electrocortical activity associated with attention and performance monitoring despite an absence of behavioural changes, indicating deleterious effects before behavioural changes are observed. Therefore, relying on behavioural tests to determine at what point an individual becomes unsafe to operate machinery or perform various tasks may be misleading.
SOCIAL ACCEPTANCE AND SELF-ESTEEM: TUNING THE SOCIOMETER TO INTERPERSONAL VALUE
(University of Waterloo, 2007-05-14T21:06:27Z) Anthony, Danu Beltara
The author drew on sociometer theory to propose that self-esteem is attuned to traits that garner others’ acceptance, and the traits that garner acceptance depend on one’s social role. Attunement of self-esteem refers to the linkage, or connection, between self-esteem and specific traits, which may be observed most clearly in the association between self-esteem and specific self-evaluations. In most roles, appearance and popularity determine acceptance, so self-esteem is most attuned to those traits. At the same time, interdependent social roles emphasize the value of communal qualities, so occupants of those roles have self-esteem that is more attuned to communal qualities than is the general norm. To avoid the biases of people's personal theories, attunement of self-esteem to particular traits was assessed indirectly via the correlation between self-esteem and self-ratings (Study 2), with cognitive accessibility measures (Study 3), by observing the responsiveness of people’s self-concepts to social cues about the self (Study 4), and with an experiment involving social decision-making (Study 5). As hypothesized, self-esteem was generally more attuned to appearances than communal qualities, but interdependent social roles predicted heightened attunement of self-esteem to qualities like kindness and understanding.
The Source of the Positivity Bias in Older Adults' Emotional Memory
(University of Waterloo, 2007-05-18T17:11:35Z) Tomaszczyk, Jennifer Christina
According to socioemotional selectivity theory (SST), old age is associated with a greater emphasis on self-regulation of emotional states, a focus that fosters a bias in processing positively valenced material in older adults. There is disagreement, however, about whether the “positivity bias” suggested by SST influences performance on memory tasks. Some studies suggest that older adults remember more positive than negative information, or simply less negative information, relative to younger adults, whereas other studies report no such differences. This thesis examined (1) whether variations across studies in encoding instructions or in personal relevance of study materials could account for these inconsistencies, and (2) whether differences in attention at encoding to positive, negative, and neutral stimuli could account for the positivity bias in older adults’ later memory for the stimuli. In Experiment 1, younger and older adults were instructed either to passively view positive, negative, and neutral pictures or to actively categorize them by valence. On a subsequent incidental recall test, older adults recalled equal numbers of positive and negative pictures, whereas younger adults recalled negative pictures best. There was no effect of encoding instructions. Crucially, when pictures were grouped into high and low personal relevance according to participants’ ratings, a positivity bias emerged only for low relevance pictures. In Experiment 2, attention to pictures at encoding was directly manipulated through use of a divided attention paradigm. Although divided attention lowered recall in both age groups, attention did not interact with age and valence. Taken together, the results suggest that variability in the personal relevance of study pictures may be the factor underlying cross-study differences in whether a positivity bias is observed in older adults’ memory.
Spatial deficits in visuomotor control following right parietal injury
(University of Waterloo, 2007-05-22T16:32:56Z) Broderick, Carol Elizabeth
Superior parietal cortex has been implicated in visuomotor guidance and is proposed to be specialised for action in the lower visual field and peripersonal space. Two patients, one with a right superior parietal lesion leading to optic ataxia (ME), and one with a lesion affecting right inferior parietal cortex (LH), were compared to elderly controls (n=8) and young controls (n=8) on a reciprocal pointing task with movements made in the near-far direction (i.e., sagittal plane) or right-left direction (i.e., fronto-parallel plane). In contrast to both control groups, who demonstrated a speed-accuracy trade-off in movement time and peak velocity, neither of the patients did. When the time spent post-peak velocity (represented as a percentage of total movement time) was examined, both patients demonstrated larger times post-peak velocity than controls for all movement directions. Furthermore, while rightward movements of the right hand had higher times post-peak velocity than leftward movements there were no directional patterns for near-far movements which contrasted with controls who had larger times post-peak velocity for near movements. The patient with the more superior lesion (ME) had the greatest difficulty with movements made back toward the body suggestive of a role for superior parietal cortex in the fine tuning of movements made in this region of space (i.e., personal or peripersonal space). In contrast, all directions of movement seemed to be equally affected in the patient with a more inferior lesion. These results are discussed in terms of the different roles played by inferior and superior parietal cortex in the control of visually guided movements.
Agreeableness and Close Relationships: Is it Trust That Really Matters?
(University of Waterloo, 2007-06-28T15:45:58Z) Perunovic, Mihailo
Three correlational studies and 2 experiments examined the influence of agreeable people’s trust on their close relationships. Studies 1-3 employed correlational methods to examine the association between agreeableness and interpersonal trust (felt security; Study 1) and the applicability of the dependence regulation model (Murray, Holmes, & Griffin, 2000) to the romantic relationships of agreeable people (Studies 2 & 3). Studies 4 and 5 employed experimental methods that manipulated felt security (trust) to examine how relationship threats differentially affect agreeable versus antagonistic people (those low in agreeableness). Results indicated that not only does felt security consistently mediate the association between agreeableness and important relationship quality variables, but that this is a causal association. That is, these studies provide evidence that agreeable people have better relationships than antagonistic people because they are chronically more trusting, and hence, less prone to seeing signs of rejection where none exists.

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