Psychology, Department of

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Isolating the Neural Substrates of Visually Guided Attention Orienting in Humans

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-04-12
Abstract: 

The neural processes that enable healthy humans to orient attention to sudden visual events are poorly understood because they are tightly intertwined with purely sensory processes. Here we isolated visually guided orienting activity from sensory activity using event-related potentials (ERPs). By recording ERPs to a lateral stimulus and comparing waveforms obtained under conditions of attention and inattention, we identified an early positive deflection over the ipsilateral visual cortex that was associated with the covert orienting of visual attention to the stimulus. Across five experiments with male and female adults participants, this ipsilateral visual orienting activity (VOA) could be distinguished from purely sensory-evoked activity and from other top-down spatial attention effects. The VOA was linked with behavioral measures of orienting, being significantly larger when the stimulus was detected rapidly than when it was detected more slowly, and its presence was independent of saccadic eye movements towards the targets. The VOA appears to be a specific neural index of the visually guided orienting of attention to a stimulus that appears abruptly in an otherwise uncluttered visual field.

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Article
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Traumatic Brain Injury in Precariously Housed Persons: Incidence and Risks

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2022-02-01
Abstract: 

Background Homeless and precarious housed persons are particularly prone to traumatic brain injuries (TBIs), but existent incidence rates are hampered by poor case acquisition. We rigorously documented TBIs in precariously housed persons transitioning in and out of homelessness.

Methods Between December 2016 and May 2018, 326 precariously housed participants enrolled in a longitudinal study in Vancouver, Canada were assessed monthly for TBI occurrences after education on sequelae. Over one participant-year, 2433 TBI screenings were acquired for 326 person-years and variables associated with odds of incident TBI were evaluated.

Findings One hundred participants acquired 175 TBIs, yielding an observed incidence proportion of 30¢7% and event proportion of 53¢7%. Of the injured, 61% reported one TBI and 39% reported multiple injuries. Acute intoxication was present for more than half of the TBI events assessed. Additionally, 9¢7% of TBI events occurred in the context of a drug overdose. Common injury mechanisms were falls (45¢1%), assaults (25¢1%), and hitting one’s head on an object (13¢1%). In this community-based but non-randomly recruited sample, exploratory analyses identified factors associated with odds of an incident TBI over one year of follow-up, including: schizophrenia disorders (odds ratio (OR) = 0¢43, 95% confidence interval (CI) 0¢19, 0¢94), role functioning (OR = 0¢69, 95% CI 0¢52, 0¢91), opioid dependence (OR = 2¢17, 95% CI 1¢27, 3¢72) and those reporting past TBIs (OR = 1¢99, 95% CI 1¢13, 3¢52).

Interpretation Given the ubiquity of TBIs revealed in this precariously housed sample, we identify an underappreciated and urgent healthcare priority. Several factors modified the odds of incident TBI, which can facilitate investigations into targeted prevention efforts.

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Dynamic Inhibitory Control Prevents Salience-Driven Capture of Visual Attention

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2022-01-05
Abstract: 

The salience-driven selection theory is comprised of three main tenets: (a) the most salient stimulus within a monitored region of the visual field captures attention, (b) the only way to prevent salience-driven distraction is by narrowly focusing attention elsewhere, and (c) all other goal-driven processes are possible only after the most salient item has been attended. Evidence for and against this theory has been provided from two experimental paradigms. Here, event-related potentials (ERPs) recorded in a novel Go/No-Go paradigm disconfirmed all three of tenets of the theory. Participants were instructed to search cyan-item displays for a salient orientation singleton (Go trials) and to ignore randomly intermixed yellow-item displays that could also contain an orientation singleton (No-Go trials). ERP components associated with attentional orienting (N2pc), distractor suppression (PD), and stimulus relevance (P2a) were isolated to test predictions stemming from the salience-driven selection theory. On No-Go trials, the salient oddball elicited a PD rather than an N2pc, indicating that it was suppressed, not attended. Moreover, a P2a emerged before the N2pc on Go trials, demonstrating that observers first evaluated the global color of each display and then decided to search for the oddball (Go trials) or to ignore it (No-Go trials). We conclude that goal-driven processes can lead to the prevention of salience-driven attention capture by salient visual objects within the attentional window.

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Conceptualizations of Knowledge in Structuring Approaches to Moral Development: A Process-Relational Approach

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-12-16
Abstract: 

Like other aspects of child development, views of the nature and development of morality depend on philosophical assumptions or worldviews presupposed by researchers. We analyze assumptions regarding knowledge linked to two contrasting worldviews: Cartesian-split-mechanistic and process-relational. We examine the implications of these worldviews for approaches to moral development, including relations between morality and social outcomes, and the concepts of information, meaning, interaction and computation. It is crucial to understand how researchers view these interrelated concepts in order to understand approaches to moral development. Within the Cartesian-split-mechanistic worldview, knowledge is viewed as representation and meaning is mechanistic and fixed. Both nativism and empiricism are based in this worldview, differing in whether the source of representations is assumed to be primarily internal or external. Morality is assumed to pre-exist, either in the genome or the culture. We discuss problems with these conceptions and endorse the process-relational paradigm, according to which knowledge is constructed through interaction, and morality begins in activity as a process of coordinating perspectives, rather than the application of fixed rules. The contrast is between beginning with the mind or beginning with social activity in explaining the mind.

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The Role of Selective Attention in the Positivity Offset: Evidence from Event Related Potentials

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-11-03
Abstract: 

Some research suggests that positive and negative valence stimuli may be processed differently. For example, negative material may capture and hold attention more readily than equally arousing positive material. This is called the negativity bias, and it has been observed as both behavioural and electroencephalographic (EEG) effects. Consequently, it has been attributed to both automatic and elaborative processes. However, at the lowest levels of arousal, faster reaction times and stronger EEG responses to positive material have been observed. This is called the positivity offset, and the underlying cognitive mechanism is less understood. To study the role of selective attention in the positivity offset, participants completed a negative affective priming (NAP) task modified to dissociate priming for positive and negative words. The task required participants to indicate the valence of a target word, while simultaneously ignoring a distractor. In experiment 1, a behavioural facilitation effect (faster response time) was observed for positive words, in stark contrast to the original NAP task. These results were congruent with a previously reported general categorization advantage for positive material. In experiment 2, participants performed the task while EEG was recorded. In additional to replicating the behavioural results from experiment 1, positive words elicited a larger Late Positive Potential (LPP) component on ignored repetition relative to control trials. Surprisingly, negative words elicited a larger LPP than positive words on control trials. These results suggest that the positivity offset may reflect a greater sensitivity to priming effects due to a more flexible attentional set.

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The Trajectory of Targets and Critical Lures in the Deese/Roediger–McDermott Paradigm: A Systematic Review

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-12-03
Abstract: 

The Deese/Roediger–McDermott (DRM) paradigm has been used extensively to examine false memory. During the study session, participants learn lists of semantically related items (e.g., pillow, blanket, tired, bed), referred to as targets. Critical lures are items which are also associated with the lists but are intentionally omitted from study (e.g., sleep). At test, when asked to remember targets, participants often report false memories for critical lures. Findings from experiments using the DRM show the ease with which false memories develop in the absence of suggestion or misinformation. Given this, it is important to examine factors which influence the generalizability of the findings. One important factor is the persistence of false memory, or how long false memories last. Therefore, we conducted a systemic review to answer this research question: What is the persistence of false memory for specific items in the DRM paradigm? To help answer this question our review had two research objectives: (1) to examine the trajectory of target memory and false memory for critical lures and (2) to examine whether memory for targets exceeded false memory for critical lures. We included empirical articles which tested memory for the same DRM lists with at least two testing sessions. We discuss the results with respect to single-session delays, long-term memory recall and recognition, remember and know judgments for memory, and the effect of development, valence, warning, and connectivity on the trajectory of memory. Overall, the trajectory of targets showed a relatively consistent pattern of decrease across delay. The trajectory of critical lures was inconsistent. The proportion of targets versus critical lures across delay was also inconsistent. Despite the inconsistencies, we conclude that targets and critical lures have a dissimilar trajectory across delay and that critical lures are more persistent than targets. The findings with respect to long-term recall and recognition are consistent with both Fuzzy Trace Theory and Associative-Activation Theory of the DRM effect. The generation of false memory with brief delays (3–4 s) is better explained by Associative-Activation Theory. Examining the connectivity between target items, and critical lures, and the effect that has during study and retrieval, can provide insight into the persistence of false memory for critical lures.

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Article
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Attention Capture by Trains and Faces in Children with and Without Autism Spectrum Disorder

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-06-18
Abstract: 

This study examined involuntary capture of attention, overt attention, and stimulus valence and arousal ratings, all factors that can contribute to potential attentional biases to face and train objects in children with and without autism spectrum disorder (ASD). In the visual domain, faces are particularly captivating, and are thought to have a ‘special status’ in the attentional system. Research suggests that similar attentional biases may exist for other objects of expertise (e.g. birds for bird experts), providing support for the role of exposure in attention prioritization. Autistic individuals often have circumscribed interests around certain classes of objects, such as trains, that are related to vehicles and mechanical systems. This research aimed to determine whether this propensity in autistic individuals leads to stronger attention capture by trains, and perhaps weaker attention capture by faces, than what would be expected in non-autistic children. In Experiment 1, autistic children (6–14 years old) and age- and IQ-matched non-autistic children performed a visual search task where they manually indicated whether a target butterfly appeared amongst an array of face, train, and neutral distractors while their eye-movements were tracked. Autistic children were no less susceptible to attention capture by faces than non-autistic children. Overall, for both groups, trains captured attention more strongly than face stimuli and, trains had a larger effect on overt attention to the target stimuli, relative to face distractors. In Experiment 2, a new group of children (autistic and non-autistic) rated train stimuli as more interesting and exciting than the face stimuli, with no differences between groups. These results suggest that: (1) other objects (trains) can capture attention in a similar manner as faces, in both autistic and non-autistic children (2) attention capture is driven partly by voluntary attentional processes related to personal interest or affective responses to the stimuli.

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Transforming Connections: A Trauma-Informed and Attachment-Based Program to Promote Sensitive Parenting of Trans and Gender Non-conforming Youth

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-07-26
Abstract: 

Gender non-conforming and trans youth experience high rates of bullying and victimization, placing them at risk for serious mental health challenges. Parent support is one of the most significant protective factors in this population, and yet few programs are specifically developed to promote parenting sensitivity, understanding, and acceptance. Connect, a trauma-informed and attachment-based group program for caregivers of at-risk adolescents, has been shown to reduce parent stress and depressed mood, increase parents' sense of efficacy and satisfaction, and reduce parent-teen conflict. Teens benefit from increased attachment security and improved mental health and well-being. Treatment effects have been documented to continue for up to 2 years post-treatment. This paper describes the adaptation of the Connect program to create a new program, Transforming Connections, for caregivers of transgender and gender non-conforming youth. Participants in the first three groups were 20 parents of 16 gender non-conforming youth (ages 12–18). Common themes in group discussions related to gender included: coming out, connecting with peers, affirming pronouns/names, medical transition, parental reactions (e.g., confusion, isolation, grief, acceptance), and concerns about safety and mental health. All parents completed the full program, attending on average 9 of 10 sessions. Caregivers reported feeling respected, safe, and welcomed in the program and indicated that learning about attachment enhanced their understanding of their teen and their gender journey as well as themselves as a parent. Additionally, all parents reported applying the ideas discussed in the group frequently (60%) or somewhat frequently (40%). The majority indicated that their relationship with their teen had improved somewhat (65%) or a great deal (20%). Findings provide positive preliminary evidence of the fit and value of Transforming Connections for these families.

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Component Processes of Decision Making in a Community Sample of Precariously Housed Persons: Associations With Learning and Memory, and Health-Risk Behaviors

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-07-02
Abstract: 

The Iowa Gambling Task (IGT) is a widely used measure of decision making, but its value in signifying behaviors associated with adverse, “real-world” consequences has not been consistently demonstrated in persons who are precariously housed or homeless. Studies evaluating the ecological validity of the IGT have primarily relied on traditional IGT scores. However, computational modeling derives underlying component processes of the IGT, which capture specific facets of decision making that may be more closely related to engagement in behaviors associated with negative consequences. This study employed the Prospect Valence Learning (PVL) model to decompose IGT performance into component processes in 294 precariously housed community residents with substance use disorders. Results revealed a predominant focus on gains and a lack of sensitivity to losses in these vulnerable community residents. Hypothesized associations were not detected between component processes and self-reported health-risk behaviors. These findings provide insight into the processes underlying decision making in a vulnerable substance-using population and highlight the challenge of linking specific decision making processes to “real-world” behaviors.

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Do Structured Risk Assessments Predict Violent, Any, and Sexual Offending Better Than Unstructured Judgment? An Umbrella Review

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2021-02
Abstract: 

Although it is widely believed that risk assessment tools lead to more accurate estimates of risk of violence and offending than unstructured clinical judgments, the nature and quality of evidence that supports this view is unclear. As such, we conducted an umbrella review of systematic reviews. Through a search of 15 databases, we identified nine systematic reviews, including six meta-analyses and three narrative systematic reviews, that compared unstructured and structured risk judgments for any, violent, and sexual offending. Each review was independently coded by two raters. Raters also coded the 46 primary studies on unstructured judgment included in these reviews. Although the reviews concluded that structured risk judgments are superior to unstructured judgments, the data supporting these conclusions have limitations. None of the systematic reviews directly compared risk assessment tools with unstructured judgments. In addition, two thirds of the primary studies included in the systematic reviews were from the 1980s or earlier, and 89% had serious methodological limitations that created a high risk of bias. In many cases, the primary studies did not examine unstructured judgments per se but instead used proxies such as legal and administrative decisions. As such, there is a pressing need for an updated systematic review that focuses on direct comparison studies and carefully addresses study limitations. To address this gap, we have initiated a preregistered systematic review.

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