Cognitive control of eye movements in reading and visual search: Evidence from frequency-based effects

Experiments in this dissertation investigate the role of cognition in eye-movement behavior during scanning and reading. Shorter and fewer fixations on the more frequent and predictable words have been observed during reading, but not when scanning text for a target word, e.g., zebra (e.g., Rayner & Raney, 1996). Past research has employed these effects of word frequency and predictability to argue that cognition drives eye movements during reading, but not during scanning. Similarly, the present studies use effects of stimulus frequency and predictability to index cognitive control of eye-movement behavior. Experiments 1 and 2 focus on the frequency effects for non-word and word stimuli, respectively. Experiment 1 employed clusters of Landolt Cs to examine how the gap size of and frequency of exposure to clusters affected eye movements during a scanning task. The findings demonstrated that, in parallel to word frequency effects observed in reading, more frequent clusters elicited fewer and shorter fixations. Experiment 2 compared eye-movement behavior on fully-crossed high- and low-frequency adjective-noun pairs embedded in paragraphs when participants were reading vs. scanning for a target word with an asterisk (e.g., “h*rse”), a word containing the letter "q" (e.g., “quilt”), or a word rhyming with "blue" (e.g., “shoe”). The results demonstrated that eye-movement measures are affected by frequency in the tasks requiring in-depth processing, such as reading and rhyme-judgment, but not in shallow-processing tasks like asterisk-detection. Experiments 3 and 4 focus on the frequency-based predictability effects for non-word and word stimuli, respectively. Experiment 3 employed similar materials to Experiment 1 and, in addition, manipulated frequency for pairs of clusters. The more predictable clusters in the repeating pairs elicited fewer fixations, providing tentative evidence of transitional predictability effects during scanning. Experiment 4 examined the effect of transitional probability in reading by increasing the frequency of co-occurrence for pairs of words (e.g., tulip’s blossoms) in paragraphs of text. The more predictable words elicited shorter first fixation durations, suggesting that co-occurrence frequency may result in forming short-term predictions during reading. Cumulatively, the findings demonstrate that cognitive effects are not unique to reading, and afford a more sophisticated characterization of the cognitive-oculomotor coordination

Decision-Making Competence and Attempted Suicide

Objective: The propensity of people vulnerable to suicide to make poor life decisions is increasingly well documented. Do they display an extreme degree of decision biases? The present study used a behavioral decision approach to examine the susceptibility of low-lethality and high-lethality suicide attempters to common decision biases, which may ultimately obscure alternative solutions and deterrents to suicide in a crisis. Method: We assessed older and middle-aged individuals who made high-lethality (medically serious; N=31) and low-lethality suicide attempts (N=29). Comparison groups included suicide ideators (N=30), non-suicidal depressed (N=53), and psychiatrically healthy participants (N=28). Attempters, ideators, and non-suicidal depressed participants had unipolar non-psychotic major depression. Decision biases included sunk cost (inability to abort an action for which costs are irrecoverable), framing (responding to superficial features of how a problem is presented), under/overconfidence (appropriateness of confidence in knowledge), and inconsistent risk perception. Data were collected between June of 2010 and February of 2014. Results: Both high- and low-lethality attempters were more susceptible to framing effects, as compared to the other groups included in this study (p< 0.05, ηp2 =.06). In contrast, low-lethality attempters were more susceptible to sunk costs than both the comparison groups and high-lethality attempters (p< 0.01, ηp2 =.09). These group differences remained after accounting for age, global cognitive performance, and impulsive traits. Premorbid IQ partially explained group differences in framing effects. Conclusion: Suicide attempters’ failure to resist framing may reflect their inability to consider a decision from an objective standpoint in a crisis. Low-lethality attempters’ failure to resist sunk cost may reflect their tendency to confuse past and future costs of their behavior, lowering their threshold for acting on suicidal thoughts

Thermal Control of Plasmonic Surface Lattice Resonances

Plasmonic metasurfaces exhibiting collective responses known as surface lattice resonances (SLRs) show potential for realizing tunable and flat photonic components for wavelength-selective processes, including lasing and optical nonlinearities. However, post-fabrication tuning of SLRs remains challenging, limiting the applicability of SLR-based components. Here, we demonstrate how the properties of high quality factor SLRs are easily modified by breaking the symmetry of the nanoparticle surroundings. We break the symmetry by changing the refractive index of the overlying immersion oil simply by controlling the ambient temperature of the device. We show that already modest temperature changes of 10{\deg}C can increase the quality factor of the investigated SLR from 400 to 750. Our results demonstrate accurate and reversible modification of the properties of the SLRs, paving the way towards tunable SLR-based photonic devices. On a more general level, our results demonstrate how symmetry breaking of the surrounding dielectric environment can be utilized for efficient and potentially ultrafast modification of the SLR properties

Transdiagnostic risk of mental disorders in offspring of affected parents:a meta-analysis of family high-risk and registry studies

The offspring of parents with mental disorders are at increased risk for developing mental disorders themselves. The risk to offspring may extend transdiagnostically to disorders other than those present in the parents. The literature on this topic is vast but mixed. To inform targeted prevention and genetic counseling, we performed a comprehensive, PRISMA 2020-compliant meta-analysis. We systematically searched the literature published up to September 2022 to retrieve original family high-risk and registry studies reporting on the risk of mental disorders in offspring of parents with any type of mental disorder. We performed random-effects meta-analyses of the relative risk (risk ratio, RR) and absolute risk (lifetime, up to the age at assessment) of mental disorders, defined according to the ICD or DSM. Cumulative incidence by offspring age was determined using meta-analytic Kaplan-Meier curves. We measured heterogeneity with the I2 statistic, and risk of bias with the Quality In Prognosis Studies (QUIPS) tool. Sensitivity analyses addressed the impact of study design (family high-risk vs. registry) and specific vs. transdiagnostic risks. Transdiagnosticity was appraised with the TRANSD criteria. We identified 211 independent studies that reported data on 3,172,115 offspring of parents with psychotic, bipolar, depressive, disruptive, attention-deficit/hyperactivity, anxiety, substance use, eating, obsessive-compulsive, and borderline personality disorders, and 20,428,575 control offspring. The RR and lifetime risk of developing any mental disorder were 3.0 and 55% in offspring of parents with anxiety disorders; 2.6 and 17% in offspring of those with psychosis; 2.1 and 55% in offspring of those with bipolar disorder; 1.9 and 51% in offspring of those with depressive disorders; and 1.5 and 38% in offspring of those with substance use disorders. The offspring's RR and lifetime risk of developing the same mental disorder diagnosed in their parent were 8.4 and 32% for attention-deficit/hyperactivity disorder; 5.8 and 8% for psychosis; 5.1 and 5% for bipolar disorder; 2.8 and 9% for substance use disorders; 2.3 and 14% for depressive disorders; 2.3 and 1% for eating disorders; and 2.2 and 31% for anxiety disorders. There were 37 significant transdiagnostic associations between parental mental disorders and the RR of developing a different mental disorder in the offspring. In offspring of parents with psychosis, bipolar and depressive disorder, the risk of the same disorder onset emerged at 16, 5 and 6 years, and cumulated to 3%, 19% and 24% by age 18; and to 8%, 36% and 46% by age 28. Heterogeneity ranged from 0 to 0.98, and 96% of studies were at high risk of bias. Sensitivity analyses restricted to prospective family high-risk studies confirmed the pattern of findings with similar RR, but with greater absolute risks compared to analyses of all study types. This study demonstrates at a global, meta-analytic level that offspring of affected parents have strongly elevated RR and lifetime risk of developing any mental disorder as well as the same mental disorder diagnosed in the parent. The transdiagnostic risks suggest that offspring of parents with a range of mental disorders should be considered as candidates for targeted primary prevention.</p

Normalization of Prevention Principles and Practices to Reduce Substance Use Disorders Through an Integrated Dissemination and Implementation Framework

Major research breakthroughs over the past 30 years in the field of substance use prevention have served to: (1) enhance understanding of pharmacological effects on the central and peripheral nervous systems and the health and social consequences of use of psychoactive substances, particularly for children and adolescents; (2) delineate the processes that increase vulnerability to or protect from initiation of substance use and progression to substance use disorders (SUDs) and, based on this understanding, (3) develop effective strategies and practices to prevent the initiation and escalation of substance use. The challenge we now face as a field is to “normalize” what we have learned from this research so that it is incorporated into the work of those involved in supporting, planning, and delivering prevention programming to populations around the world, is integrated into health and social service systems, and helps to shape public policies. But we wish to go further, to incorporate these effective prevention practices into everyday life and the mind-sets of the public, particularly parents and educators. This paper reviews the advances that have been made in the field of prevention and presents a framework and recommendations to achieve these objectives generated during several meetings of prevention and implementation science researchers sponsored by the International Consortium of Universities for Drug Demand Reduction (ICUDDR) that guides a roadmap to achieve “normalization.

Deviant Peer Affiliation and Antisocial Behavior: Interaction with Monoamine Oxidase A (MAOA) Genotype

Although genetic and environmental factors are separately implicated in the development of antisocial behavior (ASB), interactive models have emerged relatively recently, particularly those incorporating molecular genetic data. Using a large sample of male Caucasian adolescents and young adults from the National Longitudinal Study of Adolescent Health (Add Health), the association of deviant peer affiliation, the 30-base pair variable number tandem repeat polymorphism in promoter region of the monoamine oxidase-A (MAOA) gene, and their interaction, with antisocial behavior (ASB) was investigated. Weighted analyses accounting for over-sampling and clustering within schools as well as controlling for age and wave suggested that deviant peer affiliation and MAOA genotype were each significantly associated with levels of overt ASB across a 6-year period. Only deviant peer affiliation was significantly related to covert ASB, however. Additionally, there was evidence suggestive of a gene-environment interaction (G × E) where the influence of deviant peer affiliation on overt ASB was significantly stronger among individuals with the high-activity MAOA genotype than the low-activity genotype. MAOA was not significantly associated with deviant peer affiliation, thus strengthening the inference of G × E rather than gene-environment correlation (rGE). Different forms of gene-environment interplay and implications for future research on ASB are discussed

Cortisol and externalizing behavior in children and adolescents: Mixed meta-analytic evidence for the inverse relation of basal cortisol and cortisol reactivity with externalizing behavior

An inverse relation between cortisol (re)activily and externalizing behavior has been hypothesized, but research findings seem equivocal. We tested this hypo(re)activity hypothesis in two meta-analyses, one for basal cortisol (k = 72 studies, N = 5,480) and one for cortisol reactivity to a stressor (k = 29 studies, N = 2,601). No association was found between cortisol reactivity and externalizing behaviors (r = -.04, 95% CI = -.11, .02). However, the relation between basal cortisol and externalizing behavior was significant but small (r = -.05, 95% CI = -.10, -.002). The age of the children significantly moderated this relation: Externalizing behavior was associated with higher basal cortisol (hyperactivity) in preschoolers (r =.09, 95% CI =.002, .17), and with lower basal cortisol (hypoactivity) in elementary school-aged children (r = -.14, 95% CI = -.19, -.08). There was no significant relation between cortisol and externalizing behavior in adolescents. © 2008 Wiley Periodicals, Inc