Central Fixations are Inadequately Controlled by Instructions Alone: Implications for Studying Cerebral Asymmetry

A fundamental concern when using visual presentations to study cerebral asymmetry is to ensure that stimuli are presented with the same degree of retinal eccentricity from a central fixation point in either visual field. However, a widely used procedure intended to control fixation location merely instructs participants to fixate appropriately without any other means of ensuring that central fixations actually occur. We assessed the validity of assuming that instructions alone ensure central fixation by using the traditional R VF advantage for words and either (a) only instructions to fixate centrally, or (b) an eye-tracking device that ensured central fixation on every trial. Experiments 1 and 2 found that when only instructions were given, the vast majority of fixations were not central, and more occurred to the right of centre than to the left. Moreover, the prevalence of non-central fixations was otherwise disguised by the finding that both fixation procedures produced similar R VF advantages in overt performance. The impact of typical non-central fixations on performance was revealed by systematically manipulating fixation location in Experiment 3, where deviations in fixation of only 0.25 from centre had a reliable impact on visual field effects. Implications of these findings for studies of cerebral asymmetry are discussed.     

The covariation of trait anger and borderline personality: a bivariate twin-siblings study

Anger can be defined as an emotion consisting of feelings of variable intensity, from mild irritation or annoyance to intense fury and rage. Borderline personality disorder (BPD) is characterized by impulsivity and instability of interpersonal relationships, of self-image, and of negative affects. Borderline personality and trait anger are often observed together. The present study examined the extent to which a genetic association explains the covariation between a trait measure of borderline personality and trait anger. To this end, self-report data of 5,457 twins and 1,487 of their siblings registered with the Netherlands Twin Register and the East Flanders Prospective Twin Survey were analyzed using genetic structural equation modeling. A significant phenotypic correlation was observed between the two traits (rP = .52). This correlation was explained by genetic (54%) and by environmental influences (46%). A shared genetic risk factor is thus one of the explanations for the covariation of borderline personality and trait anger.     

Effects of a brief media intervention on expectations, attitudes, and intentions of mental health help seeking

This study examined the effects of a mass-media video intervention on expectations, attitudes, and intentions to seek help from professional mental health care services. A public service announcement-style, mass-media video intervention was developed, with prior empirical research on help-seeking behaviors organized according to the theory of reasoned action/planned behavior. In total, 228 participants were randomly assigned to 1 of 2 conditions: (a) the media-exposed intervention group, who watched programming in which the media intervention was inserted, and (b) the control group, who watched the same programming without the media intervention. The media intervention was not influential on expectation and belief-based barrier variables. However, the media intervention was effective at increasing positive attitudes toward help seeking. Findings regarding the intervention's ability to increase help-seeking intentions for interpersonal problems were complex. Implications of these findings for future research are discussed.     

Resistance to change and relapse of observing

Four experiments examined relapse of extinguished observing behavior of pigeons using a two-component multiple schedule of observing-response procedures. In both components, unsignaled periods of variable-interval (VI) food reinforcement alternated with extinction and observing responses produced stimuli associated with the availability of the VI schedule (i.e., S+). The components differed in the rate of food arranged (Rich = VI 30 s; Lean = VI 120 s). In Experiment 1, following baseline training, extinction of observing involved removal of both food and S+ deliveries, and reinstatement was examined by presenting either response-independent food or S+ deliveries. In Experiment 2, extinction involved removal of only food deliveries while observing responses continued to produce S+. Reinstatement was examined by delivering food contingent upon the first two food-key responses occurring in the presence of the S+. Experiment 3 assessed ABA renewal of observing by extinguishing food-key and observing responses in the presence of one contextual stimulus (i.e., B) and then returning to the original training context (i.e., A) during continued extinction. Experiment 4 examined resurgence by introducing food reinforcement for an alternative response during extinction, and subsequently removing that alternative source of food. Across experiments, relative resistance to extinction and relapse of observing tended to be greater in the component previously associated with the higher rate of primary reinforcement. Relapse of observing or attending to stimuli associated with primary reinforcement appears to be impacted by frequency of primary reinforcement in a manner similar to responding maintained directly by primary reinforcement.     

Substance Use Progression from Adolescence to Early Adulthood: Effortful Control in the Context of Friendship Influence and Early-Onset Use

In a sample of 998 ethnically diverse adolescents, a multiagent, multimethod approach to the measurement of adolescent effortful control, adolescent substance use, and friendship influence was used to predict escalations to early-adult tobacco, alcohol, and marijuana use by ages 22-23. Structural equation modeling revealed that adolescent substance use and friends' substance use tended to be highly correlated and together were robust predictors of a problematic pattern of usage for all substances in early adulthood. In addition, the adolescent effortful control construct directly predicted progressions to problematic use of tobacco and marijuana, but not for alcohol. In the alcohol model, effortful control interacted with the construct of substance use lifestyle (based on adolescent alcohol use and friends' substance use) when predicting problematic alcohol use in early adulthood. Results held when comparing across genders and across ethnic groups. These findings emphasize the importance of addressing adolescent self-regulation in interventions designed to treat and prevent early-adult substance abuse.     

Factor Structure of a Sluggish Cognitive Tempo Scale in Clinically-Referred Children

“Sluggish cognitive tempo” (SCT) is a construct hypothesized to describe a constellation of behaviors that includes daydreaming, lethargy, drowsiness, difficulty sustaining attention, and underactivity. Although the construct has been inconsistently defined, measures of SCT have shown associations with symptoms of attention-deficit/hyperactivity disorder (ADHD), particularly inattention. Thus, better characterization of SCT symptoms may help to better predict specific areas of functional difficulty in children with ADHD. The present study examined psychometric characteristics of a recently developed 14-item scale of SCT (Penny et al., Psychological Assessment 21:380–389, 2009), completed by teachers on children referred for outpatient neuropsychological assessment. Exploratory factor analysis identified three factors in the clinical sample: Sleepy/Sluggish, Slow/Daydreamy, and Low Initiation/Persistence. Additionally, SCT symptoms, especially those loading on the Sleepy/Sluggish and Slow/Daydreamy factors, correlated more strongly with inattentive than with hyperactive/impulsive symptoms, while Low Initiation/Persistence symptoms added significant unique variance (over and above symptoms of inattention) to the predictions of impairment in academic progress.