Learning efficient visual search for stimuli containing diagnostic spatial configurations and color-shape conjunctions

Visual search is often slow and difficult for complex stimuli such as feature conjunctions. Search efficiency, however, can improve with training. Search for stimuli that can be identified by the spatial configuration of two elements (e.g., the relative position of two colored shapes) improves dramatically within a few hundred trials of practice. Several recent imaging studies have identified neural correlates of this learning, but it remains unclear what stimulus properties participants learn to use to search efficiently. Influential models, such as reverse hierarchy theory, propose two major possibilities: learning to use information contained in low-level image statistics (e.g., single features at particular retinotopic locations) or in high-level characteristics (e.g., feature conjunctions) of the task-relevant stimuli. In a series of experiments, we tested these two hypotheses, which make different predictions about the effect of various stimulus manipulations after training. We find relatively small effects of manipulating low-level properties of the stimuli (e.g., changing their retinotopic location) and some conjunctive properties (e.g., color-position), whereas the effects of manipulating other conjunctive properties (e.g., color-shape) are larger. Overall, the findings suggest conjunction learning involving such stimuli might be an emergent phenomenon that reflects multiple different learning processes, each of which capitalizes on different types of information contained in the stimuli. We also show that both targets and distractors are learned, and that reversing learned target and distractor identities impairs performance. This suggests that participants do not merely learn to discriminate target and distractor stimuli, they also learn stimulus identity mappings that contribute to performance improvements.     

Efficacy of Guided iCBT for Depression and Mediation of Change by Cognitive Skill Acquisition

Guided internet CBT (iCBT) is a promising treatment for depression; however, it is less well known through what mechanisms iCBT works. Two possible mediators of change are the acquisition of cognitive skills and increases in behavioral activation. We report results of an 8-week waitlist controlled trial of guided iCBT, and test whether early change in cognitive skills or behavioral activation mediated subsequent change in depression. The sample was 89 individuals randomized to guided iCBT (n = 59) or waitlist (n = 30). Participants were 75% female, 72% Caucasian, and 33 years old on average. The PHQ9 was the primary outcome measure. Mediators were the Competencies of Cognitive Therapy Scale–Self Report and the Behavioral Activation Scale for Depression–Short Form. Treatment was Beating the Blues plus manualized coaching. Outcomes were analyzed using linear mixed models, and mediation with a bootstrap resampling approach. The iCBT group was superior to waitlist, with large effect sizes at posttreatment (Hedges’ g = 1.45). Dropout of iCBT was 29% versus 10% for waitlist. In the mediation analyses, the acquisition of cognitive skills mediated subsequent depression change (indirect effect = -.61, 95% bootstrapped biased corrected CI: -1.47, -0.09), but increases in behavioral activation did not. iCBT is an effective treatment for depression, but dropout rates remain high. Change in iCBT appears to be mediated by improvements in the use of cognitive skills, such as critically evaluating and restructuring negative thoughts.     

Modelling audiovisual integration of affect from videos and music

Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component stimuli presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal.     

Situational meaninglessness and state boredom: Cross-sectional and experience-sampling findings

Theories of boredom assert that boredom is a product of situational meaninglessness. We conducted two studies to test if the perceived meaningfulness of a situation is associated with state boredom, above and beyond sadness, personality traits, and boredom proneness. In Study 1, 105 participants (72.4% female: mean age?=?33.9 years, SD?=?17.5) described situations in which they experienced boredom, no boredom, engagement, or sadness. They then rated the level of state boredom, sadness, and meaninglessness that they experienced in that situation. As hypothesized, state boredom was associated with situational meaninglessness, before and after controlling for sadness. In Study 2, 148 participants (73.0% female; mean age?=?19.2 years, SD?=?1.8) first provided baseline data on personality traits and boredom proneness. Through a smartphone app-based experience-sampling method, they then responded to a brief questionnaire multiple times a day, across 7 days. The questionnaire asked about the nature of their current activity, whether the activity was done alone or with other people, and their affective state. Results from multilevel modelling of 3022 entries suggest that perceived meaningfulness of the activity was negatively associated with state boredom, above and beyond sadness, personality, and boredom proneness. We also found that being with others during the activity acted as a moderator; activities lower in perceived meaningfulness were associated with higher ratings of state boredom when done with others than when done alone. These results demonstrate that perceptions of meaninglessness characterize state boredom.     

Predictive laws of association in statistics and physics

In the present paper we face the problem of estimating cell probabilities in the case of a two-dimensional contingency table from a predictive point of view. The solution is given by a double stochastic process. The first subprocess, the unobservable one, is supposed to be exchangeable and invariant. For the second subprocess, the observable one, we suppose it is independent conditional on the first one.     

Depression and Suicidal Ideation After Predictive Testing for Huntington's Disease: A Two-Year Follow-up Study

The present study reports a two-year follow-up of psychological effects of predictive testing for Huntington's disease. Questionnaires assessing depression, general health, well-being, self injurious behavior, life satisfaction, and lifestyle were completed by 35 carriers and 58 non-carriers before the predictive test, and 2, 6, 12, and 24 months afterwards. Both carriers and non-carriers showed high suicidal ideation before the predictive testing. Depression scores and frequency of suicidal thoughts increased for carriers, compared to non-carriers, over time. There were no differences regarding life satisfaction or life style between carriers and non-carriers. Predictive testing was beneficial in reducing overall ill-health symptoms and increasing well-being for those initially expressing concern about Huntington's disease. The importance of assessing suicidal ideation and of continuing to provide adequate support is emphasized.     

Histamine enhances inhibitory avoidance memory consolidation through a H2 receptor-dependent mechanism

Several evidences suggest that brain histamine is involved in memory consolidation but the actual contribution of the hippocampal histaminergic system to this process remains controversial. Here, we show that when infused into the CA1 region of the dorsal hippocampus immediately after training in an inhibitory avoidance task, but not later, histamine induced a dose-dependent promnesic effect without altering locomotor activity, exploratory behavior, anxiety state or retrieval of the avoidance response. The facilitatory effect of intra-CA1 histamine was mimicked by the histamine N-methyltransferase inhibitor SKF-91844 as well as by the H2 receptor agonist dimaprit and it was blocked completely by the H2 receptor antagonist ranitidine. Conversely, the promnesic action of histamine was unaffected by the H1 receptor antagonist pyrilamine, the H3 receptor antagonist, thioperamide, and the NMDAr polyamine-binding site antagonist ifenprodil. By themselves, ranitidine, pyrilamine, thioperamide, and ifenprodil did not affect IA memory consolidation. Our data indicate that, when given into CA1, histamine enhances memory consolidation through a mechanism that involves activation of H2 receptors; however, endogenous CA1 histamine does not seem to participate in the consolidation of IA memory at least at the post-training times analyzed.     

The psychology of engagement with indigenous identities: a cultural perspective

In a questionnaire study among 124 students at Haskell Indian Nations University, the authors investigated the hypothesis that engagement with Indigenous identity--assessed along three dimensions including degree (identification scale), content (panethnic or tribal nation), and context (reservation or nonreservation)--can serve as a psychological resource for well-being and liberation from oppression. Consistent with this hypothesis, degree of identification was positively correlated with community efficacy and perception of racism. Apparently inconsistent with this hypothesis, degree of identification among students who had resided on a reservation was negatively correlated with the Social Self-Esteem subscale of the Current Thoughts Scale. Rather than evidence against the identity-as-resource hypothesis, this pattern may reflect the cultural grounding of self-esteem and tools designed to measure it.