ERPs and contextual semantic discrimination: degrees of congruence in wakefulness and sleep

This study explores whether the brain can discriminate degrees of semantic congruency during wakefulness and sleep. Experiment 1 was conducted during wakefulness to test degrees of congruency by means of N400 amplitude. In Experiment 2, the same paradigm was applied to a different group of participants during natural night sleep. Stimuli were 108 sentences (definitions with two attributes) with four possible degrees of congruence as ending targets. In both studies, the amplitude of N400-like effect showed modulation according to the degree of congruency. The results indicate that the brain can accomplish sentential semantic discriminations not only in wakefulness but also in sleep.     

Clarifying the convergence between obsessive compulsive personality disorder criteria and obsessive compulsive disorder

In this study we examined the convergence between obsessive-compulsive personality disorder (OCPD) criteria and obsessive-compulsive disorder (OCD). Baseline assessments of 629 participants of the Collaborative Longitudinal Personality Disorders Study were used to examine the associations between OCPD criteria and diagnoses of OCD. Three of the eight OCPD criteria--hoarding, perfectionism, and preoccupation with details--were significantly more frequent in subjects with OCD (n = 89) than in subjects without OCD (n = 540). Logistic regressions were used to predict the probability of each OCPD criterion as a function of Axis I diagnoses (OCD, additional anxiety disorders, and major depressive disorder). Associations between OCD and these three OCPD criteria remained significant in the logistic regressions, showing unique associations with OCD and odds ratios ranging from 2.71 to 2.99. In addition, other anxiety disorders and major depressive disorder showed few associations with specific OCPD criteria. This study suggests variability in the strength of the relationships between specific OCPD criteria and OCD. The findings also support a unique relationship between OCPD symptoms and OCD, compared to other anxiety disorders or major depression. Future efforts to explore the link between Axis I and Axis II disorders may be enriched by conducting analyses at the symptom level.     

Fragment difficulty in priming on word-completion tests

Word-fragment completion is a frequently used test in implicit memory research. In this test priming is the relevant variable. Priming is obtained by subtracting the proportion of nonstudied word fragments correctly completed (called "completion difficulty baseline") from the studied word fragments correctly completed. Since completion difficulty can spuriously vary greatly between experimental conditions, its effect on magnitude of priming is studied. Normative frequency of occurrence of target words was considered because their influence over performance is known. In an experiment using a word-fragment completion test, participants' completion of fragments at three levels of completion difficulty and two levels of frequency was tested. Analysis showed that completion difficulty had a significant effect on global priming. The priming magnitude was higher for Difficult and Moderately Difficult fragments than for Easy ones. An interaction between fragment difficulty and normative word frequency was observed. When the fragments were easy to complete, the expected effect of higher priming for low-frequency words than for high-frequency words was not observed.     

Faces are "spatial"--holistic face perception is supported by low spatial frequencies

Faces are perceived holistically, a phenomenon best illustrated when the processing of a face feature is affected by the other features. Here, the authors tested the hypothesis that the holistic perception of a face mainly relies on its low spatial frequencies. Holistic face perception was tested in two classical paradigms: the whole-part advantage (Experiment 1) and the composite face effect (Experiments 2-4). Holistic effects were equally large or larger for low-pass filtered faces as compared to full-spectrum faces and significantly larger than for high-pass filtered faces. The disproportionate composite effect found for low-pass filtered faces was not observed when holistic perception was disrupted by inversion (Experiment 3). Experiment 4 showed that the composite face effect was enhanced only for low spatial frequencies, but not for intermediate spatial frequencies known be critical for face recognition. These findings indicate that holistic face perception is largely supported by low spatial frequencies. They also suggest that holistic processing precedes the analysis of local features during face perception.     

Further examination of measurement properties of Spanish version of the Sexual Desire Inventory with undergraduates and adolescent students

The factor structure and construct validity of a Spanish version of Spector, Carey, and Steinberg's Sexual Desire Inventory was examined with structural equation modelling and a nonclinical sample (N = 608). Confirmatory factor analysis indicated that Dyadic and Solitary sexual desire scales measured two factorially distinct constructs. Their internal consistency reliabilities were .87 and .88, respectively. Structural equation analysis indicated that both subscales are distinguishable from similarly conceptualized correlates of sexual desire: the Impersonal subscale of the Sex Fantasy Questionnaire and the Erotophilia measure of the Sexual Opinion Survey. However, the data raised some questions about an empirical distinction between dyadic sexual desire and intimate sexual fantasy.     

Searching beneath the shelf in macaque monkeys: evidence for a gravity bias or a foraging bias?

The reasons underpinning search biases in 2 species of macaque monkeys (Macaca mulatta and Macaca arctoides) were explored over the course of 3 experiments requiring monkeys to search for a hidden food reward. The results reveal that monkeys are adept at exploiting perceptual cues to locate a food reward but are unable to use physical constraints such as solidity as cues to the reward's location. Monkeys prefer to search for a food reward beneath a solid shelf, not because they have an expectation that the reward should be there, but rather because, in the absence of usable cues, this bias emerges as a default search option. It is hypothesized that this bias may have its roots in a history of competition for food resources.     

Demonstration and evaluation of a method for assessing mediated moderation

Mediated moderation occurs when the interaction between two variables affects a mediator, which then affects a dependent variable. In this article, we describe the mediated moderation model and evaluate it with a statistical simulation using an adaptation of product-of-coefficients methods to assess mediation. We also demonstrate the use of this method with a substantive example from the adolescent tobacco literature. In the simulation, relative bias (RB) in point estimates and standard errors did not exceed problematic levels of ±10%, although systematic variability in RB was accounted for by parameter size, sample size, and nonzero direct effects. Power to detect mediated moderation effects appears to be severely compromised under one particular combination of conditions: when the component variables that make up the interaction terms are correlated and partial mediated moderation exists. Implications for the estimation of mediated moderation effects in experimental and nonexperimental research are discussed.     

Inattentional blindness for negative relationships in human causal learning

The present study focuses on the effect of selective attention on causal learning. Three effects of the level of attention to predictive symptoms in positive and negative contingency learning tasks are reported. First, participants accurately detected a positive relationship between an incidental cue and a contingent outcome, although judgements were slightly lower than those for the attended cue. Second, participants were unable to detect negative relationships between incidental cues and outcomes, which suggests a major role of selective attention in this type of learning. Third, participants retrieved the frequency of each trial type more accurately in the attended conditions than in the incidental conditions. These findings show how attention guides and constrains human causal learning and reveal an inattentional blindness effect for negative contingency learning.     

Comparison of two self-report instruments for assessing binge eating in bariatric surgery candidates

This study compared two self-report methods for assessing binge eating in severely obese bariatric surgery candidates. Participants were 249 gastric bypass candidates who completed the Questionnaire on Eating and Weight Patterns-Revised (QEWP-R) and the Eating Disorder Examination-Questionnaire (EDE-Q) prior to surgery. Participants were classified by binge eating status (i.e., no or recurrent binge eating) with each of the measures. The degree of agreement was examined, as well as the relationship between binge eating and measures of convergent validity. The two measures identified a similar number of patients with recurrent binge eating (i.e., at least 1 binge/week); however, overlap was modest (kappa=.26). Agreement on twice weekly binge eating was poor (kappa=.05). The QEWP-R and EDE-Q both identified clinically meaningful groups of binge eaters. The EDE-Q appeared to differentiate between non/infrequent bingers and recurrent bingers better than the QEWP-R, based on measures of convergent validity. In addition, the EDE-Q demonstrated an advantage because it identified binge eaters with elevated weight and shape overconcern. Using the self-report measures concurrently did not improve identification of binge eating in this study. More work is needed to determine the construct validity and clinical utility of these measures with gastric bypass patients.     

Processing controlled PROs in Spanish

Two experiments were carried out to investigate the processing of the empty category PRO and the time-course of this in Spanish. Eye movements were recorded while participants read sentences in which a matrix clause was followed by a subordinate infinitival clause, so that the subject or the object of the main clause could act as controller of PRO, and therefore as implicit grammatical subject of the infinitive. In Experiment 1, verb control information was manipulated: The matrix clause contained either subject-control verbs like prometer ('promise') or object-control verbs like forzar ('force'). In Experiment 2, the preposition that headed adverbial subordinate clauses was manipulated: Two different kinds of infinitival adverbial clauses were used, expressing purpose (preposition para) and reason (preposition por) and in which control information is primarily induced by the prepositions (para tends to trigger subject-control; por object-control). Experiment 1 showed that readers make immediate use of verb control information to recover the antecedent of the empty category PRO in Spanish obligatory control constructions. The data obtained in Experiment 2 suggest that during the processing of the empty category PRO in purpose vs. reason adverbial subordinate infinitival clauses the control information induced by the prepositions por vs. para is not initially used as a constraint to guide the selection of the nominal antecedent of PRO. In addition, both experiments showed that PRO antecedent selection is a very fast process and that, together with verb control information, recency played an important role. The results are discussed in terms of current psycholinguistic hypotheses about empty categories and in relation to formal linguistic hypotheses about PRO control. We argue that obligatory control ties (which are co-referential ties) are processed fast because they are launched from the same lexical platform that launches all fast syntactic connections (complements, as opposed to modifiers). In short, that such lexically-specified co-referential ties are regulated by linguistic form.