Immediate and long-term priming effects are independent of prime awareness

Subliminal primes are assumed to produce weaker and short-lived effects on subsequent behavior compared to clearly visible primes. However, this difference in priming effect may be due to differences in signal strength, rather than level of awareness. In the present study we manipulated prime discriminability by using metacontrast masks and pseudomasks, while keeping the prime strength equal. This manipulation resulted in large differences in discriminability of the primes. However, both immediate response priming and long-term response priming (measured with conflict adaptation) was equal for the poorly discriminable and well discriminable primes, and equal for groups that differed markedly in terms of how well they could discriminate the primes. Our findings imply that discriminability of information is independent of both the immediate and long-term effects that information can have on behavior.     

Napping promotes inter-session habituation to emotional stimuli

The effects of a daytime nap on inter-session habituation to aversive visual stimuli were investigated. Healthy young adult volunteers viewed repeated presentations of highly negative and emotionally neutral (but equally arousing) International Affective Picture System (IAPS) photographs during two afternoon sessions separated by 2.5h. Half of the photographs were shown at both sessions (Repeated Sets) and half differed between sessions (Novel Sets). For each stimulus presentation, evoked skin conductance response (SCR), heart-rate deceleration (HRD) and corrugator supercilii EMG response (EMG), were computed and range corrected using respective maximum session-1 responses. Following each presentation, subjects rated each photograph on dimensions of pleasantness and arousability. During the inter-session interval, Nap subjects had a 120-min polysomnographically monitored sleep opportunity, whereas Wake subjects watched a non-stimulating video. Nap and Wake subjects did not differ in their subjective ratings of photographs. However, for Repeated-Set photographs, Nap subjects demonstrated greater inter-session habituation in SCR and EMG but a trend toward lesser inter-session habituation in HRD. These group differences were absent for Novel-Set photographs. Group differences across all measures were greater for negative stimuli. Occurrence of SWS during the nap was associated with greater inter-session habituation of EMG whereas occurrence of REM was associated with lesser inter-session habituation of SCR to negative stimuli. Sleep may therefore promote emotional adjustment at the level of somatic responses. Physiological but not subjective inter-session habituation to aversive images was enhanced by a daytime nap.     

Psychometric properties of the five facet mindfulness questionnaire in depressed adults and development of a short form

In recent years, there has been a growing interest in therapies that include the learning of mindfulness skills. The 39-item Five Facet Mindfulness Questionnaire (FFMQ) has been developed as a reliable and valid comprehensive instrument for assessing different aspects of mindfulness in community and student samples. In this study, the psychometric properties of the Dutch FFMQ were assessed in a sample of 376 adults with clinically relevant symptoms of depression and anxiety. Construct validity was examined with confirmatory factor analyses and by relating the FFMQ to measures of psychological symptoms, well-being, experiential avoidance, and the personality factors neuroticism and openness to experience. In addition, a 24-item short form of the FFMQ (FFMQ-SF) was developed and assessed in the same sample and cross-validated in an independent sample of patients with fibromyalgia. Confirmatory factor analyses showed acceptable model fit for a correlated five-factor structure of the FFMQ and good model fit for the structure of the FFMQ-SF. The replicability of the five-factor structure of the FFMQ-SF was confirmed in the fibromyalgia sample. Both instruments proved highly sensitive to change. It is concluded that both the FFMQ and the FFMQ-SF are reliable and valid instruments for use in adults with clinically relevant symptoms of depression and anxiety.     

Differential item functioning on the Five Facet Mindfulness Questionnaire is minimal in demographically matched meditators and nonmeditators

A recent study of the Five Facet Mindfulness Questionnaire reported high levels of differential item functioning (DIF) for 18 of its 39 items in meditating and nonmeditating samples that were not demographically matched. In particular, meditators were more likely to endorse positively worded items whereas nonmeditators were more likely to deny negatively worded (reverse-scored) items. The present study replicated these analyses in demographically matched samples of meditators and nonmeditators (n = 115 each) and found that evidence for DIF was minimal. There was little or no evidence for differential relationships between positively and negatively worded items for meditators and nonmeditators. Findings suggest that DIF based on items' scoring direction is not problematic when the Five Facet Mindfulness Questionnaire is used to compare demographically similar meditators and nonmeditators.     

Conditioned fear is modulated by D2 receptor pathway connecting the ventral tegmental area and basolateral amygdala

Excitation of the mesocorticolimbic pathway, originating from dopaminergic neurons in the ventral tegmental area (VTA), may be important for the development of exaggerated fear responding. Among the forebrain regions innervated by this pathway, the amygdala is an essential component of the neural circuitry of conditioned fear. The functional role of the dopaminergic pathway connecting the VTA to the basolateral amygdala (BLA) in fear and anxiety has received little attention. In vivo microdialysis was performed to measure dopamine levels in the BLA of Wistar rats that received the dopamine D(2) agonist quinpirole (1 μg/0.2 μl) into the VTA and were subjected to a fear conditioning test using a light as the conditioned stimulus (CS). The effects of intra-BLA injections of the D(1) antagonist SCH 23390 (1 and 2 μg/0.2 μl) and D(2) antagonist sulpiride (1 and 2 μg/0.2 μl) on fear-potentiated startle (FPS) to a light-CS were also assessed. Locomotor performance was evaluated by use of open-field and rotarod tests. Freezing and increased dopamine levels in the BLA in response to the CS were both inhibited by intra-VTA quinpirole. Whereas intra-BLA SCH 23390 did not affect FPS, intra-BLA sulpiride (2 μg) inhibited FPS. Sulpiride's ability to decrease FPS cannot be attributed to nonspecific effects because this drug did not affect motor performance. These findings indicate that the dopamine D(2) receptor pathway connecting the ventral tegmental area and the basolateral amygdala modulates fear and anxiety and may be a novel pharmacological target for the treatment of anxiety.     

Semantic priming effects in a lexical decision task: comparing third graders and college students in two different stimulus onset asynchronies

Differences in the semantic priming effect comparing child and adult performance have been found by some studies. However, these differences are not well established, mostly because of the variety of methods used by researchers around the world. One of the main issues concerns the absence of semantic priming effects on children at stimulus onset asynchrony (SOA) smaller than 300ms. The aim of this study was to compare the semantic priming effect between third graders and college students at two different SOAs: 250ms and 500ms. Participants performed lexical decisions to targets which were preceded by semantic related or unrelated primes. Semantic priming effects were found at both SOAs in the third graders' group and in college students. Despite the fact that there was no difference between groups in the magnitude of semantic priming effects when SOA was 250ms, at the 500ms SOA their magnitude was bigger in children, corroborating previous studies. Hypotheses which could explain the presence of semantic priming effects in children's performance when SOA was 250ms are discussed, as well as hypotheses for the larger magnitude of semantic priming effects in children when SOA was 500ms.     

Evaluating risk propensity using an objective instrument

Risk propensity is the stable tendency to choose options with a lower probability of success, but greater rewards. Its evaluation has been approached from various perspectives: from self-report questionnaires to objective tests. Self-report questionnaires have often been criticized due to interference from voluntary and involuntary biases, in addition to their lack of predictive value. Objective tests, on the other hand, require resources that make them difficult to administer to large samples. This paper presents an easy-to-administer, 30-item risk propensity test. Each item is itself an objective test describing a hypothetical situation in which the subject must choose between three options, each with a different gain function but equivalent in expected value. To assess its psychometric fit, the questionnaire was administered to 222 subjects, and we performed a test of its reliability as well as exploratory factor analysis. The results supported a three-factor model of risk (Sports and Gambling, Long-term Plans, and Loss Management). After making the necessary adjustments and incorporating a global factor of risk propensity, confirmatory factor analysis was done, revealing that the data exhibited adequate goodness of fit.     

Acculturative stress in Latin-American immigrants: an assessment proposal

The aim of this paper was to develop an instrument to assess levels of stress experienced by Latin-American immigrants in their acculturative process in Spain. A sample of 692 immigrants from Latin America, aged 20 to 63 years, took part on this study (54.9% males and 45.1% females). A 24-item questionnaire with high reliability (.92) was elaborated. Six factors related to acculturative stress were found: 1) discrimination and rejection; 2) differences with the out-group (native Spaniards); 3) citizenship problems and legality; 4) problems concerning social relationships with other immigrants; 5) nostalgia and longing; and 6) family break-up. Our findings show that participants have a high level of stress related to nostalgia and longing, family break-up, and the perception of discrimination and rejection by natives. The usefulness of the instrument and its applications and restrictions are discussed.     

On the usefulness of 'what' and 'where' pathways in vision

The primate visual brain is classically portrayed as a large number of separate 'maps', each dedicated to the processing of specific visual cues, such as colour, motion or faces and their many features. In order to understand this fractionated architecture, the concept of cortical 'pathways' or 'streams' was introduced. In the currently prevailing view, the different maps are organised hierarchically into two major pathways, one involved in recognition and memory (the ventral stream or 'what' pathway) and the other in the programming of action (the dorsal stream or 'where' pathway). In this review, we question this heuristically influential but potentially misleading linear hierarchical pathway model and argue instead for a 'patchwork' or network model.     

Cortical electrophysiological network dynamics of feedback learning

Understanding the neurophysiological mechanisms of learning is important for both fundamental and clinical neuroscience. We present a neurophysiologically inspired framework for understanding cortical mechanisms of feedback-guided learning. This framework is based on dynamic changes in systems-level oscillatory synchronization, reflecting changes in synaptic plasticity between stimulus-processing and motor areas that are modulated in a top-down fashion by different areas of the prefrontal cortex. We make new and testable predictions for how large-scale cortical networks support learning from feedback. Testing these predictions may provide new insights into the basic mechanisms underlying learning and how these mechanisms may be impaired in clinical disorders in which feedback learning is compromised.