Influence of typical size of objects in a categorization task]

This study explores the influence of typical size during a categorization task. The specificity of this experimental work is based on the homogeneity of the graphic stimuli size. We have created a typical size standard of our stimuli, that concerns the real size of the objects represented by the drawings of homogeneous sizes. Then, a priming experiment was performed in which the prime and target drawings had two types of relations: a typical size, and a categorial. The participants are na?ve as to the typical size relation between prime and target. The results show a positive priming effect of the typical size but not of the category. The results are discussed in term of theoretical approach developed by Barsalou and his colleagues (1999, 2003). In this theoretical framework, the typical size can be considered as a perceptual knowledge. In that way, we propose that participants could automatically simulate the typical size as soon as they perceived the drawings of objects with homegenous sizes.     

A test of the diffusion model explanation for the worst performance rule using preregistration and blinding

People with higher IQ scores also tend to perform better on elementary cognitive-perceptual tasks, such as deciding quickly whether an arrow points to the left or the right Jensen (2006). The worst performance rule (WPR) finesses this relation by stating that the association between IQ and elementary-task performance is most pronounced when this performance is summarized by people’s slowest responses. Previous research has shown that the WPR can be accounted for in the Ratcliff diffusion model by assuming that the same ability parameter—drift rate—mediates performance in both elementary tasks and higher-level cognitive tasks. Here we aim to test four qualitative predictions concerning the WPR and its diffusion model explanation in terms of drift rate. In the first stage, the diffusion model was fit to data from 916 participants completing a perceptual two-choice task; crucially, the fitting happened after randomly shuffling the key variable, i.e., each participant’s score on a working memory capacity test. In the second stage, after all modeling decisions were made, the key variable was unshuffled and the adequacy of the predictions was evaluated by means of confirmatory Bayesian hypothesis tests. By temporarily withholding the mapping of the key predictor, we retain flexibility for proper modeling of the data (e.g., outlier exclusion) while preventing biases from unduly influencing the results. Our results provide evidence against the WPR and suggest that it may be less robust and less ubiquitous than is commonly believed.     

A randomized controlled trial of expressive writing in breast cancer survivors with lymphedema

Objective: Breast cancer survivors who develop lymphedema report poorer quality of life (QoL) than those without lymphedema. Expressive writing is a potential intervention to address QoL.

Design: Adult women (N = 107) with breast cancer and chronic Stage II lymphedema were randomised to writing about thoughts and feelings specific to lymphedema and its treatment (intervention) or about daily activities (control) for four, 20-min sessions.

Main Outcome Measures: Outcome measures were several indicators of QoL assessed at baseline, one, three, and six months post-intervention (total scores and subscales of Upper Limb Lymphedema 27 and Functional Assessment of Cancer Therapy–Breast). Hypothesised moderators of change in QoL were dispositional optimism, avoidant behaviours, and time since lymphedema diagnosis.

Results: There was no statistically significant intent-to-treat main effects of expressive writing on QoL. Statistically significant moderating effects on change in different indicators of QoL were observed for all three moderators. Expressive writing was more effective for improving QoL in women who were higher on optimism, lower on avoidance and had less time since a lymphedema diagnosis.

Conclusion: These results provide further evidence that there are subsets of individuals for whom expressive writing is more effective. Future research may investigate targeting expressive writing based on identified moderators.     

Endurance exercise selectively impairs prefrontal-dependent cognition

Two experiments are reported that examine the possibility that exercise selectively influences different types of cognition. To our knowledge, these experiments represent the first attempt to study higher-cognitive processes during exercise. Theoretical thinking was guided by the transient hypofrontality hypothesis. In both experiments, athletes who exercised at a sustained, moderate pace were compared to sedentary controls on two neuropsychological tests, one that is generally regarded as heavily dependent on prefrontal cognition and one that is relatively insensitive to prefrontal operation. Results showed that during exercise performance on tests demanding prefrontal-dependent cognition was impaired, while at the same time, cognitive processes requiring little prefrontal activity were unaffected.     

Keeping it short: a comparison of methods for brief picture presentation

Abstract— Research has shown that backward masking is a powerful tool for studying unconscious mental processes. Whereas studies have traditionally presented stimuli using cathode-ray tube (CRT) monitors or mechanical shutters together with slide projectors, recent studies (mainly in functional magnetic resonance imaging, fMRI) have begun to use methods based on liquid crystal displays (LCDs) and thin-film transistor (TFT) technology. However, because of differences in technology, all methods may not be equally suited for masking. When methods were compared for their accuracy in presenting pictures at short durations, LCD and TFT presentations had poor accuracy, but shutter and CRT presentations had better accuracy. Because CRTs interfere with the imaging process in fMRI, we recommend the use of mechanical shutters. However, our results may not generally apply to all displays, so we advise researchers to validate the presentation parameters of their displays. The procedure described here may be useful for that purpose.     

Functional and pharmacological characterization of the first specific agonist and antagonist for the V1b receptor in mammals

By activating three distinct vasopressin receptor isoforms called V1a-R, V1b-R (V3-R) and V2-R, vasopressin (VP) mediates a wide number of biological effects in mammals and may be involved in several pathological states. Up to now only specific V1a and V2 receptor agonists and antagonists have been successfully designed. The role of the V1b-R still remains partially unknown, due to the lack of selective V1b-R ligands and orally-active molecules, which are crucial tools for investigating the central and peripheral functions or pathological disorders associated with this receptor. In this review, we report the biological and pharmacological properties of the first two specific V1b-R ligands: d[Cha4] AVP, a high affinity V1b-R agonist and SSR149415, a potent orally-active V1b-R antagonist with good selectivity with respect to other VP/OT receptor isoforms and able to control ACTH secretion in vitro and in vivo. Indeed, these molecules constitute invaluable tools for exploring the central and peripheral roles of VP mediated via V1b receptors. Interestingly, SSR149415 displays potent anxiolytic and antidepressant-like activities, indicating that this new class of drugs has a promising therapeutical potential in the treatment of stress-related disorders, anxiety and depression.     

Neural correlates of dual task interference in rapid visual streams: an fMRI study

In rapid streams of visual stimuli, identification of a first target interferes with identification of a second target presented within the next half second (the attentional blink or AB). It has been suggested that rapid perceptual decisions under masking interference involve interactions between frontal and posterior cortex. We investigated the neural correlates of the AB using functional magnetic resonance imaging (fMRI). Twelve subjects viewed rapid streams of black letters in which were embedded two white target letters (T1 and T2) separated by either 300 or 700 ms. As expected, fewer correct T2 identifications were observed in the short-delay condition. Corresponding fMRI statistical images showed increased activation in inferotemporal and posterior parietal cortex, but also in lateral frontal cortex and cerebellum in the short-delay condition suggesting that these brain regions are associated with perceptual decisions under masking interference.     

Nonfatal suicide-related behavior among inmates: testing for gender and type differences

Suicide-related behavior (SRB) is significantly more prevalent among female (40.8%) than among male (28%) inmates, although suicide risk is higher among the latter. When instrumental behavior (IB) is excluded and only suicidal acts (SA) considered, rates for the two groups are more comparable (11.9% and 16%, respectively). Compared with other female inmates, the SRB group is more suicidal, hostile, and impulsive and more likely to have been previously victimized and to be diagnosed with Axis I and II disorders. Women with IB are not significantly different from those with SA, except that their behavior provides significantly greater tension release.     

Appraisal process in sheep (Ovis aries): interactive effect of suddenness and unfamiliarity on cardiac and behavioral responses

Appraisal theories state that an emotion results from an individual's evaluation of a stimulating event, which is based on a set of criteria. Each criterion triggers specific expressions that can be modulated by the outcome of other criteria. The authors analyzed the effects of the criteria of suddenness, unfamiliarity, and their combination on behavioral and cardiac responses in lambs (Ovis aries). Lambs were exposed to a visual stimulus that appeared either rapidly or slowly and was either unfamiliar or familiar. Suddenness induced a startle response and an increase in heart rate. Unfamiliarity induced an orientation response. The combination of suddenness and unfamiliarity enhanced both the heart rate increase and the behavioral orientation response. These results support the hypotheses of specificity and modulation of emotional expressions.     

Coordination between breathing and mental grouping of pianistic finger movements

6 pianists (age 22 to 43 years) performed a simple finger exercise at a spontaneously chosen most comfortable tempo on a Yamaha-Disklavier piano. Five versions of the exercise, notated in quarter notes, were presented with different types of meters: (1) 3/4, (2) 4/4, (3) 5/4, (4) 6/4, and (5) 7/4. The onsets of finger strokes were measured while respiration was recorded in parallel by means of a thermistor placed at the front of the dominant nostril. The chosen tempo (finger-beat-rate) was about 3 Hz on all trials but not exactly constant. Correspondingly, the meter-rate chosen was faster for 3/4 and 4/4 meter (around 1 Hz), slower for 5/4, 6/4, and 7/4 meter (around 0.5 Hz). Mean breathing rate while playing the piano (0.38 Hz) was significantly higher than while resting (0.22 Hz, p<.05). Pooling the data of all subjects, the ratios of instantaneous meter and breathing rates clustered around different integer values, depending on the type of meter. Also the individual data indicated integer ratios between instantaneous meter and breathing rates. Even periods of constant phase relations between onsets of the meter and of inspiration could be observed. Thus, the mental process of grouping the same piece of music by various musical meters interacts with unconscious breathing rhythm.