Finger posing primes number comprehension

Canonical finger postures, as used in counting, activate number knowledge, but the exact mechanism for this priming effect is unclear. Here we dissociated effects of visual versus motor priming of number concepts. In Experiment 1, participants were exposed either to pictures of canonical finger postures (visual priming) or actively produced the same finger postures (motor priming) and then used foot responses to rapidly classify auditory numbers (targets) as smaller or larger than 5. Classification times revealed that manually adopted but not visually perceived postures primed magnitude classifications. Experiment 2 obtained motor priming of number processing through finger postures also with vocal responses. Priming only occurred through canonical and not through non-canonical finger postures. Together, these results provide clear evidence for motor priming of number knowledge. Relative contributions of vision and action for embodied numerical cognition and the importance of canonicity of postures are discussed.     

Internal organs,integral selves,and good communities: opt-out organ procurement policies and the ‘separateness of persons’

Most people accept that if they can save someone from death at very little cost to themselves, they must do so; call this the ‘duty of easy rescue.’ At least for many such people, an instance of this duty is to allow their vital organs to be used for transplantation. Accordingly, ‘opt-out’ organ procurement policies, based on a powerfully motivated responsibility to render costless or very low-cost lifesaving aid, would seem presumptively permissible. Counterarguments abound. Here I consider, in particular, objections that assign a moral distinctiveness to the physical boundaries of our bodies and that concern autonomy and trust. These objections are singled out as they seem particularly pertinent to the stress I place on a distinctive benefit of the particular policy I defend. An opt-out system, resting not on the authority of ‘presumed consent’ but on the recognition of a duty to one another, has the prospect of prompting people to understand more richly the ways in which they are both physically embodied and communally embedded.     

the role of personality in stress perception across different vocational types

In this study, the authors investigated the relationship between personality (measured by the subscales of the NEO Five‐Factor Inventory [NEO‐FFI]; Costa & McCrae, 1992) and stress (measured by the Overall Job Satisfaction scale [Warr, Cook, & Wall, 1979], and Cooper's Job Stress Scale [Cooper, 1981]) across different vocational types as described in Holland's (1966, 1997) theory. A sample of 729 employees participated in the survey. Individuals with high NEO‐FFI scores on neuroticism more often perceived distress across several vocational types. Individuals with high NEO‐FFI scores on conscientiousness more often perceived eustress across several vocational types. Extraversion was related to more eustress in Social and Conventional vocational types, openness to experience to more distress in Realistic and Social vocational types and to less eustress in Conventional vocational types; agreeableness was related to more eustress in Investigative and Conventional vocational types. A relation conclusively exists between personality and perception of distress and eustress for different vocational types.     

Comment on Bohannon (2011): "Five-repetition sit-to-stand test: usefulness for older patients in a home-care setting"

Bohannon (2011) found that the five-repetition sit-to-stand test had limited usefulness for older patients in a home-care setting because most of the patients were not able to perform the test. However, the five-repetition sit-to-stand test can be modified in several ways, if assessment of lower limbs' performance is required by functional testing. Depending on the cohort and on parameters of interest, functional tests and objective biomechanical measures can be used.     

Testing overall and moderator effects in random effects meta‐regression

Random effects meta‐regression is a technique to synthesize results of multiple studies. It allows for a test of an overall effect, as well as for tests of effects of study characteristics, that is, (discrete or continuous) moderator effects. We describe various procedures to test moderator effects: the z, t, likelihood ratio (LR), Bartlett‐corrected LR (BcLR), and resampling tests. We compare the Type I error of these tests, and conclude that the common z test, and to a lesser extent the LR test, do not perform well since they may yield Type I error rates appreciably larger than the chosen alpha. The error rate of the resampling test is accurate, closely followed by the BcLR test. The error rate of the t test is less accurate but arguably tolerable. With respect to statistical power, the BcLR and t tests slightly outperform the resampling test. Therefore, our recommendation is to use either the resampling or the BcLR test. If these statistics are unavailable, then the t test should be used since it is certainly superior to the z test.     

The relevance of the nature of learned associations for the differentiation of human memory systems

In a previous functional magnetic resonance imaging (fMRI) study we demonstrated an involvement of the medial temporal lobe (MTL) during an implicit learning task. We concluded that the MTL was engaged because of the complex contingencies that were implicitly learned. In addition, the basal ganglia demonstrated effects of a paralleled proceduralization of fixed stimulus-response associations. In the present study we directly tested the hypothesis that the MTL activation depends upon implementing the complex regularity in task material, whereas activation of basal ganglia does not. Therefore, we rearranged task material such that it did not contain any complex regularity. The statistical comparison of behavioral and fMRI data between the materials allowed for isolating effects that were directly related to the implicit learning process regarding the complex regularity. The results showed a reliable difference of fMRI signal limited to the MTL, indicating a specific functional role of the MTL in implicit learning of complex contingencies. Furthermore, no difference of BOLD (Blood-Oxygenation Level Dependent) signal in the basal ganglia and cerebellum were detected, supporting the assumption of a functional involvement of the structures in proceduralization of simple stimulus-response associations but not in implicitly learning complex relations. We therefore conclude that the nature of the learned associations is relevant for determining the neuronal focus of learning, rather than the accompanying awareness.     

In vitro analog of classical conditioning of feeding behavior in aplysia

The feeding behavior of Aplysia californica can be classically conditioned using tactile stimulation of the lips as a conditioned stimulus (CS) and food as an unconditioned stimulus (US). Moreover, several neural correlates of classical conditioning have been identified. The present study extended previous work by developing an in vitro analog of classical conditioning and by investigating pairing-specific changes in neuronal and synaptic properties. The preparation consisted of the isolated cerebral and buccal ganglia. Electrical stimulation of a lip nerve (AT4) and a branch of the esophageal nerve (En2) served as the CS and US, respectively. Three protocols were used: paired, unpaired, and US alone. Only the paired protocol produced a significant increase in CS-evoked fictive feeding. At the cellular level, classical conditioning enhanced the magnitude of the CS-evoked synaptic input to pattern-initiating neuron B31/32. In addition, paired training enhanced both the magnitude of the CS-evoked synaptic input and the CS-evoked spike activity in command-like neuron CBI-2. The in vitro analog of classical conditioning reproduced all of the cellular changes that previously were identified following behavioral conditioning and has led to the identification of several new learning-related neural changes. In addition, the pairing-specific enhancement of the CS response in CBI-2 indicates that some aspects of associative plasticity may occur at the level of the cerebral sensory neurons.     

The role of task rules and stimulus–response mappings in the task switching paradigm

Switch costs occur whenever participants are asked to switch between two or more task sets. In a typical task switching experiment, participants have to switch between two task sets composed of up to four different stimuli per task set. These 2 (task sets) x 4 (stimuli) contain only 8 different stimulus-response (S-R) mappings, and the question is why participants base their task performance on task sets instead of S-R mappings. The current experiments compared task performance based on task rules with performance based on single stimulus-response mappings. Participants were led to learn eight different S-R mappings with or without fore-knowledge about two underlying task sets. Without task set information no difference between shifts and repetitions occurred, whereas introducing task sets at the beginning led to significant switch costs. Most importantly, introducing task sets in the middle of the experiment also resulted in significant switch costs. Furthermore, introducing task rules at the beginning of the experiment lead to slower RTs when simple stimuli (Experiment 1) had to be processed. This detrimental effect disappeared with more complex stimuli (Experiment 2). Results will be discussed with respect to cognitive control.