Short-term limb immobilization affects motor performance

C. Ghez, J. Gordon, and M. R Ghilardi (1995; J. Gordon, M. R Ghilardi, & C. Ghez, 1995; R. L. Sainburg, M. R Ghilardi, H. Poizner, & C. Ghez, 1995) have found that proprio-ceptive deafferentation impairs feedforward and feedback mechanisms that control reaching movements. In the present study, the authors found immobilization-induced changes in limb kinematics, including joint motion, in 32 healthy participants who performed out-and-back movements before and after 0, 6, or 12 hr of immobilization of the left arm. Control participants did not undergo the arm immobilization procedure. Immobilization for 12 hr, but not 6 hr, caused trajectories with increased hand-path areas and altered interjoint coordination. The abnormalities were smaller in amplitude but similar in quality to those reported in deafferented patients (R. L. Sainburg et al.). In addition, movement onset point significantly drifted after immobilization. Thus, short-term limb disuse can affect interjoint coordination by acting on feedforward mechanisms. These behavioral alterations are potentially related to cortical plastic changes.     

Galileo's eye: a new vision of the senses in the work of Galileo Galilei

Reflections on the senses, and particularly on vision, permeate the writings of Galileo Galilei, one of the main protagonists of the scientific revolution. This aspect of his work has received scant attention by historians, in spite of its importance for his achievements in astronomy, and also for the significance in the innovative scientific methodology he fostered. Galileo's vision pursued a different path from the main stream of the then contemporary studies in the field; these were concerned with the dioptrics and anatomy of the eye, as elaborated mainly by Johannes Kepler and Christoph Scheiner. Galileo was more concerned with the phenomenology rather than with the mechanisms of the visual process. His general interest in the senses was psychological and philosophical; it reflected the fallacies and limits of the senses and the ways in which scientific knowledge of the world could be gathered from potentially deceptive appearances. Galileo's innovative conception of the relation between the senses and external reality contrasted with the classical tradition dominated by Aristotle; it paved the way for the modern understanding of sensory processing, culminating two centuries later in Johannes Müller's elaboration of the doctrine of specific nerve energies and in Helmholtz's general theory of perception.     

Perceived sexual harassment at work: meta-analysis and structural model of antecedents and consequences

Although sexual harassment has been extensively studied, empirical research has not led to firm conclusions about its antecedents and consequences, both at the personal and organizational level. An extensive literature search yielded 42 empirical studies with 60 samples. The matrix correlation obtained through meta-analytic techniques was used to test a structural equation model. Results supported the hypotheses regarding organizational environmental factors as main predictors of harassment.     

The effect of barrier underestimation on weight management and exercise change

Over 60% of all Americans are classified as overweight or obese. This represents a major public health concern, as obesity is a risk factor for many other health ailments. While many people intend to lose weight, they often have difficulty changing their current behavioral patterns (as evidenced by modest correlations between intention and behavior). Therefore, one of the major challenges for obesity research is to address the gap between intentions to lose weight and actual behavior. The current study hypothesized that one reason for the intention-behavior discrepancy is that people mis-estimate the barriers that they will encounter as they follow through with their intentions. Specifically, we hypothesized that people underestimate barriers to exercise and diet, and because of these underestimations, there is a discrepancy between their intentions and behavior. To test these hypotheses, we surveyed faculty and staff at Rutgers University (N = 422) at two time points, 1 year apart. The results indicate that barriers to dieting behaviors are significantly underestimated and this underestimation partially explained the discrepancy between intentions and behavior. The results for barriers to exercise behavior were less consistent, however. As a whole, these results suggest a possible point of behavioral intervention for weight loss.     

A mental number line in human newborns

Humans represent numbers on a mental number line with smaller numbers on the left and larger numbers on the right side. A left‐to‐right oriented spatial–numerical association, (SNA), has been demonstrated in animals and infants. However, the possibility that SNA is learnt by early exposure to caregivers’ directional biases is still open. We conducted two experiments: in Experiment 1, we tested whether SNA is present at birth and in Experiment 2, we studied whether it depends on the relative rather than the absolute magnitude of numerousness. Fifty‐five‐hour‐old newborns, once habituated to a number (12), spontaneously associated a smaller number (4) with the left and a larger number (36) with the right side (Experiment 1). SNA in neonates is not absolute but relative. The same number (12) was associated with the left side rather than the right side whenever the previously experienced number was larger (36) rather than smaller (4) (Experiment 2). Control on continuous physical variables showed that the effect is specific of discrete magnitudes. These results constitute strong evidence that in our species SNA originates from pre‐linguistic and biological precursors in the brain.     

Cathodal tDCS of the Left Posterior Parietal Cortex Increases Proprioceptive Drift

In aiming movements the limb position drifts away from the defined target after some trials without visual feedback, a phenomenon defined as proprioceptive drift (PD). There are no studies investigating the association between the posterior parietal cortex (PPC) and PD in aiming movements. Therefore, cathodal and sham transcranial direct current stimulation (tDCS) were applied to the left PPC concomitantly with the performance of movements with or without vision. Cathodal tDCS applied without vision produced a higher level of PD and higher rates of drift accumulation while it decreased peak velocity and maintained the number of error corrections, not affecting movement amplitude. The proprioceptive information seems to produce an effective reference to movement, but with PPC stimulation it causes a negative impact on position.     

Not all positive categories are alike: Exploring the superiority of the self as a positive source for associative attitude change via intersecting regularities

In associative evaluative learning, attitudes can originate from intersecting regularities between a target and both positive- and self-related stimuli. Liking for a focal target is primarily driven by its reference to one source, but it might be qualified by the reference to a contrast target. This contribution focuses on how the nature of positive and contrast sources affects learning via intersecting regularities. In two studies (N = 199 and N = 185), the self and another positive category lead to increased implicit and explicit liking, regardless of the contrast source's valence. In Study 3 (N = 128), confronting the self and the positive category in the same paradigm yields only implicit preferences for self-related targets. Both implicitly and explicitly, this preference for self- over positive-related target was moderated by self-positivity. Our findings confirm the robustness of learning via intersecting regularities and suggest that the self is a special evaluative source.     

Looking into your eyes: observed pupil size influences approach-avoidance responses

The eyes reveal important social messages, such as emotions and whether a person is aroused and interested or bored and fatigued. A growing body of research has also shown that individuals with large pupils are generally evaluated positively by observers, while those with small pupils are perceived negatively. Here, we examined whether observed pupil size influences approach-avoidance tendencies. Participants performed an Approach-Avoidance Task using faces with large and small pupil sizes. Results showed that pupil size influences the accuracy of arm movements. Specifically, individuals were less prone to approach a face with small pupils than a face with large pupils. Conversely, participants were less prone to avoid a face with large pupils than a face with small pupils. Collectively, these findings suggest that perceivers attend to a facial cue – pupil size – when interacting with others.     

Am I guilty or not? Deontological guilt,uncertainty, and checking behavior

Literature suggests that checking behaviors are aimed at reducing feelings of uncertainty both in clinical samples with obsessive‐compulsive disorder and in general population. Previous studies also showed that deontological guilt is an emotion often associated with obsessive‐compulsive disorder. Thus, the aim of the current study was to investigate the differences in checking behaviors in the condition of high versus low uncertainty, by exploring the moderating role of deontological versus altruistic guilt. Participants were 108 undergraduate Italian university students who took part in a visual search task designed to elicit checking behavior. Ahead of the visual task, participants were administered one scenario in order to manipulate either deontological or altruistic guilt. The results showed that in the condition of uncertainty, compared with the condition of certainty, participants spent more time in checking behaviors and that such a difference was more consistent when participants experienced deontological rather than altruistic guilt. Limitations and further directions are discussed.     

Right hemisphere involvement in non-fluent primary progressive aphasia

We described a 56-years-old man with a diagnosis of "non-fluent primary progressive aphasia" (NfPPA). An accurate neuropsychological, neurological and neuroimaging evaluation was performed in order to assess clinical and behavioural features of the patient. From a neuropsychological point of view, the patient showed a typical cognitive profile of subjects affected by NfPPA: a prominent language deficit, associated with impairments in several cognitive domains after three years from the onset of the symptomatology. The most intriguing feature is that SPECT revealed hypoperfusion in the right frontal cortex, albeit the patient is right-handed. This unexpected finding shows that NfPPA may arise not only from cortical abnormalities in the language-dominant left hemisphere, but also from right hemisphere involvement in a right hander (crossed aphasia).