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.     

How task errors affect subsequent behavior: Evidence from distributional analyses of task-switching effects

Switch costs in task switching are often assumed to reflect the strengthening of task-related associations. Recently, we provided evidence that committing an error leads to the strengthening of the wrong task (Steinhauser & Hübner, 2006). In the present study, we report how error-induced control compensates for the effects of error strengthening. We hypothesized that, although error detection cannot prevent an error from being strengthened, it initiates processes that suppress the negative consequences of error strengthening on subsequent trials. Because error-induced control is known to operate slowly, we predicted that a compensatory effect should be observable only for slow responses. In three task-switching experiments, these predictions were confirmed by distributional analyses. The results extend our understanding of the interplay between procedural learning and executive control.     

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.     

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.     

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.     

itsme: Interaction Design Innovating Workstations

Background  In the last 30 years, there has been little innovation in workstations. The desktop metaphor has become the standard user interface, with its pros (e.g., ease of learning) and cons (e.g., interaction constraints for skilled users, lack of context awareness). Objectives  In this paper, we present itsme, an Italian initiative to design the next-generation workstation. Interaction design is the basis of the project, as well as the involvement of a wide community of contributing users. Results  The early design phases of the project led to the definition of a new metaphor for personal computing, based on stories and venues. The metaphor is being adopted for the development of a novel front-end for the Linux operating system, aimed at fulfilling the needs and desires of knowledge workers.

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).     

Overestimation of the projected size of objects on the surface of mirrors and windows

Four experiments investigated judgments of the size of projections of objects on the glass surface of mirrors and windows. The authors tested different ways of explaining the task to overcome the difficulty that people had in understanding what the projection was, and they varied the distance of the observer and the object to the mirror or window and varied the size of the mirror. The authors compared estimations of projected size with estimations of the physical size of the object that produced the projection. For both mirrors and windows, observers accurately judged the physical size of objects but greatly overestimated the projected size of the same objects. Indeed, judgments of projected size were more similar to physical than to projected size. People were also questioned verbally about their knowledge of projected size relative to physical size. The errors produced for these conceptual questions were similar to those found in the perceptual estimation tasks. Together, these results suggest that projections of objects on mirrors and windows are treated in the same way and that observers cannot perceive such projections as distal objects.     

Temporal order judgment reveals how number magnitude affects visuospatial attention

The existence of spatial components in the mental representation of number magnitude has raised the question regarding the relation between numbers and spatial attention. We present six experiments in which this relation was examined using a temporal order judgment task to index attentional allocation. Results demonstrate that one important consequence of numerical processing is the automatic allocation of spatial attention, which in turn affects the perception of the temporal order of visual events. Given equal onset time, left-side stimuli are perceived to occur before right-side stimuli when a small number (1, 2) is processed, whereas right-side stimuli are perceived to occur before left-side stimuli when a larger number (8, 9) is processed. In addition, we show that this attentional effect is specific to quantity processing and does not generalize to non-numerical ordinal sequences.     

The IAT as a predictor of food choice: The case of fruits versus snacks

One of the issues concerning the application of implicit measures like the IAT is whether they can be successfully applied to consumer choices. The empirical evidence of the predictive validity of the IAT so far has been mixed, both at the level of eating habits and of specific behavioural food choices. Moreover, whereas the predictive validity of the IAT has been tested in a number of studies, its incremental validity has not been studied as thoroughly. In this contribution, four studies, run at different points in time and analysed as a single sample (N = 399), tested the predictive and incremental validity of an IAT of attitudes towards fruits versus snacks on the choice of a fruit or a snack at the end of the experimental session. Specifically, an additive pattern in which both implicit and explicit measures predict independently, and an interactive one in which implicit and explicit measures predict interactively, were tested for the prediction of the behavioural preference towards snacks or fruits. The results showed that the IAT has both predictive and incremental validity, over and above the significant prediction provided by explicit measures for behavioural food choice. Furthermore, no interaction effect between implicit and explicit measures in the behavioural prediction was obtained, supporting the additive rather than the interactive pattern. Finally, only the explicit attitude towards snacks predicted behavioural choice whereas the explicit attitude towards fruits did not. This result indirectly suggests that a single target IAT might be fruitfully adopted in future research.