Long-term bone remodelling around 'legendary' cementless femoral stems.

Bone remodelling around a stem is an unavoidable long-term physiological process highly related to implant design. For some predisposed patients, it can lead to periprosthetic bone loss secondary to severe stress-shielding, which is thought to be detrimental by contributing to late loosening, late periprosthetic fracture, and thus rendering revision surgery more complicated.However, these concerns remain theoretical, since late loosening has yet to be documented among bone ingrowth cementless stems demonstrating periprosthetic bone loss associated with stress-shielding.

Evidence for the triadic model of adolescent brain development: Cognitive load and task-relevance of emotion differentially affect adolescents and adults.

In adults, cognitive control is supported by several brain regions including the limbic system and the dorsolateral prefrontal cortex (dlPFC) when processing emotional information. However, in adolescents, some theories hypothesize a neurobiological imbalance proposing heightened sensitivity to affective material in the amygdala and striatum within a cognitive control context. Yet, direct neurobiological evidence is scarce.

Electrophysiological evidence for the involvement of proactive and reactive control in a rewarded stop-signal task.

Reward availability is known to facilitate various cognitive operations, which is usually studied in cue-based paradigms that allow for enhanced preparation in reward-related trials. However, recent research using tasks that signal reward availability via task-relevant stimuli suggests that reward can also rapidly promote performance independent of global strategic preparation. Notably, this effect was also observed in a reward-related stop-signal task, in which behavioral measures of inhibition speed were found to be shorter in trials signaling reward.

The dynamics of proactive and reactive cognitive control processes in the human brain.

In this study, we leveraged the high temporal resolution of EEG to examine the neural mechanisms underlying the flexible regulation of cognitive control that unfolds over different timescales. We measured behavioral and neural effects of color-word incongruency, as different groups of participants performed three different versions of color-word Stroop tasks in which the relative timing of the color and word features varied from trial to trial. For this purpose, we used a standard Stroop color identification task with equal congruent-to-incongruent proportions (50%/50%), along with two versions of the "Reverse Stroop" word identification tasks, for which we manipulated the incongruency proportion (50%/50% and 80%/20%).

Task preparation processes related to reward prediction precede those related to task-difficulty expectation.

Recently, attempts have been made to disentangle the neural underpinnings of preparatory processes related to reward and attention. Functional magnetic resonance imaging (fMRI) research showed that neural activity related to the anticipation of reward and to attentional demands invokes neural activity patterns featuring large-scale overlap, along with some differences and interactions. Due to the limited temporal resolution of fMRI, however, the temporal dynamics of these processes remain unclear.

The influence of different Stop-signal response time estimation procedures on behavior-behavior and brain-behavior correlations.

The fundamental cognitive-control function of inhibitory control over motor behavior has been extensively investigated using the Stop-signal task. The critical behavioral parameter describing stopping efficacy is the Stop-signal response time (SSRT), and correlations with estimates of this parameter are commonly used to establish that other variables (e.g.

Electrophysiological recordings in humans reveal reduced location-specific attentional-shift activity prior to recentering saccades.

Being able to effectively explore the visual world is of fundamental importance, and it has been suggested that the straight-ahead gaze position within the egocentric reference frame ("primary position") might play a special role in this context. In the present study we employed human electroencephalography (EEG) to examine neural activity related to the spatial guidance of saccadic eye movements. Moreover, we sought to investigate whether such activity would be modulated by the spatial relation of saccade direction to the primary gaze position (recentering saccades).

Differential functional roles of slow-wave and oscillatory-α activity in visual sensory cortex during anticipatory visual-spatial attention.

Markers of preparatory visual-spatial attention in sensory cortex have been described both as lateralized, slow-wave event-related potential (ERP) components and as lateralized changes in oscillatory-electroencephalography alpha power, but the roles of these markers and their functional relationship are still unclear. Here, 3 versions of a visual-spatial cueing paradigm, differing in perceptual task difficulty and/or response instructions, were used to investigate the functional relationships between posterior oscillatory-alpha changes and our previously reported posterior, slow-wave biasing-related negativity (swBRN) ERP activity. The results indicate that the swBRN reflects spatially specific, pretarget preparatory activity sensitive to the expected perceptual difficulty of the target detection task, correlating in both location and strength with the early sensory-processing N1 ERP to the target, consistent with reflecting a preparatory baseline-shift mechanism.