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Ash E.L.,Attention
Aging Health | Year: 2011

As the worlds population continues to age, the issues of age-related memory impairment become increasingly important and relevant to individual health and quality of life, as well as an increasing public health and societal concern. The concept of mild cognitive impairment (MCI) has emerged as a response to the desire and need to identify an indolent clinical condition that would reliably predict progression to dementia, particularly Alzheimers disease (AD). As a result of decades of research in the field of neurodegeneration, it is becoming increasingly evident that neurodegenerative diseases begin years before the onset of clinical symptoms, and that standard clinical practice may be relatively insensitive at identifying early neurodegenerative states. The MCI concept was developed to identify the clinical parameters that define the earliest stages of the neurodegenerative process. The essence of the MCI classification is that of mild but measurable cognitive changes indicating a predisposition to progression to dementia, prior to the onset of functional decline. MCI and, more specifically, amnestic MCI were initially proposed as pathological transitional states that ultimately progress to full blown AD. However, after more than a decade of observations, it has been found that MCI subjects do not uniformly progress to dementia or AD and may revert back to normal cognitive states. While the concept of MCI may represent a valid model for characterization of the earliest stages of dementia and for delineation of risk factors, the operational definition may not adequately convey the intended concepts, and as such should be viewed with caution. Additional modifications to the concept and its operationalization are suggested in order to better identify patients with incipient AD and to guide clinical and research practices. © 2011 Future Medicine Ltd. Source


Ayeni O.R.,McMaster University | Alradwan H.,McMaster University | de Sa D.,McMaster University | Philippon M.J.,Attention
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2014

Purpose: With further understanding of the function and the importance of the hip labrum, greater attention has been paid to preserve and repair the damaged labrum. Hip labrum reconstruction has been described to optimize hip preservation when the labrum is deficient. This systematic review aimed to explore and identify the reported indications and outcomes in patients who undergo labral reconstruction of the hip joint. Methods: The electronic databases EMBASE, MEDLINE, and PubMed were searched for all available dates up to July 2013. Further hand search of the reference sections of the included studies was done. Two reviewers searched, screened, and evaluated the included studies for data quality using the Methodological Index for Non-Randomized Studies (MINORS) Scale. Data were also abstracted in duplicate, and agreement and descriptive statistics are presented. Results: There were 5 eligible studies (3 case series, 1 prospective cohort, and 1 retrospective chart review) with a total of 128 patients, and an average 11/16 quality on the MINORS score included in this review. All patients were diagnosed with femoroacetabular impingement and underwent labral reconstruction. Ninety-four patients were assessed at follow-up (73.4 % survivorship) between a reported mean range of 10 and 49 months. There was variability between the studies with regard to the graft types utilized (ilio-tibial band, Gracilis tendon, Ligamentum teres), surgical approaches [open (18.7 %) vs. arthroscopic (81.3 %)], and the reported outcome measures. Overall, improvement was observed in the patient-reported outcomes and functional scores (mHHS, HOS, UCLA, NASH, and SF-12). The failure rate or conversion to THA rate in all available patients was 20 %. The most common indication for labrum reconstruction was a young, active patient with minimal arthritis and non-salvageable or deficient labrum. Other indications included instability, pain, and hypotrophic dysfunctional labrum. Conclusion: Based on the current available evidence, hip labrum reconstruction is a new technique that shows short-term improvement in patient-reported outcomes and functional scores post-operatively. The main indication for reconstruction was a deficient labrum due to previous surgical excision or irreparable tears in young patients with no significant arthritis. Long-term follow-up results with higher quality studies are still lacking based on this review. Level of evidence: II. © 2013 Springer-Verlag Berlin Heidelberg. Source


Wolfe J.M.,Attention
Attention, Perception, and Psychophysics | Year: 2014

Visual working memory is a volatile, limited-capacity memory that appears to play an important role in our impression of a visual world that is continuous in time. It also mediates between the contents of the mind and the contents of that visual world. Research on visual working memory has become increasingly prominent in recent years. The articles in this special issue of Attention, Perception, & Psychophysics describe new empirical findings and theoretical understandings of the topic. © 2014, The Psychonomic Society, Inc. Source


Neutral cues, after being reliably paired with noxious events, prompt defensive engagement and amplified sensory responses. To examine the neurophysiology underlying these adaptive changes, we quantified the contrast-response function of visual cortical population activity during differential aversive conditioning. Steady-state visual evoked potentials (ssVEPs) were recorded while participants discriminated the orientation of rapidly flickering grating stimuli. During each trial, luminance contrast of the gratings was slowly increased and then decreased. Right-tilted gratings (CS+) were paired with loud white noise but left-tilted gratings (CS-) were not. The contrast-following waveform envelope of ssVEPs showed selective amplification of the CS+ only during the high-contrast stage of the viewing epoch. Findings support the notion that motivational relevance, learned in a time frame of minutes, affects vision through a response gain mechanism. © 2014 Society for Psychophysiological Research. Source


McGinnis E.M.,Attention | Keil A.,Attention
PLoS ONE | Year: 2011

Identifying targets in a stream of items at a given constant spatial location relies on selection of aspects such as color, shape, or texture. Such attended (target) features of a stimulus elicit a negative-going event-related brain potential (ERP), termed Selection Negativity (SN), which has been used as an index of selective feature processing. In two experiments, participants viewed a series of Gabor patches in which targets were defined as a specific combination of color, orientation, and shape. Distracters were composed of different combinations of color, orientation, and shape of the target stimulus. This design allows comparisons of items with and without specific target features. Consistent with previous ERP research, SN deflections extended between 160-300 ms. Data from the subsequent P3 component (300-450 ms post-stimulus) were also examined, and were regarded as an index of target processing. In Experiment A, predominant effects of target color on SN and P3 amplitudes were found, along with smaller ERP differences in response to variations of orientation and shape. Manipulating color to be less salient while enhancing the saliency of the orientation of the Gabor patch (Experiment B) led to delayed color selection and enhanced orientation selection. Topographical analyses suggested that the location of SN on the scalp reliably varies with the nature of the to-be-attended feature. No interference of non-target features on the SN was observed. These results suggest that target feature selection operates by means of electrocortical facilitation of feature-specific sensory processes, and that selective electrocortical facilitation is more effective when stimulus saliency is heightened. © 2011 McGinnis and Keil. Source

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