44 research outputs found
A cueing technique in choice reaction tlme
Much of the fluctuation in choice RT data is assumed to arise from variations in perceptual and response biases correlated with sequential patterns of trial events. Inserting a predictive cue prior to the stimulus on each trial apparently induces a strong bias not only toward that particular stimulus, but also toward its modality and toward the associated response. Trial-to-trial sequential effects under cued conditions were markedly smaller than those obtained in a noncued control condition. © 1970 Psychonomic Society, Inc
Left, right, left, right, eyes to the front! Müller-Lyer bias in grasping is not a function of hand used, hand preferred or visual hemifield, but foveation does matter
We investigated whether the control of movement of the left hand is more likely to involve the use of allocentric information than movements performed with the right hand. Previous studies (Gonzalez et al. in J Neurophys 95:3496–3501, 2006; De Grave et al. in Exp Br Res 193:421–427, 2009) have reported contradictory findings in this respect. In the present study, right-handed participants (N = 12) and left-handed participants (N = 12) made right- and left-handed grasps to foveated objects and peripheral, non-foveated objects that were located in the right or left visual hemifield and embedded within a Müller-Lyer illusion. They were also asked to judge the size of the object by matching their hand aperture to its length. Hand apertures did not show significant differences in illusory bias as a function of hand used, handedness or visual hemifield. However, the illusory effect was significantly larger for perception than for action, and for the non-foveated compared to foveated objects. No significant illusory biases were found for reach movement times. These findings are consistent with the two-visual system model that holds that the use of allocentric information is more prominent in perception than in movement control. We propose that the increased involvement of allocentric information in movements toward peripheral, non-foveated objects may be a consequence of more awkward, less automatized grasps of nonfoveated than foveated objects. The current study does not support the conjecture that the control of left-handed and right-handed grasps is predicated on different sources of information
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Abstraction-based efficiency in the lexicon
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90732.pdf (publisher's version ) (Open Access)Listeners learn from their past experience of listening to spoken words, and use this learning to maximise the efficiency of future word recognition. This paper summarises evidence that the facilitatory effects of drawing on past experience are mediated by abstraction, enabling learning to be generalised across new words and new listening situations. Phoneme category retuning, which allows adaptation to speaker-specific articulatory characteristics, is generalised on the basis of relatively brief experience to words previously unheard from that speaker. Abstract knowledge of prosodic regularities is applied to recognition even of novel words for which these regularities were violated. Prosodic word-boundary regularities drive segmentation of speech into words independently of the membership of the lexical candidate set resulting from the segmentation operation. Each of these different cases illustrates how abstraction from past listening experience has contributed to the efficiency of lexical recognition.18 p
Amyloid-Directed Antibodies: Past, Present, and Future.
BACKGROUND: Alzheimer\u27s disease (AD) is the most common neurodegenerative disorder in patient demographics over 65 years old causing debilitating cognitive impairment. Most commonly, AD is diagnosed clinically as probable AD , and definitive diagnosis is confirmed through postmortem brain autopsies to detect extracellular amyloid-β (Aβ) plaques and intraneuronal hyperphosphorylated tau tangles. The exact mechanism causing AD is still unknown, but treatments for AD have been actively investigated. Currently, immunotherapies have shown substantial promise in reducing the pathologic and clinical signs of AD.
OBJECTIVE: This review aims to evaluate passive immunotherapies deemed to have promise for further development and use in the treatment of AD.
METHODS: Immunotherapies were selected via a narrative review of medications that have potential clinical effectiveness with a status of FDA accepted, FDA fast-track, FDA status pending, or emerging therapies poised to pursue FDA approval.
RESULTS: This review has yielded two anti-Aβ monoclonal antibodies (mAb) that are currently fully FDA approved, one mAb granted FDA fast-track status, two therapies on hold, three discontinued medications, and three promising emerging therapies.
CONCLUSIONS: We conclude that, in the near future, passive immunotherapies will be the preferred and evidence-based method of treatment for AD with the presence of brain Aβ deposits for both symptom management and potential slowing of disease progression. Specifically, lecanemab and donanemab will require further clinical studies to optimize patient selection based on safety profiles. Despite some key limitations, these two drugs are paving the way for disease-modifying treatments in patients displaying early signs of amyloid pathology
