Expectation and Attention in Visual Cognition

描述（由申请人提供）：对视觉环境的准确解读对我们的生存至关重要。然而，视觉感知面临着两大制约。首先，视觉系统的计算限制使得它不可能同时高保真地分析我们周围环境的所有方面。为了应对这一挑战，视觉依赖于注意力机制，优先处理那些被认为与我们的健康最相关的环境方面。第二，视觉信息本质上是模糊的，因为许多不同的物体可以投射出相同的视网膜图像，而一个物体可以投射出许多不同的图像。大脑通过利用环境中的统计规律来形成感知预期，提供关于最可能的视觉数据的上下文敏感指导，从而应对这一挑战。尽管期望和关注在日常生活中紧密地交织在一起，但它们通常要么单独研究，要么相互混淆，因此对它们的关系仍然知之甚少。我们在此认为，解开注意力（刺激相关性）和期望（刺激概率）对感知的双重影响是我们理解视觉认知取得重大进展的关键，包括解决注意力文献中长期存在的争论（注意力是以加法还是乘法的方式起作用？）注意力起作用早还是晚？)此外，这个问题与临床状况密切相关，在这种情况下，细心和预测过程似乎缺乏，

DESCRIPTION (provided by applicant): An accurate interpretation of the visual environment is crucial to our survival. However, visual perception is faced with two major constraints. First, computational limitations of the visual system render it impossible to simultaneously analyze all aspects of our surroundings with high fidelity. To meet this challenge, vision relies on mechanisms of attention, prioritizing the processing of those aspects of the environment deemed most relevant to our wellbeing. Second, visual information is inherently ambiguous, as many distinct objects can cast an identical retinal image, while a single object can cast many different images. The brain meets this challenge by exploiting statistical regularities in the environment to form perceptual expectations, providing context- sensitive guidance regarding the most probable visual data. Though expectation and attention are closely interwoven in everyday life, they have typically either been investigated in isolation or confounded with each other, such that their relation remains poorly understood. We here argue that the disentangling of the twin influences of attention (stimulus relevance) and expectation (stimulus probability) on perception is a key to major advances in our understanding of visual cognition, including the resolution of longstanding debates in the attention literature (does attention act in an additive o a multiplicative fashion? Does attention act early or late?). Moreover, this question is deeply relevant to clinical conditions in which attentive and predictive processes appear to be deficient, such as attention deficit hyperactivity disorder and schizophrenia. The overall goal of this projec is to determine the computational and neural mechanisms of expectation and attention in visual cognition. We break down this goal into three specific aims. Firstly, we will dissect the computational mechanisms by which expectation and attention modulate visual perception, by examining the timing (early vs. late) and nature (additive vs. multiplicative) of their respective influences on signal detection and visual neural responses. Secondly, we will determine whether and how attention and expectation interact in their modulation of visual processing. Finally, we will exploit the computational metrics developed in this work to lay the foundations for translational computational neuropsychiatry applications, by linking individual differences in attention and expectation model parameters in healthy subjects to variance in personality traits that constitute known risk-factors for clinical diseases whose etiology involves deficits in attentive and predictive processing. These aims will be addressed with a combination of computational simulations, psychophysical testing, self- report, functional magnetic resonance imaging (fMRI), electro-, and magneto-encephalography (EEG, MEG). The proposed work bridges traditionally segregated research on attention and expectation, and advances our knowledge of how humans make sense of, and prioritize, their visual environment. It is furthermore directly relevant to improving our understanding of potential 'failure modes' of visual cognition in patient populations who have difficulty with controlling attention or with accurately predicting and interpreting sensory information.