Andrew R. Hollingworth - US grants

The visual perception of natural scenes is a dynamic process during which local objects are selected by movements of the eyes and attention. The selective nature of scene perception paces strong constraints on the construction of a visual representation of a scene, as previously selected items must be retained in memory and integrated to form a representation of the scene as a whole. The goal of the proposed research is to investigate the nature of the visual representation constructed during the viewing of natural scenes. Change detection and forced-choice discrimination procedures will be used to investigate four primary questions. First, do visual representations decay upon the withdrawal of attention from an object, and is attending to an object a necessary condition for detecting change to that object? Second, do limitations on change detection (i.e. change blindness) derive solely from constraints on visual memory or do retrieval and comparison constraints play a role in change detection failure? Third, to what extent is the retrieval of object information mediated by spatial position. Fourth, how quickly does visual memory for a local object decay during the viewing of a natural scene? This research will help to determine the specificity of visual memory for natural scenes, the relationship between visual memory attention, and the mechanisms of visual memory encoding and retrieval.

[unreadable] DESCRIPTION (provided by applicant): People make tens of thousands of saccadic eye movements each day, and a substantial proportion of these fail to land on the intended object. To be efficient, the visual system must rapidly correct these errors and make a corrective saccade to the intended object. Previous research has shown that gaze correction is fast and automatic under simple laboratory conditions, in which only a single object is present. In the natural world, however, there are many possible gaze targets, and determining which object was the original saccade target will often require the use of a memory representation of the target object. However, no previous studies have attempted to demonstrate that memory is used to correct saccade errors. In the proposed research, we plan to show that memory for the saccade target is indeed used to correct saccade errors, and that these corrections are fast, accurate, automatic, and perhaps even unconscious. Our central hypothesis is that visual short-term memory (VSTM) stores target information across the saccade so that the target object can be discriminated from other visible objects and gaze can by efficiently corrected. To test this idea, we developed a new paradigm to simulate saccade error, in which a stimulus array is shifted slightly during a saccade so that the eyes land between the target object and a distractor object. Our preliminary results suggest that memory-based gaze correction under these conditions is accurate, fast, and automatic. The proposed work will explore the nature of the memory representations used for these gaze corrections, including (a) testing whether the memory representations are stored in VSTM, (b) examining what information is stored in these representations, (c) exploring how these representations are combined bottom-up sensory information, and (d) determining whether the representations include information about other nearby objects. These studies will advance our understanding of basic mechanisms of gaze correction that support efficient interaction with objects and agents in the world. Most complex visual tasks (preparing food, driving) depend on fixating a series of objects, and gaze correction plays an important role in ensuring that the eyes are directed efficiently to goal-relevant objects. Thus, the proposed research will provide essential information for understanding conditions that involve deficits in the control of gaze. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Intelligent, goal-directed behavior depends on orienting the eyes efficiently to task-relevant objects in the world. In previous work, we have demonstrated that the visual working memory (VWM) system exerts top-down control over saccade target selection, guiding the eyes to goal-relevant objects. Before a saccade, features of the saccade target are encoded into VWM. These are retained across the saccade and compared with object information when the eyes land. In the common circumstance that the eyes fail to land on the original target, remembered properties of the target are used to guide attention and gaze, automatically, toward a matching object, ensuring that the eyes are directed efficiently to the original target. This specific behavior reflects a general interactive relationship between saccade target selection and VWM: Selection of the saccade target object controls encoding into VWM, and the content of VWM, in turn, biases saccade target selection in favor of objects that match the features stored in memory. In the present project, we propose to explore the locus of the interaction between VWM and saccade target selection. We will test the hypothesis that VWM activation influences low-level sensory processing of saccade targets, influencing even the most rapid and elementary forms of saccadic orienting. In addition, we propose to examine core processing components of the interaction between VWM and gaze control, including 1) the ability to adapt VWM content and attentional biases on the basis of changing task demands and 2) the mechanisms by which saccade target properties are encoded in VWM. Finally, we will develop a neural field model that integrates current models eye movement planning and models of VWM, providing a formal framework for understanding their relationship. These studies will advance our understanding of the basic mechanisms of gaze control that support efficient interaction with objects and agents in the world. PUBLIC HEALTH RELEVANCE: Everyday human behavior requires efficiently directing the eyes to objects that are relevant to the task at hand. The present project aims to provide a clearer understanding of the mechanisms by which working memory systems interact with the control of saccadic eye movements to guide the eyes toward pertinent objects. Understanding the low-level mechanisms by which visual working memory modulates the selection of saccade targets has the potential to inform not only research on eye movements but also basic research on working memory, attention, and visual search.

? DESCRIPTION (provided by applicant): Male-initiated sexual aggression toward female acquaintances is a major public-health problem in adolescence and early adulthood. The efficacy of existing prevention programs has been disappointing, necessitating the conduct of innovative basic science research that will lay the foundation for the development of novel prevention strategies. Risk of sexual aggression between acquaintances is associated both theoretically and empirically with alcohol use and with misperception of women's sexual-interest cues. Research also demonstrates that alcohol consumption decreases men's sensitivity to women's sexual interest, but the mechanisms underlying this effect are unknown. The current project draws upon methods from cognitive and vision science to evaluate the role of overt visual attention (i.e., moment-by-moment eye movements) in men's perception of women's sexual-interest cues, and to examine the influence of alcohol consumption on men's attention and decision-making when judging sexual interest. The goals are to determine (1) whether men's visual attention to women's faces, women's bodies, and the background context account for men's use of dating-relevant cues when judging women's sexual interest; (2) whether moderate alcohol consumption influences visual attention and use of dating-relevant cues; and (3) whether visual attention accounts for the association between alcohol consumption and use of dating-relevant cues. Eighty 21-25 year old participants will complete alcohol and no-alcohol sessions in a counterbalanced order. While their eye movements are monitored, participants will view 200 unique scenes that depict a woman who varies along sexual interest, provocativeness-of-dress, and attractiveness dimensions in a background context that varies in sexual relevance. Participants will judge the woman's sexual interest after viewing each scene. In a third session, participants will complete assessments of drinking patterns, alcohol expectancies, rape supportive attitudes, insensitivity to women's rejection cues in a simulated rape, and past history of sexual aggression. Multilevel modeling will be used to evaluate the hypothesized links between alcohol condition, visual attention, and men's use of dating-relevant cues. The explicit translational goal of the project is to leverage theories and methods from basic cognitive and vision science to advance understanding of the effect of alcohol consumption on men's perceptions of women. The present project will lay the groundwork for the future development of cognitive-training strategies that target the precise visual-attention patterns generating individul differences in sexual- interest judgments and consumption-related reductions in men's sensitivity.

PROJECT SUMMARY/ABSTRACT Breast cancer has the highest incidence of cancer for women in the U.S. and across the world. Despite advances in technology?from film-screen images to Full Field Digital Mammography (FFDM) and now to Digital Breast Tomosynthesis (DBT)?the yearly miss rate has remained stubbornly stable, ranging between 10-30% at screening. Technology alone is not reducing errors of omission; we need to understand the specific challenges faced by the human readers interpreting the images, and the specific errors that they lead to. Satisfaction of Search (SOS) refers to the fact that, after having detected a first lesion in a case, the miss rate for additional lesions in the same case is substantially elevated. This specific type of error has been shown to account for 30% of misses in the domains of Radiology where it has been studied, including chest radiography and Computed Tomography. And yet, it has never been studied in the domain of breast cancer. Thus, there is a critical need to determine how SOS contributes to errors in breast cancer screening. In the present project we will determine the rates of occurrence and the underlying causes of SOS in FFDM and DBT. We have devised a novel method that overcomes limitations of previous methods and that is optimized for use in FFDM and DBT. Previous approaches to studying SOS involved the photographic addition of artificial lesions to images, which is not feasible for breast imaging. Instead, we will construct a database of naturally occurring cases that is structured for studying SOS. This will involve the collection of multiple-lesion cases and controlled single-lesions cases, where the former are matched with the latter on key diagnostic dimensions, such as lesion type, lesion size, and breast density. In two main experiments (one with FFDM and one with DBT), radiologists will read cases from the experimental set, marking the locations and diagnoses for benign and malignant lesions. Signal-detection analyses over dual- and single-lesion cases will be used to estimate the rate of SOS. Eye position and pupil diameter will be tracked as participants read each case. These data will allow us to assess the prevalence of different known causes of SOS: (a) premature termination, in which search following first lesion detection is less comprehensive compared with single-lesion control cases; (b) perceptual set, in which, after having detected a first lesion, participants are biased to find subsequent lesions with similar perceptual features, leading to reduced sensitivity in the detection of perceptually dissimilar targets; and (c) resource depletion, in which the demands of maintaining information about a first-detected lesion in memory reduce available perceptual/cognitive resources, thereby reducing the efficiency of subsequent search. Understanding the rates and underlying causes of SOS in breast cancer detection will lay the foundation for planned future work to develop training programs and best practices that mitigate the specific causes of SOS errors and thereby reduce miss rates in breast cancer screening.