Computational visual attention systems and their cognitive foundation: A survey

Permission to make digital/hard copy of all or part of this material without fee for personal or classroom use provided that the copies are not made or distributed for profit or commercial advantage, the ACM copyright/server notice, the title of the publication, and its date appear, and notice is given that copying is by permission of the ACM, Inc. To copy otherwise, to republish, to post on servers, or to redistribute to lists requires prior specific permission and/or a fee. (c) 2010 ACMBased on concepts of the human visual system, computational visual attention systems aim to detect regions of interest in images. Psychologists, neurobiologists, and computer scientists have investigated visual attention thoroughly during the last decades and profited considerably from each other. However, the interdisciplinarity of the topic holds not only benefits but also difficulties: concepts of other fields are usually hard to access due to differences in vocabulary and lack of knowledge of the relevant literature. This paper aims to bridge this gap and bring together concepts and ideas from the different research areas. It provides an extensive survey of the grounding psychological and biological research on visual attention as well as the current state of the art of computational systems. Furthermore, it presents a broad range of applications of computational attention systems in fields like computer vision, cognitive systems and mobile robotics. We conclude with a discussion on the limitations and open questions in the field

Computational visual attention systems and their cognitive foundation: A survey

Permission to make digital/hard copy of all or part of this material without fee for personal or classroom use provided that the copies are not made or distributed for profit or commercial advantage, the ACM copyright/server notice, the title of the publication, and its date appear, and notice is given that copying is by permission of the ACM, Inc. To copy otherwise, to republish, to post on servers, or to redistribute to lists requires prior specific permission and/or a fee. (c) 2010 ACMBased on concepts of the human visual system, computational visual attention systems aim to detect regions of interest in images. Psychologists, neurobiologists, and computer scientists have investigated visual attention thoroughly during the last decades and profited considerably from each other. However, the interdisciplinarity of the topic holds not only benefits but also difficulties: concepts of other fields are usually hard to access due to differences in vocabulary and lack of knowledge of the relevant literature. This paper aims to bridge this gap and bring together concepts and ideas from the different research areas. It provides an extensive survey of the grounding psychological and biological research on visual attention as well as the current state of the art of computational systems. Furthermore, it presents a broad range of applications of computational attention systems in fields like computer vision, cognitive systems and mobile robotics. We conclude with a discussion on the limitations and open questions in the field

An Information Theoretic Approach to Characterizing the Attention Shifts in the Fruit Fly During Flight

To successfully navigate the complex visual world, animals must extract relevant information from the deluge of light-carried signals that arrive at their eyes. Early vision filters are passive, energy-saving gates that block out irrelevant signals. The remaining incoming signals are then subject to active filtering by visual attention systems which are energetically expensive, especially for smaller animals, which are subject to similar survival challenges as larger animals. Among visual behaviors performed by insects, flight stabilization demands one of the highest rates of information uptake. Flying insects must quickly respond to flight disturbances to avoid navigation errors and collisions. Active flight is energy-intensive, but the variable environmental and flight conditions make passive filtering unreliable to infer self-motion. Dipterans (flies and mosquitoes) are a prosperous order of insects that owe their success to impressive flying skills. Though many visual adaptations for flight have been well characterized, little research has been dedicated to the active attention processes required for flight stabilization. In this dissertation, I investigated how the visual attention systems of fruit flies work to maximize relevant information uptake during flight. I have focused on three main questions: (1) Do flies shift attention away from regions impacted heavily by motion-blur? (2) Do flies’ attention systems prioritize regions with higher quality images? (3) Does the attention system only filter noisy regions, or does it weigh the regional image quality against other sources of information present? I used a virtual reality flight arena to convince stationary, tethered fruit flies that they were actually flying. I tested whether flies were attentive to visual regions by showing local perturbations and measuring corrective steering responses. I found that fast-flying flies (1) shift their attention to the slower frontal parts of their visual field; (2) shift their attention forward when flying in dim and low contrast environments; (3) weigh other relevant information with image clarity. My findings provide a better understanding of how the energy-limited visual systems of fruit flies can process all the information required to stabilize flight

A BIASED COMPETITION COMPUTATIONAL MODEL OF SPATIAL AND OBJECT-BASED ATTENTION MEDIATING ACTIVE VISUAL SEARCH

A computational cognitive neuroscience approach was used to examine processes of visual attention in the human and monkey brain. The aim of the work was to produce a biologically plausible neurodynamical model of both spatial and object-based attention that accounted for observations in monkey visual areas V4, inferior temporal cortex (IT) and the lateral intraparietal area (LIP), and was able to produce search scan path behaviour similar to that observed in humans and monkeys. Of particular interest currently in the visual attention literature is the biased competition hypothesis (Desimone & Duncan. 1995). The model presented here is the first active vision implementation of biased competition, where attcntional shifts are overt. Therefore, retinal inputs change during the scan path and this approach raised issues, such as memory for searched locations across saccades, not addressed bv previous models with static retinas. This is the first model to examine the different time courses associated with spatial and object-based effects at the cellular level. Single cell recordings in areas V4 (Luck et al., 1997; Chelazzi et al., 2001) and IT (Chelazzi ct al., 1993, 1998) were replicated such that attentional effects occurred at the appropriate time after onset of the stimulus. Object-based effects at the cellular level of the model led to systems level behaviour that replicated that observed during active visual search for orientation and colour feature conjunction targets in psychophysical investigations. This provides a valuable insight into the link between cellular and system level behaviour in natural systems. At the systems level, the simulated search process showed selectivity in its scan path that was similar to that observed in humans (Scialfa & Joffe, 1998; Williams & Reingold, 2001) and monkeys (Motter & Belky. 1998b), being guided to target coloured locations in preference to locations containing the target orientation or blank areas. A connection between the ventral and dorsal visual processing streams (Ungerleider & Mishkin. 1982) is suggested to contribute to this selectivity and priority in the featural guidance of search. Such selectivity and avoidance of blank areas has potential application in computer vision applications. Simulation of lesions within the model and comparison with patient data provided further verification of the model. Simulation of visual neglect due to parietal cortical lesion suggests that the model has the capability to provide insights into the neural correlates of the conscious perception of stimuli The biased competition approach described here provides an extendable framework within which further "bottom-up" stimulus and "top-down" mnemonic and cognitive biases can be added, in order to further examine exogenous versus endogenous factors in the capture of attention