Visual memory for objects following foveal vision loss.

Abstract

Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual long-term memory for objects in patients suffering from foveal vision loss due to age-related macular degeneration. We measured patients' change detection sensitivity after a period of free scene exploration monocularly with their worse eye when possible, and under binocular vision, comparing sensitivity and eye movements to matched normal-sighted controls. A highly salient cue was used to capture attention to a nontarget location before a target change occurred in half of the trials, ensuring that change detection relied on memory. Patients' monocular and binocular sensitivity to object change was comparable to controls, even after more than 4 intervening fixations, and not significantly correlated with visual impairment. We conclude that extrafoveal vision suffices for efficient encoding into visual long-term memory.

Impairment of visual memory for objects in natural scenes by simulated central scotomata

“…This research question was inspired by previous studies demonstrating that visual long-term memory for an object depends on previous fixation (Hollingworth, 2006)-and concurrent attending (Deubel & Schneider, 1996;Hoffman & Subramaniam, 1995)-of the object. Therefore, it was surprising that in a recent study on patients suffering from natural central vision loss, their explicit visual long-term memory was as accurate as for healthy, age-matched controls (Geringswald et al, 2015). We had reasoned that intact attentive object encoding was due to the successful development of saccadic rereferencing to an extrafoveal retinal location (von Noorden & Mackensensen, 1962;White & Bedell, 1990;Whittaker et al, 1991).…”

“…The stimuli used in the experiment were the same as in our previous study (Geringswald et al, 2015). Fortyeight experimental scenes and four additional practice scenes, created with the 3D Traumhaus Designer 9 Premium software (2009), depicted typical indoor environments, such as kitchens or living rooms, and contained 10 to 21 semantically consistent, everyday objects.…”

“…In a similar fashion, attentive encoding into visual long-term memory may be impaired when attention needs to be decoupled from the fovea during scene exploration. We recently investigated this question in a sample of patients with age-related macular degeneration (AMD), in whom central vision was degraded (Geringswald, Herbik, Hofmüller, Hoffmann, & Pollmann, 2015). Patients were asked to freely explore and memorize everyday objects in natural, computer-generated real-world scenes and were then probed for one specific target object that could either remain the same or be replaced by an object from the same semantic category (token change) in an otherwise identical test scene.…”

Predictive visual search: Role of environmental regularities in the learning of context cues

“…Sample size was determined on the basis of previous studies that investigated perceptual learning of the target in relation to an invariant context of distractor elements, importantly also including Chun's pioneering work (e.g., Chun & Jiang, 1998Chun & Phelps, 1999). These studies (see also Assumpção, Shi, Zang, Müller, & Geyer, 2015;Geringswald, Herbik, Hofmüller, Hoffmann, & Pollmann, 2015;Geyer, Zehetleitner, & Müller, 2010; typically tested between five and 14 participants on the visual search/contextual-cueing task. On the basis of effect size measures provided in these studies (Assumpção et al, 2015;Geringswald et al, 2015;Zellin et al, 2014), we determined that our sample size would be appropriate to detect an f(U) effect size of 1.0 with 85% power (partial eta 2 = 0.4, groups = 2, number of measurements = 4), given an alpha level of .05 and a nonsphericity correction of 1.…”

“…These studies (see also Assumpção, Shi, Zang, Müller, & Geyer, 2015;Geringswald, Herbik, Hofmüller, Hoffmann, & Pollmann, 2015;Geyer, Zehetleitner, & Müller, 2010; typically tested between five and 14 participants on the visual search/contextual-cueing task. On the basis of effect size measures provided in these studies (Assumpção et al, 2015;Geringswald et al, 2015;Zellin et al, 2014), we determined that our sample size would be appropriate to detect an f(U) effect size of 1.0 with 85% power (partial eta 2 = 0.4, groups = 2, number of measurements = 4), given an alpha level of .05 and a nonsphericity correction of 1. To minimize transfer effects, the experiments were performed in individual sessions, which were separated by at least 10 days.…”