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Saccade and memory

Sven Ohl, Martin Rolfs
Visual short-term memory (VSTM) is a crucial repository of information when events unfold rapidly before our eyes, yet it maintains only a fraction of the sensory information encoded by the visual system. Here, we tested the hypothesis that saccadic eye movements provide a natural bottleneck for the transition of fragile content in sensory memory to VSTM. In 4 experiments, we show that saccades, planned and executed after the disappearance of a memory array, markedly bias visual memory performance. First, items that had appeared at the saccade target were more readily remembered than items that had appeared elsewhere, even though the saccade was irrelevant to the memory task (Experiment 1)...
October 20, 2016: Journal of Experimental Psychology. Learning, Memory, and Cognition
Martijn J Schut, Jasper H Fabius, Nathan Van der Stoep, Stefan Van der Stigchel
One of the factors contributing to a seamless visual experience is object correspondence-that is, the integration of pre- and postsaccadic visual object information into one representation. Previous research had suggested that before the execution of a saccade, a target object is loaded into visual working memory and subsequently is used to locate the target object after the saccade. Until now, studies on object correspondence have not taken previous fixations into account. In the present study, we investigated the influence of previously fixated information on object correspondence...
October 14, 2016: Attention, Perception & Psychophysics
Yixiu Wang, Bin Wang, Xiaofeng Wu, Liming Zhang
The estimation of gaze shift has been an important research area in saliency modeling. Gaze movement is a dynamic progress, yet existing estimation methods are limited to estimating scanpaths within only one saliency map, providing results with unsatisfactory accuracy. A bio-inspired method for gaze shift prediction is thus proposed. We take the effect of foveation into account in the proposed model, which plays an important role in the search for dynamic salient regions. The saccadic bias of gaze shifts and the mechanism of inhibition of return in short-term memory are also considered...
October 14, 2016: Cognitive Processing
Annie L Shelton, Kim Cornish, Meaghan Clough, Sanuji Gajamange, Scott Kolbe, Joanne Fielding
Executive dysfunction has been demonstrated among premutation (PM) carriers (55-199 CGG repeats) of the Fragile X mental retardation 1 (FMR1) gene. Further, alterations to neural activation patterns have been reported during memory and comparison based functional magnetic resonance imaging (fMRI) tasks in these carriers. For the first time, the relationships between fMRI neural activation during an interleaved ocular motor prosaccade/antisaccade paradigm, and concurrent task performance (saccade measures of latency, accuracy and error rate) in PM females were examined...
October 14, 2016: Human Brain Mapping
Marco Bertamini, Michael H Herzog, Nicola Bruno
We present a series of patterns, in which texture is perceived differently at fixation in comparison to the periphery, such that a physically uniform stimulus yields a nonuniform percept. We call this the Honeycomb illusion, and we discuss it in relation to the similar Extinction illusion (Ninio & Stevens, 2000). The effect remains strong despite multiple fixations, dynamic changes, and manipulations of the size of texture elements. We discuss the phenomenon in relation to how vision achieves a detailed and stable representation of the environment despite changes in retinal spatial resolution and dramatic changes across saccades...
July 2016: I-Perception
Mo Chen, Bing Li, Jing Guang, Linyu Wei, Si Wu, Yu Liu, Mingsha Zhang
Although the cerebral cortex is thought to be composed of functionally distinct areas, the actual parcellation of area and assignment of function are still highly controversial. An example is the much-studied lateral intraparietal cortex (LIP). Despite the general agreement that LIP plays an important role in visual-oculomotor transformation, it remains unclear whether the area is primary sensory- or motor-related (the attention-intention debate). Although LIP has been considered as a functionally unitary area, its dorsal (LIPd) and ventral (LIPv) parts differ in local morphology and long-distance connectivity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jun Kunimatsu, Masaki Tanaka
The ability to adjust movement timing is essential in daily life. Explorations of the underlying neural mechanisms have reported a gradual increase or decrease in neuronal activity prior to self-timed movements within the cortico-basal ganglia loop. Previous studies in both humans and animals have shown that endogenous dopamine (DA) plays a modulatory role in self-timing. However, the specific site of dopaminergic regulation remains elusive because the systemic application of DA-related substances can directly alter both cortical and subcortical neuronal activities...
September 17, 2016: Neuroscience
Annelieke C Kruithof, Shikiko Watanabe, Pierre Am Peeters, Marieke L de Kam, Rob Gja Zuiker, Jasper Stevens, Joop Ma van Gerven, Armel Stockis
This double-blind, randomized, three-way crossover study explored the potential pharmacokinetic and pharmacodynamic interactions between ethanol and brivaracetam in 18 healthy males, as required for the development of CNS-active drugs. Subjects received (A) ethanol+brivaracetam, (B) ethanol placebo+brivaracetam and (C) ethanol+brivaracetam placebo. Ethanol was infused as a 5.5-hour intravenous clamp with the first 0.5-hour as loading phase to a target level of 0.6 g/L, and brivaracetam was orally administered as a single 200 mg dose...
September 20, 2016: Journal of Psychopharmacology
Simona Caldani, Maria Pia Bucci, Jean-Charles Lamy, Magali Seassau, Narjes Bendjemaa, Rémi Gadel, Raphael Gaillard, Marie-Odile Krebs, Isabelle Amado
Schizophrenia is a neurodevelopmental disease with cognitive and motor impairments. Motor dysfunctions, such as eye movements or Neurological Soft Signs (NSS), are proposed as endophenotypic markers. Antisaccade (AS) and memory-guided saccades (MGS), two markers of inhibitory control mechanism, are altered in both patients with schizophrenia and their relatives, although these tools may have different sensitivities. Recently, emphasis has been put on identifying markers predictive of psychosis transition in subjects with ultra-high-risk psychosis in order to develop targeted prevention...
September 14, 2016: Schizophrenia Research
Paul J Boon, Artem V Belopolsky, Jan Theeuwes
Visual-spatial working memory (VSWM) helps us to maintain and manipulate visual information in the absence of sensory input. It has been proposed that VSWM is an emergent property of the oculomotor system. In the present study we investigated the role of the oculomotor system in updating of spatial working memory representations across saccades. Participants had to maintain a location in memory while making a saccade to a different location. During the saccade the target was displaced, which went unnoticed by the participants...
2016: PloS One
Ali Ghazizadeh, Whitney Griggs, Okihide Hikosaka
Among many objects around us, some are more salient than others (i.e., attract our attention automatically). Some objects may be inherently salient (e.g., brighter), while others may become salient by virtue of their ecological relevance through experience. However, the role of ecological experience in automatic attention has not been studied systematically. To address this question, we let subjects (macaque monkeys) view a large number of complex objects (>300), each experienced repeatedly (>5 days) with rewarding, aversive or no outcome association (mere-perceptual exposure)...
2016: Frontiers in Neuroscience
Ali Ghazizadeh, Whitney Griggs, Okihide Hikosaka
For most animals, survival depends on rapid detection of rewarding objects, but search for an object surrounded by many others is known to be difficult and time consuming. However, there is neuronal evidence for robust and rapid differentiation of objects based on their reward history in primates (Hikosaka, Kim, Yasuda, & Yamamoto, 2014). We hypothesized that such robust coding should support efficient search for high-value objects, similar to a pop-out mechanism. To test this hypothesis, we let subjects (n = 4, macaque monkeys) view a large number of complex objects with consistently biased rewards with variable training durations (1, 5, or 30 + days)...
August 1, 2016: Journal of Vision
Paul Zerr, Katharine N Thakkar, Siarhei Uzunbajakau, Stefan Van der Stigchel
In saccade sequences without visual feedback endpoint errors pose a problem for subsequent saccades. Accurate error compensation has previously been demonstrated in double step saccades (DSS) and is thought to rely on a copy of the saccade motor vector. However, these studies typically use fixed target vectors on each trial, calling into question the generalizability of the findings due to the high stimulus predictability. We present a random walk DSS paradigm (random target vector amplitudes and directions) to provide a more complete, realistic and generalizable description of error compensation in saccade sequences...
October 2016: Vision Research
Hans Strenge
EMDR is an effective treatment for people diagnosed with posttraumatic stress disorder. The traditional technique of EMDR combines the activation of distressing reminders with guided rhythmic eye movements. The present article reviews the current state of research on the neurobiological correlates of the eye movements occurring during EMDR. The distinction between saccades and smooth pursuit eye movements allows for detailed analyses of ocular motor connections with cerebral networks of attention, memory and emotion...
August 2016: Psychotherapie, Psychosomatik, Medizinische Psychologie
Glenn Gunzelmann, Don R Lyon
Spatial memory and reasoning rely heavily on allocentric (often map-like) representations of spatial knowledge. While research has documented many ways in which spatial information can be represented in allocentric form, less is known about how such representations are constructed. For example: Are the very early, pre-attentive parts of the process hard-wired, or can they be altered by experience? We addressed this issue by presenting sub-saccadic (53 ms) masked stimuli consisting of a target among one to three reference features...
July 27, 2016: Cognitive Processing
M Berk Mirza, Rick A Adams, Christoph D Mathys, Karl J Friston
This paper describes an active inference scheme for visual searches and the perceptual synthesis entailed by scene construction. Active inference assumes that perception and action minimize variational free energy, where actions are selected to minimize the free energy expected in the future. This assumption generalizes risk-sensitive control and expected utility theory to include epistemic value; namely, the value (or salience) of information inherent in resolving uncertainty about the causes of ambiguous cues or outcomes...
2016: Frontiers in Computational Neuroscience
Kelly Shen, Gleb Bezgin, Rajajee Selvam, Anthony R McIntosh, Jennifer D Ryan
Visual behavior is guided by memories from prior experience and knowledge of the visual scene. The hippocampal system (HC), in particular, has been implicated in the guidance of saccades: Amnesic patients, following damage to the HC, exhibit selective deficits in their gaze patterns. However, the neural circuitry by which mnemonic representations influence the oculomotor system remains unknown. We used a data-driven, network-based approach on directed anatomical connectivity from the macaque brain to reveal an extensive set of polysnaptic pathways spanning the extrastriate, posterior parietal and prefrontal cortices that potentially mediate the exchange of information between the memory and visuo-oculomotor systems...
July 5, 2016: Journal of Cognitive Neuroscience
Wayne E Mackey, Orrin Devinsky, Werner K Doyle, John G Golfinos, Clayton E Curtis
The neural mechanisms that support working memory (WM) depend on persistent neural activity. Within topographically organized maps of space in dorsal parietal cortex, spatially selective neural activity persists during WM for location. However, to date, the necessity of these topographic subregions of human parietal cortex for WM remains unknown. To test the causal relationship of these areas to WM, we compared the performance of patients with lesions to topographically organized parietal cortex with those of controls on a memory-guided saccade (MGS) task as well as a visually guided saccade (VGS) task...
September 1, 2016: Journal of Neurophysiology
Yalda Mohsenzadeh, Suryadeep Dash, J Douglas Crawford
In the oculomotor system, spatial updating is the ability to aim a saccade toward a remembered visual target position despite intervening eye movements. Although this has been the subject of extensive experimental investigation, there is still no unifying theoretical framework to explain the neural mechanism for this phenomenon, and how it influences visual signals in the brain. Here, we propose a unified state-space model (SSM) to account for the dynamics of spatial updating during two types of eye movement; saccades and smooth pursuit...
2016: Frontiers in Systems Neuroscience
I Koychev, D Joyce, E Barkus, U Ettinger, A Schmechtig, C T Dourish, G R Dawson, K J Craig, J F W Deakin
The development of drugs to improve cognition in patients with schizophrenia is a major unmet clinical need. A number of promising compounds failed in recent clinical trials, a pattern linked to poor translation between preclinical and clinical stages of drug development. Seeking proof of efficacy in early Phase 1 studies in surrogate patient populations (for example, high schizotypy individuals where subtle cognitive impairment is present) has been suggested as a strategy to reduce attrition in the later stages of drug development...
2016: Translational Psychiatry
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