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Reward saccade

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
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
Brónagh McCoy, Jan Theeuwes
The present study examines the extent to which distractors that signal the availability of monetary reward on a given trial affect eye movements. We used a novel eye movement task in which observers had to follow a target around the screen while ignoring distractors presented at varying locations. We examined the effects of reward magnitude and distractor location on a host of oculomotor properties, including saccade latency, amplitude, landing position, curvature, and erroneous saccades towards the distractor...
August 31, 2016: Journal of Neurophysiology
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
Céline Paeye, Alexander C Schütz, Karl R Gegenfurtner
We use eye movements to gain information about our visual environment; this information can indirectly be used to affect the environment. Whereas eye movements are affected by explicit rewards such as points or money, it is not clear whether the information gained by finding a hidden target has a similar reward value. Here we tested whether finding a visual target can reinforce eye movements in visual search performed in a noise background, which conforms to natural scene statistics and contains a large number of possible target locations...
August 1, 2016: Journal of Vision
Kinan Muhammed, Sanjay Manohar, Michael Ben Yehuda, Trevor T-J Chong, George Tofaris, Graham Lennox, Marko Bogdanovic, Michele Hu, Masud Husain
Apathy is a debilitating and under-recognized condition that has a significant impact in many neurodegenerative disorders. In Parkinson's disease, it is now known to contribute to worse outcomes and a reduced quality of life for patients and carers, adding to health costs and extending disease burden. However, despite its clinical importance, there remains limited understanding of mechanisms underlying apathy. Here we investigated if insensitivity to reward might be a contributory factor and examined how this relates to severity of clinical symptoms...
October 2016: Brain: a Journal of Neurology
Annegret Meermeier, Svenja Gremmler, Markus Lappe
When we observe a scene, we shift our gaze to different points of interest via saccadic eye movements. Saccades provide high resolution views of objects and are essential for vision. The successful view of an interesting target might constitute a rewarding experience to the oculomotor system. We measured the influence of image content on learning efficiency in saccade control. We compared meaningful pictures to luminance and spatial frequency-matched random noise images in a saccadic adaptation paradigm. In this paradigm a shift of the target during the saccades results in a gradual increase of saccade amplitude...
June 1, 2016: Journal of Vision
Weijie Ye, Shenquan Liu, Xuanliang Liu, Yuguo Yu
Decision-making is a flexible process dependent on the accumulation of various kinds of information; however, the corresponding neural mechanisms are far from clear. We extended a layered model of the frontal eye field to a learning-based model, using computational simulations to explain the cognitive process of choice tasks. The core of this extended model has three aspects: direction-preferred populations that cluster together the neurons with the same orientation preference, rule modules that control different rule-dependent activities, and reward-based synaptic plasticity that modulates connections to flexibly change the decision according to task demands...
September 2016: Neural Networks: the Official Journal of the International Neural Network Society
Chris van der Togt, Liviu Stănişor, Arezoo Pooresmaeili, Larissa Albantakis, Gustavo Deco, Pieter R Roelfsema
How do you make a decision if you do not know the rules of the game? Models of sensory decision-making suggest that choices are slow if evidence is weak, but they may only apply if the subject knows the task rules. Here, we asked how the learning of a new rule influences neuronal activity in the visual (area V1) and frontal cortex (area FEF) of monkeys. We devised a new icon-selection task. On each day, the monkeys saw 2 new icons (small pictures) and learned which one was relevant. We rewarded eye movements to a saccade target connected to the relevant icon with a curve...
August 2016: Cerebral Cortex
Daniel Pearson, Raphaella Osborn, Thomas J Whitford, Michel Failing, Jan Theeuwes, Mike E Le Pelley
Recent research has shown that reward learning can modulate oculomotor and attentional capture by physically salient and task-irrelevant distractor stimuli, even when directing gaze to those stimuli is directly counterproductive to receiving reward. This value-modulated oculomotor capture effect may reflect biased competition in the oculomotor system, such that the relationship between a stimulus feature and reward enhances that feature's representation on an internal priority map. However, it is also possible that this effect is a result of reward reducing the threshold for a saccade to be made to salient items...
October 2016: Attention, Perception & Psychophysics
Joshua I Glaser, Daniel K Wood, Patrick N Lawlor, Pavan Ramkumar, Konrad P Kording, Mark A Segraves
When a saccade is expected to result in a reward, both neural activity in oculomotor areas and the saccade itself (e.g., its vigor and latency) are altered (compared with when no reward is expected). As such, it is unclear whether the correlations of neural activity with reward indicate a representation of reward beyond a movement representation; the modulated neural activity may simply represent the differences in motor output due to expected reward. Here, to distinguish between these possibilities, we trained monkeys to perform a natural scene search task while we recorded from the frontal eye field (FEF)...
August 1, 2016: Journal of Neurophysiology
Nicolas Wattiez, Tymothée Poitou, Sophie Rivaud-Péchoux, Pierre Pouget
The time to initiate a movement can, even implicitly, be influenced by the environment. All primates, including humans, respond faster and with greater accuracy to stimuli that are brighter, louder or associated with larger reward, than to neutral stimuli. Whether this environment also modulates the executive functions which allow ongoing actions to be suppressed remains an issue of debate. In this study, we investigated the implicit learning of spatial selectivity of movement inhibition in humans and macaque monkeys performing a saccade-countermanding task...
July 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Sanjay G Manohar, Masud Husain
Although medial frontal brain regions are implicated in valuation of rewards, evidence from focal lesions to these areas is scant, with many conflicting results regarding motivation and affect, and no human studies specifically examining incentivisation by reward. Here, 19 patients with isolated, focal damage in ventral and medial prefrontal cortex were selected from a database of 453 individuals with subarachnoid haemorrhage. Using a speeded saccadic task based on the oculomotor capture paradigm, we manipulated the maximum reward available on each trial using an auditory incentive cue...
March 2016: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Bastien Berret, Frédéric Jean
UNLABELLED: To want something now rather than later is a common attitude that reflects the brain's tendency to value the passage of time. Because the time taken to accomplish an action inevitably delays task achievement and reward acquisition, this idea was ported to neural movement control within the "cost of time" theory. This theory provides a normative framework to account for the underpinnings of movement time formation within the brain and the origin of a self-selected pace in human and animal motion...
January 27, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Thomas R Reppert, Karolina M Lempert, Paul W Glimcher, Reza Shadmehr
UNLABELLED: During value-based decision-making, individuals consider the various options and select the one that provides the maximum subjective value. Although the brain integrates abstract information to compute and compare these values, the only behavioral outcome is often the decision itself. However, if the options are visual stimuli, during deliberation the brain moves the eyes from one stimulus to the other. Previous work suggests that saccade vigor, i.e., peak velocity as a function of amplitude, is greater if reward is associated with the visual stimulus...
November 18, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Zeinab Bolandnazar, Bianca Lennarz, Koorosh Mirpour, James Bisley
Finding objects among distractors is an essential everyday skill, which is often tested with visual search tasks using static items in the display. Although these kinds of displays are ideal for studying search behavior, the neural encoding of the visual stimuli can occur rapidly, which limits the analysis that can be done on the accumulation of evidence. Searching for a target among multiple random dot motion (RDM) stimuli should allow us to study the effect of attention on the accumulation of information during visual search...
2015: Journal of Vision
Samy Rima, Benoit Cottereau, Jean-Baptiste Durand
Reward seeking shapes our interactions with the environment, but whether it also influences how we perceive it remains controversial. Notably, there is currently a debate on whether objects that are more likely to provide high reward might be perceived bigger than those associated with low reward. The aim of this study is to test this « wishful seeing » hypothesis in non-human primates. Two macaque monkeys performed a two-alternative forced choice (2 AFC) size discrimination task during several weeks. Following an initial fixation period, the animals were required to make a saccade towards the biggest of two simultaneously displayed discs, located in diametrically opposite positions relatively to the fixation point (7° eccentricity)...
2015: Journal of Vision
Koorosh Mirpour, James Bisley
We are able to find objects in a cluttered scene quickly and effortlessly. To achieve this, the brain creates a priority map of the visual world, which incorporates both pre-attentive and cognitive inputs to represent the importance of stimuli in the scene, and which uses inhibitory tagging to track items that have been viewed. Eye movements are then guided by this map. We have previously shown that activity in the lateral intraparietal area (LIP) acts like a priority map, but the absolute responses do not correlate directly with behavior: they have to be normalized first...
2015: Journal of Vision
Li Zhang, Rudiger von der Heydt
Neurons in early visual cortex are selective for local visual features but their responses can also be influenced by factors like border ownership and selective attention. Most of what we know about the function of these neurons is based on neurophysiological studies in monkeys that hold their direction of gaze fixed while isolated visual stimuli are presented (controlled viewing). However, during natural behavior, primates visually explore cluttered environments by changing gaze direction several times each second (free viewing)...
2015: Journal of Vision
Jean-Bernard Damasse, Laurent Madelain, Laurent Perrinet, Anna Montagnini
When an object is moving in the visual field, we are able to accurately track it with a combination of saccades and smooth eye movements. These movements allow us to align and stabilize the object on the fovea, thus enabling visual analysis with high acuity. Importantly, when predictive information is available about the target motion, anticipatory smooth pursuit eye movements (aSPEM) are efficiently generated before target appearance, which reduces the typical sensorimotor delay between target motion onset and foveation...
2015: Journal of Vision
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