scholarly journals Coding of spatial attention priorities and object features in the macaque lateral intraparietal cortex

2017 ◽  
Vol 5 (5) ◽  
pp. e13136 ◽  
Author(s):  
Ekaterina Levichkina ◽  
Yuri B. Saalmann ◽  
Trichur R. Vidyasagar
Keyword(s):  
Spatial Attention ◽  
Lateral Intraparietal Cortex ◽  
Object Features

scholarly journals Shape selectivity and remapping in dorsal stream visual area LIP

2014 ◽  
Vol 111 (3) ◽  
pp. 613-627 ◽  
Author(s):  
Janani Subramanian ◽  
Carol L. Colby
Keyword(s):  
Receptive Field ◽  
Information Transfer ◽  
Spatial Information ◽  
Dorsal Stream ◽  
Shape Selectivity ◽  
Visual Stream ◽  
Shape Information ◽  
Lateral Intraparietal Cortex ◽  
Shape Selective ◽  
Object Features

We explore the visual world by making rapid eye movements (saccades) to focus on objects and locations of interest. Despite abrupt retinal image shifts, we see the world as stable. Remapping contributes to visual stability by updating the internal image with every saccade. Neurons in macaque lateral intraparietal cortex (LIP) and other brain areas update information about salient locations around the time of a saccade. The depth of information transfer remains to be thoroughly investigated. Area LIP, as part of the dorsal visual stream, is regarded as a spatially selective area, yet there is evidence that LIP neurons also encode object features. We sought to determine whether LIP remaps shape information. This knowledge is important for understanding what information is retained from each glance. We identified 82 remapping neurons. First, we presented shapes within the receptive field and tested for shape selectivity in a fixation task. Among the remapping neurons, 28 neurons (34%) were selective for shape. Second, we presented the same shapes in the future location of the receptive field around the time of the saccade and tested for shape selectivity during remapping. Thirty-one (38%) neurons were selective for shape. Of 11 neurons that were shape selective in both tasks, 5 showed significant correlation between shape selectivity in the two tasks. Across the population, there was a weak but significant correlation between responses to shape in the two tasks. Our results provide neurophysiological evidence that remapped responses in area LIP can encode shape information as well as spatial information.

scholarly journals Neural Representations of Task-relevant and Task-irrelevant Features of Attended Objects

2021 ◽  
Author(s):  
Jiageng Chen ◽  
Paul S Scotti ◽  
Emma W Dowd ◽  
Julie D Golomb
Keyword(s):  
Spatial Attention ◽  
Relevant Feature ◽  
Multiple Objects ◽  
Multiple Features ◽  
Feature Representations ◽  
Neural Representations ◽  
Task Irrelevant ◽  
Object Features ◽  
The Brain ◽  
And Task

Visual attention plays an essential role in selecting task-relevant and ignoring task-irrelevant information, for both object features and their locations. In the real world, multiple objects with multiple features are often simultaneously present in a scene. When spatial attention selects an object, how are the task-relevant and task-irrelevant features represented in the brain? Previous literature has shown conflicting results on whether and how irrelevant features are represented in visual cortex. In an fMRI task, we used a modified inverted encoding model (IEM, e.g., Sprague & Serences, 2015) to test whether we can reconstruct the task-relevant and task-irrelevant features of spatially attended objects in a multi- feature (color + orientation), multi-item display. Subjects were briefly shown an array of three colored, oriented gratings. Subjects were instructed as to which feature (color or orientation) was relevant before each block, and on each trial were asked to report the task-relevant feature of the object that appeared at a spatially pre-cued location, using a continuous color or orientation wheel. By applying the IEM, we achieved reliable feature reconstructions for the task-relevant features of the attended object from visual ROIs (V1 and V4v) and Intraparietal sulcus. Preliminary searchlight analyses showed that task-irrelevant features of attended objects could be reconstructed from activity in some intraparietal areas, but the reconstructions were much weaker and less reliable compared with task-relevant features. These results suggest that both relevant and irrelevant features may be represented in visual and parietal cortex but in different forms. Our method provides potential tools to noninvasively measure unattended feature representations and probe the extent to which spatial attention acts as a "glue" to bind task-relevant and task-irrelevant features.

Visual Spatial Attention in Migraine Sufferers in Postictal and Interictal Phases: An Event-Related Potential Study

2001 ◽  
Vol 15 (1) ◽  
pp. 22-34 ◽  
Author(s):  
D.H. de Koning ◽  
J.C. Woestenburg ◽  
M. Elton
Keyword(s):  
Cerebral Cortex ◽  
Visual Attention ◽  
Migraine Attack ◽  
Spatial Attention ◽  
Event Related Potential ◽  
Significant Enhancement ◽  
Pathophysiological Mechanism ◽  
Attention Task ◽  
Visual Spatial Attention ◽  
Visual Spatial

Migraineurs with and without aura (MWAs and MWOAs) as well as controls were measured twice with an interval of 7 days. The first session of recordings and tests for migraineurs was held about 7 hours after a migraine attack. We hypothesized that electrophysiological changes in the posterior cerebral cortex related to visual spatial attention are influenced by the level of arousal in migraineurs with aura, and that this varies over the course of time. ERPs related to the active visual attention task manifested significant differences between controls and both types of migraine sufferers for the N200, suggesting a common pathophysiological mechanism for migraineurs. Furthermore, migraineurs without aura (MWOAs) showed a significant enhancement for the N200 at the second session, indicating the relevance of time of measurement within migraine studies. Finally, migraineurs with aura (MWAs) showed significantly enhanced P240 and P300 components at central and parietal cortical sites compared to MWOAs and controls, which seemed to be maintained over both sessions and could be indicative of increased noradrenergic activity in MWAs.

Controlling spatial attention without central attentional resources: Evidence from electrophysiology

2009 ◽  
Author(s):  
Khara Croswaite ◽  
Mei-Ching Lien ◽  
Eric Ruthruff ◽  
Min-Ju Liao
Keyword(s):  
Spatial Attention ◽  
Attentional Resources

Reading Without Spatial Attention: What Is So Special About Stroop?

2011 ◽  
Author(s):  
Matthew Thomas ◽  
Semeon Risom ◽  
Mei-Ching Lien ◽  
Eric Ruthruff ◽  
Joel Lachter
Keyword(s):  
Spatial Attention

Feature Detection Requires Spatial Attention

2007 ◽  
Author(s):  
Jan Theeuwes ◽  
Erik van der Burg ◽  
Artem V. Belopolsky
Keyword(s):  
Spatial Attention ◽  
Feature Detection
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