Voluntary attention improves performance similarly around the visual field

2020 ◽  
Author(s):  
Simran Purokayastha ◽  
Mariel Roberts ◽  
Marisa Carrasco
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Target Location ◽  
Polar Angle ◽  
Exogenous Attention ◽  
Orientation Discrimination ◽  
Endogenous Attention ◽  
Voluntary Attention ◽  
Perceptual Asymmetries ◽  
Improved Performance

Performance as a function of polar angle at isoeccentric locations across the visual field is known as a performance field (PF) and is characterized by two asymmetries: the HVA (Horizontal-Vertical Anisotropy) and VMA (Vertical Meridian Asymmetry). Exogenous (involuntary) spatial attention does not affect the shape of the PF, improving performance similarly across polar angle. Here we investigated whether endogenous (voluntary) spatial attention, a flexible mechanism, can attenuate these perceptual asymmetries. Twenty participants performed an orientation discrimination task while their endogenous attention was either directed to the target location or distributed across all possible locations. The effects of attention were assessed either using the same stimulus contrast across locations, or equating difficulty across locations using individually-titrated contrast thresholds. In both experiments, endogenous attention similarly improved performance at all locations, maintaining the canonical PF shape. Thus, despite its voluntary nature, like exogenous attention, endogenous attention cannot alleviate perceptual asymmetries at isoeccentric locations.

scholarly journals Differential effects of endogenous and exogenous attention on sensory tuning

2021 ◽  
Author(s):  
Antonio Fernandez ◽  
Sara Okun ◽  
Marisa Carrasco
Keyword(s):  
Spatial Frequency ◽  
Exogenous Attention ◽  
Orientation Discrimination ◽  
Endogenous Attention ◽  
Differential Effects ◽  
Spatial Frequencies ◽  
Tuning Width ◽  
Visual Tasks ◽  
Within Subjects ◽  
Improved Performance

Covert spatial attention benefits performance in many visual tasks (e.g. orientation discrimination, visual search). However, in texture segmentation tasks in which increasing spatial resolution can be detrimental, endogenous and exogenous attention have differential effects on performance. Here we tested whether these differences manifest in sensory representations. We used reverse correlation to assess, in a within-subjects design, whether and how endogenous and exogenous attention differentially alter the representation of orientations and spatial frequencies. The same observers detected a vertical grating embedded in noise following central (endogenous attention; Experiment 1) or peripheral (exogenous attention; Experiment 2) pre-cues. We found that both endogenous and exogenous attention similarly improved performance at the attended location by enhancing the gain of all orientations without changing tuning width. Additionally, endogenous attention enhanced the gain of spatial frequencies above and below the target spatial frequency, whereas exogenous attention preferentially enhanced the gain of spatial frequencies higher than the target spatial frequency. We conclude that these changes in sensory tuning may underlie differential effects of endogenous and exogenous attention on performance.

scholarly journals Differential impact of endogenous and exogenous attention on activity in human visual cortex

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Dugué ◽  
Elisha P. Merriam ◽  
David J. Heeger ◽  
Marisa Carrasco
Keyword(s):  
Visual Cortex ◽  
Visual Information ◽  
Exogenous Attention ◽  
Orientation Discrimination ◽  
Endogenous Attention ◽  
Involuntary Attention ◽  
Differential Impact ◽  
Visual Hierarchy ◽  
Evoked Activity ◽  
Fmri Analysis

AbstractHow do endogenous (voluntary) and exogenous (involuntary) attention modulate activity in visual cortex? Using ROI-based fMRI analysis, we measured fMRI activity for valid and invalid trials (target at cued/un-cued location, respectively), pre- or post-cueing endogenous or exogenous attention, while participants performed the same orientation discrimination task. We found stronger modulation in contralateral than ipsilateral visual regions, and higher activity in valid- than invalid-trials. For endogenous attention, modulation of stimulus-evoked activity due to a pre-cue increased along the visual hierarchy, but was constant due to a post-cue. For exogenous attention, modulation of stimulus-evoked activity due to a pre-cue was constant along the visual hierarchy, but was not modulated due to a post-cue. These findings reveal that endogenous and exogenous attention distinctly modulate activity in visuo-occipital areas during orienting and reorienting; endogenous attention facilitates both the encoding and the readout of visual information whereas exogenous attention only facilitates the encoding of information.

scholarly journals Asymmetries around the visual field: From retina to cortex to behavior

2022 ◽  
Vol 18 (1) ◽  
pp. e1009771
Author(s):  
Eline R. Kupers ◽  
Noah C. Benson ◽  
Marisa Carrasco ◽  
Jonathan Winawer
Keyword(s):  
Visual Field ◽  
Visual Processing ◽  
Polar Angle ◽  
Spatial Filtering ◽  
Orientation Discrimination ◽  
Support Vector ◽  
Additional Contribution ◽  
Full Account ◽  
Observer Model ◽  
Cone Density

Visual performance varies around the visual field. It is best near the fovea compared to the periphery, and at iso-eccentric locations it is best on the horizontal, intermediate on the lower, and poorest on the upper meridian. The fovea-to-periphery performance decline is linked to the decreases in cone density, retinal ganglion cell (RGC) density, and V1 cortical magnification factor (CMF) as eccentricity increases. The origins of polar angle asymmetries are not well understood. Optical quality and cone density vary across the retina, but recent computational modeling has shown that these factors can only account for a small percentage of behavior. Here, we investigate how visual processing beyond the cone photon absorptions contributes to polar angle asymmetries in performance. First, we quantify the extent of asymmetries in cone density, midget RGC density, and V1 CMF. We find that both polar angle asymmetries and eccentricity gradients increase from cones to mRGCs, and from mRGCs to cortex. Second, we extend our previously published computational observer model to quantify the contribution of phototransduction by the cones and spatial filtering by mRGCs to behavioral asymmetries. Starting with photons emitted by a visual display, the model simulates the effect of human optics, cone isomerizations, phototransduction, and mRGC spatial filtering. The model performs a forced choice orientation discrimination task on mRGC responses using a linear support vector machine classifier. The model shows that asymmetries in a decision maker’s performance across polar angle are greater when assessing the photocurrents than when assessing isomerizations and are greater still when assessing mRGC signals. Nonetheless, the polar angle asymmetries of the mRGC outputs are still considerably smaller than those observed from human performance. We conclude that cone isomerizations, phototransduction, and the spatial filtering properties of mRGCs contribute to polar angle performance differences, but that a full account of these differences will entail additional contribution from cortical representations.

scholarly journals Differential impact of endogenous and exogenous attention on activity in human visual cortex

2018 ◽  
Author(s):  
Laura Dugué ◽  
Elisha P. Merriam ◽  
David J. Heeger ◽  
Marisa Carrasco
Keyword(s):  
Visual Cortex ◽  
Visual Information ◽  
Exogenous Attention ◽  
Orientation Discrimination ◽  
Endogenous Attention ◽  
Involuntary Attention ◽  
Differential Impact ◽  
Visual Hierarchy ◽  
Evoked Activity ◽  
Fmri Analysis

ABSTRACTHow do endogenous (voluntary) and exogenous (involuntary) attention modulate activity in visual cortex? Using ROI-based fMRI analysis, we measured fMRI activity for valid and invalid trials (target at cued/un-cued location, respectively), pre- or post-cueing endogenous or exogenous attention, while participants performed the same orientation discrimination task. We found stronger modulation in contralateral than ipsilateral visual regions, and higher activity in valid-than invalid-trials. For endogenous attention, modulation of stimulus-evoked activity due to a pre-cue increased along the visual hierarchy, but was constant due to a post-cue. For exogenous attention, modulation of stimulus-evoked activity due to a pre-cue was constant along the visual hierarchy, but was not modulated due to a post-cue. These findings reveal that endogenous and exogenous attention distinctly modulate activity in visuo-occipital areas during orienting and reorienting; endogenous attention facilitates both the encoding and the readout of visual information whereas exogenous attention only facilitates the encoding of information.

scholarly journals An image-computable model of how endogenous and exogenous attention differentially alter visual perception

2021 ◽  
Vol 118 (33) ◽  
pp. e2106436118
Author(s):  
Michael Jigo ◽  
David J. Heeger ◽  
Marisa Carrasco
Keyword(s):  
Visual Field ◽  
Exogenous Attention ◽  
Behavioral Performance ◽  
Endogenous Attention ◽  
Involuntary Attention ◽  
Improve Performance ◽  
Visual Detail ◽  
Visual Tasks ◽  
Sensory Encoding ◽  
Operating Regimes

Attention alters perception across the visual field. Typically, endogenous (voluntary) and exogenous (involuntary) attention similarly improve performance in many visual tasks, but they have differential effects in some tasks. Extant models of visual attention assume that the effects of these two types of attention are identical and consequently do not explain differences between them. Here, we develop a model of spatial resolution and attention that distinguishes between endogenous and exogenous attention. We focus on texture-based segmentation as a model system because it has revealed a clear dissociation between both attention types. For a texture for which performance peaks at parafoveal locations, endogenous attention improves performance across eccentricity, whereas exogenous attention improves performance where the resolution is low (peripheral locations) but impairs it where the resolution is high (foveal locations) for the scale of the texture. Our model emulates sensory encoding to segment figures from their background and predict behavioral performance. To explain attentional effects, endogenous and exogenous attention require separate operating regimes across visual detail (spatial frequency). Our model reproduces behavioral performance across several experiments and simultaneously resolves three unexplained phenomena: 1) the parafoveal advantage in segmentation, 2) the uniform improvements across eccentricity by endogenous attention, and 3) the peripheral improvements and foveal impairments by exogenous attention. Overall, we unveil a computational dissociation between each attention type and provide a generalizable framework for predicting their effects on perception across the visual field.

scholarly journals The Role of Transient Attention in the Radial-tangential Anisotropy of Crowding

2021 ◽  
Author(s):  
Bahiyya Kewan-Khalayly ◽  
Marta Migó ◽  
Amit Yashar
Keyword(s):  
Object Recognition ◽  
Macular Degeneration ◽  
Spatial Attention ◽  
Essential Role ◽  
Target Location ◽  
Horizontal Meridian ◽  
Critical Spacing ◽  
Improved Performance ◽  
Radial Arrangement

Abstract Crowding refers to the failure to identify a peripheral object due to its proximity to other objects (flankers). This phenomenon can lead to reading and object recognition impairments, and is associated with macular degeneration, amblyopia, and dyslexia. Crucially, the minimal target-flanker spacing required for the crowding interference (critical spacing) increases with eccentricity. This spacing is also larger when target and flankers appear along the horizontal meridian (radial arrangement) than when the flankers appear above and below the target (tangential arrangement). This phenomenon is known as radial–tangential anisotropy. Previous studies have demonstrated that transient attention can reduce crowding interference. However, it is still unclear whether and how attention interacts with the radial–tangential anisotropy. To address this issue, we manipulated transient attention by using a cue either at the target (valid) or fixation (neutral) location, in both radial and tangential target-flanker arrangements. Results showed that critical spacing was larger in the radial than in the tangential arrangement, and that cueing the target location improved performance and reduced the critical spacing for both radial and tangential arrangements, to the same extent. Together, our findings suggest that transient spatial attention plays an essential role in crowding but not in the radial-tangential anisotropy.

scholarly journals Left parietal tACS at alpha frequency induces a shift of visuospatial attention

2019 ◽  
Author(s):  
T. Schuhmann ◽  
S. K. Kemmerer ◽  
F. Duecker ◽  
T.A. de Graaf ◽  
S. ten Oever ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Parietal Cortex ◽  
Visuospatial Attention ◽  
High Density ◽  
Exogenous Attention ◽  
Alpha Power ◽  
Endogenous Attention ◽  
Alpha Frequency ◽  
Stimulus Detection ◽  
Left Parietal Cortex

AbstractBackgroundVoluntary shifts of visuospatial attention are associated with a lateralization of occipitoparietal alpha power (7-13Hz), i.e. higher power in the hemisphere ipsilateral and lower power contralateral to the locus of attention. Recent noninvasive neuromodulation studies demonstrated that alpha power can be experimentally increased using transcranial alternating current stimulation (tACS).Objective/HypothesisWe hypothesized that tACS at alpha frequency over the left parietal cortex induces shifts of attention to the left hemifield. However, spatial attention shifts not only occur voluntarily (endogenous), but also stimulus-driven (exogenous). In order to study the task-specificity of the potential effects of tACS on attentional processes, we administered three conceptually different spatial attention tasks.Methods36 healthy volunteers were recruited from an academic environment. In two seperate sessions, we applied either high-density tACS at 10Hz, or sham tACS, for 35-40 minutes to their left parietal cortex. We systematically compared performance on endogenous attention, exogenous attention, and stimulus detection tasks.ResultsIn the Endogenous attention task, we found a greater leftward bias in reaction times during left parietal 10Hz tACS as compared to sham. There were no stimulation effects in the exogenous attention or stimulus detection task.ConclusionThe study shows that high-density tACS at 10Hz can be used to modulate visuospatial attention performance. The tACS effect is task-specific, indicating that not all forms of attention are equally susceptible to the stimulation.

Orienting and Focusing in Voluntary and Involuntary Visuospatial Attention Conditions

2010 ◽  
Vol 24 (3) ◽  
pp. 198-209 ◽  
Author(s):  
Yan Wang ◽  
Jianhui Wu ◽  
Shimin Fu ◽  
Yuejia Luo
Keyword(s):  
Gain Control ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Orientation Discrimination ◽  
Involuntary Attention ◽  
Attention Condition ◽  
Voluntary Attention ◽  
Visual Spatial ◽  
Related Potentials ◽  
Underlying Mechanisms

In the present study, we used event-related potentials (ERPs) and behavioral measurements in a peripherally cued line-orientation discrimination task to investigate the underlying mechanisms of orienting and focusing in voluntary and involuntary attention conditions. Informative peripheral cue (75% valid) with long stimulus onset asynchrony (SOA) was used in the voluntary attention condition; uninformative peripheral cue (50% valid) with short SOA was used in the involuntary attention condition. Both orienting and focusing were affected by attention type. Results for attention orienting in the voluntary attention condition confirmed the “sensory gain control theory,” as attention enhanced the amplitude of the early ERP components, P1 and N1, without latency changes. In the involuntary attention condition, compared with invalid trials, targets in the valid trials elicited larger and later contralateral P1 components, and smaller and later contralateral N1 components. Furthermore, but only in the voluntary attention condition, targets in the valid trials elicited larger N2 and P3 components than in the invalid trials. Attention focusing in the involuntary attention condition resulted in larger P1 components elicited by targets in small-cue trials compared to large-cue trials, whereas in the voluntary attention condition, larger P1 components were elicited by targets in large-cue trials than in small-cue trials. There was no interaction between orienting and focusing. These results suggest that orienting and focusing of visual-spatial attention are deployed independently regardless of attention type. In addition, the present results provide evidence of dissociation between voluntary and involuntary attention during the same task.

On Why Objects Appear Smaller in the Visual Periphery

2019 ◽  
Vol 31 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Wladimir Kirsch ◽  
Roland Pfister ◽  
Wilfried Kunde
Keyword(s):  
Visual Field ◽  
Visual System ◽  
Structural Properties ◽  
Spatial Attention ◽  
Visuospatial Attention ◽  
Peripheral Target ◽  
Perceptual Distortion ◽  
Visual Periphery ◽  
Peripheral Location ◽  
Exogenous Cue

An object appears smaller in the periphery than in the center of the visual field. In two experiments ( N = 24), we demonstrated that visuospatial attention contributes substantially to this perceptual distortion. Participants judged the size of central and peripheral target objects after a transient, exogenous cue directed their attention to either the central or the peripheral location. Peripheral target objects were judged to be smaller following a central cue, whereas this effect disappeared completely when the peripheral target was cued. This outcome suggests that objects appear smaller in the visual periphery not only because of the structural properties of the visual system but also because of a lack of spatial attention.

Occipitoparietal alpha-band responses to the graded allocation of top-down spatial attention

2014 ◽  
Vol 112 (6) ◽  
pp. 1307-1316 ◽  
Author(s):  
Isabel Dombrowe ◽  
Claus C. Hilgetag
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Brain Regions ◽  
Alpha Band ◽  
Top Down ◽  
Attentional Resources ◽  
Parietal Lobes ◽  
Visual Spatial ◽  
Entire Visual Field ◽  
Band Activity

The voluntary, top-down allocation of visual spatial attention has been linked to changes in the alpha-band of the electroencephalogram (EEG) signal measured over occipital and parietal lobes. In the present study, we investigated how occipitoparietal alpha-band activity changes when people allocate their attentional resources in a graded fashion across the visual field. We asked participants to either completely shift their attention into one hemifield, to balance their attention equally across the entire visual field, or to attribute more attention to one-half of the visual field than to the other. As expected, we found that alpha-band amplitudes decreased stronger contralaterally than ipsilaterally to the attended side when attention was shifted completely. Alpha-band amplitudes decreased bilaterally when attention was balanced equally across the visual field. However, when participants allocated more attentional resources to one-half of the visual field, this was not reflected in the alpha-band amplitudes, which just decreased bilaterally. We found that the performance of the participants was more strongly reflected in the coherence between frontal and occipitoparietal brain regions. We conclude that low alpha-band amplitudes seem to be necessary for stimulus detection. Furthermore, complete shifts of attention are directly reflected in the lateralization of alpha-band amplitudes. In the present study, a gradual allocation of visual attention across the visual field was only indirectly reflected in the alpha-band activity over occipital and parietal cortexes.

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