Dynamic estimation of the attentional field from visual cortical activity
- Department of Psychological & Brain Sciences, Boston University, United States
Figures
Figure 1
Experimental design and behavioral performance.
(a) Task schematic. Participants were instructed to maintain central fixation and use covert spatial attention to determine whether there were more numbers or letters present within a cued region of a white noise annulus. On each trial, the red cue was displayed alone for 1.35 s and remained present throughout the trial. Twenty digits and letters were then presented for 0.5 s, equally spaced and overlaid on the annulus. Participants had 1.25 s to indicate via button press whether more digits or letters were present in the cued region. The cue remained stable for five trials (10 TRs, 15.5 s), had a width of 1, 3, 5, or 9 segments (18°, 54°, 90°, or 162°), and was centered on any of the 20 digit/letter slots. (b) Behavioral task performance: group mean accuracy for each cue width. Error bars are SEM; gray circles show individual participants (n=8). (c) Group mean gaze eccentricity (in degrees of visual angle) for each cue width, conventions as in (b).
Figure 2
Spatial distribution of attentional modulation.
(a) BOLD response projected into the visual field for each attentional cue width. Heatmaps represent the group mean BOLD activity using each voxel’s population receptive field (pRF) location within the visual field, shown separately for V1, V2, and V3. Maps were rotated to align all attentional cue locations to 0° polar angle (rightward). Concentric circles indicated by black dashed lines represent the location of the white noise annulus. (b) Average spatial modulation profiles at the eccentricity of the annulus. The spatial profiles were recentered to 0° polar angle based on the cue location. Solid lines represent the group mean BOLD response and shaded regions the SEM across participants (n=8).
Figure 3
Modeling approach.
(a) The generalized Gaussian model is characterized by parameters for location , scale , and shape . (b) Example model fits for two spatial profiles. Dots indicate BOLD response for two attentional cues differing in position and width. Solid lines indicate the best fitting model estimate. To quantify the attentional field, we extracted the location and gain (dashed arrows), as well as the width (full width at half maximum (FWHM); solid arrows).
Figure 4
Attentional field parameter estimates for an example participant.
The full parameter estimate distributions across blocks for location, width, gain, and baseline are shown for one example participant in V1, V2, and V3. Median parameter estimates are shown by the white points, with the box plot representing the 25th to 75th percentile, and whiskers extending to all non-outlier points.
Figure 5
Attentional field parameter estimates.
Group results for location, width, gain, and baseline estimates. Overall group mean and SEM (n=8) are shown in solid black, separated by cue width and brain region. Individual participant median estimates are shown in gray. The example participant from Figure 4 is indicated by a denser dashed dark gray line with triangle symbols to aid in comparison.
Figure 6
Effect of number of TRs.
Model fits were computed using BOLD data averaged across different temporal intervals (1, 2, 3, 5, or 10 TRs). Group means (with SEM (n=8)) are plotted for (a) full width at half maximum (FWHM), (b) absolute angular error, (c) gain, (d) baseline offset, and (e) R2, separated by cue width, brain region, and the number of TRs used for each model fit.
Figure 7
Spatial distribution of perceptual modulation.
(a) Spatial profiles of perceptual modulation. Solid lines represent the group mean BOLD activity and shaded regions the SEM (n=5). (b) Group-level parameter estimates. Overall group mean and SEM are shown for the absolute angular error, full width at half maximum (FWHM), gain, and baseline, separated by contrast width and brain region. (c) Comparison of FWHM estimates obtained from the attentional manipulation and the physical contrast manipulation. Dot color indicates brain region; each point represents the mean FWHM for a given width condition across participants.
Author response image 1
No moving average smoothing.
Author response image 2
Author response image 3
Author response image 4
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Dynamic estimation of the attentional field from visual cortical activity
eLife 14:RP104222.
https://doi.org/10.7554/eLife.104222.3
