Article Figures & Data
Figures
- Figure 1.
Experimental paradigm. A, Example stimuli in the visual localizer scan for category-selective regions in the ventral temporal cortex. See Extended Data Figure 1-1 for list of all stimuli used in the experiment. B, ROIs in one example participant. Regions in color were defined using the localizer in panel A. Regions in black were defined from the language localizer scan, and regions in white were obtained from a previous study (White et al., 2023). See Extended Data Figure 1-2 for ROIs all individual participants. C, Example stimuli in the main experiment. D, Mean accuracy in the three behavioral tasks plotted as a function of the character string's position in degrees of visual angle. Error bars are ±1 SEM. Stars and horizontal lines depict statistically significant task effects (*p < 0.05, **p < 0.01, ***p < 0.0001).
- Figure 2.
The VWFA's activity reflects an interaction of stimulus features and task demands. A, Mean percent signal change (p.s.c.) as a function of stimulus type and task condition in left hemisphere VWFAs. “Text” includes both real words and pseudowords (which are separately analyzed in panel C). Error bars represent ±1 SEM. Horizontal bars and stars indicate statistical significance for the main effect of stimuli and pairwise t tests between tasks. B, Task effects computed as the mean difference in percent signal change from the fixation task as baseline. Error bars indicate 95% confidence intervals. Horizontal bars and stars indicate a significant difference in the effect of engaging in the lexical task (compared with fixation task) on responses to text versus false fonts. The effect of the stimulus color task did not differ across stimulus types. For task differences in individual participants, see Extended Data Figure 2-1. C, Responses to words versus pseudowords in the three tasks. The lexicality effect is only observable during the lexical decision task. Error bars are ±1 SEM. D, Responses in the VWFAs as a function of stimulus position, separately for each task and stimulus type (green, text; purple, false fonts). Error bars are ±1 SEM.
- Figure 3.
Task and stimulus effects are absent in other regions of left occipital and temporal lobes. Each panel plots mean BOLD responses in one ROI, formatted as in Figure 2A. See Extended Data Figure 3-1 for statistics on these control regions and Extended Data Figure 3-2 for right hemisphere ROIs.
- Figure 4.
Task and stimulus effects in two left frontal regions. A, B, Mean percent signal change as a function of stimulus type and task in two frontal regions in the left hemisphere. Format as in Figure 2A. C, D, Difference in mean percent signal change from fixation task baseline. Format as in Figure 2C; error bars indicate 95% confidence intervals. E, F, Responses to real words versus pseudowords in each task (format as in Fig. 2E).
- Figure 5.
Whole-cortex analysis of the interaction between task and stimulus type. A, Surface map (in the fsaverage template) of the interaction between stimulus type (text, false fonts) and task (lexical decision, fixation color). For each stimulus type, we computed differences in responses during the lexical decision task and the fixation color task. We then computed a difference of these difference maps for the two stimulus types. The resulting contrast map shows all nodes that had t values >3. Black outlines represent the patches with FDR-corrected p < 0.05. B, Lateral view of the left hemisphere, with the same interaction contrast as the colored blobs (corrected p < 0.05). The outlines represent the ROIs analyzed in Figure 4: the two regions outlined in black together form “Language Broca's area” and the more posterior area in whit is “Word Form Broca's.”
- Figure 6.
Functional connectivity shows task-dependent communication between Broca's area and the VWFA. A, Whole-brain connectivity with the seed region in left language Broca's area (black outline) during the lexical decision task for all stimulus types. The color map represents Pearson's correlation coefficients (minimum r > 0.11; p < 0.05; FDR corrected). The two black outlines on the left ventral surface represent the peaks of the contrast between words and all other categories in the category localizer experiment, in the average brain. Thus, they roughly correspond to the most likely locations of VWFA-1 and VWFA-2. B, Average correlation coefficients between left language Broca's area and the left VWFA (collapsing VWFA-1 and VWFA-2). We first averaged responses for each condition within each of the two ROIs, demeaned them, and then computed pairwise correlation coefficients. The correlations were highest during the lexical decision task for both types of stimuli. Error bars are ±1 SEM. Horizontal lines and stars indicate statistical significance (*p < 0.05, **p < 0.01, ***p < 0.001). C, Correlation maps like in panel A, but for three different seed regions: Word Form Broca's area, left VWFA-1, and left VWFA-2.
- Figure 7.
Relationship between reaction times and BOLD responses. A, Whole-cortex correlations between response times and magnitude of BOLD response. The color map represents Pearson's correlation coefficients (minimum r > 0.03; q < 0.05). The data in all panels corresponds to trials with correct behavioral responses only. The top panel shows correlations for the lexical decision task, and the bottom panel for the fixation color task. B, Mean left VWFA response magnitudes as a function of mean response times in each stimulus and task condition (correct trials only). Error bars represent ±1 SEM. The top panel averages over all stimulus locations, and the bottom is only for trials with stimuli at the central (foveal) location.
Tables
Region of interest Hemisphere Number of subjects VWFA1 Left 15 VWFA1 Right 9 VWFA2 Left 16 VWFA2 Right 4 Language Broca's Left 16 Language Broca's Right 16 FFA1 Left 16 FFA1 Right 16 FFA2 Left 14 FFA2 Right 16 OTS-Limbs Left 16 OTS-Limbs Right 16 STS Left 16 STS Right 14 MFUS-Text Left 8 MFUS-Text Right 2 Number of participants (N) in whom each ROI could be defined, reported separately for each hemisphere. Two other ROIs (V4 and Word Form Broca's) were defined using data from White et al. (2023) and applied to all participants.
ROI Stimulus Task Mean ΔPSC SEM 95% CI t-value BF p-value VWFA Text LD - FC 0.13 0.02 0.08, 0.18 6.85 242.22 <0.01 LD - SC 0.1 0.02 0.06, 0.14 6.41 391.07 <0.01 SC - FC 0.03 0.02 0.02, 0.07 1.55 1.05 0.13 False fonts LD - FC −0.06 0.02 −0.12, −0.003 2.58 8.44 0.02 LD - SC −0.09 0.02 −0.14, −0.04 4 26.95 <0.001 SC - FC 0.03 0.02 −0.03, 0.08 1.15 1.79 0.25 Word form Broca's Text LD - FC 0.11 0.02 0.07, 0.15 6.66 884.14 <0.001 LD - SC 0.09 0.02 0.06, 0.13 6.05 334.98 <0.001 SC - FC 0.01 0.02 −0.02, 0.05 0.91 0.88 0.37 False fonts LD - FC −0.1 0.02 −0.15, 0.04 4.27 56.96 <0.001 LD - SC −0.11 0.02 −0.17, −0.06 5.27 156.28 <0.001 SC - FC 0.02 0.02 −0.03, 0.07 0.9 0.51 0.37 Language Broca's Text LD - FC 0.07 0.01 0.04, 0.10 5.73 83.58 <0.001 LD - SC 0.07 0.01 0.04, 0.10 6.02 544.78 <0.001 SC - FC 0 0.01 −0.03, 0.03 0.03 0.26 0.98 False fonts LD - FC −0.05 0.02 −0.09, 0.004 2.66 4.44 0.01 LD - SC −0.06 0.02 −0.10, −0.02 3.47 13.49 0.002 SC - FC 0.01 0.02 −0.03, 0.05 0.75 0.37 0.46 Across pairs of tasks, separately for text and false font stimuli, in the left VWFA and the two Broca's areas. See Extended Data Table 2-1 for statistics on VWFA-1 and VWFA-2 separately. For each ROI, the six p values are corrected for false discovery rate. PSC, percent signal change; SEM, standard error of mean; CI, confidence interval; LD, lexical decision task; FC, fixation color task; SC, stimulus color task; BF, Bayes factor.
Stimulus Task Mean Δ r SEM 95% CI t value BF p value Text LD - FC 0.18 0.03 0.11, 0.25 6.33 3.21 × 106 <0.001 LD - SC 0.17 0.04 0.08, 0.26 4.91 4.64 × 105 <0.001 SC - FC 0.01 0.03 −0.07, 0.09 0.3 0.12 0.75 False fonts LD - FC 0.15 0.04 0.05, 0.24 3.68 49.97 0.001 LD - SC 0.05 0.03 −0.05, 0.16 1.24 0.40 0.22 SC - FC 0.09 0.04 0.01, 0.2 2.09 1.29 0.06 Statistics on how functional connectivity between the language Broca's Area and the left VWFA (collapsing over VWFA-1 and VWFA-2) differed across pairs of tasks. This is calculated separately for trials with text stimuli (both words and pseudowords) and false fonts. “Mean Δ r” is the mean difference in the correlation coefficient r across the two tasks listed in each row. p values are FDR corrected for multiple comparisons. LD, lexical decision task; FC, fixation color task; SC, stimulus color task.
Figure 1-1
All words and pseudowords used in the experiment. Download Figure 1-1, DOCX file.
Figure 1-2
Regions of interest in individual subject anatomical surface space. Download Figure 1-2, TIF file.
Table 2-1
Statistics for stimulus and task differences for VWFA-1 and -2, reported separately. Download Table 2-1, DOCX file.
Figure 2-1
Individual participants’ mean beta responses in the left VWFA (VWFA-1 and VWFA-2 together) for A) text (real words and pseudowords) and B) false fonts. In each panel, each participant contributes two points that are connected by a vertical line. The horizontal position of each point represents that subject’s VWFA response during the fixation task. The vertical position of the darker points represents the response during the lexical decision task, and the vertical position of the lighter points represents the stimulus color task. Download Figure 2-1, TIF file.
Figure 3-1
Statistics for task effects on responses to each stimulus type for all control ROIs in the left hemisphere. P-values are corrected for multiple comparisons using FDR correction. All p-values were corrected for post-hoc tests within ROIs, and then concatenated and corrected for multiple comparisons across ROIs. Adjusted P-values are reported in the final column of the table. Download Figure 3-1, DOCX file.
Figure 3-2
Mean BOLD percent signal change as a function of stimulus and task types in control ROIs in the right hemisphere. Error bars represent standard error of the mean. Download Figure 3-2, TIF file.
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