Figure 4. Cue-locked response amplitudes depend on view angle, speed, and cue frequency, but a large fraction exhibit choice-related modulations that increase during the course of the trial.

(a) Response amplitudes of two example right-cue-locked cells (one cell per row) vs. (columns) the visual angle at which the cue appeared (${\varphi }_{cue}$), running speed ($v$), and $y$ location of the cue in the cue region. Points: amplitude data in blue (red) according to the upcoming right (left) choice. Lines: AIC_C-weighted model mean functions for right- vs. left-choice trials (lines); the model predicts the data to be random samples from a Gamma distribution with this behavior-dependent mean function. The data in the right two columns were restricted to a subset where angular receptive field effects are small, corresponding to the indicated area in the leftmost plots. (b) Same as (a) but for two (left-cue-locked) cells with broader angular receptive fields. (c) Percentages of cells that significantly favor various amplitude modulation models (likelihood ratio <0.05, defaulting to null model if none are significant), in the indicated cortical areas and layers. For layer 2/3 data, V1 has a significantly higher fraction of cells preferring the null model than other areas (p = 0.02, two-tailed Wilcoxon rank-sum test). For layer 5 data, V1 has a significantly lower choice-model preferring fraction than the other areas (p = 0.003). (d) Distribution (kernel density estimate) of adaptation/enhancement factors for cells that favor the SSA model. A factor of 1 corresponds to no adaptation, while for other values the subsequent response is scaled by this amount with exponential recovery toward 1. Error bars: S.E.M. Stars: significant differences in means (Wilcoxon rank-sum test). (e) Comparison of the behaviorally deduced weighting of cues (green, same as Figure 1e) to the neural choice modulation strength vs. location in the cue region (for contralateral-cue-locked cells only, but ipsilateral-cue-locked cells in Figure 4—figure supplement 2g have similar trends). The choice modulation strength is defined using the amplitude-modulation model predictions, and is the difference between predicted amplitudes on preferred-choice minus anti-preferred-choice trials, where preferred choice means that the neuron will have higher amplitudes on trials of that choice compared to trials of the opposite (anti-preferred) choice. For comparability across cells, the choice modulation strength is normalized to the average amplitude for each cell (Materials and methods). Lines: mean across cue-locked cells, computed separately for positively vs. negatively choice-modulated cells (data from all brain regions). Bands: S.E.M.

Figure 4—figure supplement 1. Qualitatively similar cue-locked amplitude modulations in control experiments with view angle restricted to be zero in the cue region.

(a–b,e–f) As in Figure 4, except using data from the control experiments. (c–d,g) As in Figure 4—figure supplement 2a–b,d, except using data from the θ-controlled experiments.

Figure 4—figure supplement 2. Additional statistics for amplitude modulations of cue-locked cells.

(a) Distribution of AIC_C likelihood ratios for various amplitude-modulation models vs. the null hypothesis where cell responses only depend on an angular receptive field and speed. Colored areas corresponds to cells for which the indicated model is the best model for that cell (likelihood ratio n < 0.05). Data were pooled across all sessions. Note the logarithmic x-axis scale. (b) As in (a), distribution of AIC_C likelihood ratios for cue-counts model vs. the SSA model. Colored areas corresponds to cells for which the cue-counts model was the best model for that cell (likelihood ratio <0.05). (c) Distribution (kernel density estimate) of predicted speed-induced changes in amplitudes for a change in speed of 10 cm/s. Data were pooled across layers. Error bars: S.E.M. across cells. Stars: significant differences in means (Wilcoxon rank-sum test). (d) Distribution of adaptation/enhancement timescales for cells that favor the SSA model, defined as the time taken for the amplitude to recover to baseline by a factor of $1/e$. Error bars: S.E.M. across cells. Stars: significant differences in means (Wilcoxon rank-sum test). (e) Distribution of choice modulation effect sizes for cue-locked cells in various areas/layers, defined as the maximum difference in predicted responses on contralateral- vs. ipsilateral-choice trials, divided by the mean response. Cells with numerically near-zero modulations (${\displaystyle \left|\delta A^{choice}\right|\le {10}^{-4}}$) were excluded. Error bars: S.E.M. across cells. (f) Proportions out of all significantly cue-counts-modulated cells for which the best model is that which depends on the difference (left columns) in or single-side counts (middle and right columns) of cues, and shown separately for contralateral- and ipsilateral-cue-locked cells. Error bars: 95% C.I. across cells. (g) As in Figure 4e, but for ipsilateral-cue-locked cells. (h) As in Figure 4c, but for mice of two different strains. Data were pooled across layers.