Task design for Experiments 1–3.

<p>A central fixation point was presented for a variable duration between 1,000–1,500 ms (randomly determined) followed by a 700-ms stimulus array and, after a 70-ms blank display, a 280-ms backwards-mask display. After another 650-ms blank display, a 200-ms retrocue was presented indicating which of the three stimuli they had to report at the end of the trial. After a final 1000-ms blank display, participants reported the target orientation using the computer mouse.</p

Recall precision for each condition separately of Experiment 2.

<p>Error bars reflect ± 1 standard error of the mean.</p

Modelling parameters for each condition separately of Experiment 2.

<p>Error bars reflect ± 1 standard error of the mean.</p

Modelling parameters for each condition separately of Experiment 3.

<p>Error bars reflect ± 1 standard error of the mean.</p

Recall precision for Experiment 1 for sub-threshold (1% contrast) and supraliminal (18%–50% contrast) conditions.

<p>Error bars reflect ± 1 standard error of the mean.</p

Reaction times results.

<p><i>(</i><b><i>a</i></b><i>)</i> Main effect of temporal <i>rhythms</i> and <i>symbolic</i> cues <i>(b)</i> Effects of temporal rhythms and predictive cues broken down by task instructions. The bars represent reaction time values left y-axis), and accuracy data is represented by the lines (right y-axis). Error bars represent standard errors of the means (SE).</p

Optimised parameters of the winning HGF model.

<p>Optimised parameters of the winning HGF model.</p

Task design and performance.

<p>(A) Participants performed location and latency discrimination of visual targets. An auditory cue consisted of an ascending (orange) or a descending (blue) pair of tones (cue composition), presented at a high or low pitch. The pitch of the cue could predict the location (left versus right) of the visual target, while the composition of the cue could predict the latency (early versus late) of the target, followed by a speeded discrimination response. Participants performed location or latency discrimination in separate blocks. (B) Cue validity varied unbeknownst to the participants over the course of the experiment. Spatial (blue) and temporal (red) validity levels were uncorrelated and changed implicitly. Alternating tasks (black) were prompted by explicit instructions. (C) Predictability interacted with task relevance in both tasks, improving accuracy when the predictions were relevant. The main effect of relevance reflected the differences in accuracy between tasks. <i>N</i> = 17; error bars: SEM; post-hoc <i>t</i> tests * <i>p</i> < 0.05; ^~ <i>p</i> < 0.1. Data pertaining to this figure are available on Figshare <a href="https://figshare.com/s/2d2755bfdeea1cbb415f" target="_blank">https://figshare.com/s/2d2755bfdeea1cbb415f</a>. ISI, inter-stimulus interval; ITI, inter-trial interval; n.s., not significant; RT, reaction time.</p

Behavioural modelling.

<p>(A) The HGF comprises an observer part, describing the beliefs inferred at 3 levels (low: predictions about target location/latency; middle: cue-target validity level; high: volatility of cue validity), and the response part, linking these beliefs to predicted responses. The full model assumes all 3 levels and a weighted influence of relevant (saturated blue/red) and irrelevant (unsaturated) predictions on participants’ responses. Grey: model states; orange: model parameters. (B) Three alternative observer models (HGF3, HGF2, RW) and 2 alternative response models (task-general: weighted influence of relevant and irrelevant predictions; task-specific: exclusive influence of relevant predictions) were subject to Bayesian model selection. Plot shows log-model evidence relative to the weakest model and indicates task-specific HGF2 as winning. (C) HGF-derived trial-by-trial time-series (representative participant) of predictions about target location/latency (; upper panels) and cue validity (; middle panels) and PEs about target location/latency (|<i>ε</i>₂|; lower panels). (D) Mean correlations between HGF regressors. (E) Correlation between the prior variance of validity level updates and mean accuracy across participants. Data pertaining this figure are available on Figshare <a href="https://figshare.com/s/2d2755bfdeea1cbb415f" target="_blank">https://figshare.com/s/2d2755bfdeea1cbb415f</a>. HGF, Hierarchical Gaussian Filter; HGF2, 2-level HGF; HGF3, 3-level HGF; PE, prediction error; RW, Rescorla-Wagner.</p

Source reconstruction results.

<p>Source reconstruction results.</p