highspeed-analysis/code/highspeed-analysis-behavior.Rmd

## Behavior

### Initialization

#### Load data and files

We set the paths and source the basic setup script:

```{r, warning=FALSE, message=FALSE}
knitr::opts_chunk$set(echo = TRUE)
# find the path to the root of this project:
if (!requireNamespace("here")) install.packages("here")
if ( basename(here::here()) == "highspeed" ) {
  path_root = here::here("highspeed-analysis")
} else {
  path_root = here::here()
}
# source all relevant functions from the setup R script:
source(file.path(path_root, "code", "highspeed-analysis-setup.R"))
```

#### Signal-detection labeling

We assign labels from signal detection theory that will be used in one of the analyses below:

```{r}
# denotes misses (key was not pressed and stimulus was upside-down):
dt_events$sdt_type[
  dt_events$key_down == 0 & dt_events$stim_orient == 180] <- "miss"
# denotes hits (key was pressed and stimulus was upside-down):
dt_events$sdt_type[
  dt_events$key_down == 1 & dt_events$stim_orient == 180] <- "hit"
# denotes correct rejection (key was not pressed and stimulus was upright):
dt_events$sdt_type[
  dt_events$key_down == 0 & dt_events$stim_orient == 0] <- "correct rejection"
# denotes false alarms (key was pressed and stimulus was upright):
dt_events$sdt_type[
  dt_events$key_down == 1 & dt_events$stim_orient == 0] <- "false alarm"
```

### Stimulus timings

We calculate the differences between consecutive stimulus onsets:

```{r}
dt_events %>%
  # get duration of stimuli by calculating differences between consecutive onsets:
  .[, duration_check := shift(onset, type = "lead") - onset,
    by = .(subject, run_study)] %>%
  # get the difference between the expected and actual stimulus duration:
  .[, duration_diff := duration_check - duration, by = .(subject, run_study)] %>%
  # for each condition and trial check participants' responses:
  .[, by = .(subject, condition, trial), ":=" (
    # for each trial check if a key has been pressed:
    trial_key_down = ifelse(any(key_down == 1, na.rm = TRUE), 1, 0),
    # for each trial check if the participant was accurate:
    trial_accuracy = ifelse(any(accuracy == 1, na.rm = TRUE), 1, 0)
  )] %>%
  .[, trial_type := factor(trial_type, levels = rev(unique(trial_type)))]
```


```{r}
timings_summary = dt_events %>%
  filter(condition %in% c("sequence", "repetition") & trial_type == "interval") %>%
  setDT(.) %>%
  .[, by = .(subject, condition, trial_type), {
    results = t.test(duration_diff, mu = 0.001, alternative = "two.sided")
    list(
      mean = mean(duration_diff, na.rm = TRUE),
      sd = sd(duration_diff, na.rm = TRUE),
      min = min(duration_diff, na.rm = TRUE),
      max = max(duration_diff, na.rm = TRUE),
      num = .N,
      tvalue = results$statistic,
      df = results$parameter,
      pvalue = results$p.value,
      pvalue_round = round_pvalues(results$p.value)
    )
  }] %>%
  .[, trial_type := factor(trial_type, levels = rev(unique(trial_type)))] %>%
  setorder(., condition, trial_type)
rmarkdown::paged_table(timings_summary)
```

We plot the differences in expected versus actual timings of individual stimuli in the behavioral task:

```{r}
ggplot(data = dt_events, aes(
  y = as.numeric(duration_diff),
  x = as.factor(trial_type),
  fill = as.factor(trial_type)), na.rm = TRUE) +
  facet_grid(vars(as.factor(trial_key_down)), vars(as.factor(condition))) +
  geom_point(
    aes(y = as.numeric(duration_diff), color = as.factor(trial_type)),
    position = position_jitter(width = .15), size = .5, alpha = 1, na.rm = TRUE) +
  geom_boxplot(width = .1, outlier.shape = NA, alpha = 0.5, na.rm = TRUE) +
  scale_color_brewer(palette = "Spectral") +
  scale_fill_brewer(palette = "Spectral") +
  #coord_capped_flip(left = "both", bottom = "both", expand = TRUE) +
  coord_flip() +
  theme(legend.position = "none") +
  xlab("Trial event (in serial order)") +
  ylab("Difference between expected and actual timing (in s)") +
  theme(strip.text = element_text(margin = margin(unit(c(t = 2, r = 2, b = 2, l = 2), "pt")))) +
  theme(legend.position = "none") +
  theme(panel.background = element_blank())
```

```{r, echo=FALSE, eval=FALSE}
ggsave(filename = "highspeed_plot_behavior_timing_differences.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures, scale = 1,
       dpi = "retina", width = 6, height = 4)
```

We check the timing of the inter-trial interval on oddball trials:

```{r}
dt_odd_iti_mean = dt_events %>%
  # filter for the stimulus intervals on oddball trials:
  filter(condition == "oddball" & trial_type == "interval") %>% 
  setDT(.) %>%
  # calculate the mean duration of the oddball intervals for each participant:
  .[, by = .(subject), .(
    mean_duration = mean(duration, na.rm = TRUE),
    num_trials = .N
  )] %>%
  verify(num_trials == 600)
rmarkdown::paged_table(head(dt_odd_iti_mean))
```

### Behavioral performance

#### Mean accuracy

We calculate the mean behavioral accuracy across all trials of all three task conditions (slow, sequence, and repetition trials):

```{r, echo=TRUE}
# behavioral chance level is at 50%:
chance_level = 50
dt_acc = dt_events %>%
  # filter out all events that are not related to a participants' response:
  filter(!is.nan(accuracy)) %>%
  # filter for only upside down stimuli on slow trials:
  filter(!(condition == "oddball" & stim_orient == 0)) %>%
  setDT(.) %>%
  # check if the number of trials matches for every subject:
  verify(.[(condition == "oddball"), by = .(subject), .(
    num_trials = .N)]$num_trials == 120) %>%
  verify(.[(condition == "sequence"), by = .(subject), .(
    num_trials = .N)]$num_trials == 75) %>%
  verify(.[(condition == "repetition"), by = .(subject), .(
    num_trials = .N)]$num_trials == 45) %>%
  # calculate the average accuracy for each participant and condition:
  .[, by = .(subject, condition), .(
    mean_accuracy = mean(accuracy, na.rm = TRUE) * 100,
    num_trials = .N)] %>%
  # check if the accuracy values are between 0 and 100:
  assert(within_bounds(lower.bound = 0, upper.bound = 100), mean_accuracy) %>%
  # create new variable that specifies excluded participants:
  mutate(exclude = ifelse(mean_accuracy < chance_level, "yes", "no")) %>%
  # create a short name for the conditions:
  mutate(condition_short = substr(condition, start = 1, stop = 3)) %>%
  # reorder the condition factor in descending order of accuracy:
  transform(condition_short = fct_reorder(
    condition_short, mean_accuracy, .desc = TRUE))
rmarkdown::paged_table(dt_acc)
```

We create a list of participants that will be excluded because their performance is below the 50% chance level in either or both sequence and repetition trials:

```{r, echo=TRUE}
# create a list with all excluded subject ids and print the list:
subjects_excluded = unique(dt_acc$subject[dt_acc$exclude == "yes"])
print(subjects_excluded)
```

We calculate the mean behavioral accuracy across all three task conditions (slow, sequence, and repetition trials), *excluding* participants that performed below chance on either or both sequence and repetition trials:

```{r, echo=TRUE, results="hold"}
dt_acc_mean = dt_acc %>%
  # filter out all data of excluded participants:
  filter(!(subject %in% unique(subject[exclude == "yes"]))) %>%
  # check if the number of participants matches expectations:
  verify(length(unique(subject)) == 36) %>%
  setDT(.) %>%
  # calculate mean behavioral accuracy across participants for each condition:
  .[, by = .(condition), {
    ttest_results = t.test(
      mean_accuracy, mu = chance_level, alternative = "greater")
    list(
      pvalue = ttest_results$p.value,
      pvalue_rounded = round_pvalues(ttest_results$p.value),
      tvalue = round(ttest_results$statistic, digits = 2),
      conf_lb = round(ttest_results$conf.int[1], digits = 2),
      conf_ub = round(ttest_results$conf.int[2], digits = 2),
      df = ttest_results$parameter,
      num_subs = .N,
      mean_accuracy = round(mean(mean_accuracy), digits = 2),
      SD = round(sd(mean_accuracy), digits = 2),
      cohens_d = round((mean(mean_accuracy) - chance_level) / sd(mean_accuracy), 2),
      sem_upper = mean(mean_accuracy) + (sd(mean_accuracy)/sqrt(.N)),
      sem_lower = mean(mean_accuracy) - (sd(mean_accuracy)/sqrt(.N))
    )}] %>%
  verify(num_subs == 36) %>%
  # create a short name for the conditions:
  mutate(condition_short = substr(condition, start = 1, stop = 3)) %>%
  # reorder the condition factor in descending order of accuracy:
  transform(condition_short = fct_reorder(condition_short, mean_accuracy, .desc = TRUE))
# show the table (https://rstudio.github.io/distill/tables.html):
rmarkdown::paged_table(dt_acc_mean)
```

#### Above-chance performance

We plot only data of above-chance performers:

```{r, echo = FALSE}
fig_behav_all = ggplot(data = subset(dt_acc, exclude == "no"), aes(
  x = as.factor(condition_short), y = as.numeric(mean_accuracy),
  group = as.factor(condition_short), fill = as.factor(condition_short))) +
  geom_bar(stat = "summary", fun = "mean", color = "black", fill = "white") +
  geom_dotplot(binaxis = "y", stackdir = "center", stackratio = 0.5,
               color = "black", fill = "lightgray", alpha = 0.5,
               inherit.aes = TRUE, binwidth = 2) +
  geom_errorbar(stat = "summary", fun.data = "mean_se", width = 0.0, color = "black") +
  ylab("Accuracy (%)") + xlab("Condition") +
  scale_color_manual(values = c("darkgray", "red"), name = "Outlier") +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  guides(shape = FALSE, color = FALSE, fill = FALSE) +
  coord_capped_cart(left = "both", expand = TRUE, ylim = c(0, 100)) +
  theme(legend.position = "none") +
  theme(panel.border = element_blank()) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        axis.ticks.x = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
fig_behav_all
```

#### Figure S1a

We plot data of all participants with below chance performers highlighted in red.

```{r, echo=TRUE}
fig_behav_all_outlier = ggplot(data = dt_acc_mean,
  mapping = aes(x = as.factor(condition_short), y = as.numeric(mean_accuracy),
                group = as.factor(condition_short), fill = as.factor(condition_short))) +
  geom_bar(aes(fill = as.factor(condition)), stat = "identity",
           color = "black", fill = "white") +
  geom_point(data = subset(dt_acc, exclude == "no"),
             aes(color = as.factor(exclude)),
             position = position_jitter(width = 0.2, height = 0, seed = 2),
             alpha = 0.5, inherit.aes = TRUE, pch = 21,
             color = "black", fill = "lightgray") +
  geom_point(data = subset(dt_acc, exclude == "yes"),
             aes(color = as.factor(exclude), shape = as.factor(subject)),
             position = position_jitter(width = 0.05, height = 0, seed = 4),
             alpha = 1, inherit.aes = TRUE, color = "red") +
  geom_errorbar(aes(ymin = sem_lower, ymax = sem_upper), width = 0.0, color = "black") +
  ylab("Accuracy (%)") + xlab("Condition") +
  scale_color_manual(values = c("darkgray", "red"), name = "Outlier") +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  coord_capped_cart(left = "both", bottom = "none", expand = TRUE, ylim = c(0, 100)) +
  theme(axis.ticks.x = element_line(color = "white"),
        axis.line.x = element_line(color = "white")) +
  guides(shape = FALSE, fill = FALSE) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        axis.ticks.x = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
fig_behav_all_outlier
```

#### Source Data File Fig. S1a

```{r, echo=TRUE}
dt_acc %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_s1a.csv"),
            row.names = FALSE)
```

### Slow trials

#### Mean accuracy (all trials)

We calculate the mean accuracy on slow trials (oddball task condition) across all trials in the final sample (only participants who performed above chance):

```{r, echo=TRUE}
# we use the dataframe containing the accuracy data
dt_acc_odd = dt_acc %>%
  # filter for oddball / slow trials only:
  filter(condition == "oddball") %>%
  # exclude participants with below chance performance::
  filter(!(subject %in% subjects_excluded)) %>%
  # verify that the number of participants (final sample) is correct:
  verify(all(.N == 36))
```

We plot the mean behavioral accuracy on slow trials (oddball task condition) in the final sample:

```{r, echo=TRUE, fig.width=3}
fig_behav_odd = ggplot(data = dt_acc_odd, aes(
  x = "mean_acc", y = as.numeric(mean_accuracy))) +
  geom_bar(stat = "summary", fun = "mean", fill = "lightgray") +
  #geom_dotplot(binaxis = "y", stackdir = "center", stackratio = 0.5,
  #             color = "black", fill = "lightgray", alpha = 0.5,
  #             inherit.aes = TRUE, binwidth = 0.5) +
  geom_point(position = position_jitter(width = 0.2, height = 0, seed = 2),
             alpha = 0.5, inherit.aes = TRUE, pch = 21,
             color = "black", fill = "lightgray") +
  geom_errorbar(stat = "summary", fun.data = "mean_se", width = 0.0, color = "black") +
  ylab("Accuracy (%)") + xlab("Condition") +
  scale_color_manual(values = c("darkgray", "red"), name = "Outlier") +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  #coord_capped_cart(left = "both", bottom = "none", expand = TRUE, ylim = c(90, 100)) +
  theme(plot.title = element_text(size = 12, face = "plain")) +
  theme(axis.ticks.x = element_line(color = "white"),
        axis.line.x = element_line(color = "white")) +
  theme(axis.title.x = element_text(color = "white"),
        axis.text.x = element_text(color = "white")) +
  ggtitle("Slow") +
  theme(plot.title = element_text(hjust = 0.5))
fig_behav_odd
```

#### Mean accuracy (per run)

We calculate the mean behavioral accuracy on slow trials (oddball task condition) for each of the eight task runs *for each* participant:

```{r}
# calculate the mean accuracy per session and run for every participant:
dt_odd_behav_run_sub = dt_events %>%
  # exclude participants performing below chance:
  filter(!(subject %in% subjects_excluded)) %>%
  # select only oddball condition and stimulus events:
  filter(condition == "oddball" & trial_type == "stimulus") %>%
  # filter for upside-down trials (oddballs) only:
  filter(stim_orient == 180) %>%
  setDT(.) %>%
  # calculate mean accuracy per session and run:
  .[, by = .(subject, session, run_study, run_session), .(
    mean_accuracy = mean(accuracy))] %>%
  # express accuracy in percent by multiplying with 100:
  transform(mean_accuracy = mean_accuracy * 100) %>%
  # check whether the mean accuracy is within the expected range of 0 to 100:
  assert(within_bounds(lower.bound = 0, upper.bound = 100), mean_accuracy)
```

We calculate the mean behavioral accuracy on slow trials (oddball task condition) for each of the eight task runs *across* participants:

```{r}
# calculate mean accuracy per session and run across participants:
dt_odd_behav_run_mean = dt_odd_behav_run_sub %>%
  setDT(.) %>%
  # average across participants:
  .[, by = .(session, run_study, run_session), .(
    mean_accuracy = mean(mean_accuracy),
    num_subs = .N,
    sem_upper = mean(mean_accuracy) + (sd(mean_accuracy)/sqrt(.N)),
    sem_lower = mean(mean_accuracy) - (sd(mean_accuracy)/sqrt(.N))
  )] %>%
  verify(num_subs == 36) %>%
  # z-score the accuracy values:
  mutate(mean_accuracy_z = scale(mean_accuracy, scale = TRUE, center = TRUE))
```

We run a LME model to test the linear effect of task run on behavioral accuracy:

```{r, results="hold", echo=TRUE}
lme_odd_behav_run = lmerTest::lmer(
  mean_accuracy ~ run_study + (1 + run_study | subject),
  data = dt_odd_behav_run_sub, na.action = na.omit, control = lcctrl)
summary(lme_odd_behav_run)
anova(lme_odd_behav_run)
```

We run a second model to test run- and session-specific effects:

```{r, results="hold"}
dt <- dt_odd_behav_run_sub %>%
  transform(run_session = as.factor(paste0("run-0", run_session)),
            session = as.factor(paste0("ses-0", session)))
```

```{r, results="hold"}
lme_odd_behav_run = lmerTest::lmer(
  mean_accuracy ~ session + run_session + (1 + session + run_session | subject),
  data = dt, na.action = na.omit, control = lcctrl)
summary(lme_odd_behav_run)
emmeans(lme_odd_behav_run, list(pairwise ~ run_session | session))
anova(lme_odd_behav_run)
rm(dt)
```

#### Figure S1c

We plot the behavioral accuracy on slow trials (oddball task condition) across task runs (x-axis) for each study session (panels):

```{r, echo=TRUE}
# change labels of the facet:
facet_labels_new = unique(paste0("Session ", dt_events$session))
facet_labels_old = as.character(unique(dt_events$session))
names(facet_labels_new) = facet_labels_old
# plot behavioral accuracy across runs:
plot_odd_run = ggplot(data = dt_odd_behav_run_mean, mapping = aes(
  y = as.numeric(mean_accuracy), x = as.numeric(run_session))) +
  geom_ribbon(aes(ymin = sem_lower, ymax = sem_upper), alpha = 0.5, fill = "gray") +
  geom_line(color = "black") +
  facet_wrap(~ as.factor(session), labeller = as_labeller(facet_labels_new)) +
  ylab("Accuracy (%)") + xlab("Run") +
  ylim(c(90, 100)) +
  coord_capped_cart(left = "both", bottom = "both", expand = TRUE, ylim = c(90,100)) +
  theme(axis.ticks.x = element_text(color = "white"),
        axis.line.x = element_line(color = "white")) +
  theme(strip.text.x = element_text(margin = margin(b = 2, t = 2))) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        axis.ticks.x = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
plot_odd_run
```

#### Source Data File Fig. S1c

```{r}
dt_odd_behav_run_mean %>%
  select(-num_subs, -mean_accuracy_z) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_s1c.csv"),
            row.names = FALSE)
```

#### Misses vs. false alarms

We calculate the mean frequency of misses (missed response to upside-down images) and false alarms (incorrect response to upright images):

```{r, echo=TRUE}
dt_odd_behav_sdt_sub = dt_events %>%
  # exclude participants performing below chance:
  filter(!(subject %in% subjects_excluded)) %>%
  # select only oddball condition and stimulus events:
  filter(condition == "oddball" & trial_type == "stimulus") %>%
  setDT(.) %>%
  # create new variable with number of upside-down / upright stimuli per run:
  .[, by = .(subject, session, run_session, stim_orient), ":=" (
    num_orient = .N
  )] %>%
  # get the number of signal detection trial types for each run:
  .[, by = .(subject, session, run_session, sdt_type), .(
    num_trials = .N,
    freq = .N/unique(num_orient)
  )] %>%
  # add missing values:
  complete(nesting(subject, session, run_session), nesting(sdt_type),
           fill = list(num_trials = 0, freq = 0)) %>%
  transform(freq = freq * 100) %>%
  filter(sdt_type %in% c("false alarm", "miss"))
```

We run a LME model to test the effect of signal detection type (miss vs. false alarm), task run and session on the frequency of those events:

```{r, results = "hold"}
lme_odd_behav_sdt = lmer(
  freq ~ sdt_type + run_session * session + (1 + run_session + session | subject),
  data = subset(dt_odd_behav_sdt_sub), na.action = na.omit, control = lcctrl)
summary(lme_odd_behav_sdt)
anova(lme_odd_behav_sdt)
emmeans_results = emmeans(lme_odd_behav_sdt, list(pairwise ~ sdt_type))
emmeans_pvalues = round_pvalues(summary(emmeans_results[[2]])$p.value)
emmeans_results
```

#### Figure S1b

We plot the frequency of misses and false alarms as a function of task run and study session:

```{r, echo=TRUE}
plot_odd_sdt = ggplot(data = dt_odd_behav_sdt_sub, mapping = aes(
  y = as.numeric(freq), x = as.numeric(run_session),
  fill = as.factor(sdt_type), color = as.factor(sdt_type))) +
  stat_summary(geom = "bar", fun = mean, position = position_dodge(),
               na.rm = TRUE) +
  stat_summary(geom = "errorbar", fun.data = mean_se,
               position = position_dodge(0.9), width = 0, color = "black") +
  facet_wrap(~ as.factor(session), labeller = as_labeller(facet_labels_new)) +
  geom_dotplot(
    aes(group = interaction(run_session, session, sdt_type)),
    binaxis = "y", stackdir = "center", stackratio = 0.2, alpha = 0.7,
    inherit.aes = TRUE, binwidth = 0.2, position = position_dodge(),
    color = "black") +
  ylab("Frequency (%)") + xlab("Run") +
  coord_capped_cart(left = "both", bottom = "both",
                    expand = TRUE, ylim = c(0, 15)) +
  scale_fill_viridis(name = "Error", discrete = TRUE) +
  scale_color_viridis(name = "Error", discrete = TRUE) +
  theme(strip.text.x = element_text(margin = margin(b = 2, t = 2))) +
  theme(legend.position = "top", legend.direction = "horizontal",
        legend.justification = "center", legend.margin = margin(0, 0, 0, 0),
        legend.box.margin = margin(t = 0, r = 0, b = -5, l = 0)) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks.x = element_line(color = "white")) +
  theme(axis.line.x = element_line(color = "white")) +
  theme(axis.ticks.y = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
plot_odd_sdt
```

#### Source Data File Fig. S1b

```{r}
dt_odd_behav_sdt_sub %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_s1b.csv"),
            row.names = FALSE)
```

### Sequence trials

#### Effect of sequence speed

We calculate the mean behavioral accuracy on sequence trials for each of the five sequence speeds (inter-stimulus intervals):

```{r, echo=TRUE}
dt_seq_behav = dt_events %>%
  # filter behavioral events data for sequence trials only:
  filter(condition == "sequence") %>%
  setDT(.) %>%
  # create additional variables to describe each trial:
  .[, by = .(subject, trial), ":=" (
    trial_key_down = ifelse(any(key_down == 1, na.rm = TRUE), 1, 0),
    trial_accuracy = ifelse(any(accuracy == 1, na.rm = TRUE), 1, 0),
    trial_target_position = serial_position[which(target == 1)],
    trial_speed = unique(interval_time[which(!is.na(interval_time))])
  )] %>%
  # filter for choice trials only:
  filter(trial_type == "choice") %>%
  setDT(.) %>%
  # group speed conditions into fast and slow conditions:
  mutate(speed = ifelse(trial_speed %in% c(2.048, 0.512), "slow", "fast")) %>%
  # define variable factors of interest as numeric:
  transform(trial_speed = as.numeric(trial_speed)) %>%
  transform(trial_target_position = as.numeric(trial_target_position)) %>%
  setDT(.)
```

```{r}
dt_seq_behav_speed = dt_seq_behav %>%
  # filter out excluded subjects:
  filter(!(subject %in% subjects_excluded)) %>%
  setDT(.) %>%
  # average accuracy for each participant:
  .[, by = .(subject, trial_speed), .(
    num_trials = .N,
    mean_accuracy = mean(accuracy)
  )] %>%
  transform(mean_accuracy = mean_accuracy * 100) %>%
  setDT(.) %>%
  verify(all(num_trials == 15)) %>%
  verify(.[, by = .(trial_speed), .(
    num_subjects = .N
  )]$num_subjects == 36) %>%
  setorder(subject, trial_speed) %>%
  mutate(trial_speed = as.numeric(trial_speed)) %>%
  setDT(.)
```

We run a LME model to test the effect of sequence speed (inter-stimulus interval) on mean behavioral accuracy on sequence trials:

```{r, results="hold", echo=TRUE}
lme_seq_behav = lmer(
  mean_accuracy ~ trial_speed + (1 + trial_speed | subject),
  data = dt_seq_behav_speed, na.action = na.omit, control = lcctrl)
summary(lme_seq_behav)
anova(lme_seq_behav)
emmeans_results = emmeans(lme_seq_behav, list(pairwise ~ trial_speed))
emmeans_pvalues = round_pvalues(summary(emmeans_results[[2]])$p.value)
emmeans_results
emmeans_pvalues
```

We compare mean behavioral accuracy at each sequence speed level to the chancel level of 50%:

```{r}
chance_level = 50
dt_seq_behav_mean = dt_seq_behav_speed %>%
  # average across participants:
  .[, by = .(trial_speed), {
    ttest_results = t.test(
      mean_accuracy, mu = chance_level, alternative = "greater")
  list(
    mean_accuracy = round(mean(mean_accuracy), digits = 2),
    sd_accuracy = round(sd(mean_accuracy), digits = 2),
    tvalue = round(ttest_results$statistic, digits = 2),
    conf_lb = round(ttest_results$conf.int[1], digits = 2),
    conf_ub = round(ttest_results$conf.int[2], digits = 2),
    pvalue = ttest_results$p.value,
    cohens_d = round((mean(mean_accuracy) - chance_level)/sd(mean_accuracy), 2),
    df = ttest_results$parameter,
    num_subs = .N,
    sem_upper = mean(mean_accuracy) + (sd(mean_accuracy)/sqrt(.N)),
    sem_lower = mean(mean_accuracy) - (sd(mean_accuracy)/sqrt(.N))
  )}] %>%
  verify(num_subs == 36) %>%
  mutate(sem_range = sem_upper - sem_lower) %>%
  mutate(pvalue_adjust = p.adjust(pvalue, method = "fdr")) %>%
  mutate(pvalue_adjust_round = round_pvalues(pvalue_adjust))
# print paged table:
rmarkdown::paged_table(dt_seq_behav_mean)
```

We calculate the reduction in mean behavioral accuracy comparing the fastest and slowest speed condition:

```{r}
a = dt_seq_behav_mean$mean_accuracy[dt_seq_behav_mean$trial_speed == 2.048]
b = dt_seq_behav_mean$mean_accuracy[dt_seq_behav_mean$trial_speed == 0.032]
reduced_acc = round((1 - (b/a)) * 100, 2)
sprintf("reduction in accuracy: %.2f", reduced_acc)
```

#### Figure 1e

```{r, echo=TRUE}
fig_seq_speed = ggplot(data = dt_seq_behav_speed, mapping = aes(
  y = as.numeric(mean_accuracy), x = as.factor(as.numeric(trial_speed)*1000),
  fill = as.factor(trial_speed), color = as.factor(trial_speed))) +
  geom_bar(stat = "summary", fun = "mean") +
  geom_dotplot(binaxis = "y", stackdir = "center", stackratio = 0.5,
               color = "black", alpha = 0.5,
               inherit.aes = TRUE, binwidth = 2) +
  geom_errorbar(stat = "summary", fun.data = "mean_se", width = 0.0, color = "black") +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  ylab("Accuracy (%)") + xlab("Sequence speed (ms)") +
  scale_fill_viridis(discrete = TRUE, guide = FALSE, option = "cividis") +
  scale_color_viridis(discrete = TRUE, guide = FALSE, option = "cividis") +
  coord_capped_cart(left = "both", bottom = "both", expand = TRUE, ylim = c(0, 100)) +
  theme(plot.title = element_text(size = 12, face = "plain")) +
  theme(axis.ticks.x = element_blank(), axis.line.x = element_blank()) +
  ggtitle("Sequence") +
  theme(plot.title = element_text(hjust = 0.5)) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks.x = element_line(color = "white")) +
  theme(axis.line.x = element_line(color = "white")) +
  theme(axis.ticks.y = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
fig_seq_speed
```

#### Source Data File Fig. 1e

```{r}
dt_seq_behav_speed %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_1e.csv"),
            row.names = FALSE)
```

#### Effect of target position

We calculate the mean behavioral accuracy on sequence trials for each of possible serial position of the target stimulus:

```{r}
dt_seq_behav_position = dt_seq_behav %>%
  # filter out excluded subjects:
  filter(!(subject %in% subjects_excluded)) %>% setDT(.) %>%
  # average accuracy for each participant:
  .[, by = .(subject, trial_target_position), .(
    num_trials = .N,
    mean_accuracy = mean(accuracy)
  )] %>%
  verify(.[, by = .(trial_target_position), .(
    num_subs = .N
  )]$num_subs == 36) %>%
  transform(mean_accuracy = mean_accuracy * 100) %>%
  setorder(subject, trial_target_position)
```

```{r}
lme_seq_behav_position = lmer(
  mean_accuracy ~ trial_target_position + (1 + trial_target_position | subject),
  data = dt_seq_behav_position, na.action = na.omit, control = lcctrl)
summary(lme_seq_behav_position)
anova(lme_seq_behav_position)
```

#### Figure S1d

```{r, echo=TRUE}
fig_seq_position = ggplot(data = dt_seq_behav_position, mapping = aes(
  y = as.numeric(mean_accuracy), x = as.factor(trial_target_position),
  fill = as.factor(trial_target_position), color = as.factor(trial_target_position))) +
  geom_bar(stat = "summary", fun = "mean") +
  geom_dotplot(binaxis = "y", stackdir = "center", stackratio = 0.5,
               color = "black", alpha = 0.5,
               inherit.aes = TRUE, binwidth = 2) +
  geom_errorbar(stat = "summary", fun.data = "mean_se", width = 0.0, color = "black") +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  ylab("Accuracy (%)") + xlab("Target position") +
  scale_fill_manual(values = color_events, guide = FALSE) +
  scale_color_manual(values = color_events, guide = FALSE) +
  coord_capped_cart(left = "both", bottom = "both", expand = TRUE, ylim = c(0, 100)) +
  theme(axis.ticks.x = element_blank(), axis.line.x = element_blank()) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks.x = element_line(color = "white")) +
  theme(axis.line.x = element_line(color = "white")) +
  theme(axis.ticks.y = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
fig_seq_position
```

#### Source Data File Fig. S1d

```{r}
dt_seq_behav_position %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_s1d.csv"),
            row.names = FALSE)
```

### Repetition trials

#### Mean accuracy

We calculate mean behavioral accuracy in repetition trials for each participant:

```{r}
dt_rep_behav = dt_events %>%
  # filter for repetition trials only:
  filter(condition == "repetition") %>% setDT(.) %>%
  # create additional variables to describe each trial:
  .[, by = .(subject, trial), ":=" (
    trial_key_down = ifelse(any(key_down == 1, na.rm = TRUE), 1, 0),
    trial_accuracy = ifelse(any(accuracy == 1, na.rm = TRUE), 1, 0),
    trial_target_position = serial_position[which(target == 1)],
    trial_speed = unique(interval_time[which(!is.na(interval_time))])
  )] %>%
  # select only choice trials that contain the accuracy data:
  filter(trial_type == "choice") %>% setDT(.) %>%
  verify(all(trial_accuracy == accuracy)) %>%
  # average across trials separately for each participant:
  .[, by = .(subject, trial_target_position), .(
    num_trials = .N,
    mean_accuracy = mean(accuracy)
  )] %>%
  verify(all(num_trials == 5)) %>%
  # transform mean accuracy into percent (%)
  transform(mean_accuracy = mean_accuracy * 100) %>%
  # check if accuracy values range between 0 and 100
  verify(between(x = mean_accuracy, lower = 0, upper = 100)) %>%
  mutate(interference = ifelse(
    trial_target_position == 2, "fwd", trial_target_position)) %>%
  transform(interference = ifelse(
    trial_target_position == 9, "bwd", interference))
```

We run separate one-sided one-sample t-tests to access if mean behavioral performance for every repetition condition differs from a 50% chance level:

```{r}
chance_level = 50
dt_rep_behav_chance = dt_rep_behav %>%
  # filter out excluded subjects:
  filter(!(subject %in% subjects_excluded)) %>%
  setDT(.) %>%
  # average across participants:
  .[, by = .(trial_target_position), {
    ttest_results = t.test(
      mean_accuracy, mu = chance_level, alternative = "greater")
  list(
    mean_accuracy = round(mean(mean_accuracy), digits = 2),
    sd_accuracy = round(sd(mean_accuracy), digits = 2),
    tvalue = round(ttest_results$statistic, digits = 2),
    pvalue = ttest_results$p.value,
    conf_lb = round(ttest_results$conf.int[1], digits = 2),
    conf_ub = round(ttest_results$conf.int[2], digits = 2),
    cohens_d = round((mean(mean_accuracy) - chance_level)/sd(mean_accuracy), 2),
    df = ttest_results$parameter,
    num_subs = .N,
    sem_upper = mean(mean_accuracy) + (sd(mean_accuracy)/sqrt(.N)),
    sem_lower = mean(mean_accuracy) - (sd(mean_accuracy)/sqrt(.N))
  )}] %>% verify(num_subs == 36) %>%
  mutate(sem_range = sem_upper - sem_lower) %>%
  setDT(.) %>%
  filter(trial_target_position %in% seq(2,9)) %>%
  # create additional variable to label forward and backward interference:
  mutate(interference = ifelse(
    trial_target_position == 2, "fwd", trial_target_position)) %>%
  transform(interference = ifelse(
    trial_target_position == 9, "bwd", interference)) %>%
  mutate(pvalue_adjust = p.adjust(pvalue, method = "fdr")) %>%
  mutate(pvalue_adjust_round = round_pvalues(pvalue_adjust)) %>%
  mutate(significance = ifelse(pvalue_adjust < 0.05, "*", "")) %>%
  mutate(cohens_d = paste0("d = ", cohens_d, significance)) %>%
  mutate(label = paste0(
    trial_target_position - 1, "/", 10 - trial_target_position)) %>%
  setDT(.) %>%
  setorder(trial_target_position)
# print table:
rmarkdown::paged_table(dt_rep_behav_chance)
```

#### Figure 1f

We plot the results of the forward and backward interference conditions:

```{r, echo=TRUE}
plot_data = dt_rep_behav_chance %>% filter(trial_target_position %in% c(2,9))
fig_behav_rep = ggplot(data = plot_data, mapping = aes(
  y = as.numeric(mean_accuracy), x = fct_rev(as.factor(interference)),
  fill = as.factor(interference))) +
  geom_bar(stat = "summary", fun = "mean") +
  geom_dotplot(data = dt_rep_behav %>%
                 filter(!(subject %in% subjects_excluded)) %>%
                 filter(trial_target_position %in% c(2,9)) %>% setDT(.) %>%
                 .[, by = .(subject, interference), .(
                   mean_accuracy = mean(mean_accuracy)
                 )],
               binaxis = "y", stackdir = "center", stackratio = 0.5,
               color = "black", alpha = 0.5, inherit.aes = TRUE, binwidth = 2) +
  geom_errorbar(aes(ymin = sem_lower, ymax = sem_upper), width = 0.0, color = "black") +
  ylab("Accuracy (%)") + xlab("Interfererence") +
  ggtitle("Repetition") +
  theme(plot.title = element_text(hjust = 0.5)) +
  scale_fill_manual(values = c("red", "dodgerblue"), guide = FALSE) +
  coord_capped_cart(left = "both", bottom = "both", expand = TRUE, ylim = c(0,100)) +
  theme(axis.ticks.x = element_blank(), axis.line.x = element_blank()) +
  theme(plot.title = element_text(size = 12, face = "plain")) +
  #scale_y_continuous(labels = label_fill(seq(0, 100, 12.5), mod = 2), breaks = seq(0, 100, 12.5)) +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  #geom_text(aes(y = as.numeric(mean_accuracy) + 10, label = pvalue_adjust_round), size = 3) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks.x = element_line(color = "white")) +
  theme(axis.line.x = element_line(color = "white")) +
  theme(axis.ticks.y = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
fig_behav_rep
```

#### Source Data File Fig. 1f

```{r}
dt_rep_behav %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_1f.csv"),
            row.names = FALSE)
```

#### Figure S1e

We plot the results of all intermediate repetition conditions:

```{r, echo=TRUE}
plot_data = dt_rep_behav_chance %>% filter(trial_target_position %in% seq(2,9))
plot_behav_rep_all = ggplot(data = plot_data, mapping = aes(
  y = as.numeric(mean_accuracy), x = as.numeric(trial_target_position),
  fill = as.numeric(trial_target_position))) +
  geom_bar(stat = "identity") +
  geom_dotplot(data = dt_rep_behav %>%
                 filter(!(subject %in% subjects_excluded)) %>%
                 filter(trial_target_position %in% seq(2,9)) %>% setDT(.) %>%
                 .[, by = .(subject, trial_target_position), .(
                   mean_accuracy = mean(mean_accuracy)
                 )],
               aes(x = as.numeric(trial_target_position),
                   fill = as.numeric(trial_target_position),
                   group = as.factor(trial_target_position)),
               binaxis = "y", stackdir = "center", stackratio = 0.5,
               inherit.aes = TRUE, binwidth = 2, color = "black", alpha = 0.5) +
  geom_errorbar(aes(ymin = sem_lower, ymax = sem_upper), width = 0.0, color = "black") +
  geom_text(aes(y = as.numeric(mean_accuracy) + 7, label = cohens_d), size = 2.5) +
  ylab("Accuracy (%)") + xlab("First / second item repetitions") +
  scale_fill_gradient(low = "dodgerblue", high = "red", guide = FALSE) +
  coord_capped_cart(left = "both", bottom = "both", expand = TRUE, ylim = c(0,100)) +
  scale_x_continuous(labels = plot_data$label, breaks = seq(2, 9, 1)) +
  geom_hline(aes(yintercept = 50), linetype = "dashed", color = "black") +
  theme(axis.ticks.x = element_blank(), axis.line.x = element_blank()) +
  theme(axis.text = element_text(color = "black")) +
  theme(axis.ticks.x = element_line(color = "white")) +
  theme(axis.line.x = element_line(color = "white")) +
  theme(axis.ticks.y = element_line(color = "black")) +
  theme(axis.line.y = element_line(colour = "black"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank())
plot_behav_rep_all
```

#### Source Data File Fig. S1e

```{r}
dt_rep_behav %>%
  select(-num_trials) %>%
  write.csv(., file = file.path(path_sourcedata, "source_data_figure_s1e.csv"),
            row.names = FALSE)
```

```{r, echo=TRUE, eval=FALSE}
ggsave(filename = "highspeed_plot_behavior_repetition_supplement.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures,
       scale = 1, dpi = "retina", width = 5, height = 3, units = "in")
```

We run a LME model to test the effect of repetition condition on mean behavioral accuracy in repetition trials:

```{r}
lme_rep_behav_condition = lmer(
  mean_accuracy ~ trial_target_position + (1 + trial_target_position|subject),
  data = dt_rep_behav, na.action = na.omit, control = lcctrl)
summary(lme_rep_behav_condition)
anova(lme_rep_behav_condition)
```

### Figure Main

We plot the figure for the main text:

```{r, echo=FALSE}
plot_grid(fig_behav_odd, fig_seq_speed, fig_behav_rep, ncol = 3,
          rel_widths = c(2, 4.5, 2.5), labels = c("d", "e", "f"))
```

```{r, echo=FALSE, eval=FALSE}
ggsave(filename = "highspeed_plot_behavior_horizontal.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures,
       scale = 1, dpi = "retina", width = 7, height = 3, units = "in")
```

```{r, echo=FALSE}
ggsave(filename = "wittkuhn_schuck_figure_1ef.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures,
       scale = 1, dpi = "retina", width = 7, height = 3, units = "in")
```


### Figure SI

We plot the figure for the supplementary information:

```{r, echo=FALSE}
plot_grid(
  plot_grid(
    fig_behav_all_outlier, plot_odd_sdt, plot_odd_run,
    rel_widths = c(3.5, 6, 5), ncol = 3, nrow = 1, labels = c("a", "b", "c")),
  plot_grid(
    fig_seq_position, plot_behav_rep_all, labels = c("d", "e"),
    ncol = 2, nrow = 1, rel_widths = c(4, 6)),
  nrow = 2)
```

```{r, echo=FALSE, eval=FALSE}
ggsave(filename = "highspeed_plot_behavior_supplement.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures, scale = 1,
       dpi = "retina", width = 8, height = 5)
```

```{r}
ggsave(filename = "wittkuhn_schuck_figure_s1.pdf",
       plot = last_plot(), device = cairo_pdf, path = path_figures, scale = 1,
       dpi = "retina", width = 8, height = 5)
```

## Participants

We analyze characteristics of the participants:

```{r, results="hold"}
# read data table with participant information:
dt_participants <- do.call(rbind, lapply(Sys.glob(path_participants), fread))
# remove selected participants from the data table:
dt_participants = dt_participants %>%
  filter(!(participant_id %in% subjects_excluded)) %>%
  setDT(.)
base::table(dt_participants$sex)
round(sd(dt_participants$age), digits = 2)
base::summary(
  dt_participants[, c("age", "digit_span", "session_interval"), with = FALSE])
round(sd(dt_participants$session_interval), digits = 2)
```