I basically want to make a PSTH plot as shown in the attachment. the data is shown in the attachment, I wrote the code below and made a dot graph as shown in attachment, the next I should make the PSTH graph as shown in attachment. the teacher just said I can make this PSTH graph in a very similar way I made the dot graph. but I am confused, I've never made PSTH graph before and don't even understand why the y-axis is with decimals, shouldn't they represent the times of trails so should be integers like 1,2,3,4.. ? would anyone help me with the PSTH plot? it will help a lot, thanks!!

# Look for all of the spike times that are greater than (=come after) the time

# of the start of the trial, minus 1 second AND are less than (=come before) the start # time plus 9 seconds, so a total of 10 seconds.

# The & operator checks that both conditions are met.

trial <- times$Time[times$Time > (learnEvents$On[1] - 1) &

times$Time < (learnEvents$On[1] + 9)]

# We want to center our plot around the time when the image was shown

# We subtract the time of the beginning of the stimulus from every time so that

# this becomes time 0

trial <- trial - learnEvents$On[1]

# Plot the action potential times. Note that we specify ylim so that we can # add one line of dots for each trial!

stripchart(trial, pch = 20,

ylim = c(0, nrow(learnEvents)),

main = "Learn",

cex = 0.5, xlim = c(-1, 9))

# We can now add the rest of the trials.

# We start from 2 as we already plotted number 1! for (i in 2:nrow(learnEvents))

{

# This is the same as above, but now we are getting event 2, then 3, and so on

trial <- times$Time[times$Time>(learnEvents$On[i] - 1) &

times$Time<(learnEvents$On[i] + 9)]

# Note that we always subtract the time of the first event!

trial <- trial - learnEvents$On[i]

# The at parameter defines the height at which to plot the points stripchart(trial, pch = 20, add = TRUE, at = i, cex = 0.5)

}

# We plot a rectangle around the time the image was shown

# rgb specifies a colour as red, green, blue and transparency (from 0 to 1) rect(xleft = 0, ybottom = 0,

```
xright = learnEvents$Off[1] - learnEvents$On[1], ytop = nrow(learnEvents),
col = rgb(0.4, 0.4, 0.4, 0.2), border = NA)!!
```

![Jietu20201117-174700@2x|636x500](upload://t8OOM![Jietu20201117-174700@2x|636x500]