Keyboard Timeout set to a jitter

mckd

Hey Everyone,

Right now I am trying to implement a jitter to my experiment but I need to keyboard to timeout in response to the jitter. In order to do this, I have used inline script to set up my keyboard. Right now I get the following error: "TypeError: keyboard() takes at least 1 argument (0 given)"

from random import randint
from openexp.keyboard import keyboard

#start timer
t0 = clock.time()

#calculate jitter length
offset_time = randint(850, 1150)

#initiate keyboard, set wait time to the jitter
my_keyboard = keyboard(keylist=['space'], timeout=offset_time)
start_time = clock.time()

#get keyboard response
key, end_time = my_keyboard.get_key()
var.response = key
var.response_time = end_time - start_time

#calculate offset wait time (in case of early keypress), using the jitter
t1 = clock.time()
current = (t1-t0)
if current < offset_time:
    time = offset_time-current
    self.sleep(int(time))

sebastiaan

Hi,

The error is because you're mixing the old (≤ 2.9) and new (≥ 3.0) ways of creating a keyboard object.

The old way is to import the keyboard function (from openexp.keyboard import keyboard), and pass exp as the first argument. You're doing the former, but not the latter.

# <= 2.9
from openexp.keyboard import keyboard
k = keyboard(exp) # Plus optional keywords

The new way is to not important anything, and not pass exp as first argument. So it's much cleaner.

# >= 3.0
k = keyboard() # Plus optional keywords

Does that make sense?

See also:

• http://osdoc.cogsci.nl/3.1/manual/python/keyboard/

Cheers,
Sebastiaan

mckd

Sebastiaan,

This absolutely makes sense. I removed the import and it appears to be working perfectly now. I had another problem come up though, when I try to evaluate whether or not a correct response is given, in the case where the correct response is 'None' (i.e., no keyboard response is the correct response), I can't get the program to evaluate that as a "correct response". I tried adding print lines and "correct_response" is 'None' and the response is 'None' but when I compare the values in an if-statement it evaluates as false! Any ideas?

from random import randint

#start timer
t0 = clock.time()

#calculate jitter length
offset_time = randint(850, 1150)

#initiate keyboard, set wait time to the jitter
my_keyboard = keyboard(keylist=['space', '1'], timeout=offset_time)
start_time = clock.time()

#get keyboard response
key, end_time = my_keyboard.get_key()
var.response = key
var.response_time = end_time - start_time

#Set correct response
if var.response == var.correct_response:
    correct = 1
else:
    correct = 0
var.correct = correct

#print for debug
print("--Trial--")
print(var.response)
print(var.response_time)
print(var.correct_response)
print(var.response == var.correct_response)
print(var.correct)

#calculate offset wait time (in case of early keypress), using the jitter
t1 = clock.time()
current = (t1-t0)
if current < offset_time:
    time = offset_time-current
    self.sleep(int(time))

eduard

Hey,

In case no response is given, your variable key, is of None type. The variables in your loop table are implicitly converted to a number or to a string (where applicable). So typing None, will eventually be converted to "None". Do you see what I mean? (If not you can print the types of your response and your correct response variable. To make it work, you can also convert your key variable to a string (e.g. var.response = unicode(key).
Does this make sense?

Eduard

mckd

Eduard,

That absolutely makes sense and it absolutely worked. Thank you so much for your response!