Expyriment: Attentional Blink Demo

blink_demo.py

# -*- coding: utf-8 -*-

"""
Attentional Blink experiment

Find the two numbers in the stream.

Enter "999" to quit experiment.

"""

from expyriment import *
import random

control.set_develop_mode(True) # <--  comment
########### DESIGN ####################

##Colour schemes:
bg_colour = misc.constants.C_GREY
#bg_colour = misc.constants.C_BLACK

exp = design.Experiment("Blinking_Magnitude", background_colour=bg_colour,
                        foreground_colour = misc.constants.C_BLACK)

#Variables:
numbers = [1,2,3,4,6,7,8,9]
letters = [letter for letter in 'ABCDEFGHJKLMNPQRSTUVWXYZ']
ISI = 100 #Inter-Stimulus-Interval: 100 ms
items = 16 #Number of letters per trial (+ 2 Numbers)
textsize = 44 #Stimuli size

for bl_name in ["Block1"]:
    block = design.Block(name=bl_name)
    for lag in range(1,8+1):
        for t1 in numbers:
            for t2 in numbers:
                if t1 != t2:
                    tr = design.Trial()
                    tr.set_factor("lag", lag)
                    tr.set_factor("T1", t1)
                    tr.set_factor("T2", t2)
                    t1pos = design.randomize.rand_int(3,7)
                    tr.set_factor("T1_pos", t1pos)
                    #make rsvp stimulus stream
                    random.shuffle(letters)
                    stream = letters[0:items]
                    stream.insert(t1pos-1, t1)
                    stream.insert(t1pos-1+lag, t2)
                    for stim in stream:
                            tr.add_stimulus(stimuli.TextLine(text=str(stim),
                                            text_colour = misc.constants.C_BLACK,
                                            text_size=textsize))

                    block.add_trial(tr)
    block.shuffle_trials()
    exp.add_block(block)


exp.data_variable_names = ["trial_cnt", "T1_Position", "Time_lag",
                           "T1", "T2", "Difference",
                           "T1_Resp", "T2_Resp",
                           "RT", "Correct", "Reversed"]

######### INITIALIZE ##############
control.initialize(exp)

blank = stimuli.BlankScreen()
blank.preload()
fixcross = stimuli.FixCross()
fixcross.preload()

number_input = io.TextInput(message="Answer:",
                    message_text_size = 24,
                    user_text_size = 24,
                    ascii_filter=range(ord("1"), ord("9")+1))
#Trial:
def run_trial(trial, trial_cnt):
    blank.present()
    exp.clock.wait(1000 - trial.preload_stimuli())

    fixcross.present()
    exp.clock.wait(1000) #1 second Fixation Cross

    # present stream
    for stim in trial.stimuli:
        stim.present()
        exp.clock.wait(ISI)

    blank.present()
    trial.unload_stimuli()

    exp.clock.reset_stopwatch()
    input_ok = False
    while(not input_ok):
        exp.keyboard.clear()
        answer = number_input.get()
        if answer == "999":
            control.end()
            quit()
        if len(answer) == 2:
            input_ok = True
        else:
            stimuli.TextLine("Enter the two numbers:", text_size=24).present()
            exp.clock.wait(3000)

    RT = exp.clock.stopwatch_time

    n1 = answer[0]
    n2 = answer[1]
    t1 = trial.get_factor("T1")
    t2 = trial.get_factor("T2")

    correct = (t1, t2) == (int(n1), int(n2)) #did the subject enter the correct numbers?
    reverse = False
    if not correct:
        reverse = (t1, t2) == (int(n2), int(n1)) #correct numbers but wrong order?

    semantic_diff = t2-t1 #semantic difference between the presented numbers

    exp.data.add([ trial_cnt, trial.get_factor("T1_pos"),
                   trial.get_factor("lag"),
                   t1, t2, abs(semantic_diff),
                   str(n1), str(n2), RT,
                   int(correct), int(reverse)])
    exp.data.save()



######### START ##############
control.start(exp)
#instruction:
stimuli.TextScreen("Find the two numbers!", "Enter '999' to quit experiment")
exp.keyboard.wait(misc.constants.K_SPACE)

# training
for x in range(10):
    trial = exp.blocks[0].get_random_trial()
    run_trial(trial, -1)

stimuli.TextScreen(u"Questions?", "", heading_size=40).present()
exp.keyboard.wait(misc.constants.K_SPACE)

# Experiment

for block in exp.blocks:
    stimuli.TextScreen("Experiment starts now!", u"press space bar...").present()
    exp.keyboard.wait(misc.constants.K_SPACE)
    for cnt, trial in enumerate(block.trials):
        run_trial(trial, cnt)
        if cnt in [90, 180, 270, 360]:
            stimuli.TextScreen("Pause!", u"press space bar...").present()
            exp.keyboard.wait(misc.constants.K_SPACE)

####### END EXPERIMENT ########
control.end(goodbye_text="Thank you very much for participating in our experiment",
             goodbye_delay=2000)