1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
A parity judgment task to assess the SNARC effect.
See e.g.:
Gevers, W., Reynvoet, B., & Fias, W. (2003). The mental representation of
ordinal sequences is spatially organized. Cognition, 87(3), B87-95.
"""
from expyriment import design, control, stimuli
from expyriment.misc import constants
control.set_develop_mode(False)
########### DESIGN ####################
exp = design.Experiment(name="SNARC")
# Design: 2 response mappings x 8 stimuli x 10 repetitions
for response_mapping in ["left_odd", "right_odd"]:
block = design.Block()
block.set_factor("mapping", response_mapping)
#add trials to block
for digit in [1, 2, 3, 4, 6, 7, 8, 9]:
trial = design.Trial()
trial.set_factor("digit", digit)
block.add_trial(trial, copies=10)
block.shuffle_trials()
exp.add_block(block)
exp.add_experiment_info("This a just a SNARC experiment.")
#add between subject factors
exp.add_bws_factor('mapping_order', ['left_odd_first', 'right_odd_first'])
#prepare data output
exp.data_variable_names = ["block", "mapping", "trial", "digit", "ISI",
"btn", "RT", "error"]
#set further variables
t_fixcross = 500
min_max_ISI = [200, 750] # [min, max] inter_stimulus interval
ITI = 1000
t_error_screen = 1000
no_training_trials = 10
######### INITIALIZE ##############
control.initialize(exp)
# Prepare and preload some stimuli
blankscreen = stimuli.BlankScreen()
blankscreen.preload()
fixcross = stimuli.FixCross()
fixcross.preload()
error_beep = stimuli.Tone(duration=200, frequency=2000)
error_beep.preload()
#define a trial
def run_trial(cnt, trial):
# present Fixation cross and prepare trial in the meantime
fixcross.present()
exp.clock.reset_stopwatch()
ISI = design.randomize.rand_int(min_max_ISI[0], min_max_ISI[1])
digit = trial.get_factor("digit")
target = stimuli.TextLine(text=str(digit), text_size=60)
target.preload()
exp.clock.wait(t_fixcross - exp.clock.stopwatch_time)
#present blankscreen for a random interval
blankscreen.present()
exp.clock.wait(ISI)
# Present target & record button response
target.present()
btn, rt = exp.keyboard.wait([constants.K_LEFT, constants.K_RIGHT])
#Error feedback if required
if block.get_factor("mapping") == "left_odd":
error = (digit % 2 == 0 and btn == constants.K_LEFT) or \
(digit % 2 == 1 and btn == constants.K_RIGHT)
else:
error = (digit % 2 == 1 and btn == constants.K_LEFT) or \
(digit % 2 == 0 and btn == constants.K_RIGHT)
if error:
error_beep.present()
#write data and clean up while inter-trial-interval
blankscreen.present()
exp.clock.reset_stopwatch()
exp.data.add([block.id, block.get_factor("mapping"),
cnt, target.text, ISI,
btn, rt, int(error)])
exp.data.save()
target.unload()
exp.clock.wait(ITI - exp.clock.stopwatch_time)
######### START ##############
control.start(exp)
# permute block order across subjects
if exp.get_permuted_bws_factor_condition('mapping_order') == "right_odd_first":
exp.swap_blocks(0, 1)
# Run the actual experiment
for block in exp.blocks:
# Show instruction screen
if block.get_factor("mapping") == "left_odd":
instruction = "Press LEFT arrow key for ODD\n" + \
"and RIGHT arrow key for EVEN numbers."
else:
instruction = "Press RIGHT arrow key for ODD\n" + \
"and LEFT arrow key for EVEN numbers."
stimuli.TextScreen("Indicate the parity of the numbers", instruction +
"\n\nPress space bar to start training.").present()
exp.keyboard.wait(constants.K_SPACE)
#training trials
for cnt in range(0, no_training_trials):
trial = block.get_random_trial()
run_trial(-1 * (1 + cnt), trial) #training trails has negative trial numbers
# Show instruction screen
stimuli.TextScreen("Attention!", instruction +
"\n\nThe experimental block starts now.").present()
exp.keyboard.wait(constants.K_SPACE)
# experimental trials
for cnt, trial in enumerate(block.trials):
run_trial(cnt, trial)
####### END EXPERIMENT ########
control.end(goodbye_text="Thank you very much for participating in our experiment",
goodbye_delay=5000)
|
