trial_runner.py

from os.path import basename, splitext
from random import randint
from psychopy import core, event


def start(win, fixation_screen, pause_screen, stim_list, stim_order, maker, data_file, hardware=None):
    # Set trial constants
    start_alpha = 1.0
    change_time = 6000  # milliseconds # TODO:change happens in 2 sec blocks
    change_rate = 1000 / 60.0
    change_value = change_time / change_rate
    constants = (start_alpha, change_time, change_rate, change_value)
    '''
    all_stim_list = []
    for i in xrange(len(stim_order) / len(stim_list)):
        shuffle(stim_list)
        all_stim_list.extend(stim_list)
    '''
    trial_clock = core.Clock()

    for trial_number, conditions in enumerate(stim_order):
        block_number = ((trial_number + 1) / len(stim_order)) + 1

        stim_pairs = stim_list[trial_number]
        # print stim_pairs
        stim_pair = select_stimuli(stim_pairs, conditions[0], conditions[1])
        # print stim_pair
        image_1 = basename(stim_pair[1])
        image_2 = basename(stim_pair[0])
        change_type = str(conditions[1])
        stimuli_number = image_1.split('_')[0]
        stimuli_orientation = image_1.split('_')[1]
        trial_info = {'img1': image_1, 'img2': image_2, 'trl-': trial_number, 'bloc': block_number,
                      'img#': stimuli_number, 'orie': stimuli_orientation, 'CTyp': change_type}

        stim_pair = (maker(win, stim_pair[0]), maker(win, stim_pair[1]))

        if hardware:
            hardware.sync()
        display_fixation(win, fixation_screen, 1000, 1500)
        if hardware:
            hardware.send_event(key='imag', label='ImageAppears', description='Image appeared on-screen',
                                table=trial_info)
        trial(win, trial_clock, stim_pair, constants)
        # TODO:Move response to post-image so no motor artifact in trial. Include randomized response buttons for each
        # TODO: trial to avoid preparatory activity, indicate onscreen what each button represents for that trial (e.g. 1=change detected, 4=change not detected)
        pause, response, response_time = check_response(event.getKeys(timeStamped=trial_clock))
        if pause:
            escape = pause_screen.show()
            if escape:
                break
        else:
            win.flip(clearBuffer=True)
        data_file.write_data([block_number,
                              trial_number,# 'Cumulative_trial_number' \
                              image_1,# 'Image_Start' \
                              image_2,# 'Image_Finish' \
                              stimuli_number,# 'Stimuli_Number' \
                              stimuli_orientation,# 'Stimuli_Orientation' \
                              change_type,# 'Change' \
                              str(conditions[1] is not None),# 'Correct_Response' \
                              str(response),# 'Response' \
                              str(response and conditions[1]),# 'Correct' \
                              str(response_time),# 'Response_Time' \
                              str(trial_clock.getTime())# 'Trial_time'
                              ])


def trial(win, clock, stimuli, constants):
    ch_value = constants[3]
    win.callOnFlip(clock.reset)
    for j in xrange(0, len(stimuli), 2):
        stimuli[j].draw()
        stimuli[j + 1].draw()
        win.flip()
        for i in xrange(int(ch_value) - 1):
            stimuli[j].draw()
            if stimuli[j+1].opacity > 0.0:
                stimuli[j + 1].opacity -= 1 / ch_value
            stimuli[j + 1].draw()
            win.flip()


def select_stimuli(stim_list, orientation, abs_pres):
    """

    :param stim_list: list of 4 potential stimuli variants
    :param orientation: Which image orientation to use, left or right
    :param abs_pres: Which presentation style to perform, disappear or appear
    :return: list of stimuli in order of presentation style, 2nd image fades out while 1st image emerges.
    """
    return_list = [None, None]
    if abs_pres is 'present':
        alt_abs_pres = 'in'
    elif abs_pres is 'absent':
        alt_abs_pres = 'neither'
    else:
        alt_abs_pres = None
    for stim in stim_list:
        stim_split = splitext(stim.lower())[0].split('_')
        if orientation.lower() in stim_split:
            if abs_pres:
                if abs_pres in stim_split or alt_abs_pres in stim_split:
                    return_list[0] = stim
                else:
                    return_list[1] = stim
            elif 'present' in stim_split or 'in' in stim_split:
                return_list = list((stim, stim))
                return return_list
    return return_list


def display_fixation(win, fixation_screen, ISI_min, ISI_max):
    fixation_screen.draw()
    win.flip()
    ISI = randint(ISI_min, ISI_max) / 1000.0
    core.wait(ISI)
    return ISI


def check_response(keys_tuple):
    # # Checking for and clearing out all uses of 'esc' from the keys_tuple list
    #
    pause = False
    pop_list = []
    for index, key_tuple in enumerate(keys_tuple):
        if 'escape' in key_tuple:
            pop_list.insert(0, index)
            pause = True
    for popper in pop_list:
        keys_tuple.pop(popper)

    # # Check if there's any responses left, and if so, return the first one.
    #
    response, response_time = (None, None)
    if keys_tuple:
        response_tuple = keys_tuple[0]
        response, response_time = response_tuple

    return pause, response, response_time