Screen Module

class Screen(const)

A class to create a screen for the experiment

Parameters:

const – local constants.py module (see example_experiment/constants.py) as example

check_mark(color='green', flip=True)

A method to draw a check mark on the screen

Parameters:

• color (str) – color of the check mark

• flip – whether to flip the screen after drawing the check mark

error_cross(color='red', flip=True)

A method to draw an error cross on the screen

Parameters:

• color (str) – color of the error cross

• flip – whether to flip the screen after drawing the error cross

fixation_cross(color='white', flip=True)

A method to draw a fixation cross on the screen

Parameters:

• color (str) – color of the fixation cross

• flip – whether to flip the screen after drawing the fixation cross

flip(marker=False, clock=None)

Flip the window, optionally leaving a photodiode / MEG-timing marker.

Behaves like self.window.flip() but adds two things needed for MEG/EEG (or any hardware) timing:

• marker=True draws the photodiode square (self.pd_square) white in a screen corner on this flip. A photodiode taped over that corner then records the true stimulus onset directly into the MEG/EEG file.

• clock (e.g. ttl_clock.clock) is used to timestamp the flip via callOnFlip; the time is stored and returned so the caller can log it (the flip_time column) for alignment with the recording.

Parameters:

• marker (bool) – if True, flash the photodiode square on this flip.

• clock (psychopy.core.Clock or None) – clock to timestamp the flip on.

Returns:

float or None – time of the flip on clock (None if no clock given).

start_screen(color='white')

A method to draw a start screen on the screen

store_flip_time(clock)

callOnFlip callback: capture the flip time right after the buffer swap.