Add N400 semantic ERP experiment

eegnb/experiments/__init__.py

@@ -1,7 +1,7 @@
 from .visual_n170.n170 import VisualN170
 from .visual_p300.p300 import VisualP300
 from .visual_ssvep.ssvep import VisualSSVEP
-
+from .semantic_n400.n400 import TextN400
 # PTB does not yet support macOS Apple Silicon,
 # this experiment needs to run as i386 if on macOS.
 import sys

eegnb/experiments/semantic_n400/n400.py

@@ -0,0 +1,139 @@
+""" eeg-notebooks/eegnb/experiments/semantic_n400/n400.py """
+
+import os
+from time import time
+from glob import glob
+from random import choice, shuffle
+from psychopy import visual, core, event
+
+from eegnb.devices.eeg import EEG
+from eegnb.stimuli import N400_TEXT
+from eegnb.experiments import Experiment
+from typing import Optional
+
+import pandas as pd
+import numpy as np
+
+
+class TextN400(Experiment.BaseExperiment):
+
+    def __init__(self, duration=120, eeg: Optional[EEG]=None, save_fn=None,
+            n_trials=200, iti=0.5, soa=0.5, jitter=0.2):
+
+
+        exp_name = "Text N400" 
+
+        super(TextN400, self).__init__(exp_name, duration, eeg, save_fn, n_trials, iti, soa, jitter)
+
+
+
+        self.markernames = {
+            'congruent': 1,
+            'incongruent': 2
+        }
+
+    def load_stimulus(self):
+        """
+        Loads the text stimuli (congruent and incongruent sentences/words)
+        from the specified folders.
+        """
+
+        text_stim_path = N400_TEXT 
+
+
+        congruent_files = glob(os.path.join(text_stim_path, "congruent", "*.txt"))
+        self.congruent_stims = [] 
+        for f in congruent_files:
+            with open(f, 'r') as file:
+
+                self.congruent_stims.extend([line.strip() for line in file if line.strip()])
+
+
+        incongruent_files = glob(os.path.join(text_stim_path, "incongruent", "*.txt"))
+        self.incongruent_stims = [] 
+        for f in incongruent_files:
+            with open(f, 'r') as file:
+                self.incongruent_stims.extend([line.strip() for line in file if line.strip()])
+
+
+        num_congruent = len(self.congruent_stims) 
+        num_incongruent = len(self.incongruent_stims)
+
+
+        total_stims_available = num_congruent + num_incongruent
+        if total_stims_available == 0:
+            raise ValueError("No stimulus text files found in the congruent or incongruent folders!")
+
+
+        ratio_congruent = num_congruent / total_stims_available
+        ratio_incongruent = num_incongruent / total_stims_available
+
+        trials_to_use_congruent = min(num_congruent, int(self.n_trials * ratio_congruent))
+        trials_to_use_incongruent = min(num_incongruent, int(self.n_trials * ratio_incongruent))
+
+
+        self.n_trials = trials_to_use_congruent + trials_to_use_incongruent
+
+
+        selected_congruent = np.random.choice(self.congruent_stims, size=trials_to_use_congruent, replace=True).tolist()
+        selected_incongruent = np.random.choice(self.incongruent_stims, size=trials_to_use_incongruent, replace=True).tolist()
+
+        trial_data = []
+        for stim_text in selected_congruent:
+            trial_data.append({'stim_text': stim_text, 'type': 'congruent'})
+        for stim_text in selected_incongruent:
+            trial_data.append({'stim_text': stim_text, 'type': 'incongruent'})
+
+
+        shuffle(trial_data)
+
+
+        self.trials = pd.DataFrame(trial_data)
+        self.trials['iti'] = self.iti + np.random.rand(len(self.trials)) * self.jitter
+        self.trials['soa'] = self.soa
+
+
+
+        self.text_stim = visual.TextStim(win=self.window, text="", color='white', height=0.1) 
+        self.fixation = visual.GratingStim(win=self.window, size=0.2, pos=[0, 0], sf=0, rgb=[1, 0, 0])
+        self.fixation.setAutoDraw(True)
+
+
+        self.window.flip()
+
+        return None
+
+    def present_stimulus(self, idx: int):
+        """
+        Presents the current word/sentence stimulus and sends a marker to the EEG.
+        """
+
+        current_trial = self.trials.iloc[idx]
+        word_to_display = current_trial['stim_text']
+        stim_type = current_trial['type']
+        marker_value = self.markernames[stim_type]
+
+
+        self.text_stim.text = word_to_display
+        self.text_stim.draw()
+        self.fixation.draw() 
+
+
+        self.window.flip()
+
+
+        if self.eeg:
+            timestamp = time()
+
+            marker = [int(marker_value)] if self.eeg.backend == "muselsl" else int(marker_value) 
+            self.eeg.push_sample(marker=marker, timestamp=timestamp)
+
+
+        core.wait(self.soa)
+
+
+        self.text_stim.text = '' 
+        self.window.flip()
+
+
+        core.wait(current_trial['iti'])

eegnb/stimuli/__init__.py

@@ -2,3 +2,4 @@
 
 FACE_HOUSE = path.join(path.dirname(__file__), "visual", "face_house")
 CAT_DOG = path.join(path.dirname(__file__), "visual", "cats_dogs")
+N400_TEXT = path.join(path.dirname(path.abspath(__file__)), "text")

eegnb/stimuli/text/LICENSE.txt

@@ -0,0 +1,3 @@
+All the text data were taken from N400Stimset_stimuli_parameters.tsv from the paper given below
+Evoking the N400 event-related potential (ERP) component using a publicly available novel set of sentences with semantically incongruent or congruent eggplants 
+they are Public Domain (CC0).

eegnb/stimuli/text/congruent/C_text1.txt

@@ -0,0 +1 @@
+The cake is in the oven to bake.

eegnb/stimuli/text/congruent/C_text2.txt

@@ -0,0 +1 @@
+In the winter the pond will freeze.

eegnb/stimuli/text/congruent/C_text3.txt

@@ -0,0 +1 @@
+The soccer team scored a goal.

eegnb/stimuli/text/congruent/C_text4.txt

@@ -0,0 +1 @@
+My mom puts money in the bank.

eegnb/stimuli/text/congruent/C_text5.txt

@@ -0,0 +1 @@
+His mom makes her own pie crust.

eegnb/stimuli/text/incongruent/IC_text1.txt

@@ -0,0 +1 @@
+He puts gas in his chest.

eegnb/stimuli/text/incongruent/IC_text2.txt

@@ -0,0 +1 @@
+He put on his shoes to go apple.

eegnb/stimuli/text/incongruent/IC_text3.txt

@@ -0,0 +1 @@
+Babies sleep in shot.

eegnb/stimuli/text/incongruent/IC_text4.txt

@@ -0,0 +1 @@
+The angry boys got in a mouse.

eegnb/stimuli/text/incongruent/IC_text5.txt

@@ -0,0 +1 @@
+The cake is in the oven to milk.