Objectives: Deaf subjects with hearing aids or cochlear implants generally find it challenging to understand speech in noisy environments where a great deal of listening effort and cognitive load are invested.In prelingually deaf children, such difficulties may have detrimental consequences on the learningprocess and, later in life, on academic performance. Despite the importance of such a topic, currently,there is no validated test for the assessment of cognitive load during audiological tasks. Recently, alphaand theta EEG rhythm variations in the parietal and frontal areas, respectively, have been used as indicators of cognitive load in adult subjects.The aim of the present study was to investigate, by means of EEG, the cognitive load of pediatric subjectsaffected by asymmetric sensorineural hearing loss as they were engaged in a speech-in-noise identifi-cation task.Methods: Seven children (4F and 3M, age range ¼ 8e16 years) affected by asymmetric sensorineuralhearing loss (i.e. profound degree on one side, mild-to-severe degree on the other side) and using ahearing aid only in their better ear, were included in the study. All of them underwent EEG recordingduring a speech-in-noise identification task: the experimental conditions were quiet, binaural noise,noise to the better hearing ear and noise to the poorer hearing ear. The subjects' Speech RecognitionThresholds (SRT) were also measured in each test condition. The primary outcome measures were:frontal EEG Power Spectral Density (PSD) in the theta band and parietal EEG PSD in the alpha band, asassessed before stimulus (word) onset.Results: No statistically significant differences were noted among frontal theta power levels in the fourtest conditions. However, parietal alpha power levels were significantly higher in the “binaural noise”and in the “noise to worse hearing ear” conditions than in the “quiet” and “noise to better hearing ear”conditions (p < 0.001). SRT scores were consistent with task difficulty, but did not correlate with alphaand theta power level variations.Conclusion: This is the first time that EEG has been applied to children with sensorineural hearing losswith the purpose of studying the cognitive load during effortful listening. Significantly higher parietalalpha power levels in two of three noisy conditions, compared to the quiet condition, are consistent withincreased cognitive load. Specifically, considering the time window of the analysis (pre-stimulus), parietal alpha power levels may be a measure of cognitive functions such as sustained attention and selective inhibition. In this respect, the significantly lower parietal alpha power levels in the mostchallenging listening condition (i.e. noise to the better ear) may be attributed to loss of attention and tothe subsequent fatigue and “withdrawal” from the task at hand.
EEG activity as an objective measure of cognitive load during effortful listening: A study on pediatric subjects with bilateral, asymmetric sensorineural hearing loss
Giulia Cartocci;
2017-01-01
Abstract
Objectives: Deaf subjects with hearing aids or cochlear implants generally find it challenging to understand speech in noisy environments where a great deal of listening effort and cognitive load are invested.In prelingually deaf children, such difficulties may have detrimental consequences on the learningprocess and, later in life, on academic performance. Despite the importance of such a topic, currently,there is no validated test for the assessment of cognitive load during audiological tasks. Recently, alphaand theta EEG rhythm variations in the parietal and frontal areas, respectively, have been used as indicators of cognitive load in adult subjects.The aim of the present study was to investigate, by means of EEG, the cognitive load of pediatric subjectsaffected by asymmetric sensorineural hearing loss as they were engaged in a speech-in-noise identifi-cation task.Methods: Seven children (4F and 3M, age range ¼ 8e16 years) affected by asymmetric sensorineuralhearing loss (i.e. profound degree on one side, mild-to-severe degree on the other side) and using ahearing aid only in their better ear, were included in the study. All of them underwent EEG recordingduring a speech-in-noise identification task: the experimental conditions were quiet, binaural noise,noise to the better hearing ear and noise to the poorer hearing ear. The subjects' Speech RecognitionThresholds (SRT) were also measured in each test condition. The primary outcome measures were:frontal EEG Power Spectral Density (PSD) in the theta band and parietal EEG PSD in the alpha band, asassessed before stimulus (word) onset.Results: No statistically significant differences were noted among frontal theta power levels in the fourtest conditions. However, parietal alpha power levels were significantly higher in the “binaural noise”and in the “noise to worse hearing ear” conditions than in the “quiet” and “noise to better hearing ear”conditions (p < 0.001). SRT scores were consistent with task difficulty, but did not correlate with alphaand theta power level variations.Conclusion: This is the first time that EEG has been applied to children with sensorineural hearing losswith the purpose of studying the cognitive load during effortful listening. Significantly higher parietalalpha power levels in two of three noisy conditions, compared to the quiet condition, are consistent withincreased cognitive load. Specifically, considering the time window of the analysis (pre-stimulus), parietal alpha power levels may be a measure of cognitive functions such as sustained attention and selective inhibition. In this respect, the significantly lower parietal alpha power levels in the mostchallenging listening condition (i.e. noise to the better ear) may be attributed to loss of attention and tothe subsequent fatigue and “withdrawal” from the task at hand.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
