Filters for optimal smoothing of acoustic and electric blink reflex EMG responses to determine blink response magnitude

Abstract

Citation for published version (APA):van Boxtel, A. (2010). Filters for optimal smoothing of acoustic and electric blink reflex EMG responses to determine blink response magnitude. Biological Psychology, 85, 299-305. General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.-Users may download and print one copy of any publication from the public portal for the purpose of private study or research -You may not further distribute the material or use it for any profit-making activity or commercial gain -You may freely distribute the URL identifying the publication in the public portal Take down policyIf you believe that this document breaches copyright, please contact us providing details, and we will remove access to the work immediately and investigate your claim. The functional (i.e., kinematic) aspects of the blink reflex depend on the size of the integrated orbicularis oculi EMG response. Peak amplitude of smoothed rectified EMG is often used as an approximation of integrated EMG. A comparison was made between the outputs of 24 different smoothing filters, correlating peak amplitude of acoustic or electric blink reflexes with integrated EMG. The coefficient of determination (R 2 ) was largest (i.e., ≥.95 for acoustic and ≥.90 for electric blink reflexes) when using either (1) a first-order resistor-capacitor filter with a time constant of 50 or 100 ms, (2) a boxcar filter averaging 51 or 101 data points, or (3) an unequal-weight finite impulse response filter with a cutoff frequency of 5 or 10 Hz. These filters are thus recommended when determining peak amplitude. Applying a baseline correction on peak amplitude and integrated EMG produced slightly smaller values of R 2 compared with uncorrected measures.

Age-related differences in judgments of inappropriate behavior are related to humor style preferences.

“…Clip types (control vs. inappropriate) were presented in a random order (not in blocks). In order to make comparisons between different age groups, we computed Z -scores for our EMG measure by subtracting the mean baseline activity and normalizing it using the baseline standard deviation (van Boxtel, 2010). This method of normalizing the data has been used when comparing different age groups on physiological measures (Shiota & Levenson, 2009).…”

Back and front peripersonal space: behavioural and EMG evidence of top–down and bottom–up mechanisms

“…EMG responses were then quantified in terms of (i) Onset Latency (latency between the start of each stimulus and blinking onset; (ii) Peak Latency (latency between the start of the stimulus and the peak of blinking; (iii) Peak amplitude. The aforementioned metrics are indeed retained the most representative in quantifying the response to a blinking stimulus from electromyographic signals (Blumenthal et al 2005 ; Blumenthal 1996 ; Berg and Balaban 1999 ; van Boxtel 2010 ).…”

Evaluating the Modulation of the Acoustic Startle Reflex in Children and Adolescents via Vertical EOG and EEG: Sex, Age, and Behavioral Effects

“…First, VEOG signals were bandpass filtered at 28–300 Hz, as the typical power spectra of acoustically elicited eyeblink ( Blumenthal et al, 2005 ; San-Martin et al, 2018 ). This filtering configuration cancels out low-frequency artifacts caused by eye stretching, overlapping electrode collars, retinal potentials, and other facial muscle activity, as well as by high-frequency artifacts associated with instrumentation noise and electromagnetic interference of power line harmonics ( van Boxtel, 2010 ). Filtering was performed via an infinite impulse response (fourth-order Butterworth filter, roll-off 24 dB per octave) ( van Boxtel et al, 1998 ).…”

“…There was also no significant difference between males (responsive trials 22.78 ± 1.39 in PPI; 22.72 ± 1.63 in PPF) and females (22.65 ± 1.25 in PPI; 22.26 ± 1.41 in PPF) in the number of responsive trials [PPI: t (61) = 0.41, p = 0.68; PPF: t (61) = 1.19, p = 0.24]. The mean amplitude and peak latency were detected from each VEOG channel within the poststartle window at 20–150 ms. Those measures were extracted for each individual trial, and the single-subject measure was derived by averaging across trials ( Blumenthal et al, 2005 ; van Boxtel, 2010 ).…”