1. Effects of inhibition training on event-related potential markers of inhibitory control in heavy drinkers
Mrunal Bandawar , MBBS1,2 ; Matt Field, PhD1
1 University of Liverpool, Liverpool, UK
2National Institute of Mental Health And Neurosciences, Bangalore, India
Introduction
Analysis
The P300 was evident at both stop-signal delays (between 300–400 ms on trials with a 150 ms stop-signal delay, and between 400–600 ms on trials with a 250 ms stop-signal delay).
We performed a 3 (electrode: Fz, Cz, Pz) × 3 (Group: inhibitory training, active control and mindfulness) ANOVA. There were significant main effects of electrode (F(2, 45)= 4.459, p<0.01; p300 was larger at the central and frontal electrodes).
This reflected larger P300 amplitudes in the central and frontal electrode at both the stop-signal delay. On post hoc analysis, mindfulness group had significantly lower amplitude than the other two groups at the frontal and central electrodes at the .05 level of significance.
The N200 amplitudes had a non-significant difference. 1
Eye movement artefact correction through Independent Component Analysis in EEGLAB. 2
Time locked epochs were extracted from -500ms to 1000 ms for Go stimulus, stop signal at 150 ms and 250 ms. 3
Epochs with step like and movement artefacts were rejected.
Averaging was performed.
Inhibition control training could influence health behaviour, perhaps short term (Allom et al., 2015).
Games are used for cognitive training and have shown promising results in the ADHD and mild cognitive impairment population.
Cognitive training with use of a serious game has been found to decrease relapse in alcoholics. (Gamito et al., 2014).
Brief Mindfulness Intervention was found to be effective in the reduction of binge drinking episodes in college students (Mermelstein et al., 2015).
Reduced amplitude of P300 had been proved as a biomarker and endophenotype for alcoholism (Kamarajan et al., 2005a,b).
Amplitude of P300 had been shown to predict At lab alcohol consumption (Jones et al., 2013).
The present study is designed to find out the effect of inhibitory control training on P300, through a smart phone game and Brief Mindfulness Intervention in heavy drinkers.
Figure2: Graph showing the mean amplitudes of P300 at Cz electrode
Results
Methods and Materials
The study is still in progress and aims to recruit 60 participants who regularly consume alcohol in excess of UK government guidelines (14 units per week for women, 21 units per week for men) between age of 18 to 35 years.
48 participants have been recruited so far.
Participants performed 30 minutes of activity (described below) provided in the respective group following which EEG was recorded with the help of the 64 channels Biosemi system with the stop-signal task activity performed on the computer screen.
Figure 1: Waveforms showing activity at Cz electrode
Waveform of Stop signal at 150ms
P300
N200
Recruitment after consent (n=48)
Random division to one of the group
Discussion
Significantly low P300 was observed in mindfulness group compared to the inhibitory training and active control group, which may be due to better conflict resolution ability after performing the Brief Mindfulness Intervention.
These results are consistent with previous studies which reported on electrophysiology of mindfulness intervention (Sanger et al., 2015).
Mindfulness could be used to address the P300 which is associated with executive attention, memory updating and retrieval, the dopaminergic reward system and the areas of Prefrontal and Anterior Cingulate Cortex (Polich 2007) and as a biomarker for alcoholism (Kamarajan et al., 2005a).
Future research could explore the effect produced by the inhibitory component in the game using a within group design.
Time frequency analysis may be helpful to further explain the current results.
Inhibition Training Group (n=16)
Go- Coloured fruits
Stop- Discoloured Fruits
Mindfulness Group (n=16)
Listen through headphones to step wise audio instructions for mindfulness
Waveform of Stop signal at 250ms
Active Control Group (n=16)
Go- Coloured fruits
P300
N200
Inhibitory Training Group
Active Control Group
Mindfulness
EEG(Biosemi 64 channel)
Stop Signal Task with stop signal delay of 150 and 250 ms
Debriefing
References
Contact
Acknowledgement
Allom et al., Does inhibitory control training improve health behaviour? A meta-analysis (2015)
Gamito et al., Executive functioning in alcoholics following an m-health cognitive stimulation program: Randomized controlled trial (2014)
Mermelstein et al., A Brief Mindfulness Intervention for College Student Binge Drinkers: A Pilot Study (2014)
Kamarajan et al., Alcoholism is a disinhibitory disorder: Neurophysiological evidence from a Go/No-Go task (2005a)
Kamarajan et al., Spatial-anatomical mapping of NoGo-P3 in the offspring of alcoholics: Evidence of cognitive and neural disinhibition as a risk for alcoholism (2005b)
Jones et al., P300 during response inhibition is associated with ad-lib alcohol consumption in social drinkers (2013)
Sanger et al., Mindfulness training for adolescents: A neurodevelopmental perspective on investigating modifications in attention and emotion regulation using event-related brain potentials (2015)
Polich et al., Updating P300: An integrative theory of P3a and P3b.(2007)
We appreciate the contribution of Dr. H.S. Guruprasad and team from Dept. of Computer science, BMS college of Engineering, Bangalore, India in coding and designing of the game used as the intervention.
Dr. Mrunal Bandawar
University of Liverpool
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