Background & Aims
It is suggested that applications involving lateralization are an effective approach that can be used as an alternative to conservative approaches in pathological pain syndromes such as Complex Regional Pain Syndrome Type-1 and phantom pain (1). Cortical disinhibition and deafferentation lead to impairments in body schema perception (2-4). In line with all these reasons, the necessity of applying lateralization training is crucial to restore cortical reorganization (1, 5). Since investigating the responses in frequency bands separately through brain oscillation analyses will provide more comprehensive information in understanding cognitive functions (6), it was aimed to investigate this aspect of hand lateralization training in amputees. Differently from other studies, we used a right-left discrimination paradigm with personal perspectives.
Methods
13 participants in the amputee group (woman/man: 11/2; mean age: 43.0 ± 10.44 years; mean education: 12.2 ± 4.43 years) and 12 participants in the control group (woman/man: 7/5; mean age: 36.08 ± 14.01; mean education: 15.1 ± 2.64 years) were included into the study. Electroencephalography (EEG) records were taken from all participants before and after hand lateralization training. Hand visuals were categorized in the way of laterality (right vs. left) and perspective (1st vs. 3rd personal perspective). Both behavioral outcomes and brain oscillatory characteristics (i.e., frequency and amplitude) of the EEG were analyzed. EEG signal was amplified with a BrainAmp 32-Channel MR System (Brain Product GmbH, Germany). The sampling rate was 500 Hz, and the band limits were 0.01–250 Hz. EEG recordings were performed using ‘‘BrainCap with Multitrodes’’ model cap which has 32 electrode locations and electrodes were placed according to the international 10/20 system on the scalp.
Results
In comparisons before and after training, individuals’ accuracy rate and reaction time performances improved. Accuracy responses were lower for hand images presented from a third-person perspective. Regarding right-left hand perception, delta (1-4 Hz) power responses of amputees were higher. It was found that delta responses were modulated in right hand perception, whereas theta responses were modulated in left hand perception. Delta phase responses were high in egocentric hand perception. It was found that theta power and phase responses modulated with lateralization training.
Conclusions
The high level of responses to first-person perspectives in the delta phase can be explained as this perspective being perceived more easily or individuals being better adapted to this visual. The increase in delta power and phase responses observed for the right hand shows that participants perceived the right hand more easily in both groups where there were more right dominant participants. Regarding theta oscillation responses of right-left hand perception, an increase in the theta power spectrum for the left hand was detected. This may be because the participants are mostly right dominant, so they pay more perceptual attention to the left side. The increase in theta power and phase responses after lateralization training suggests that there is a habituation and/or learning effect. It can be concluded that low frequency bands play a role in the perception of body image in relation to the cognitive processes of hand laterality and personal perspective perception.
References
1.Moseley GL, Flor H. Targeting cortical representations in the treatment of chronic pain: a review. Neurorehabilitation and neural repair. 2012;26(6):646-52.
2.Lyu Y, Guo X, Bekrater-Bodmann R, Flor H, Tong S. An event-related potential study on the time course of mental rotation in upper-limb amputees. Clin Neurophysiol. 2017;128(5):744-50.
3.Medina J, Coslett HB. Understanding body representations. Taylor & Francis; 2016. p. 1-4.
4.Melzack R, Wall PD. Pain mechanisms: a new theory. Science. 1965;150(3699):971-9.
5.Moseley GL. Graded motor imagery for pathologic pain: a randomized controlled trial. Neurology. 2006;67(12):2129-34.
6.Basar E, Basar-Eroglu C, Guntekin B, Yener GG. Brain’s alpha, beta, gamma, delta, and theta oscillations in neuropsychiatric diseases: proposal for biomarker strategies. Suppl Clin Neurophysiol. 2013;62:19-54.
Presenting Author
Burcu Dilek
Poster Authors
Burcu Dilek
PhD
Trakya University
Lead Author
Ebru Yıldırım
Istanbul Medipol University
Lead Author
Dariusz Zapala
The John Paul II Catholic University of Lublin, Faculty of Social Sciences, Institute of Psychology
Lead Author
Pawel Augustynowicz
The John Paul II Catholic University of Lublin, Faculty of Social Sciences, Institute of Psychology
Lead Author
Bahar Guntekin
Istanbul Medipol University
Lead Author
Lütfü Hanoglu
Istanbul Medipol University
Lead Author
Topics
- Specific Pain Conditions/Pain in Specific Populations: Neuropathic Pain - Central