Assessing Cognitive Workload in Motor Decision-Making through Functional Connectivity Analysis: Towards Early Detection and Monitoring of Neurodegenerative Diseases

Abstract

Neurodegenerative diseases (NDs), such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis, and frontotemporal dementia, among others, are increasingly prevalent in the global population. The clinical diagnosis of these NDs is based on the detection and characterization of motor and non-motor symptoms. However, when these diagnoses are made, the subjects are often in advanced stages where neuromuscular alterations are frequently irreversible. In this context, we propose a methodology to evaluate the cognitive workload (CWL) of motor tasks involving decision-making processes. CWL is a concept widely used to address the balance between task demand and the subject’s available resources to complete that task. In this study, multiple models for motor planning during a motor decision-making task were developed by recording EEG and EMG signals in n=17 healthy volunteers (9 males, 8 females, age 28.66±8.8 years). In the proposed test, volunteers have to make decisions about which hand should be moved based on the onset of a visual stimulus. We computed functional connectivity between the cortex and muscles, as well as among muscles using both corticomuscular and intermuscular coherence. Despite three models being generated, just one of them had strong performance. The results showed two types of motor decision-making processes depending on the hand to move. Moreover, the central processing of decision-making for the left hand movement can be accurately estimated using behavioral measures such as planning time combined with peripheral recordings like EMG signals. The models provided in this study could be considered as a methodological foundation to detect neuromuscular alterations in asymptomatic patients, as well as to monitor the process of a degenerative disease.

Decision-Making Time Analysis for Assessing Processing Speed in Athletes during Motor Reaction Tasks

“…For instance, prior studies in right-handed participants [ 45 , 46 ] showed broad activation across parietal and frontal regions in the left hemisphere during movements for either hand, whereas activation of homologous regions only in the right hemisphere tends to be more limited to left-hand actions. This evidence suggests that the motor planning in control participants differs between hemispheres, as observed in our previous work [ 25 ]. This could be explained by the greater inhibitory mechanisms of the left hemisphere for the right hand during movement preparation in right-handers, as suggested by Klein et al [ 37 ].…”

“…This synchronization ensured continuous alignment of all three types of signals, thereby preventing any lag or delay that could compromise data accuracy. Extensive details of the instrumental setup can be found in a previous study [ 25 ]. The three types of signal are depicted in Figure 2 A.…”

“…The experimental protocol was based on a previous study [25]. The procedure took place in a quiet room designed for neuroscience research, where the room temperature was maintained within the range of 20 to 24 • C. The room was equipped with amenities for noise isolation and minimizing distractions.…”