Neuroscience
-
Review
Dualism, Materialism, and the relationship between the brain and the mind in experiencing pain.
Characterizing the relationship between the brain and the mind is essential, both for understanding how we experience sensations and for attempts to create machine-based artificial intelligence. Materialists argue that the brain and the mind are both physical/material in nature whereas Cartesian dualists posit that the brain is material, the mind is non-material, and that they are separate. Recent investigations into the mechanisms responsible for pain can resolve this issue. ⋯ The material brain and immaterial mind are therefore separate and we can no longer attribute painfulness solely to the activities of the brain. This is a radical departure from the contemporary view of brain functions and supports Cartesian Dualism. Consequently, consciousness and higher mental functions cannot be duplicated by mimicking the activities of the brain.
-
Dual-task paradigms, which involve performing cognitive and motor tasks simultaneously, are commonly used to study how attentional resources are allocated and managed under varying task demands. This study aimed to investigate cognitive-motor interferences (CMI) under different levels of cognitive and motor task difficulty without instruction on task prioritization. 17 healthy young adults performed an auditory oddball task with increasing cognitive and motor (walking vs. sitting) difficulty. Cognitive and motor performances, along with P3 (P3a and P3b) brainwave components, were analysed. ⋯ Our study suggests managing attentional resources to balance cognitive and motor tasks rather than linearly increasing task complexity. Viewing dual tasks as a new, integrated task is proposed, supported by previous neural network integration studies. Thus, understanding how the brain organizes tasks in response to constraints is crucial for comprehending complex task execution.
-
Cortical activity is coupled with streams of sensory stimulation. The coupling with the temporal envelope of heard speech is known as the cortical tracking of speech (CTS), and that with movement kinematics is known as the corticokinematic coupling (CKC). Simultaneous measurement of both couplings is desirable in clinical settings, but it is unknown whether the inherent dual-tasking condition has an impact on CTS or CKC. ⋯ Despite the subtle behavioral effects, CTS and CKC are not evidently altered by the dual-task setting inherent to recording them simultaneously and can be evaluated simultaneously using EEG in clinical settings.
-
Theta oscillations in observers' temporal cortex index postural instability of point-light displays.
This study investigates whether postural equilibration follows the same principles of motor resonance as goal-oriented actions, namely, whether an individual activates the same neuronal substrates when experiencing postural perturbation as when observing another individual in this condition. To address this question, we examined electroencephalographic dynamics while subjects observed point-light displays featuring an unstable human display, a stable human display, and their respective scrambled counterparts lacking shape information and biological motion. We focused on theta band (4-7 Hz), which is a fundamental frequency for modulating brain activity during challenging balance tasks and reflects postural stability monitoring. ⋯ By contrast, the stronger theta response to the stable display as compared to the unstable one could be due to the difficulty of recognizing low-motion biological stimuli, or alternatively, to a facilitation of stimulus processing and strengthening of the mirroring response. The response facilitation for stable posture, coupled with a diminished response to the unstable display, could contribute to a broader mechanism mitigating postural threats and ensuring stable balance. Future investigations should leverage these findings to explore how posture-related responses correlate with perceptual and motor expertise, and to more clearly define these mechanisms during dynamic social interactions.
-
Meta Analysis
Mendelian randomization in Alzheimer's disease and mild cognitive impairment: Hippocampal volume associations.
This study investigates the association between cognitive dysfunction and hippocampal volumes in Alzheimer's Disease (AD) and Mild Cognitive Impairment (MCI) using Mendelian randomization. A meta-analysis of 503 healthy controls, 562 MCI patients, and 389 CE patients revealed significant reductions in hippocampal and subregion volumes in MCI and AD compared to controls. While various subregions showed volume reductions, no causal relationship between hippocampal volume and AD was established through Mendelian randomization analysis. In conclusion, significant volume reductions were observed in MCI and AD patients, highlighting the complexity of the relationship between hippocampal volume and cognitive impairment.