Disturbed temporal dynamics of brain synchronization in vision loss

Area of Science:

• Neuroscience
• Visual System Research
• Brain Network Dynamics

Background:

• Vision loss results from damage along the visual pathway, impeding bottom-up processing.
• Perception relies on widespread cortical networks coordinating visual processing in space and time.
• The impact of vision loss on brain visual network activity and its relation to perception requires further investigation, particularly concerning temporal patterns.

Purpose of the Study:

• To investigate how vision loss affects the temporal activity patterns of brain visual networks.
• To determine the relationship between altered network activity and perceptual deficits in patients with vision loss.
• To analyze temporal dynamics of neural synchronization in the alpha band using electroencephalography (EEG).

Main Methods:

• Resting-state, eyes-closed electroencephalography (EEG) recorded from 19 partially blind patients and 13 healthy controls.
• Analysis of oscillatory activity power (local synchronization) and phase locking value (PLV, distant synchronization) in low- (7-9 Hz) and high-alpha (11-13 Hz) bands.
• Temporal pattern analysis using synchronized/desynchronized period length, Higuchi Fractal Dimension (HFD), and Detrended Fluctuation Analysis (DFA).

Main Results:

• Patients with vision loss exhibited less complex, more random, and noise-like temporal dynamics in high-alpha band activity compared to controls.
• Increased randomness in temporal patterns was significantly associated with worse performance in static (r = -0.54, p = 0.017) and kinetic perimetry (r = 0.47, p = 0.041).
• These findings indicate disrupted neural synchronization and communication within brain visual networks due to prolonged deafferentation.

Conclusions:

• Disturbed temporal patterns of neural synchronization in vision loss patients signify impaired communication within visual brain networks.
• The observed randomness in neural activity suggests a breakdown in coordinated processing following deafferentation.
• Impaired brain network synchronization may exacerbate the functional consequences of reduced visual input, impacting overall perception.