One-minute visual fixation can identify patients with schizophrenia

Medical Xpress / Chinese Academy of Sciences / Schizophrenia Bulletin ^ | April 25, 2023 | Liu Jia / Xu Liu et al

[ConservativeMind]

Researchers demonstrated spatial and temporal abnormalities of spontaneous fixational saccades and their correlates with positive and cognitive symptoms in schizophrenia, suggesting that fixational saccades are a promising and easily obtainable biomarker for cognitive and positive symptoms and for complementary diagnosis in schizophrenia.

Schizophrenia is a devastating heterogenous psychotic disorder characterized by debilitating positive symptoms, negative symptoms, and cognitive deficits. Positive symptoms include hallucinations, delusions, disorganized speech and bizarre behaviors. Negative symptoms constitute an absence of normal functioning.

Given the central importance of seeing to humans, visual fixation is a fundamental behavioral pattern that allows people to gather information and guide decision-making. During visual fixation, microsaccades and large saccades (macrosaccades) occur spontaneously and frequently. These fixational saccades are sensitive to the structural and functional alterations of the cortical-subcortical-cerebellar circuit, and are closely linked with cognitive processes. However, the performances of fixational saccades in patients with schizophrenia remain largely unexplored.

Researchers analyzed fixational saccades recorded from 140 drug-naïve patients with first-episode schizophrenia and 160 age-matched healthy subjects during ten separate six-second attempted fixations. They found that patients with schizophrenia exhibited significantly more vertical saccades and a greater vertical deviation of horizontal saccades. They also found that the fixational saccades, especially horizontal saccades, had longer durations, faster peak velocities, and larger amplitudes in patients than in controls.

Through careful measurements of the schizophrenia patient's cognitive capacities, researchers found that the longer duration of horizontal saccades was associated with lower cognitive performance, especially deficits in attention/vigilance and speed of processing, and that the greater vertical deviation of horizontal saccades was associated with more severe positive symptoms.

Based solely on the fixational eye movements recorded during a one-minute period, a simple machine-learning model classified patients and controls with an accuracy of 85%.

[lee martell]

Thanks. That was the word that tripped me up before. I didn’t recognize it.

[Pete from Shawnee Mission]

Stuck on a small island with all those boobies and you get island stare!

Or maybe its the Blue Feet!

[gleeaikin]

Thanks, I was going to ask someone if they could step outside the science jargon and explain “saccades.”

So I suppose the vertical saccades jump up and down, while the horizontal saccades jump from side to side?

[NobleFree]

You should read your links - then you’ll stip making yourself look silly:

“We need more case-control studies and clinical trials with a larger population to get conclusive data.”

[Does so]

To Noblefree:

“From the current data, we can conclude that the tetrahydrocannabinol (THC) component of cannabis can be the main culprit causing psychosis and schizophrenia in the at-risk population. THC can also be the one exacerbating symptoms and causing an adverse prognosis in already diagnosed patients”.

[NobleFree]

I see you replied to ConservativeMind while addressing me - very slippery.

“Can be” = is not ruled out by the available evidence. Pretty thin gruel.