Perceptual visual dependence for spatial orientation in patients with schizophrenia.

Background: Patients with schizophrenia are reported to have vestibular dysfunction and to weigh vestibular input to a lesser extent compared to healthy controls. Such deficits may increase visual dependence (VD) for spatial orientation at a perceptual level in these patients. The aim of this study is to compare VD levels between healthy control and patients with schizophrenia and to explore associations between VD and clinical measures in these patients.

Symptom severity is associated with leftward lateralization upon contextual modulation of visual vertical in patients with schizophrenia.

Background: Contextual processing dysfunction in patients with schizophrenia (SCZ) is not uniform and task-dependent. In SCZ, studies on the rod and frame test (RFT), which evaluates contextual modulation of verticality perception, are sparse. A main study that utilized a two-alternative forced choice design for judging rod verticality reported equivalent strength of RFT contextual modulation in healthy controls and SCZ.

Perceptual lateralization on the Rod-and-Frame Test in young and older adults.

Introduction: There is an overall left visual field/right hemisphere advantage in young adults for masked, tachistoscopically presented images on the Rod-and-Frame Test (RFT). This study explored potential age-related lateralization differences in processing of visual context on the RFT.

Methods: The 35 young and 33 older adults aligned a rod surrounded either by no frame, a vertical, or leftward/rightward tilted frame to their perceived vertical.

Young and Older Adults Differ in Integration of Sensory Cues for Vertical Perception.

Introduction: The subjective visual vertical (SVV) measures the perception of a person's spatial orientation relative to gravity. Weighted central integration of vestibular, visual, and proprioceptive inputs is essential for SVV perception. Without any visual references and minimal proprioceptive contribution, the static SVV reflects balance of the otolith organs.

High-normal blood glucose levels may be associated with decreased spatial perception in young healthy adults.

The negative effects of high normal glucose on cognitive function were previously reported in euglycemic individuals of middle age and the elderly population. This study aimed at examining the effect of baseline blood glucose levels on spatial ability, specifically verticality perception on the computerized rod and frame test (CRFT) in young healthy adults. 63 healthy male medical students (age range from 18-23 years), of whom 30 were non-fasting outside the month of Ramadan and 33 fasting during Ramadan of the year 2016, were recruited in order to create varying degrees of glycemia during which verticality perception was carried out.