Clinical Research Directory

Relationship Between Visuospatial Attention and Balance

The term equilibrium is related to Newton's first law and, as used in mechanics, describes the state where the effect of the forces acting on an object is zero. Equilibrium is divided into two types: static and dynamic. Static equilibrium is the ability to maintain posture without any external forces. This type of equilibrium requires the center of gravity to be kept within the support base. Dynamic equilibrium, on the other hand, is the equilibrium maintained during motion. It requires a controlled shift of the center of gravity. Equilibrium is controlled by the proprioceptive, visual, and vestibular systems. The perception of one's own motion and balance is encoded by proprioceptive and visual signals, along with the vestibular system's perception of inertial motion. Connections between the vestibular nuclei and the cerebellum, hippocampus, prefrontal and parietal cortices provide information for cognitive functions such as spatial functions, navigation, and memory. Adaptation to postural changes in complex environments is known to be achieved through the coordinated and seamless functioning of these structures. In addition to these main systems, spatial orientation has been shown to be a crucial component for balance and posture control. Information from these systems is integrated and processed depending on the task and environment. The interaction and processing of sensory components can also be influenced by ongoing body movements, anticipation, prediction, or instructions. This sensory processing process can depend on many factors. The integration process can also go through a process involving inhibition. For example, standing on the deck of a station, a moving train may cause a person to perceive their own movement. The visual inputs that produce this sensation need to be excluded or blocked from the integration process. Like reweighting, inhibition is a dynamic process. While sensory information continuously flows into the brain, incompatible sensory channel(s) must be identified and blocked from integration. Visual-spatial skills are of great importance for functional independence; they enable us to interact with our environment in 2 and 3 dimensions, perceive the shapes of objects in space, understand the location of objects in space, and understand the spatial orientation of our body. Visual-spatial abilities also include responses to scanning space, reaction speed, visualization, orientation, and sustained or focused attention. Visual stimuli provide individuals with information about the environment. Since visual-spatial codes are three-dimensional, the environment can be perceived in three dimensions. Visual-spatial attention, a component of visual-spatial components, selects relevant sensory information and supports the preparation of responses to this information. It is defined in the Lifelong Development Dictionary published by the APA as 'the way an individual distributes their attention to the visual field'. It selects relevant sensory information and supports the preparation of responses to this information. It allows for selective processing of visual information by prioritizing a specific visual field section. Visual-spatial attention can be directed from one direction to another voluntarily or involuntarily. It is known that cognitive and motor skills develop in a coordinated manner in both children and older adults and that there is a significant relationship between them. There are studies in the literature that address balance and visual-spatial skills and indicate a relationship between them. In their study investigating the relationship between these two functions in stroke patients, Embrechts et al. revealed that reduced visuospatial skills can cause balance and posture problems. It has been suggested that visuospatial input is essential for proactive planning and adjustments to maintain stability in dynamic and complex environments and allows for preventive regulation of movement patterns that provide safe movement and postural control.

Visuospatial and Affective Abilities in Parkinson Disease

The aim of the study is to investigate whether prismatic adaptation (PA) and virtual prismatic adaptation (VPA), a non-invasive neuromodulation technique, that involves the use of lenses that deviate the visual field, can modulate alexithyima and performance in visuospatial tasks in patients with Parkinson disease. Furthermore, brain activity during the prismatic adaptation and post-adaptation phases will be recorded using functional near-infrared spectroscopy (fNIRS) and high-density electroencephalography (HD-EEG). Based on these premises, the present project aims to investigate the deficits of the affective, motor and visuospatial abilities in Parkinson's patients and the modulation of disorders through prismatic adaptation (PA) and virtual prism adaptation (VPA). Finally, we would like to evaluate production of the tear film and correlate their quantity with the severity of PD as it could be proposed as a new, non-invasive biomarker.

Correlation of STN-DBS Induced Visuospatial Changes and Freezing of Gait

The purpose of this research is to determine how deep brain stimulation (DBS) for Parkinson's disease affects attention and visuospatial function. Additionally, this study will evaluate how deficits in visual attention are associated with freezing of gait (FOG) in Parkinson's disease. There is currently no reliable treatment for FOG and little is understood about the underlying reason this occurs. Some recent research has found that stimulating the right side of the brain seems to improve FOG. The right side of the brain is also paramount for visual attention, which is why investigators are conducting this study.

3-Dimensional Evaluation of Body Perception

The goal of this observational study is to evaluate the changing body perception of amputees aged 18-65 years using prostheses through different personal perspectives of the right-left distinction. In addition, we aimed to examine the relationship between possible changes in body perception and visual spatial perception and neurocognitive performances. The main questions that this study aimed to answer are as follows: 1. Is there a difference between the amputee group and the control group in terms of parameters related to body perception? 2. Is there a difference between the amputee group and the control group in terms of neurocognitive skills? 3. Is there any difference between the amputee group and the control group in terms of visual spatial perception abilities? To examine whether changes in body perception in amputees affect neurocognitive performance, visuospatial perception and perspective perception and the relationship between them will be compared with a healthy control group. The assessments to be applied to both groups can be summarised as follows: * Demographic information such as age, gender, and education level will be recorded. * Mini-mental state test will be used to assess the cognitive level. * Edinburgh Handedness Scale will be used to determine the dominant side. * Right-left discrimination and personal perspective perception will be assessed using a desktop programme. * The clock drawing test and Benton line orientation test will be used to visual spatial perception. * A computer based program called The Central Nervous System (CNS) Vital Signs Neurocognitive Test Battery will be used to asesses neurocognitive abilities.