A Potential Multimodal Test for Clinical Assessment of Visual Attention in Neurological Disorders

Abstract

Attention is an important aspect of human brain function and often affected in neurological disorders. Objective assessment of attention may assist in patient care, both for diagnostics and prognostication. We present a compact test using a combination of a choice reaction time task, eye-tracking and EEG for assessment of visual attention in the clinic. The system quantifies reaction time, parameters of eye movements (i.e. saccade metrics and fixations) and event related potentials (ERPs) in a single and fast (15 min) experimental design. We present pilot data from controls, patients with mild traumatic brain injury and epilepsy, to illustrate its potential use in assessing attention in neurological patients. Reaction times and eye metrics such as fixation duration, saccade duration and latency show significant differences (p < .05) between neurological patients and controls. Late ERP components (200–800 ms) can be detected in the central line channels for all subjects, but no significant group differences could be found in the peak latencies and mean amplitudes. Our system has potential to assess key features of visual attention in the clinic. Pilot data show significant differences in reaction times and eye metrics between controls and patients, illustrating its promising use for diagnostics and prognostication.

Decoding Attentional Task Performance Using Electroencephalogram Signals

“…The most dominant patterns of change in patients with attention deficit hyperactivity disorder, schizophrenia, and obsessive-compulsive disorder are power increases across lower frequencies (delta, 1-4 Hz and theta, 4-8 Hz) and decreases across higher frequencies (alpha, 8-13 Hz; beta, 13-30 Hz and gamma, 30-50 Hz) [25]. Impairment of visual attention is associated with differences in EEG features, network activation, and involvement of the right frontal eye field [26]. In contrast, our findings showed that frontal delta power was not correlated with task performance, while stronger occipital delta power during rest was significantly correlated with more errors, and weaker temporal and central delta power during TMT-B was significantly correlated with a longer task time.…”

Neurophysiological signatures of visual attention in absence epilepsy and mild traumatic brain injury

“…In the clinical context, the most common causes of dysfunctions of visual attention are severe head trauma, cerebral ischemia, and dementia [19]. More moderately, visual attention can be impaired in pathologies such as epilepsy and mild traumatic brain injury as well [20,21,22]. Symptoms related to compromised visual attention can be overlooked, especially when they are not trivial to detect (i.e., impaired oculomotor functions, delay in stimulus-response), disabling the everyday life of patients and placing them and others at risk of injury.…”

“…Symptoms related to compromised visual attention can be overlooked, especially when they are not trivial to detect (i.e., impaired oculomotor functions, delay in stimulus-response), disabling the everyday life of patients and placing them and others at risk of injury. Precautions to ensure patient safety come with drawbacks, including hindrances to movement, work-related tasks, and social isolation [20]. It is important to note that limitations and risks vary among different neurological conditions, highlighting the importance of personalized advice [23].…”

“…The measurement set-up comprised a custom-built computerized choice reaction time task (CRT), synchronized with a 21-channel EEG and a screen-based eye tracker. With this set-up, we have available a compact test that allows the quantitative characterization of visual attention during EEG recording [20]. More details of the measurement set-up are shown in Fig.…”

“…The changes in attention observed during an absence [30,67,113,32,166,20] presumably result from a transient impairment of specific brain areas during seizures [26], in particular, networks involved in consciousness and attention [8,7,113]. These networks -when subdivided into partial, operational definitions, such as state, awareness, and volition -have both physiological (e.g., cortico-thalamic network, anterior cingulate, frontal areas) and phenomenological (e.g., awareness, orienting, selection of external or internal inputs, voluntary control) overlapping characteristics [8,7].…”