Visuospatial Attention Allocation as an Indicator of Cognitive Deficit in Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Abstract

Traumatic Brain Injury (TBI) is defined by changes in brain function resulting from external forces acting on the brain and is typically characterized by a host of physiological and functional changes such as cognitive deficits including attention problems. In the present study, we focused on the effect of TBI on the ability to allocate attention in vision (i.e., the use of endogenous and exogenous visual cues) by systematically reviewing previous literature on the topic. We conducted quantitative synthesis of 16 selected studies of visual attention following TBI, calculating 80 effect size estimates. The combined effect size was large (g = 0.79, p < 0.0001) with medium heterogeneity (I2 = 68.39%). Subgroup analyses revealed an increase in deficit with moderate-to-severe and severe TBI as compared to mild TBI [F(2, 76) = 24.14, p < 0.0001]. Task type was another key source of variability and subgroup analyses indicated that higher order attention processes were severely affected by TBI [F(2, 77) = 5.66, p = 0.0051). Meta-regression analyses revealed significant improvement in visual attention deficit with time [p(mild) = 0.031, p(moderate-to-severe) = 0.002, p(severe) < 0.0001]. Taken together, these results demonstrate that visual attention is affected by TBI and that regular assessment of visual attention, using a systematic attention allocation task, may provide a useful clinical measure of cognitive impairment and change after TBI.

Changes in the components of visual attention following traumatic brain injury: A systematic review and meta-analysis

“…The finding of an overall large effect indicates that visual attention can be greatly impaired in patients with TBI. Our findings agree with and is supported by previous meta-analyses and systematic reviews that assessed attention following TBI [ 5 , 10 , 65 , 66 ]. However, these studies included studies that assess auditory attention or attention tasks that involve both visual and auditory stimuli, which were excluded from our analysis.…”

“…TBI also produced clear deficits in the ability to covertly orientate visual attention to a specific spatial location. Particularly, TBI patients may not benefit from valid spatial cueing in a Posner cueing task, which is consistent with our recent work that showed a clear deficits in the visuospatial attention [ 10 ]. It is apparent that both selective visual attention and to the covert orientation of visual attention were similarly affected and this may be due to the fact that both tasks require the allocation of visual to either a specific visual stimulus/stimulus or to a specific location, see [ 67 ].…”

“…Visual attention can be goal driven (endogenous/ top-down) in which there is a voluntary direction of attention to a specific location in the visual field (for review see: [ 10 ], or stimulus driven (exogenous/bottom-up) in which salient components of the stimulus (such as colour, contrast) attracts attention [ 11 , 12 ]. The operation of visual attention has been traditionally described as a moveable spotlight or zoom lens which allows the brain to focus or attend to a small spatial area (space-based) within the visual field [ 13 ], or it can be selective for object features (object-based) that are not specific to a location [ 14 , 15 ].…”

Deficits in multiple object-tracking and visual attention following mild traumatic brain injury

“…These findings perhaps suggest that the maximum attentional capacity is affected by TBI. Whilst patients with mild TBI can divide their attention to track multiple objects (agreeing with the findings of Schneider and Gouvier 36 ), their performance is not equal to control participants (i.e., they have poorer sensitivity and slower reaction times) and is susceptible to decay when tracking a large number of elements for short durations. However, for longer tracking durations (10 s) poorer mild TBI group performance was observed regardless of the number of target dots that needed to be tracked.…”

“…In contrast, other studies have failed to find evidence for visual attentional deficits following TBI 33 – 35 . However, differences in outcomes may be driven by methodological approaches and the severity of TBI (see Alnawmasi et al, 2022 for a review), and more research is needed to fully characterise the extent to which visual attention is affected by TBI 36 .…”