Attentional resource allocation during a cued saccade task

Use of eye tracking in medical education

Eye tracking has become increasingly applied in medical education research for studying the cognitive processes that occur during the performance of a task, such as image interpretation and surgical skills development. However, analysis and interpretation of the large amount of data obtained by eye tracking can be confusing. In this article, our intention is to clarify the analysis and interpretation of the data obtained from eye tracking. Understanding the relationship between eye tracking metrics (such as gaze, pupil and blink rate) and cognitive processes (such as visual attention, perception, memory and cognitive workload) is essential. The importance of calibration and how the limitations of eye tracking can be overcome is also highlighted.

The role of eye movements, attention, and hand movements on age-related differences in pegboard tests

Well-documented manual dexterity impairments in older adults may critically depend on the processing of visual information. The purpose of this study was to determine age-related changes in eye and hand movements during commonly used pegboard tests and the association with manual dexterity impairments in older adults. The relationship between attentional deficits and manual dexterity was also assessed. Eye movements and hand kinematics of 20 young (20-38 yr) and 20 older (65-85 yr) adults were recorded during 9-Hole Pegboard, Grooved Pegboard, and a visuospatial dual test. Results were compared with standardized tests of attention (The Test of Everyday Attention and Trail Making Test) that assess visual selective attention, sustained attention, attentional switching, and divided attention. Hand movement variability was 34% greater in older versus young adults when placing the pegs into the pegboard and this was associated with decreased pegboard performance, providing further evidence that increased movement variability plays a role in dexterity impairments in older adults. Older adults made more corrective saccades and spent less time gazing at the pegboard than young adults, suggesting altered visual strategies in older compared with young adults. The relationship between pegboard completion time and Trail Making Test B demonstrates an association between attentional deficits and age-related pegboard impairments. Results contribute novel findings of age-associated changes in eye movements during a commonly used manual dexterity task and offer insight into potential mechanisms underlying hand motor impairments in older adults.NEW & NOTEWORTHY This eye tracking study contributes novel findings of age-associated changes in eye movements during the commonly used pegboard tests of manual dexterity, including a greater number of corrective saccades and lesser time gazing at the pegboard holes in older compared with young adults. An association between attentional deficits and dexterity impairments in older adults is also highlighted. Results shed light on potential mechanisms underlying well-documented motor deficits in older adults.

Distinct saccade planning and endogenous visuospatial attention maps in parietal cortex: A basis for functional differences in sensory and motor attention

Parietal cortex activity contributes to higher-level cognitive processes, including endogenous visual attention and saccade planning. While visual attention is the process of selecting pertinent information from the environment, saccade planning may involve motor attention in the planning of a specific movement, including the process of selecting the correct path. We isolated areas in parietal cortex involved in saccade planning, while controlling visual attention, to understand the relationship between the two processes. Using our novel stimulus, participants performed a delayed saccade task and an endogenous covert visuospatial attention task with peripheral targets in identical locations. We compared multiple target locations across the two domains at the level of the individual to better understand variability in the relationship between these two maps. The anterior-posterior organization of saccade planning and visual attention maps varied among, but not within, participants, and 14-29% of the maps for each task overlapped one another across hemispheres. Interestingly, within the region of co-activation, over 67% of the voxels responded to the same location for both tasks. These cortical areas of overlap may represent regions of the brain specifically involved in the transfer of information from vision to action along the visuomotor pathway. These results further establish the relationship between maps associated with saccade planning and visual attention at the individual level, indicating the lack of a single saliency map in parietal cortex.

Remote concussion history does not affect visually-guided reaching in young adult females

Aim:

We examined the long-term effects of concussions in young adult females on visuomotor behavior during a visually-guided reaching task of various complexities.

Materials & methods:

20 females with a history of longer than 6 months since a concussion and 20 healthy females quickly and accurately performed a delayed reach to a previously cued target.

Results:

As both cognitive and motor load increased, task performance decreased for both groups (p < 0.05). However, contrary to our primary hypothesis, no differences in task performance were found between the two experimental groups (p > 0.05).

Conclusion:

The young adult females with a remote history of concussion demonstrated no deficits in visuomotor behavior on an attention-mediated reaching task as compared with control participants.

Current literature is inconclusive regarding the long-term effects of concussion. Some have argued that the differing results are due to many uncontrolled factors in study design. In this study, 20 females with a history of concussion more than 6 months ago and 20 healthy females performed a reaching task under different levels of difficulty. As the reaching task got harder, both groups had greater difficulty doing the task quickly and accurately (p < 0.05). Surprisingly, however, no differences in reaching performance existed between the two groups (p > 0.05). Young adult females with a remote history of concussion demonstrated no greater problems with complicated reaching tasks when compared with control participants when experimental conditions are tightly controlled.

Effects of concussions on visually guided motor actions: A literature review

Athletes must be able to successfully navigate the soccer pitch or hockey rink to win the game, requiring maximal cognitive resources to successfully compete. Concussions potentially deplete these resources, and the long-term impact of concussions on an individual's goal-directed visually guided behavior continues to elude the scientific community. While the acute effects on cognition and the motor system have been elucidated elsewhere, long-term effects on performance have been less clear. Additionally, most investigations into long-term postinjury motor behaviors have focused on balance and gait, with little focus on functional upper extremity movements. These arm movements require both cognitive and motor functions to successfully complete the task, such as visually guided reaching, and have received little attention. This review examines the current state of the literature to date on the long-term effects of concussions on cognitive and motor deficits affecting visuomotor behavior.

Altered visual strategies and attention are related to increased force fluctuations during a pinch grip task in older adults

The purpose of the study was to determine the visual strategies used by older adults during a pinch grip task and to assess the relations between visual strategy, deficits in attention, and increased force fluctuations in older adults. Eye movements of 23 older adults (>65 yr) were monitored during a low-force pinch grip task while subjects viewed three common visual feedback displays. Performance on the Grooved Pegboard test and an attention task (which required no concurrent hand movements) was also measured. Visual strategies varied across subjects and depended on the type of visual feedback provided to the subjects. First, while viewing a high-gain compensatory feedback display (horizontal bar moving up and down with force), 9 of 23 older subjects adopted a strategy of performing saccades during the task, which resulted in 2.5 times greater force fluctuations in those that exhibited saccades compared with those who maintained fixation near the target line. Second, during pursuit feedback displays (force trace moving left to right across screen and up and down with force), all subjects exhibited multiple saccades, and increased force fluctuations were associated (r_s = 0.6; P = 0.002) with fewer saccades during the pursuit task. Also, decreased low-frequency (<4 Hz) force fluctuations and Grooved Pegboard times were significantly related (P = 0.033 and P = 0.005, respectively) with higher (i.e., better) attention z scores. Comparison of these results with our previously published results in young subjects indicates that saccadic eye movements and attention are related to force control in older adults.NEW & NOTEWORTHY The significant contributions of the study are the addition of eye movement data and an attention task to explain differences in hand motor control across different visual displays in older adults. Older participants used different visual strategies across varying feedback displays, and saccadic eye movements were related with motor performance. In addition, those older individuals with deficits in attention had impaired motor performance on two different hand motor control tasks, including the Grooved Pegboard test.

Selective Age Effects on Visual Attention and Motor Attention during a Cued Saccade Task

Objective. Visual information is often used to guide purposeful movement. However, older adults have impaired responses to visual information, leading to increased risk for injuries and potential loss of independence. We evaluated distinct visual and motor attention contributions to a cued saccade task to determine the extent to which aging selectively affects these processes. Methods. Nineteen healthy young (18–28 years) and 20 older (60–90 years) participants performed a cued saccade task under two conditions. We challenged motor attention by changing the number of possible saccade targets (1 or 6). Results. Older adults had difficulty in inhibiting unwanted eye movements and had greater eye movement inaccuracy in the hard condition when compared to the younger adults and to the easy condition. Also, an inverse relation existed between performance on the visual and motor components of the task in older adults, unlike younger adults. Conclusions. Older adults demonstrated difficulty in both inhibiting irrelevant saccade targets and selecting correct saccade endpoints during more complex tasks. The shift in relations among attention measures between the younger and older participants may indicate a need to prioritize attentional resources with age. These changes may impact an older adult's ability to function in complex environments.

Relations among visual strategies, force fluctuations, and attention during a force-matching task

Greater understanding of how people use visual information to minimize force fluctuations provides critical insight into visuomotor processing. Visual strategies were examined during a force-matching task with different feedback displays. When only vertical feedback was provided, young healthy participants (N = 20, 9 men) fixated their gaze centrally. When vertical and horizontal visual feedback was provided, participants performed saccades to maintain gaze near the leading edge of the force trace. Performance on a separate attention task assessed visual and motor attention capabilities in the same participants. Selecting the correct saccade trajectory on the attention task was positively correlated with measures predicting performance on the force-matching task. Optimal visual strategies, combined with motor attention, may contribute to minimizing pinch force variability at low force.