Dual task performance in older adults: Examining visual discrimination performance whilst treadmill walking at preferred and non-preferred speeds

Driving Performance in Older Adults: Current Measures, Findings, and Implications for Roadway Safety

Background and Objectives

Over 10,000 people a day turn 65 in the United States. For many older adults, driving represents an essential component of independence and is one of the most important factors in overall mobility. Recent survey studies in older adults suggest that up to 60% of older adult drivers with mild cognitive impairment, and up to 30% with dementia, continue to drive. The purpose of this review is to provide a comprehensive and detailed resource on the topics of cognition and driving for clinicians, researchers, and policymakers working on efforts related to older adult drivers.

Research Design and Methods

Publications on PubMed and Medline and discussions with experts working in geriatrics, technology, driving policy, psychology, and diverse aspects of driving performance were utilized to inform the current review.

Results

Research indicates that there is a complex and inverse correlation between multiple cognitive measures, driving performance, and risky driving behaviors. The fragmented nature of available peer-reviewed literature, and a reliance on correlative data, do not currently allow for the identification of the temporal and reciprocal nature of the interplay between cognition and driving endpoints.

Discussion and Implications

There are currently no widely accepted definitions, conceptual models, or uniform set of analyses for conducting geriatric research that is focused on driving. Establishing conventions for conducting research that harmonizes the fields of geriatrics, cognition, and driving research is critical for the development of the evidence base that will inform clinical practice and road safety policy.

Aerobic exercise in severe mental illness: requirements from the perspective of sports medicine

Major depression, bipolar disorder, and schizophrenia are severe mental illnesses. Despite receiving psychopharmacological and psychosocial treatments, about half of patients develop a chronic course with residual cognitive and negative symptoms and have a high risk for cardiovascular disease and reduced life expectancy. Therefore, add-on innovative treatment approaches are needed to improve outcome. Aerobic exercise interventions have been shown to improve global functioning, cognition, and negative and depressive symptoms in these patients. The basic mechanism of these exercise-related changes has been reported to be improved brain plasticity, e.g., increased volume of disease-related brain regions such as the hippocampus. The optimal type, duration, and frequency of exercise have not yet been determined and need to be addressed in supervised physical exercise studies. Because of the low physical activity levels, lack of drive related to negative and depressive symptoms, and high prevalence of cardiovascular comorbidities in patients with severe mental illness, besides aiming to improve symptoms of mental illness, exercise interventions should also aim to increase cardiorespiratory fitness, which they should comprehensively assess by direct measurements of maximal oxygen uptake. Based on the recommendations for developing cardiorespiratory fitness by the American College of Sports Medicine, 150 min moderate-intensity training per week or vigorous-intensity exercise training for 75 min per week are appropriate. Most studies have had relatively short intervention periods, so future studies should focus on long-term adherence to exercise by implementing motivational strategies supported by telemedicine and by identifying and targeting typical barriers to exercise in this patient population.

Does surface slope affect dual task performance and gait? An exploratory study in younger and older adults

An increased risk of falling is associated with changes in gait while dual-tasking. The degree to which gait stability is altered during walking is influenced by an individual's cognitive and postural capacity, and the difficulty of the presented tasks. However, it is unknown how greater walking task difficulty affects gait stability in younger and older adults when dual-tasking. The purpose of the current study was to determine the effect of walking task difficulty on gait stability in younger and older adults while performing a difficult audiospatial task. Ten younger [mean (SD) age 30.8 (6.6) years; 5 women] and 10 older [66.8 (5.7) years; 6 women] healthy adults walked on a treadmill at their preferred walking speed [younger 4.8 (0.4) ms^-1, older 4.5 (0.5) ms^-1) on either a level, or downhill slope both with and without responding to an audiospatial task. Step width, step width SD and mediolateral centre of mass displacement were calculated to determine changes in gait, and response time and accuracy were calculated to determine secondary task performance. Results indicated that older adults displayed a consistently greater step width (p ≤ 0.015) and maintained their mediolateral centre of mass displacement (p > 0.05) while walking downhill and responding to the audiospatial task, compared to downhill walking only. In contrast, younger adults maintained a regular step width during both level and downhill dual-tasking compared to level and downhill walking only (p > 0.05), however displayed a lower mediolateral centre of mass displacement during level dual-task walking compared to level walking only (p = 0.013). When the difficulty of the walking task was greater, older adults increased their step width, which increased their stability.

The Effect of Walking on Auditory Localization, Visual Discrimination, and Aurally Aided Visual Search

OBJECTIVE

The present study was designed to examine the impact that walking has on performance in auditory localization, visual discrimination, and aurally aided visual search tasks.

BACKGROUND

Auditory localization and visual search are critical skills that are frequently conducted by moving observers, but most laboratory studies of these tasks have been conducted on stationary listeners who were either seated or standing during stimulus presentation.

METHOD

Thirty participants completed three different tasks while either standing still or while walking at a comfortable self-selected pace on a treadmill: (1) an auditory localization task, where they identified the perceived location of a target sound; (2) a visual discrimination task, where they identified a visual target presented at a known location directly in front of the listener; and (3) an aurally aided visual search task, where they identified a visual target that was presented in the presence of multiple visual distracters either in isolation or in conjunction with a spatially colocated auditory cue.

RESULTS

Participants who were walking performed auditory localization and aurally aided visual search tasks significantly faster than those who were standing, with no loss in accuracy.

CONCLUSION

The improved aurally aided visual search performance found in this experiment may be related to enhanced overall activation caused by walking. It is also possible that the slight head movements required may have provided auditory cues that enhanced localization accuracy.

APPLICATION

The results have potential applications in virtual and augmented reality displays where audio cues might be presented to listeners while walking.

The Effects of Blast-Related Neurotrauma on Aurally Aided Visual Search While Standing and Walking

Service members (SMs) who have suffered mild traumatic brain injury due to blast exposure (b/TBI) often report post-concussive symptoms consistent with auditory, visual, or vestibular impairments even when they score within the normal range on traditional clinical tests of sensory function. One possible explanation for this discrepancy is that patients who score in the low normal range in more than one sensory modality may be severely impaired in tasks that require multisensory integration. This study evaluated unimodal and multimodal sensory performance in SMs with b/TBI and healthy controls by having them conduct four tasks while walking or standing in an immersive virtual environment: an Auditory Localization task (AL) where they moved a cursor to the perceived location of a sound; a Visual Discrimination task (VD) where they distinguished between two visual targets; an Aurally-Aided Visual Search Task (AAVS) where they used an auditory cue to locate and identify a visual target hidden in a field of visual distractors; and a Visual-Only Visual Search task (VOVS) where they located and identified a visual target in a field of distractors with no auditory cue. The results show the b/TBI and healthy control groups performed equivalently in the AL and VD tasks, but that the b/TBI group responded roughly 15% slower in the AAVS task and 50% slower in the VOVS task. Walking had no effect on performance in the visual-only tasks, but both groups responded faster while walking in the AL and AAVS tasks without any reduction in accuracy.

Simultaneous Aerobic Exercise and Memory Training Program in Older Adults with Subjective Memory Impairments

BACKGROUND

Several modifiable lifestyle factors have been shown to have potential beneficial effects in slowing cognitive decline. Two such factors that may affect cognitive performance and slow the progression of memory loss into dementia in older adults are cognitive training and physical activity. There are currently no effective treatments for dementia; therefore, preventative strategies to delay or prevent the onset of dementia are of critical importance.

OBJECTIVE

The aim of this study was to determine the relative effectiveness of simultaneous performance of memory training and aerobic exercise to a sequential performance intervention on memory functioning in older adults.

METHODS

55 older adults (aged 60- 75) with subjective memory impairments (non-demented and non-MCI) completed the intervention that consisted of 90-minute small group classes held twice weekly. Participants were randomized to either 4-weeks of supervised strategy-based memory training done simultaneously while stationary cycling (SIM) or sequentially after the stationary cycling (SEQ). Standardized neurocognitive measures of memory, executive functioning, speed of processing, attention, and cognitive flexibility were assessed at baseline and post-intervention.

RESULTS

The SIM group, but not the SEQ group, had a significant improvement on composite memory following the intervention (t(51) = 2.7, p = 0.01, effect size (ES) = 0.42) and transfer to non-trained reasoning abilities (t(51) = 6.0, ES = 0.49) and complex attention (t(51) = 3.1, p = 0.003, ES = 0.70). Conversely, the SEQ group, but not the SIM, showed significant improvement in executive functioning (t(51) = 5.0, p = 0.0001, ES = 0.96).

CONCLUSION

These findings indicate that a 4-week simultaneous memory training and aerobic exercise program is sufficient to improve memory, attention, and reasoning abilities in older adults.

Building Computer-Based Experiments in Psychology without Programming Skills

Research in Psychology usually requires to build and run experiments. However, although this task has required scripting, recent computer tools based on graphical interfaces offer new opportunities in this field for researchers with non-programming skills. The purpose of this study is to illustrate and provide a comparative overview of two of the main free open source "point and click" software packages for building and running experiments in Psychology: PsychoPy and OpenSesame. Recommendations for their potential use are further discussed.