Increased reaction times and reduced response preparation already starts at middle age

Abstract

Generalized slowing characterizes aging and there is some evidence to suggest that this slowing already starts at midlife. This study aims to assess reaction time changes while performing a concurrent low-force and high-force motor task in young and middle-aged subjects. The high-force motor task is designed to induce muscle fatigue and thereby progressively increase the attentional demands. Twenty-five young (20–30 years, 12 males) and 16 middle-aged (35–55 years, 9 males) adults performed an auditory two-choice reaction time task (CRT) with and without a concurrent low- or high-force motor task. The CRT required subjects to respond to two different stimuli that occurred with a probability of 70 or 30%. The motor task consisted of index finger abduction, at either 10% (10%-dual-task) or 30% (30%-dual-task) of maximal voluntary force. Cognitive task performance was measured as percentage of correct responses and reaction times. Middle-aged subjects responded slower on the frequent but more accurately on the infrequent stimuli of CRT than young subjects. Both young and middle-aged subjects showed increased errors and reaction times while performing under dual-task conditions and both outcome measures increased further under fatiguing conditions. Only under 30%-dual-task demands, an age-effect on dual-task performance was present. Both single- and dual-task conditions showed that already at mid-life response preparation is seriously declined and that subjects implement different strategies to perform a CRT task.

Age-related differences in muscle recruitment and reaction-time performance

“…The difference between young and old participants was 2,4-fold higher for MT compared to PMT (Bautmans, Vantieghem et al 2011). This is in line with other RT studies (Gorus, De Raedt et al 2006;Rossit and Harvey 2008;Wolkorte, Kamphuis et al 2014) showing that the age-related increase of RT in healthy and cognitively intact older persons is most pronounced during the movement phase of the RT task. Interestingly, Bautmans et al have shown that in older persons, longer RT was significantly (p=0.001) related to a higher early co-activation of the antagonist muscle during the PMT, i.e.…”

“…Also it is observed that in elderly persons, movement preparation leads to additional cortical activity, which is most prominent in the prefrontal cortex (Vallesi, McIntosh et al 2009;Berchicci, Lucci et al 2012). Preparation of movement is suggested to be less optimal in older subjects (Wolkorte, Kamphuis et al 2014). …”

Rumination and implicit avoidance following bereavement: An approach avoidance task investigation

“…Of all demographic and loss-related variables, only age was significantly related to pushepull scores (cf. Wolkorte, Kamphuis, & Zijdewind, 2014), and was therefore used as a control variable in our main analyses.…”

Microstructural Changes of the Human Brain from Early to Mid-Adulthood

“…The study was performed on the DTI data of 111 adults aged 18–55 years selected from a publicly released dataset. A cut off age of 55 years was chosen for the consideration that it was neither too low to exclude too many subjects and decrease the statistical power, nor too high to include old adults in Wolkorte et al ( 2014 ) and Kodiweera et al ( 2016 ). To test whether there were general changes in any of the four DTI metrics, we first correlated age with the mean of each DTI metric across the voxels within the FA skeleton mask obtained using standard tract-based spatial statistics (TBSS).…”