M. Hongchul Sohn

Learn More
The conflict adaptation effect, a reduced interference effect upon the detection of a conflict signal (e.g., following an incongruent trial), has been interpreted as evidence for active regulation of top-down cognitive control. We hypothesized that the extent of conflict adaptation should be related to individuals' working memory capacity (WMC), which has(More)
We used a musculoskeletal model to investigate the possible biomechanical and neural bases of using consistent muscle synergy patterns to produce functional motor outputs across different biomechanical conditions, which we define as generalizability. Experimental studies in cats demonstrate that the same muscle synergies are used during reactive postural(More)
Neuromusculoskeletal models solve the basic problem of determining how the body moves under the influence of external and internal forces. Existing biomechanical modeling programs often emphasize dynamics with the goal of finding a feed-forward neural program to replicate experimental data or of estimating force contributions or individual muscles. The(More)
Measured muscle activation patterns often vary significantly from musculoskeletal model predictions that use optimization to resolve redundancy. Although experimental muscle activity exhibits both inter- and intra-subject variability we lack adequate tools to quantify the biomechanical latitude that the nervous system has when selecting muscle activation(More)
Although it is possible to produce the same movement using an infinite number of different muscle activation patterns owing to musculoskeletal redundancy, the degree to which observed variations in muscle activity can deviate from optimal solutions computed from biomechanical models is not known. Here, we examined the range of biomechanically permitted(More)
Humans must constantly react to their environments. In many cases, repeating a response results in performance benefits, but sometimes it results in performance costs. This dichotomy is referred to as response repetition effects (RR effects). To understand these effects, we dissociated 2 components of a response: response categories (response meaning) and(More)
In the task switch paradigm, a switch of task is typically accompanied by a change in task cue. It has been proposed that the performance deficit usually observed when switching tasks is actually the result of changing cues. To test this possibility, we used a 2:2 cue-task mapping in which each cue indicated 2 different tasks. With advance presentation of a(More)
  • 1