Figure 2.

Performance in the Cognitive and Physical Effort Tasks (Mean ± 1 SEM)

(A) In the cognitive effort task, target detection sensitivity (left panel) and reinforcement rates (right panel) were identical across groups. Controls are shown in black and pre-manifest HD in blue.

(B) In the physical effort task, pre-manifest HD and controls did not differ in the proportion of time they were able to maintain their grip over the target effort level (left panel), which was reflected in identical reinforcement rates between groups (right panel). Controls are shown in black and pre-manifest HD in red.