but have no difficulty selecting and filtering sensory input. Some think that SCT and ADHD produce different kinds of inattention: While those with ADHD can engage their attention but fail to sustain it over time, people with SCT seem to have difficulty with engaging their attention to a specific task. Accordingly, the ability to orient attention has been found to be abnormal in SCT. Both disorders interfere significantly with academic performance but may do so by different means. SCT may be more problematic with the accuracy of the work a child does in school and lead to making more errors. Conversely, ADHD may more adversely affect productivity which represents the amount of work done in a particular time interval. Children with SCT seem to have more difficulty with consistently remembering things that were previously learned and make more mistakes on memory retrieval tests than do children with ADHD. They have been found to perform much worse on psychological tests involving perceptual-motor speed or hand-eye coordination and speed. They also have a more disorganized thought process, a greater degree of sloppiness, and lose things more easily. The risk for additional learning disabilities seems equal in both ADHD and SCT (23–50%) but math disorders may be more frequent in the SCT-group. A key behavioral characteristic of those with SCT symptoms is that they are more likely to appear to be lacking motivation and may even have an unusually higher frequency of daytime sleepiness. They seem to lack energy to deal with mundane tasks and will consequently seek to concentrate on things that are mentally stimulating perhaps because of their underaroused state. Alternatively, SCT may involve a pathological form of excessive mind-wandering. Executive function The executive system of the human brain provides for the cross-temporal organization of behavior towards goals and the future and coordinates actions and strategies for everyday goal-directed tasks. Essentially, this system permits humans to self-regulate their behavior so as to sustain action and problem solving toward goals specifically and the future more generally. Dysexecutive syndrome is defined as a "cluster of impairments generally associated with damage to the frontal lobes of the brain" which includes "difficulties with high-level tasks such as planning, organising, initiating, monitoring and adapting behaviour". Such executive deficits pose serious problems for a person's ability to engage in self-regulation over time to attain their goals and anticipate and prepare for the future. Adele Diamond postulated that