What’s the difference between sluggish cognitive tempo and slow processing speed?

There is a lot of overlap between the terms “sluggish cognitive tempo” and slow processing speed. Processing speed refers to how long it takes someone to do a mental task. Sluggish cognitive tempo (SCT) is a broader term that involves daydreaming and lack of energy. SCT is also not as well defined and is more controversial.

Processing speed can be measured using standardized tests. When neuropsychologists talk about “slow processing speed,” they’re usually referring to slow performance on the Processing Speed Index subtests that are part of the Wechsler Intelligence Scale for Children (WISC). These subtests involve tasks like searching a row of shapes to see if any of them are squares.

More broadly, though, processing speed is the pace at which a person takes in and reacts to information either through sight, sound, or movement. It’s rare for someone to have difficulties in only one of these areas. Slow processing speed usually involves at least two areas.

SCT is similar to slow processing speed, but it has a much broader effect on how kids interact with their environment. They may seem sleepy or tired and tend to daydream and to move slowly. Many but not all of these kids show signs of slow processing speed on the WISC.

SCT is a relatively new concept. More studies are needed to clear up the difference between SCT and slow processing speed.

Some researchers think that SCT should be thought of as a new disorder. Other researchers think SCT is no different from the type of ADHD that does not involve hyperactivity. (This type of ADHD is sometimes called ADD. But the official name is ADHD, Predominantly Inattentive Presentation.)

But on a practical level, here are some things you can do to help if your child has SCT, slow processing speed, or both:

  • Create a homework station that’s free of visual clutter. Keep distracting sounds to a minimum. The goal is to make your child’s learning environment as efficient as possible so there is less information to process.

  • Brainstorm with your child’s teacher to find ways to increase your child’s alertness and speed. See if your child qualifies for classroom accommodations that can help with processing speed.

  • Make sure your child eats healthy food and gets enough sleep. Hunger and fatigue can affect your child’s attention and speed.

  • Play to your child’s strengths and interests. This could help kids with slow processing speed or SCT move more quickly on assignments. For example, if your child loves baseball, writing about Babe Ruth might take your child less time than writing about a topic that is less interesting to them.

  • Ask for more time on tests. A private space can also help because many kids with these issues like to talk aloud as they’re working through test questions.

  • Change the way you give directions. For example, it may help to give directions one step at a time. Giving directions in more than one way can help too, such as writing them down and saying them out loud.

  • Consult with your pediatrician if your child continues to struggle. You may also want to look into whether medication used for ADHD might be helpful.

  • Practice new skills until they become automatic. The more familiar your child becomes with a task, the greater the chance of improving processing speed. But the trick is helping your child find a balance between overlearning and feeling overwhelmed.

Aim to give your child enough time to practice and fully learn a new skill without bogging them down by overdoing it. Taking breaks during homework time can also help reduce frustration. Encourage your child to stretch their legs!


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