Understanding ADHD

Working Memory and Time Blindness in ADHD

By Dr. Douglas Cowan, Psy.D., MFT

You told him three things. He remembered one — maybe. You gave her an hour to get ready. She needed four. You reminded him about the project for two weeks. He started it the night before.

And every time, the answer is the same: "I forgot." "I didn't know it was that late." "I thought I had more time."

You wonder if he's doing it on purpose. He's not. What you're seeing has a name — and once you understand it, both of you will breathe a little easier.

What's Happening in the Brain

Two systems are involved here, and both are significantly impaired in ADHD.

The first is working memory — the brain's mental scratchpad. It's the ability to hold information in your mind just long enough to use it. Follow three-step instructions. Hold a thought while you do something else. Remember what you walked into a room to do. In ADHD, this system leaks. Information arrives and disappears before it can be acted on — not because the child isn't listening, but because the brain isn't holding. Children with ADHD consistently perform significantly worse on time-based and sequential memory tasks, not because they lack the intelligence to process the information, but because the storage system cannot keep it available long enough to use it.

The second is time blindness — a term Dr. Russell Barkley has used for decades to describe what happens when the brain's internal clock doesn't work reliably. Most people feel time passing. They sense a deadline approaching. They know instinctively when an hour has gone by. The ADHD brain doesn't do this. As Barkley describes it, people with ADHD have "an incredible difficulty with not just sensing, but governing themselves relative to time."

For people with ADHD, there are essentially only two kinds of time: now and not now. A deadline two weeks away doesn't feel like it's approaching. It doesn't feel real at all — until suddenly it's tonight.

In 2025, Barkley published an updated framework describing what he calls "intention deficit disorder" — the observation that ADHD is fundamentally a problem of converting intention into action across time. Knowing what needs to be done, intending to do it, and actually doing it at the right moment are three separate events in the ADHD brain that don't connect reliably. This is not irresponsibility. This is neurology.

Now You Understand Why

This is why he can sit down with every intention of doing his homework and emerge two hours later having done almost none of it. Time passed. He didn't feel it.

This is why she can agree sincerely to be ready by seven and still not be ready at seven-thirty. The gap between intention and action is not laziness — it is a broken internal clock combined with a memory system that drops instructions the moment something more interesting enters the room.

This is also why ADHD is fundamentally a performance problem, not a knowledge problem. These kids know what they're supposed to do. They just cannot consistently do it at the right time, in the right order, without external support. That distinction matters enormously — because the solution is not more pressure. The solution is better external structure.

What Wisdom Looks Like Here

You cannot fix working memory or time blindness by wanting them to try harder. You can — and must — build external systems that do what the brain cannot do internally.

If a child had poor eyesight, you would get him glasses. You wouldn't tell him to look harder. Working memory and time blindness are the same kind of problem. The brain needs tools — external ones — to compensate for what it cannot generate on its own. The good news is that those tools exist. They are practical, relatively inexpensive, and they work.

What To Do Starting Today

The two of you are not fighting each other. You're both fighting a neurological system that needs different support than you've been providing. Change the tools. Change the outcome.

References

  1. Barkley, R. A. (2015). Attention-deficit hyperactivity disorder: A handbook for diagnosis and treatment (4th ed.). Guilford Press.
  2. Barkley, R. A. (2025). Intention deficit disorder: Why ADHD minds struggle to meet goals with action. ADDitude Magazine.
  3. Faraone, S. V., et al. (2021). The World Federation of ADHD International Consensus Statement. Neuroscience & Biobehavioral Reviews, 128, 789–818.
  4. Wolff, N., et al. (2024). The dopamine hypothesis for ADHD. Frontiers in Psychiatry, 15, 1492126.
  5. Monastra, V. J., et al. (2005). Electroencephalographic biofeedback in the treatment of ADHD. Applied Psychophysiology and Biofeedback, 30(2), 95–114.
  6. UCI Health. (2024). Coping with time blindness and ADHD. UCI Health Blog.
About the author. Dr. Douglas Cowan, Psy.D., is a Licensed Marriage and Family Therapist with 40 years of clinical experience and over 35 years in neurofeedback, licensed and practicing since 1988. Read his full credentials →