College 2: Development of working memory

• Working memory


  One of the three core components of executive functions, along with inhibitory control and cognitive flexibility
• Scientists use different terminology to refer to the three core components of executive functions
• Working memory


  • One of the most important executive functions in a school context
  • Allows you to remember instructions
  • Perform multiple thinking steps at the same time
  • Solve a math problem in your head
  • Remember a text without having to read back
  • Remember rules of a game while you are playing
• Working memory is a better predictor than IQ for later academic achievement, such as learning math and verbal skills
• Working memory, but not IQ, predicts subsequent learning in children with learning difficulties
• Brain activity during a visuospatial working memory task predicts arithmetical performance 2 years later
• Working memory model


  Proposed by Baddeley and Hitch in 1974
• Memory span


  Number of items that can be retained in memory
• Factors that influence memory span


  • Age
  • Word length
  • Articulation rate (depends on age & familiarity/long-term memory)
• At around 5 years old, children switch from (mostly) visual to (mostly) phonological working memory
• Phonological confusability/similarity effect


  It is easier to remember words that sound different from each other (non-homophones), compared to words that sound similar (homophones)
• Picture confusion memory task

  1. Recall pictures in order of presentation

  2. 5 year olds (3 pics) vs. 10 year olds (5 pics)

  3. If verbal rehearsal strategy: long names most difficult

  4. If visual memory strategy: visually similar stimuli most difficult
• For 5-year olds: visually similar pictures most difficult, for 10-year olds: pictures with long names most difficult
• As memory development proceeds, there is less use of visual working memory
• Working memory development


  1. Maintenance

  2. Manipulation

  3. Developmental trajectory: general development working memory, different trajectories for maintaining and manipulating information
• Children aged 8-12 years perform disproportionally worse on manipulation compared to maintenance of working memory
• Unlike adolescents and adults, children fail to recruit DLPFC more strongly on manipulation trials relative to maintenance trials
• Working memory is important for school performance
• There are different developmental trajectories for visual vs phonological/verbal storage, and maintenance vs manipulation of working memory
• Spanboard task


  Measures visuospatial working memory capacity
• Digit-span task and picture-span task


  • Together provide an index of working memory capacity (working memory index)
  • Forward - Maintenance
  • Backward - Manipulation
• N-back task


  Measures maintaining and updating of information in working memory, in visuospatial or phonological modality
• How to recognize children in the classroom with low working memory skills

  • Only remembers the first or last assignment after having received three
  • Leaves a trace of belongings wherever they go
  • Struggles to complete tasks that require more than one step
  • Interrupts others
• Behavior of children with low working memory skills: poor attention span and high levels of distractibility, but not the same as ADHD which also involves problems with inhibitory control, shifting, and emotion regulation
• Training of working memory


  1. 6 weeks, 2-3 times a week, 25 minutes each time

  2. Pre-training fMRI scan

  3. Post-training fMRI scan
• After training, adolescents show adult performance levels on working memory tasks
• Working memory training leads to changes in performance and increases in brain activity (DLPFC), but does not transfer to other skills beyond working memory