Sebastian and Hernandez-Gil - Digit Span

Sebastian and Hernandez-Gil - Digit Span

1. Aim

   • wanted to study the developmental pattern of working memory over time
   • changes from ageing. eg.'dementia'
   • analyse the developmental pattern of the phonological loop in children aged 5-17 years
   • looking at the age at which the digit span stopped 'increasing in adulthood/adolescence'
   • look at the decline of digit span in older people including those with dementia
   • to see if anglo-saxon data were replicated or if higher for spanish speakers

2. Procedure

   • first part
     • gathered primary data
     • used 5-17 year olds
     • all born in spain
     • none had learning difficulties
     • control for education and cognitive differences
   • Second part
     • used secondary data
     • elderly people without impairment
     • with alzheimers and fronto-temperol dementia
     • used 25 healthier older people as a control group
     • 25 alzheimers
     • 9 fronto-temperol dementia

3. Results

   • the preschool children aged five years had a very low digit span
   • 6-8 year olds had a very similar digit span
   • the increase in one digit, occured at 9 years old and rose to 11 years old
   • older children had similar digit span to one another
   • differed from age groups above them
   • similar digit span was found in 15-17 year olds
   • researchers compared their data to data from the Wechsler Intelligence Scale for children who digit span increases with age
   • the healthier older people had a higher digit span
   • alzheimers dementia participants had the lowest mean digit span

4. Conclusions

   • main conclusion = digit span increases with age from 5-17 years old
   • contrasts with anglo-saxon data
   • sebastian and hernandez-gil highlighted the differences in word length between Spanish and English
   • spanish digit words are longer than english digit words
   • subvocal rehearsal does not start until 7 years old
   • English studies aged 5-6, digit span was around four which matches the spanish study
   • digit span of the healthy older people was similar to that of a 7 year old - shows there is a decline in digit span with age
   • the capacity of the phonological loop seems to be affected by the age but not by dementia

5. Strengths

   • the results are reliable because it was compared with data in the spanish population and with other studies
   • WISC-IV data showed a very similar pattern in development - increasing up to age 17
   • careful controls were used in the study
   • they used spanish children and the spanish language - control varaibles
   • they analyse not only for actual age using school years but also for age group so they have information from which to draw conclusions

6. Weaknesses

   • the task is artificial - we don't generally recall lists of digits
   • lack of validity
   • although experiments lack validity because of the controls and artifically of the tasks
   • the digits are subvocalised by the spanish speakers
   • the word length had affected the digit span
   • the study was done using spanish speakers only
   • the study doesn't show at what age the decrease might start