Sebastian & Hernandez-Gil- contemporary study

• Aims

  1. To investigate the development of the phonological loop in Spanish and Anglo-saxon children between 5-17 years old by testing their verbal digit span to see if its capacity increases with age.
  2. To compare the results of this study to those previously obtained using the same task in adults, elderly people and people with dementia.
• Sample

  • 570 participants who were volunteers from public and private pre-schools, primary schools and secondary schools in Madrid.
  • All participants were born in Spain and were selected according to the grade they were in.
  • 272 males and 298 females were tested.
  • Divided into 5 age categories and comparisons were made (cross-sectional design)
  • No participants had any repeated school year, hearing impairments or difficulties in reading or writing.
• Procedure

  • A digit span was used to measure the capacity of the phonological loop. Consisted of random sequences of digits read aloud at a rate of 1 per second.
  • Item gradually added to increase the sequence of the digits.
  • Had to recall in the same order as they were presented.
  • Digit span was taken as the maximum length at which participants could recall at least 2 out of 3 series with no errors.
• Data analysis

  • Analysed by school year and by developmental periods of 5 different age groups (5 years, 6-8 years, 9-11 years, 12-14 years and 15-17 years).
  • Games-Howell Pairwise Comparison test was computed to take account of the fact that the no. samples was uneven for year groups.
  • Compared findings with those of a 2008 study testing Anglo-Saxon children which used the same procedure.
• Results

  • Found that digit span increased with age
  • Mean digit span for 5 years= 3.76
  • 6 years= 4.16
  • 9 years= 5.0
  • 17 years= 5.91
• Results- Spanish vs Anglo-Saxon

  • Digits span of Spanish children increases until 17 as opposed to Anglo-Saxon where it was established that it reaches peak at 15.
  • Spanish study figures were about 1 digits below Anglo-Saxon data
  • Suggested it was due to difference in word length (takes longer to take Spanish words than English) so the trace decays e.g. cuatro and four.
• Second study- Elderly results

  • Second study used data from researchers previous study in 2010 where data was gathered about digit span in 2 elderly with no impairments, 25 Alzheimers, 9 with dementia.
  • Comparison with school children found that elderly had a higher mean digit span of 4.44 than 5 years old (3.76) and 6 year olds (4.16), but didn't differ with other year groups.
  • Alzheimer's mean digit span of 4.20 was higher than 5 year olds but not different from other year groups.
• Conclusion

  The phonological loop is affected by age and not so much by dementia.
• Strengths

  • Generalisable- large sample 570 children from a range of schools. Representative of all children across Spanish education system.
  • Standardised procedure- e.g. digits read at 1 per second. Replicated across all 570 children to check consistency and increase reliability.
  • UA- teachers delivering instructions to children of different ages. Adapt instructions e..g chunking in smaller amounts to tailor to smaller memory capacity.
• Weaknesses

  • Generalisability- only children from Madrid and discarded any with impairments. Limited to just Madrid, ethnocentric.
  • Ecological validity- remembering the sequence of random digits is not representative of how we normally use our memory. Artificial task.
  • Ethics- used children and dementia patients. May not fully understand purpose of testing so may feel they are not doing well so causes distress which challenges responsibility principle.