Sebastian and Hernandez-Gil

• Title

  Developmental pattern of digit span in Spanish population
• Aims


  1. To investigate the development of the phonological loop in children between the ages of 5 and 17 years using digit span as a measure of phonological activity.

  2. To compare the findings to their previous research of adult aged and dementia patients.
• What sample was used in part 1 of the study?

  570 volunteers selected from public and private preschools, primary schools and secondary schools in Madrid. None had hearing impairments or nay reading/writing difficulties or any other cognitive difficulties.
• What sample was used in part 2 of the study?

  Sample of 59 adults who are elderly and with dementia.
• What was the procedure of part 1?

  Task with 3 sequences of 3 digits which were read out by the experimenter at a rate of one per second. Ps were asked to listen carefully and recall in same order as they were presented.

  An additional digit increased the length of the sequence which each round.
• What was digit span taken as?

  Maximum length that the ps could recall at least 2 out of the 3 series with no errors.
• Results - part 1

  - Digit span increased with age

  - Very young children have significantly lower digit span

  -From 6-8 years old similar digit span was found

  - Increase to 4 or 5 digits rather than 3 being recalled started at around 9 years old and rose smoothly until 11.

  - Adolescents ages 12 to 14 had similar digit span but differed from older groups.

  - Digit span was similar between 15 and 17 years old

  - Data shows a lower digit span than what the Intelligence Scale for Children reports for all age groups
• What was part 2 of the study?

  Comparing results from the previous parts of the study in 2010 to older patients with dementia. All carried out the same digit span task as the ps in this study.
• Results - part 2

  - Elderly group had higher digit span than 5 year olds and 6 year olds.

  - Digit span of elderly group was not significantly different than the other year groups.

  - Patients with Alzheimer's disease digit span was higher than 5 year olds but did not differ significantly from other groups.

  - Patients with another type of dementia had digit span that was similar to younger groups like 4/5 year olds. (Frontotemporal dementia)
• Conclusions

  - Digit span is at its maximum at age 17 in Spanish population compared to age 15 in English/American population

  - Digit span is lower in Spanish pop. compared to Eng. pop.
• What is a reason for this?

  Could be due to word length effect- the longer the word the longer it takes to perform rehearsal and fewer words can be held. Spanish numbers are longer than English ones.
• When does subvocal rehearsal occur?

  At around age 7
• How does this relate to the results of the study?

  If the word length effect is related to the process of subvocal rehearsal and this only appears at around age 7, there should be no difference between Spanish and English populations, which didn't happen in the study.
• Why may have the results occured in the second study?

  Because the phonological loop is affected by age, not so much dementia. Healthy elderly controls had digit span of close to 7 year olds compared to dementia elderly ps who has similar digit span to 6 year olds.
• What was the IV in the study?

  Age
• What was the DV in the study?

  Digit span
• What research method was used?

  Lab experiment
• What experimental design was used?

  Independant measures
• Generalisability


  Men and women. Relatively equal numbers.

  Public and private schools used, variety of ages of children. Large sample. Representative of target pop.

  All from Madrid, may not generalise from this.
• Reliability


  Lab exp. High level of controls. Standardised procedures. Same order of tasks. One digit per second.

  Means we can replicate the research.
• Applications


  -Helps us to understand how the phonological loop works and what affects it. Helps us understand why Spanish digit span might be lower. Helps us understand cross cultural differences.

  -Helps us understand the extent to which working memory is affected by Alzheimer's disease and frontotemporal lobe dementia.
• Validity


  Ecological validity can be low. Artificial task as lists of numbers aren't something we learn in everyday life. Cannot generalise to everyday life. Low mundane realism.

  Lab exp. strange environment for ps (children and ps with dementia)

  Digit strings recalled is a clear measurement of digit span.

  Measured in controlled environment so controlled for extraneous variables such as distractions.
• Ethics


  No major ethical concerns

  Ps under age of 18 would need consent from their parents.

  Neither of the studies used distressing tasks