06. Contemporary Study Sebastian & Hernandez-Gil

Question 1

What were the aims of Sebastian and Hernandez-Gil’s 2012 study of the developmental pattern of digit span in Spanish pattern?

Answer 1

1. Using digit span as the measure of the phonological capacity, they aimed to investigate the development of the phonological loop in children and older adults.
   -Specifically in children aged between 5 and 17 years old, and also including changes from ageing and neurodegenerative diseases (alzheimer’s and fronto-temporal dementia).
   -They analysed the age at which digit span stopped increasing and the decline in digit span in older people by comparing their findings to previous research which used the digit span test.
2. Additionally, they wanted to investigate if Anglo-Saxon (English speakers) data, (which previously found 15 years to be the age at which digit span stops developing further) were replicated, or whether digit span would be higher, for Spanish speakers.

Question 2

What is the background information surrounding the study?

Answer 2

-Previous research had tested Anglo-Saxon (people who speak English) participants and found that digit span increases with age then levels off at 15 years.
-The researchers wanted to compare English speaking children to Spanish speaking children to test these findings.
-They also compared their findings to elderly participants to investigate the decline of capacity of the phonological loop in old age.

Question 3

What was the prior knowledge from previous models of memory?

Answer 3

The phonological loop in working memory (STM) had two parts:
-The phonological store, which retains verbal information.
-The articulatory process (subvocal rehearsal) which attempts to extend the temporary memory store by performing maintenance rehearsal.

Question 4

What was the prior knowledge from previous research on development age of the PL and sub-vocal ability.

Answer 4

-There is evidence that 3 to 4 year olds use their phonological loop, from a very young age, but subvocal rehearsal is thought to develop from 7/8 years of age, so as they cannot subvocalise and rehearse verbal information, young children forget information quite quickly due to decay.
-Diamond (2006) STM seems to improve from the age of 6 into adulthood, and this is approximately when subvocal rehearsal develops.
-Hitch (2006) the use of subvocal rehearsal explains the increase of digit span with age as the participant is then able to rehearse the information, keeping it in their STM for longer.

Question 5

What was the prior knowledge from previous research on age differences in memory?

Answer 5

-Young children have a different STM capacity than adults. It is also thought that older people in general might have a lower capacity. Healthy elderly people (no cognitive disorders) tend to be more forgetful as their cognitive abilities decrease in general. Elderly people with cognitive impairments (alzheimer’s and fronto-temporal dementia) have impaired STMs.

Question 6

Describe the sample used in your contemporary study?

Answer 6

The particpants were 570 children from pre-, primary and secondary schools (public and private) in Madrid. All were born in Spain. Through volunteer sampling, they were selected from all 13 years of Spanish education system (aged 5-17 years). No child had repeated a year and none presented with hearing disorders, reading or writing difficulty or any other cognitive impairment.

Question 7

What is a strength of the sample?

Answer 7

-The sample has high generalisability as the sample consists of 272 bits and 298 girls from 13 different schools.
-The sample is representative of a wide range of the target population, therefore findings that digit span increases gradually with age until 17, can be generalised to the wider population.

Question 8

What is a weakness of the sample?

Answer 8

Children who had repeated a year, had hearing disorders and had reading or writing difficulties were excluded. Therefore, the study lacks generalisability. Results are only generalised to children who live in Madrid and speak Spanish as there is no range of language in the procedure.

Question 9

How did the researchers control for extraneous variables?

Answer 9

1. Controlled sample and removed those repeating a year, or learning issues. To control for education and cognitive differences.
2. Standardised procedure, digits read aloud at a constant rate of one per second. This procedure ensures experience of study did not vary greatly from one participant to another. The use of a standardised procedure helped to control extraneous variables, contributing to a reasonable degree of internal validity.

Question 10

Define primary data.

Answer 10

Gathered by the researchers in an actual study at the time and for the purpose of testing one or more hypothesis.

Question 11

Define secondary data and give an example of how the researchers use secondary data?

Answer 11

-Gathered from a previous study, possibly for a different purpose and already existing when used in a new study.

Question 12

How did Sebastian and Hernandez-Gil use secondary data?

Answer 12

Used data from researchers previous study in 2010. Data gathered about digit span elderly people without impairment, those with Alzheimer’s and those with fronto-temporal dementia.

Question 13

Define digit span.

Answer 13

Digit span refers to memory span and capacity of short-term memory without rehearsal. Digits are numbers. Digit span can be tested by reading a sequence if numbers to someone. If they get that right- say a sequence of 3 numbers- then the next sequence they read would have 4 digits in it, and so on, until they get a sequence wrong. That is then their digit span.

Question 14

Describe the procedure used in the contemporary study.

Answer 14

1. The children were tested individually during break time.
2. The materials used consisted of sequences of random digits that gradually increased by one in length each time.
3. They were read aloud to each participant.
4. The task began with 3 sequences of 3 digits them 3 sequences of 4 digits and so on.
5. The particpants listened to each sequence and then were asked to repeat them in order.
6. Each child completed a practice sequence at the start.
7. Digit span was defined as the longest sequence the child could recall, two times out of the 3 presented in order, without error.

Question 15

Describe the setting of the procedure.

Answer 15

This was an experiment conducted in field settings (schools).

Question 16

What was the independent variable of the procedure?

Answer 16

Year of schooling (year group).

Operationalised: This was measured in years.

Question 17

What was the dependent variable of the procedure?

Answer 17

Mean verbal digit span.

(The researchers also made comparisons between school children, elderly adults and people
with dementia).

Operationalised: Measured as the number of digits in the sequence where they recalled at least 2 of the 3 sequences correctly (right digits, right order).

Question 18

What did the results from part one show about digit span and age?

Answer 18

The results showed a clear increase in digit span with age. The youngest age group (5 years) had a significantly lower average digit span (3.76) than the other age groups. Digit span increased significantly and smoothly up to 11 years (5.28). The rate of increase slowed and stabilised up to 17 years (5.91).

Question 19

What were the results from part 1 compared to?

Answer 19

-The researchers compared these findings to data from the earlier study with Anglo-Saxon elderly participants. Digit span in a group of healthy elderly people was significantly higher than for 5 and 6 year old children (but no different from that of older children).
-The pattern of findings for a group of people with dementia (Alzheimer’s disease) was similar to the healthy elderly people.
-In contrast, in the previously studied group of 9 patients with frontal variation fronto-temporal dementia (fvFTD), mean digit span was not significantly different from that of 5 and 6 year old children.

Question 20

What is the reason behind why Sebastian and Hernandez Gil found Spanish children to have a lower digit span (by one digit) to their Anglo-Saxon (English speaking) counterparts?

Answer 20

The word length effect (Baddeley 1975).

Question 21

Describe the word length effect (Baddeley 19755).

Answer 21

-Showed that the capacity of the phonological loop in working memory depends on word length. We are generally able to recall more short words than long ones from lists of words. This is because it takes longer to rehearse the longer words.
-The crucial factor influencing this process is the time it takes to pronounce the word (the articulation rate). This means the capacity of the phonological loop is limited not by the amount of storage space but by time. In Baddeley’s study, participants were able to recall as many words as they could pronounce in about 2 seconds.
-An impressive quantity of research confirms a close relationship between recall and reading speed/pronunciation time in many languages.
-There is even evidence of a ‘sign length effect’, deaf users of American Sign Language having poorer recall for signs that take longer to produce (Wilson and Emmorey 1988).

Question 22

In part 2, what did the researchers find when results were compared with previous research?

Answer 22

-The performance of elderly particpants was compared with the youngest in the first part of the study and showed a higher digit span than the 5 year olds.
-Performance of elderly particpants did not differ from other year groups (p>0.05)

This tells us the decline of digit span is caused by word length effect, not age.

Question 23

How can findings showing a decline in working memory and short term capacity as age increases be applied?

Answer 23

-This can be used by carers to help elderly people and try to strengthen their memory by implementing tasks and techniques that could help improve this to reduce the decline in their capacity as they get older.
-As children have a lower digit span, schools can consider this when giving students instructions and planning lessons to optimise information intake.

Question 24

How can the findings that digit span declines in old age be negatively applied?

Answer 24

It is a socially sensitive topic and the findings that digit span declines in old age could prevent the elderly from earning job positions due to the stigma that they have bad memory. This is a weakness, as application could lead to society being prejudiced to elderly people as they are being stigmatised by people thinking they have poor memory, which would be detrimental to society.

Question 25

We can we conclude from comparing the results from different groups of people?

Answer 25

The comparison of dementia groups, healthy elderly people and school children suggests that the capacity of the phonological loop component in working memory is affected more by age than by dementia.

Question 26

What can we conclude from Sebastian and Hernandez-Gils contemporary study?

Answer 26

-Digit span increases from 5 to 17 years old.
-The Anglo Saxon data had a digit span increasing to 15 years old, whereas the Spanish study found digit span continued to increase up to 17 years.
-English data showed adult digit span of approximately 7 digits, compared with Spanish data which showed approximately 1 digit fewer.
-Researcher suggests this could be to do with language as the words for Spanish numbers have more syllables than the equivalent words in English, eg ‘one’ compared with ‘uno’.
-Age appears to be the cause of poor digit span/a decline in digit span as opposed to dementia

Question 27

What can we conclude from comparing Spanish and Anglo-Saxon children?

Answer 27

Both the current study and previous research with Anglo-Saxon elderly particpants show that digit span increases with age up to adolescence. However, in Spanish children the increase continues until at least 17 years, whereas in English children it levels out at 15 years. Also, the average digit span was lower for Spanish children compared with English children. The researcher explains these differences in terms of the word length effect. Because it takes more time to rehearse longer words, more information is likely to be lost. The word length effect applies in this case because Spanish word for digits are longer than their English equivalents. Most Spanish digit words are 2 syllables (eg cuatro, cinco, ocho), whereas most English digits are one syllable (eg four, five, eight). Furthermore, the word length effect occurs because we rehearse words subvocally, but we don’t begin to do this until about 7 years of age. This means there should be no difference in digit span between Spanish and English children younger than 7 years.