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89
https://doi.org/10.1590/0004-282X20170186
ARTICLE
Relationship between visuospatial episodic
memory, processing speed and executive
function: are they stable over a lifespan?
As relações entre memória episódica visual-espacial, velocidade de processamento e
funções executivas são estáveis ao longo do ciclo vital?
Bruna Fulgêncio Dias1, Letícia Oliveira Rezende1, Leandro Fernandes Malloy-Diniz2, Jonas Jardim de Paula1,2
Memory is a complex cognitive system with numerous
subdivisions. It is usually divided into short-term memory
and long-term memory. Long-term memory is responsible
for storing information for later use, and is subdivided into
declarative (conscious and easily accessible by language) and
non-declarative (unconscious and procedural). In the declar-
ative memory, there is another subdivision into episodic and
semantic memory. Episodic memory, the focus of this work,
is the ability to search for content in declarative long-term
memory that depends on a specic event (episode)1.
Episodic memory depends on a set of mental processes
involving encoding, storage and retrieval of internal or
external information1. In neurobiological terms, the storage
of information in the brain depends on modications in the
structure and connectivity of nerve cells2. Memory formation
depends on brain plasticity, that is, the ability of brain cells to
change their structure and function in a manner consistent
with learning processes, and it is largely related to the func-
tioning of the hippocampus and its connections with other
brain areas3. Depending on its content, episodic memory
might also be divided in visuospatial (including information
on position, stimulus and visual contents) or verbal (depen-
dent on language skills). ese processes are aected by
aging, and visuospatial episodic memory shows considerable
1Faculdade de Ciências Médicas de Minas Gerais, Belo Horizonte MG, Brasil;
2Universidade Federal de Minas Gerais, Belo Horizonte MG, Brasil.
This research was conducted in the Faculdade de Ciências Médicas de Minas Gerais and at the Universidade Federal de Minas Gerais.
Correspondence: Jonas J. de Paula; Faculdade de Medicina da UFMG; Avenida Prof. Alfredo Balena, 190; 30130-10 Belo Horizonte MG, Brasil; E-mail:
jonasjardim@gmail.com
Conflict of interest: There is no conflict of interest to declare.
Received 24 July 2017; Received in final form 18 October 2017; Accepted 06 November 2017.
ABSTRACT
The present study evaluated the association between episodic memory, executive function and processing speed in a sample with
different age ranges. We tested the hypothesis that processing speed, executive function and memory are more strongly associated
during childhood and old age. We evaluated 571 participants, aged six to 92 years, divided into four age groups: children/adolescents,
young adults, middle-aged adults and older adults. Correlation analyses suggested that the shared variance between the processing
speed and memory is strong in childhood but weak across other age ranges. Executive function, however, had a stronger association
both in childhood and in old age, when compared with the intermediate stages. We conclude that the effects of processing speed and
executive function on memory are not stable across human development. These functions may be compensatory mechanisms for
memory functioning in childhood and old age.
Keywords: executive function; memory; aging.
RESUMO
O presente estudo avalia a associação entre velocidade de processamento, funções executivas e memória em uma amostra de diferentes
faixas etárias. O estudo testa a hipótese de que a velocidade de processamento, as funções executivas e a memória apresentam associação
mais forte na infância e na velhice. Avaliamos 571 participantes, com idade entre seis e 92 anos, divididos em quatro grupos etários:
crianças/adolescentes, adultos jovens, adultos de meia-idade e idosos. Análises de correlação sugerem que a variância compartilhada
entre velocidade de processamento e memória é forte na infância e fraca nas demais idades. Já as funções executivas apresentaram
associação forte com a memória tanto na infância quanto na velhice, quando comparadas aos estágios intermediários. Concluímos que os
efeitos da atenção sobre a memória variam em função da idade do participante. Essas funções podem ser mecanismos compensatórios
para a memória ao longo do desenvolvimento.
Palavras-chave: função executiva; memória; envelhecimento.
90 Arq Neuropsiquiatr 2018;76(2):89-92
decline with aging, with better functioning between the sec-
ond and third decade of life and subsequent reduction into
old age4. e decline in memory after young adulthood is
inherent in human development, but is still signicantly
aected by a number of factors, including the presence of
mental disorders and socio-environmental factors5.
Processing speed is a cognitive function related to how
quickly and accurately information is processed by other cog-
nitive systems, and it is strongly correlated with the integrity
of white matter6. Executive function is an umbrella term that
represents dierent cognitive processes related to attentional
control, behavioral regulation and goal-directed behavior7, and
is strongly related to the prefrontal cortex8. ese two func-
tions, processing speed and executive function, are related to
several cognitive, behavioral and functional outcomes across a
lifespan, including episodic memory changes9.
Longitudinal data suggests that throughout human devel-
opment, both the evocation of episodic memory content and
attention have an inverted “U” development10. Children and
adolescents show a progressive improvement in episodic
memory until early adult life. is means that such processes
are inecient in childhood but optimize throughout matu-
ration, peaking between the second and third decade of life,
and declining from that point onwards, following the course
of development of cognitive processes of a uid or eortful
nature10. Although individual factors (such as intelligence) or
environmental factors (such as formal schooling) may aect
the development of these functions, in populational terms,
the inverted “U” pattern shows good adjustment. Data from
studies of typical and clinical samples suggest a relationship
between episodic memory, processing speed and executive
function. Higher processing speed and better executive func-
tion may favor episodic memory, improving codication,
storage or retrieval of memory content11,12,13. Because epi-
sodic memory in childhood and older age is usually less e-
cient than in middle age, and processing speed and executive
function may improve memory functioning, we may assume
a stronger association between these at the extremes of
development (childhood and old age). In this hypothesis, the
processing speed and executive function may be called upon
as compensatory mechanisms to avoid memory failures.
e present study aimed to analyze the strength of the asso-
ciation between visuospatial episodic memory, processing speed
and cognitive control at dierent stages of a lifespan. We hypoth-
esized that there is a stronger relationship in children/older
adults when compared with middle-age adults and adolescents.
METHODS
Participants
We evaluated 571 Brazilians, aged between six and 92
years, in this study. Participants were invited through direct
contact by researchers (divided into two teams, one compris-
ing students from the Faculty of Medical Sciences of Minas
Gerais and another by students from the Federal University of
Minas Gerais), or recruited through advertisements on social
networks. e exclusion criteria were the presence of cogni-
tive, sensory or motor impairments that made the evaluation
of attention and memory, according to the screening ques-
tions in a sociodemographic questionnaire, unfeasible. We also
selected participants who were at least six years-old, due to dif-
culties in evaluating these two mental functions in younger
children. e schooling of the sample ranged from incomplete
primary education to full/post-graduate higher education.
We divided the participants into four groups:
children/adolescents (101 participants aged six to 18 years),
young adults (321 participants aged 19 to 34 years), middle-
aged adults (84 participants aged between 35 and 54 years)
and older/elderly adults (65 participants aged 55 years or
over). Table 1 presents a brief description of the participants.
Assessment of executive function, processing
speed and memory
e Five Digit Test14: is test is a numerical version of the
Stroop color-word paradigm, which evaluates the eect of
interference on the attentional system. In this test, the partici-
pant must work with numbers and quantities (1 to 5). e Five
Digit Test includes four subtests: reading, counting, choosing
and switching as shown in the Figure. e rst two are simple
attention/processing speed measures and the last two are con-
trolled attention/executive function attention. We used the
average time of reading and counting subtests as a measure of
processing speed and the mean time of inhibition and exibil-
ity scores as a measure of executive function. Higher values in
these measures indicates worse performance.
Table 1. Description of participants.
Group Sex (female)
(%)
History of mental
disorders (%)
RCFT recall Formal education
(years)
FDT processing
speed
FDT executive
function
M SD M SD M SD M SD
Children and adolescents
(n = 101) 53 1 14.90 8.80 9.30 4.14 41.92 20.73 36.54 12.68
Young adults (n = 321) 63 13 22.90 6.70 14.32 2.90 19.99 10.84 23.51 6.67
Middle-aged adults (n = 84) 75 13 18.90 6.90 15.34 4.21 24.40 10.33 26.64 7.56
Older adults (n = 65) 77 9 14.90 7.7 0 13.43 4.85 33.78 20.50 32.12 13.80
M: mean; SD: standard deviation; RCFT: Rey complex figure test; FDT: five digit test.
91
Dias BF et al. Executive function, speed and memory over a lifespan
e Rey Complex Figure Test15: is is a test to evaluate
visuospatial processing, episodic memory and planning. In
this test, participants must copy, and then recall, a complex
gure of 18 interconnected geometrical elements. Each ele-
ment is scored based on localization and precision, according
to standardized guidelines15. In this study, we adopted only the
immediate recall of the gure (three minutes after its copying)
as a measure of episodic memory. Scores range from 0 to 36,
and higher scores are indicative of better performance.
Statistical analysis
To analyze the association between attention and mem-
ory, we used Pearson’s correlation, after analyzing the dis-
tribution of the data (the measurements showed a pattern
compatible with normal distribution). We computed the cor-
relations in each of the age groups. To facilitate the interpre-
tation of the data and to avoid biases in the direction of cor-
relations, we also calculated the shared variance (r²) between
the measures of the study.
Ethical aspects
e study was approved by the Research Ethics Committee
of the Medical Sciences Faculty of Minas Gerais (CAAE:
45381515.4.0000.5134). All the participants in the research were
given a Free and Informed Consent Form, which was signed by
them or the person responsible for them, as in the case of chil-
dren and adolescents. e researchers made themselves avail-
able to the participants to clarify any doubts presented.
RESULTS
e performances of the four age groups in the measure-
ments of processing speed, executive function and episodic
memory are shown in Table 1. e mean values for each neu-
ropsychological test suggests that the measures showed the
hypothesized pattern of an inverted “U”.
Table 2 shows the correlations and shared variance
between the cognitive measures adopted in the studies. e
association of processing speed and memory was strong dur-
ing childhood/adolescence, but weak in the other age groups,
suggesting a stronger relationship between these constructs
only in the early stages of development. Executive function
showed a stronger correlation with episodic memory in
childhood and old age, and a weaker correlation in young
adulthood and middle age.
DISCUSSION
Our results suggested that the association between the pro-
cessing speed, executive function and visual episodic memory
depended on the participants’ ages. In children, we observed
a strong association between the processing speed, executive
function and memory in both automatic and controlled atten-
tion processes. In young and middle-aged adults, the associa-
tions were weak for both processes. In the elderly, there was
a weak association between the processing speed and mem-
ory but a strong association between executive function and
memory. Based on our initial hypothesis, only executive func-
tion was strongly associated with memory at the age extremes.
Although the cognitive changes associated with human
development have been extensively mapped over the last cen-
tury10, and their course is well known, there are still some open
questions about how dierent cognitive functions are asso-
ciated in dierent phases of life. e hypothesis tested in the
present study was based on the compensatory recruitment
models, as discussed by Han and colleagues16. is model pro-
poses that, in developmental stages where a mental function is
not at its optimal level, other mental functions are recruited to
maintain good functioning in the individual. e phenomenon
would be similar to that observed in acquired brain lesions
where, after compromising a mental function associated with
a certain region, the organism tries to reorganize itself, in
terms of plasticity, to compensate for the decits17.
e theory presupposes that throughout the develop-
ment there is a functional specialization of dierent cerebral
regions for the accomplishment of specic cognitive func-
tions. is specialization would reach its apex in young adult-
hood, where cognitive function would show greater specic-
ity in brain regions. Functional specialization, however, is
smaller during childhood when the still-maturing brain has
not fully developed cognitive abilities, and in old age, when
the cognitive decline in aging leads to the recruitment of
Figure. Five digit test (adapted from Paiva et al., 2016)14.
Part 1 - Readin
g
one two three one two three
Part 2 - Counting
Part 3 - Choosin
g
1
Part 4 - Shifting
2
2
3
3
3
**
*
*
*
*
one two three one two three
31
1
2
2
2
3
1
1
1
2
2
2
2
Table 2. Correlations and shared variance between episodic
memory, processing speed and executive function in different
age ranges.
Variable
Processing
Speed
Executive
Function
r r² r r²
Children and adolescents -0.545** 30% -0.435** 19%
Young adults -0.180** 3% -0.235** 6%
Middle-age adults -0.222** 5% -0.225** 5%
Older adults -0.284** 8% -0.558** 31%
**p<0.01.
92 Arq Neuropsiquiatr 2018;76(2):89-92
several mental functions for the maintenance of perfor-
mance18. is can be observed, for example, in functional
neuroimaging studies19. Our data endorse this perspective,
suggesting a greater association of executive function and
memory in age extremes, where shared variance between the
measure of executive function and memory was higher (19%
in children/adolescent and 31% in older adults) when com-
pared to young or mid-adult life (6% and 5%).
Executive functions are a set of top-down mental pro-
cesses that allow goal-directed behavior7. ey involve con-
scious processes, are energy intensive and motivational,
and strongly related to the prefrontal regions of the brain.
Executive functions connect to the attentional and memory
systems, allowing the possibility of eortful control of these
processes. In this sense, these controlled and eortful pro-
cesses would be used by children and older adults in learning
processes, supporting episodic memory. Processing speed
would have a closer relationship with memory only in child-
hood, perhaps because it represents a more global aspect of
mental functioning, which is still in specialization20.
e study has limitations that should be considered. First,
although we have a reasonable sample size in the study, the
age group division was not equal, with most participants being
young adults. e convenience sample does not represent the
variability of the Brazilian population, and reduces the general-
ization potential of our results. We also adopted the Rey Complex
Figure Test as a measure of episodic memory; however, test per-
formance depends on other factors including IQ, motor coordi-
nation and other aspects of visuospatial abilities21. Nevertheless,
the study presents positive points, such as the well-established
hypothesis, the use of representative and validated measures of
attention and memory, and good use of cross-sectional data.
In conclusion, our results suggest that the association
between attentional processes and memory varies according
to age. In children and older adults, there is a greater associa-
tion between executive function and memory. e associa-
tion of processing speed with memory was strong only dur-
ing childhood and adolescence. We believe this reects the
compensatory mechanisms that recruit additional functions
to maintain good functioning in daily life.
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