Hindawi Publishing Corporation
Neural Plasticity
Volume 2013, Article ID 306432, 11 pages
http://dx.doi.org/10.1155/2013/306432

Clinical Study
Making Memories: The Development of Long-Term Visual
Knowledge in Children with Visual Agnosia
Tiziana Metitieri,1 Carmen Barba,1 Simona Pellacani,2
Maria Pia Viggiano,1,3 and Renzo Guerrini1,3
1

Pediatric Neurology Unit, Children’s Hospital A. Meyer, University of Florence, Viale Pieraccini 24, 50139 Firenze, Italy
IRCCS Stella Maris, Viale del Tirreno 331, Calambrone, 56018 Pisa, Italy
3
Department of Neuroscience, Psychology, Pharmacology and Child Health, University of Florence, Viale Pieraccini 6,
50139 Firenze, Italy
2

Correspondence should be addressed to Tiziana Metitieri; t.metitieri@meyer.it
Received 4 May 2013; Accepted 11 September 2013
Academic Editor: Małgorzata Kossut
Copyright © 2013 Tiziana Metitieri et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies
demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of
compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study
of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory
when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual
cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2 years
and 3.7 years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We
observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate
that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception
and memory during development might modulate the long-term construction of visual representations, resulting in less severe
impairment.

1. Introduction
Visual agnosia is a modality-specific disorder of object
recognition caused by a lesion involving the visual cortex [1].
As originally described by Lissauer [2] the disorder cannot
be attributed to poor sensory processing, and recognition of
objects through other modalities can be relatively preserved.
Most of our understanding of visual agnosia derives from
investigations of adults with visual agnosia acquired after
years of normal functioning [3]. Previous findings suggest
that long-term memory and recognition can be concurrently
or differentially impaired [1]. In the majority of cases of
agnosia both memory and perception are clearly impaired
[4], though, in some, the representations stored in memory
are preserved even for objects that cannot be recognized
[5–7]. However, data from agnosics exploring the dynamic

influence of degraded perceptions on the updating of longterm visual knowledge are limited. The longitudinal investigation of the profoundly agnosic H.J.A. demonstrated a
subtle deterioration in his ability to draw objects from
memory over time [8]. These data might suggest an interplay
between perception and memory rather than their functional
independence [8]: when perceptual processing is impaired,
visual memory may gradually decline, due to less fine-tuning
of the system to the visual properties of objects.
Of particular interest may be the observation of these
dynamic changes in children with lesions which occurred
around birth in whom perceptual impairments lead to weak
updating of visual memories that starts early in life. Reported
observations of childhood visual agnosia are scarce, and, in
most of them, the causative lesion had occurred after visual
recognition of objects had been consolidated [9, 10]. Studies

2
exploring the effects of perinatal acquired brain lesions on
the development of visual perception are relatively rare [11–
15]. These studies have described nonseverely impaired visual
abilities following bilateral early damage to the primary
visual cortex. Selective impairment of visual recognition and
preserved visual memory are commonly reported findings.
Performance on visual tasks and the different degrees of
improvement at follow-up reveal the possible mechanisms of
the visual system’s developmental plasticity in child agnosia
[11]. The study of visual object recognition in children with
early brain damage might offer the opportunity of exploring
the interaction between perception and memory in the
course of development.
We investigated visual recognition and visual memory in
three children with occipital lobe lesions (the striate cortex
and to different degrees the dorsal and ventral streams) having occurred in early infancy and causing different patterns of
perceptual impairment. We attempted to define their visual
recognition deficits according to the classification of agnosia
used in adults [1, 3]. These children also manifested visual
memory impairment, which appeared to be modulated by the
structural properties of objects. We also explored the time
course of the visual memory impairment in two children we
reexamined 2 years and 3.7 years from the initial assessment.

2. Methods
Between 2008 and 2009, each child underwent a neuropsychological testing battery, evaluating general cognitive
abilities, language, visual perception, and visual memory.
Two children (G. and R.) were reassessed for language, visual
perception, and visual memory tasks between 2011 and 2012.
For tasks where normative data were not available, we
assessed as controls two groups of age-matched children
having normal or corrected to normal vision. Performances
on the Navon task were compared to those of a group of
10 children (mean age = 11.97, SD = 1.72, 4F/6M) with no
history of neurological disease (healthy controls). In order
to compare the specificity of the effect of degraded visual
perception on visual memory, we included a second group
of four control subjects (mean age = 12.25, SD = 1.26) with
unilateral early-onset brain lesions, normal general cognitive
abilities, and no evidence of visual agnosia (neurological
controls). These individuals characteristics were as follows:
F. (male, 14 years, right handed) had left mesial temporal
sclerosis and seizures; M. (male, 11 years, right handed) had
right temporal polar lesion and was a candidate for epilepsy
surgery; A. (female, 12 years, right handed) had left posterior
quadrantic dysplasia; C. (male 12 years, right handed) had
left temporal lobe dysplasia and was a candidate for epilepsy
surgery.
Informed consent was obtained before each assessment,
in accordance with the Declaration of Helsinki and with the
requirements of the Ethical committee of our Hospital.

3. Case Histories
Clinical characteristics of the three subjects are summarized
in Table 1.

Neural Plasticity
L., a 17-year-old right-handed boy, exhibited lethargy,
hypotonia, and convulsions since the second day after birth.
Hypoglycemia (plasma glucose level: 9 mg/L) was detected.
He was treated with i.v. glucose, phenobarbital, and benzodiazepines. Recurrent hypoglycemia and convulsions occurred
until 6 months of age, when he started exhibiting left hemiclonic seizures in euglycemia. A combination of vigabatrin
and valproate was effective in controlling seizures. At 9 years
of age he started to exhibit weekly drug-resistant seizures
with unresponsiveness, head deviation to the left, hypotonia,
and falls. Interictal EEG showed left temporoparietooccipital spikes and slow waves with contralateral spread. MRI
revealed a linear hyperintense signal involving bilaterally the
parietooccipital and calcarine sulci (Figure 1). Visual field
testing revealed bilateral inferior quadrantanopia. When he
was 11 years old he attracted our attention during clinical evaluation of epilepsy. Neuropsychological assessment,
including visual recognition and visual memory testing, was
conducted when he was 13 years old. After that year his family
discontinued follow-up.
G., a 14-year-old right-handed boy, had experienced heart
rate deceleration in the 36th week of pregnancy and was
delivered by caesarean section. Apgar scores were 0–7 at 1 and
5 minutes after delivery. He had normal psychomotor development. At age 2, he experienced a right unilateral, prolonged
seizure, and between age 6 and 8, three additional nocturnal
seizures with right arm jerking. Since age 8 he exhibited
diurnal seizures with initial visual hallucinations, pallor,
cyanosis, right arm jerking with head, and eye deviation to the
right. EEG showed bilateral asynchronous parietooccipital
spikes. Brain MRI revealed high signal intensity in the left
parietooccipital and calcarine sulci with atrophy of the left
occipital lobe (Figure 1). Visual field testing revealed right
inferior quadrantanopia. Carbamazepine treatment achieved
complete seizure control. His last seizure occurred at age 9.5.
Neuropsychological assessment, including visual recognition
and visual memory testing, was performed when he was 10
years old and repeated at 13 years 7 months.
R., a 15-year-old right-handed boy who had an uneventful family and personal history, was diagnosed with right
homonymous hemianopia at age 7. Three years later, seizures
appeared, characterized by amaurosis and unresponsiveness.
Brain MRI revealed an atrophic lesion involving the left
mesial temporooccipital cortex (Figure 1). Carbamazepine
was started with reduction of seizure frequency. From age 11
he experienced weekly episodes of head and eye deviation to
the right, stiffening with subsequent fall and prolonged postictal aphasia. Antiepileptic drug treatment was ineffective.
He progressively developed expressive language impairment
and learning difficulties. A protocol for presurgical evaluation
of epilepsy was started. Prolonged video-EEG recordings
captured his habitual seizures which were accompanied by a
left predominant ictal discharge.
Functional MRI demonstrated left hemispheric dominance for language. Invasive EEG using subdural grids
demonstrated that the seizure onset zone corresponded
to the lesional area. At age 13.7, left temporal lobectomy
was performed, sparing the superior (T1) and middle (T2)
temporal gyri, and parietooccipital corticectomy. Histology

Neural Plasticity

3
Table 1: Clinical characteristics for each child∗ .

Age (years)
(i) at seizure onset/
(ii) at last seizure
Birth and delivery
Visual field

L.

G.

R.

12

10

12

0,2/6; 9/still present

6/9,5

6/9,5

Perinatal hypoxia

Uneventful

Right inferior quadrantanopia
Bilateral asynchronous
temporoparietooccipital spikes
and diffuse spike and wave
discharges

Right hemianopia
Diffuse spikes and waves while
awake and diffuse polyspike
discharges during sleep, left
predominance
Diffuse spike discharge with left
predominance

Hypoglycemia (neonatal
convulsions)
Bilateral inferior quadrantanopia

Interictal EEG abnormalities

Left temporoparietooccipital
spikes and slow waves with
contralateral spread

Ictal EEG

NA

Seizure semiology

Unresponsiveness, head
deviation to the left, hypotonia,
and falls

Treatment

VPA + ESM + TPM

∗

NA
(a) During sleep: right arm
jerks and ocular revulsion
(b) While awake: visual
hallucinations, pallor, cyanosis,
right arm jerks, and head and
eye deviation to the right
CBZ

(a) Amaurosis, abnormal eye
movement, and unresponsiveness;
(b) Head and eye deviation to the
right, stiffening with frequent falls;
postictal aphasia
LTG + OxCBZ

NA: not available; CBZ: carbamazepine; ESM: ethosuccimide; LTG: lamotrigine; OxCBZ: oxcarbazepine; TPM: topiramate; VPA: valproic acid.

revealed focal cortical dysplasia type IIId. Postoperative EEG
was normal. He is seizure-free for 18 months after surgery.
He developed mild expressive language impairment requiring speech therapy. Visual field defect and verbal memory
impairment were unchanged in postsurgical evaluation and
are documented in the Results section. Neuropsychological
assessment, including visual recognition and visual memory
testing, was conducted when he was 12 years old and repeated
at the age of 14, four months after surgery.

4. Results
4.1. Neuropsychological Assessment at Baseline. This report is
divided into two subsections. In this subsection we present
data of the first neuropsychological testing administered to
G., L, and R. In the next subsection we report data on followup evaluation of G. and R.
4.1.1. Intelligence. General cognitive abilities were tested
using the Wechsler Intelligence Scale for Children-Revised
[16]. Each subject scored within average limits on the verbal
scale and below average on the performance scale. L. and R.
had Verbal IQs in the borderline range (VIQ = 74 and 77)
and G. had a Verbal IQ in the average range (VIQ = 94).
Performance IQs were mildly below average for L. and R.
(PIQ = 64 and 67) and in the borderline range for G (PIQ
= 74).
4.1.2. Verbal Fluency. Spontaneous speech was fluent or
relatively fluent with appropriate articulation, phonology,
vocabulary, syntax, and prosody for each subject. Verbal
fluency was within average range [17] for L. and G. for either
phonemic (𝑧 = −0.05 and 𝑧 = −1.5) or semantic (𝑧 = −1.65
and 𝑧 = −1.03) condition; R. had a score below average on
phonemic and on semantic fluency (𝑧 = −2.47, 𝑧 = −1.90).

4.1.3. Visual Discrimination. In a task similar to the Efron
shape test [18], we presented black geometrical shapes on
a white background, using a LCD monitor. In the first
condition, ten squares with different sizes (from 2.6 to 6.2∘ )
were presented in pairs, for 12 trials. Within a pair the size
varied according to seven levels of difference (from 0.0 to
1.2∘ ). In the second condition, a single shape (square of six
sizes, 4.0 to 7.0∘ or rectangle of six dimensions, 3.25 × 3.5 to
6.5 × 9.0∘ ) was presented, for 12 trials.
All children performed correctly at deciding if two
squares were similar (L. = 100%, G. = 92%, R. = 83%, 𝜒2 (2) =
2.12, 𝑃 = .35) and if the shape corresponded to a square or a
rectangle (L. = 92%, G. = 83%, R. = 75%; 𝜒2 (2) = 1.17, 𝑃 =
.56). R. performance was slightly worse in the above task
requiring fine-form discrimination.
In the shape discrimination task [17] children were asked
to select in ten trials which of 9 abstract line drawings
matched the target on the top of the sheet. All of them
performed correctly (L. = 90%, G. = 80%, R. = 100%).
4.1.4. Cancellation and Counting. In the visual search task
L. correctly crossed 22/24 stars (92%, the two stars missed
were one in the left and the other in the right part of the
sheet), G. correctly cancelled 19/24 stars (79%, missed stars
were not lateralized), and R. cancelled 19/24 stars (79%),
missing stars towards the right side of the sheet, thus showing
contralesional visuospatial hemineglect.
In the dot counting task, a number of black dots ranging
from 3 to 19, with 3 to 7 mm distance from each other and
6 mm diameter, were printed on 10 white sheets.
L. performed the task without errors (10/10), G. counted
correctly 9/10 dots configurations, and R. counted correctly
6/10 dots configurations, showing difficulties in counting
more than 12 dots per sheet.

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Neural Plasticity

L

(a)

(b)

(c)

(a)

(b)

(c)

(a)

(b)

(c)

G

R

Figure 1: MRI scan for each patient. L.: (a), (b) Brain MRI (axial T2 and sagittal T1 weighted images) showing bilateral periventricular
hyperintensities in the occipital lobes (white arrows) and dilatation of the occipital horn of the lateral ventricle (white arrowhead). G.: (a)–
(c). Brain MRI (axial FLAIR, coronal and axial T2 weighted images) showing bilateral periventricular hyperintensities in the parietooccipital
areas (see white arrowheads and arrows). R.: (a) Brain MRI (axial T1 weighted image) showing cortical-subcortical atrophy and abnormal
cortical sulcation in the left temporooccipital area (white arrow). (b), (c). Brain MRI (axial and sagittal FLAIR weighted images) showing
increased signal intensity in the left calcarine cortex and dilatation of the occipital horn of the left lateral ventricle (white arrowheads).

4.1.5. Naming
Drawings. L. correctly named 21/60 (35%, below average)
drawings of the Boston Naming Test (BNT) [19, 20]. Errors
were mainly visual (25%), semantic (13%), and “do not know”
responses (18%). Visual errors were incorrect generalizations
from a perceived or unperceived detail (e.g.: pretzel > handcuffs, wreath > bow, stilts > ski, unicorn > horse, palette >
paintbrush).
G. correctly named 35/60 (58%, average) drawings on the
BNT. Errors were mainly visual (16%), semantic (8%), and
adequate circumlocutions (8%). Visual errors were incorrect
generalizations from a perceived or unperceived detail (e.g.:
knocker > slingshot, asparagus > stick, trellis > ladder).
R. correctly named 34/60 drawings (57%, below average).
Errors were mainly visual (12%), semantic (12%), and “do not
know” responses (8%).
G. and R. performed a tachistoscopic presentation of the
BNT drawings 4–6 months later. Stimuli remained on the

LCD screen for 500 msec. G. showed a slight increase in
correct naming (40/60, 67%), while R. showed a relevant
decrease (22/60, 37%) in total accuracy.
Silhouettes. Children were requested to identify 48 black
drawings (24 living and 24 nonliving objects) on display until
a first attempt at naming them.
L. correctly named 23 silhouettes (48%) without differences in naming living (12/24) or nonliving objects (11/24).
G. identified 41 silhouettes (85%; 22/24 living and 19/24
nonliving). R. identified 29 silhouettes (60%; 16/24 living and
13/24 nonliving).
Overlapping Figures. Children were presented 12 series of 4
geometrical figures and 12 series of 4 letters. The overlap
concerned only one hidden figure while the remaining three
had at least some uncovered contours.
L. correctly performed on 10/12 (83%) patterns of geometrical figures and 9/12 (75%) patterns of overlapping letters.

Neural Plasticity
G. correctly identified geometrical figures on 11/12 (92%)
trials and letters on 11/12 (92%) trials. R. correctly identified
geometrical figures on 10/12 (83%) trials and letters on 10/12
(83%) trials.
Famous Faces. Sixteen pictures of the best known Italian
soccer players were presented on the LCD screen. All children
were habitual soccer fans, knew the main teams, and collected
stickers of the Italian national team.
L. recognized 1/16 (6%) football players showing a deficit
in the recognition of famous faces. G. recognized 9/16 (56%)
football players and R. 8/16 (50%).
4.1.6. Copying. The Rey Figure [21] was used to assess
drawing abilities in copying (Figure 2). L. realized a very
good copy (score 31/36), but with a very slow process,
beginning with the triangle-rectangle at the left bottom of
the figure and adding segment by segment until the end, for
about 20 minutes. G. had difficulties in copying the global
structure and only reproduced some details with general
spatial contiguity. He obtained a score of 12.5/36, below
average. R. showed difficulties in this task with closing-in
phenomenon and obtained a score of 16/36, below average.
4.1.7. Reading. Each child was asked to perform two tasks
taken from the Battery for the Evaluation of Dyslexia and
Dysorthographia (DDE-2) [22]. In the first task they were
requested to read four lists of words as quickly as they could,
and in the second task to read three lists of nonwords.
G. performed at normal levels for time and accuracy. L.
and R. were very slow in reading either words and nonwords.
Their reading speed fell below the norm for children at the
same school grade.
4.1.8. Writing. All three children were able to write correctly
words and sentences [22], spontaneously and under dictation.
4.1.9. Navon Test. Target letters (S or T) were present at
a global and/or a local level. The global letter subtended
3.276∘ × 3.66∘ of visual angle (in width and height, resp.), and
each local letter subtended 0.56∘ × 0.48∘ . The interelement
distance was 0.1∘ .
There were two conditions: a global condition, in which
the subject had to respond to global letters, ignoring local
ones, and a local condition in which the subject had to
respond to local letters, ignoring global ones. Three types of
trials were presented: congruent (global letter was the same
as the local letter), incongruent (global and local letters were
different), or neutral (the target letter was associated with
the letter X). The stimuli were presented on a PC running
E-Prime software (Version 1.2) [23]. Participants responded
via the keyboard, pressing one of the two keys assigned to
the target letters. The order of the different conditions was
balanced. There were 72 trials for each condition. Table 2
shows error rates for L., G., R., and healthy controls for the
global-local task.
A global interference effect, where local congruent letters
produce a high proportion of accuracy than local incongruent, was observed for healthy control subjects (𝜒2 (2) = 21.27,

5
𝑃 < .001). The reverse effect, local precedence, was not
observed for healthy controls in the global condition (𝜒2 (2) =
2.71, 𝑃 = .26). L., G. and R. exhibited an exaggerated
global interference effect in the local condition (𝜒2 (2) = 9.15,
𝑃 < .05). They also sustained a local interference effect
in the global condition (𝜒2 (2) = 6.99, 𝑃 < .05), although
this effect emerged only for G., and R. accuracy rates. The
contrast between the processing of local and global aspects
of hierarchical forms demonstrated a strong bias to attend to
global shape in the local condition for L., G., and R. However,
the results for both G. and R. indicate also a bias to attend to
local elements. These two children were generally impaired in
their processing of hierarchical forms. This suggests that G.
and R. find it difficult to attend to hierarchical forms mainly
when there is competition of the local/global levels, than in
trials in which competition is absent.
4.1.10. Verbal Memory. L. and G. obtained average scores (𝑧 =
−.28 and 𝑧 = .65) in paired-associated learning [17], whereas
R. learned only few and simple associations after the three
presentation of the same list of ten pairs of words. His score
was below average (𝑧 = −2.66).
Incidental semantic memory was assessed presenting 20
animal names. Each child was requested to name the color of
the animal but was not instructed to remember the items. At
the end of the incidental learning phase, children were asked
to report as many animals as they could. In the recall phase
G. reported 10/20 animals, performing within average; L. and
R. performed below average (5/20 and 6/20, resp.).
4.1.11. Visual Memory
Rey Figure Recall. All children failed the recall of the complex
figure (mean score = 3, SD = 1.32). L. could recall local details
but failed to integrate them to the global structure, whereas
G. and R. drawings were limited to very few details with no
spatial relations with respect to the model (Figure 2).
Neurological control subjects recall was in the normal
range (Mean score = 17.75, SD = 7.24).
Drawing From Memory. Subjects had to draw three objects:
a flower, a house, and a bicycle (Figure 3). All children complained about the difficulties of drawing while accomplishing
the task. They performed quite well in drawing a typical
representation of a flower and a house. For the bicycle L. and
R. omitted more visual properties, limiting their drawings to
the emerging details (wheels). R. at the end of his task said “I
would not ride that bike!”.
Benton Visual Retention Test. Children were presented 10
geometrical designs of the Benton Visual Retention Test,
(BVRT) Part A [24] for 10 seconds and asked to reproduce
them immediately afterwards. In this task the verbal component is important because subjects may remember the
names of geometric figures without relying on stored visual
representations to perform the task.
L. performed at average (8/10) and G. and R. were
below average (4/10 for both). Neurological control subjects
performed at average (Mean score = 8, SD = 0.82).

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Neural Plasticity

Copy

Recall

L

G

R

Figure 2: Rey’s figure: copy and recall after a 15-minute delay performed by L., G., and R. The good copy realized by L. required a very slow
process, beginning with the triangle-rectangle at the left top of the figure and adding segment by segment until the end. G. reproduced some
details with general spatial contiguity. R. closed in on model and showed difficulties in drawing both details and global shape. All children
had poor recall: L. could recall local details but failed to integrate them into an integrated whole, whereas G. and R. drawings were limited to
very few details.

Table 2: Percentage of error for responses in the Navon task by local and global conditions.

Healthy controls
L.
G.
R.

Congruent
1,4
4,2
8,3
4,2

Local
Incongruent
8,8
20,8
20,8
25

Neutral
1,4
16,7
4,2
12,5

Congruent
1,4
4,2
0
4,2

Global
Incongruent
3,7
4,2
20,8
16,7

Neutral
3,7
8,3
0
8,3

Neural Plasticity
Flower

7
Bicycle

L
Model

Control 1
Broom

Model

Control 2
Egg in eggcup

L

G
G

R
R

Figure 3: Examples of drawings from memory performed by L., G.,
and R. (a flower, a house, and a bicycle). Drawings were based on
typical representations of objects. L. and R. limited their drawings
of a bicycle to the emerging details (wheels).

Following the same procedure used for the BVRT we
administered two more visual memory tasks (stimulus
images courtesy of Michael J. Tarr, Center for the Neural
Basis of Cognition and Department of Psychology, Carnegie
Mellon University, http://www.tarrlab.org/).
Visual Retention of Objects. Children were presented five
drawings of objects, each on the center of a midsheet, selected
for their high familiarity and for being composed of at least
two different parts. They were broom, boat, egg in eggcup,
balloon, and bomb. These objects may benefit from verbal
rehearsal strategies for storage in memory. Each figure was
assigned a value ranging from 0 to 2 depending upon the
degree to which it was correctly drawn in local details, global
form, and orientation.
L. and G. obtained a score of 2/10 and R. scored 1/10 (mean
= 1.67, SD = 0.58). Their performance was significantly worse
than that observed in neurological control subjects (mean =
7.75, SD =.96; t(5) = 9.64, 𝑃 < .001). See examples in Figure 4.

Figure 4: Two examples of immediate visual memory for objects
performed by L., G., and R. The model is shown at the top, with
the same object recalled by two neurological control subjects on
the right. L., G., and R. had difficulties in reproducing the visual
properties of each model and their drawings were limited at most
to the typical representation of objects.

Visual Retention of Abstract Drawings. Children were presented 7 abstract designs which differed in their visual and
spatial characteristics. These designs may not benefit from
verbal rehearsal strategies to be stored in memory. Each figure
was assigned a value of 0 to 2 depending upon the degree to
which it was correctly drawn in local details, global form, and
orientation.
Children were unable to draw from memory the abstract
patterns (Figure 5), omitting or placing erroneously some
parts (Mean score = 1.83, SD = .29). Neurological control
subjects obtained a mean score of 9.25 (SD = .64; t(5) = 18.24,
𝑃 < .001).
Although perceptual tasks were performed at different
levels and degrees of impairment, each child revealed severe
impairment in visual memory, slightly modulated by visualsemantic properties of recalled objects. Table 3 summarizes
the neuropsychological results for this section.
Each child performed relatively well on tests assessing
basic aspects of visual perception. Their impairment at
constructing a perceptual representation from vision and the

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Neural Plasticity
Table 3: Performance of each agnosic child on perception and memory tasks.
L.

G.

R.

Efron tasks
Shape discrimination
Dot counting
Star cancellation

Not impaired
Not impaired
Not impaired
Not impaired

Not impaired
Not impaired
Not impaired
Impaired, not lateralized misses

Boston naming test

Below average, visual errors

Average, visual errors

BNT at 500 ms

12.5% improvement

Overlapping figures
Famous faces
Rey figure copying
Reading
Writing

—
Impaired
No differences for
living/nonliving
Slightly impaired
Impaired
Average, but very slow process
Slow
Relatively normal

Navon task

Global effect exaggerated

Verbal memory
Rey figure memory
Immediate visual memory

Not impaired
Impaired

Not impaired
Not impaired
Impaired
Normal
Relatively normal
Global and local effect
exaggerated
Not impaired
Impaired

Not impaired, some errors
Not impaired
Impaired
Impaired, right misses
Below average, visual and
semantic errors
35% Worsening
Intermediate
No differences for
living/nonliving
Slightly impaired
Not impaired
Impaired
Slow
Relatively normal
Global and local effect
exaggerated
Impaired
Impaired

(i) Benton VRT
(ii) Objects
(iii) Abstract designs

Impaired
Impaired
Impaired

Impaired
Impaired
Impaired

Impaired
Impaired
Impaired

Silhouettes

consequent inability to copy or identify a drawing are consistent with apperceptive agnosia [3, 25]. Children evidenced
qualitative differences in copying abilities and integration of
shape elements into perceptual wholes. L. was impaired at
integrating parts with whole shapes, and his performance is
consistent with integrative agnosia: he performed correctly in
the Efron test, reproduced an accurate copy of Rey’s complex
figure, had an abnormally strong bias to attend to global
shape in the Navon task, though his performance was not
facilitated by silhouettes in naming objects. R. impairment is
consistent with visual-form agnosia: he was less accurate in
the Efron test, his drawings were inaccurate, and he had an
abnormally strong bias to attend to local and global elements
in the Navon task. G. showed mild deficits in both integration
and segmentation of complex visual objects.

Not impaired
Living objects better

R. impairment in naming was likely related to language
impairment that occurred after surgery.
4.2.2. Copying: Rey Figure. G. improved his abilities in copying the global and local features, obtaining a score of 23.5/36,
now falling within average, with an increment of 46.8% on
the previous score. Similarly, R. showed an improvement of
48.4% on the actual score (of 31/36, average), compared to
the first assessment. These improvements (Figure 6) are not
explained by practice effect (at least two years have passed
since the first assessment) nor by a developmental effect
(normative data show slight differences in scores from age 11
to adulthood).
4.2.3. Visual Memory

4.2. Follow-Up for G. and R. G. and R. were reexamined after
3.7 years and 2 years, respectively, from the first evaluation.
G. was 13 years old and R was 14 years old. R. completed the
follow-up evaluation four months after neurosurgery.
4.2.1. Boston Naming Test. G. correctly named 45/60 (75%)
drawings, with a 17% improvement from the first evaluation. Errors were mainly visual and semantic. R. correctly named 9/40 drawings (22.5%), manifesting a relevant
decrease (−34.5%) in performance. Errors were mainly “do
not know” responses (30%) and adequate circumlocutions
(27.5%). While the improvement in naming observed for
G. might be interpreted as a normal developmental effect,

Rey Figure Recall. G. increased his recall of the complex figure
(12 versus 3.5, +70.8%), though his performance remained
below average (𝑧 = −2.82). R. showed a greater improvement
(18.5 versus 1.5, +91.9%) and his performance fell within
average (𝑧 = −1.15), with no difference from neurological
controls (Mean score = 17.75, SD = 7.24). See Figure 6.
Benton Visual Retention Test. G. and R. were still below
average (3/10 and 6/10, resp.), showing no improvement in the
recall of geometrical drawings.
Visual Retention of Objects. G. obtained a score of 7/10, with
a five-point improvement from the initial assessment (2/10).

Neural Plasticity

9

Broom

Egg in eggcup

G
Model

Control 3
Number 1

Model

Control 4
Number 6

L
R

Number 1

G

Number 6

G
R

Figure 5: Two examples of immediate visual memory for abstract
designs performed by L., G., and R. The model is shown at the top,
with the same object recalled by two neurological control subjects
on the right. All three children were unable to draw from memory
a coherent pattern of a model that did not allow verbal rehearsal
strategies.

Copy

Recall

R

Figure 7: Examples of immediate visual memory for objects and
abstract drawings performed by G. and R. at follow-up. Both
children improved the quality of their drawings from memory
by adding more details in an integrated whole, compared to the
previous testing.

G

R. reported a score of 2/10, one point higher than previously
observed (1/10). Two examples are illustrated in Figure 7.

R

Figure 6: Rey’s figure: Copy and Recall performed by G. and R. at
follow up. A relevant improvement was observed in their drawings,
both in the details and in their into a global shape, compared to the
first assessment.

Visual Retention of Abstract Drawings. Both children
improved the quality of their drawings from memory for
the seven abstract patterns (Figure 7): G. with a score from
1 to 5/14 and R. from 0 to 4/14, compared to the previous
assessment. However, their scores were still below the average
observed in neurological control subjects.
These results demonstrated a global improvement in
perceptual and memorial processes over time. There was
a general increase in performance at follow-up from the
previous assessment in almost all tasks, with the exception of
the Benton Visual Retention Test. Improvement was higher in
memory tasks relying on the storage of structural properties
of objects. When memory was based only on pure visual
properties this incremental effect was limited. However, R.

10
showed a deterioration in naming and no change in visual
retention of objects.

5. Discussion
We are presenting behavioural data of three children with
visual agnosia and visual memory impairment, caused by
brain lesions of the visual cortex which occurred in early
infancy.
Children exhibited relatively normal sensory and semantic memory functioning, with several difficulties in object
recognition. They also exhibited deficits in copying, naming drawings, and integrating object features. We classified
their impairments in two types of apperceptive agnosia. R.
exhibited visual-form agnosia, L. integrative agnosia, and G.
mild difficulties in segmentation and integration processes
that share some characteristics with that observed in L.
Resemblance between these findings and those described
in adult agnosics [3, 26] provides further evidence that the
associations between specific impairment and site of lesion
are concordant in both adults and children [27].
Reports on childhood agnosia are relatively rare. These
include both acquired cases of early [11, 14] and late onset
[9, 10, 12] origin. Kiper and collaborators [11] described
two patients (one of them was evaluated during childhood)
with bilateral perinatal lesions of the primary visual cortex.
They exhibited recognition deficits, which were classified
as apperceptive agnosia at different degrees of severity, and
manifested different levels of adaptive plasticity over time
[11]. Amicuzi and collaborators [14] reported a 4.6-yearold girl with bilateral occipital damage and visual agnosia
who manifested selective deficit of figure-ground segregation,
impaired visual recognition, and abnormal moving through
space. Both case reports emphasized the “fuzzy boundaries”
[28] between visual-form agnosia and integrative agnosia, as
far as children’s behavior and domain-specific functions are
concerned. Compared to adults, the differences between the
two types of agnosia are even less distinguishable, possibly
because developmental neurocognitive mechanisms are flexible and adaptive [27]. Nonetheless, these studies indicate
that the core deficit of apperceptive agnosia can indeed be
identified in children with acquired lesions of the visual
cortex.
In previously reported observations of childhood
agnosia, no evidence of visual memory impairment, as
assessed by standard tests, was uncovered [11, 14]. We
observed degraded object recognition and associated deficits
of visual memory in apperceptive agnosia. All three children
exhibited impaired visual memory and poor drawing from
memory with, however, some evidence that residual visual
knowledge might be built up relying on the structural
properties of objects.
As interpreted in the longitudinal investigation of the
adult agnosic H.J.A., when perceptual inputs are degraded,
as in apperceptive agnosia, visual memory may decline,
due to impaired fine-tuning of the system to the visual
properties of objects [8]. Conversely, we observed a longitudinal improvement of visual memory, modulated by
object properties, suggesting that underlying developmental

Neural Plasticity
mechanisms may act from infancy to late childhood. The
impairment was more severe for visual-spatial compared to
visual-object properties, showing a dissociation in processing
of visual representations. These findings are consistent with
the hypothesis of a common representation of an image that
is processed in the visual buffer [29]. At this level, a selective
damage may occur to the spatial and object mechanisms
that act on the image [30]. Developmental processes might
selectively adapt and modulate these mechanisms to the
neuroanatomical substrate for image construction. Indeed,
the improvement we observed in R. and G. visual memory
at follow-up was more apparent when the task relied on the
structural properties of objects and less so when memory
concerned only pure visual-spatial properties of objects.
These preliminary findings have important implications for
understanding the development and construction of visual
representations. More longitudinal studies are needed to shed
light on the dynamic interaction between visual perception
and visual memory during development, when the occipital
cortex is damaged from birth.

6. Conclusions
Impairments of visual recognition are relatively overlooked in
children, nevertheless they have a crucial impact on learning
as well as mobility and independent living.
Our findings indicate that impaired processing of visual
images in childhood agnosia results in impoverished visual
memories. During the course of development the dynamic
interaction between perception and memory might modulate
the long-term construction of visual representations, resulting in less severe impairment.
As suggested by previous reports, developmental brain
plasticity and compensatory behavioral adaptations allow the
emergence of surprising abilities in daily life [12]. Therefore,
an early diagnosis of visual agnosia is crucial for planning
specific rehabilitation interventions that may foster the progressive adaptation leading to a developmental process that is
unique in a child with brain damage.
Early neuropsychological rehabilitation in childhood
visual agnosia should train visual and multimodal environmental exploration, improving recognition and memory
through the processes of adaptation and compensation that
are the hallmark of development following perinatal neural
pathology.

Conflict of Interests
The authors declare that there are no sources of financial
support and there is no conflict of interests.

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