Nrurnp,rltiym, Vol 31, No . II, pp . 1255-1261, 199,_
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NOTE
UNILATERAL NEGLECT IN ROUTE DESCRIPTION
E . BISIACn,* M . BROUCHON,t M . PONCFT~ and

M . L . Rusco51¢

*Dipartimento di Psicologia Generale, University di Padova, Italy ; tU .R .A, Cognition et Mouvement,
C .N .R .S ., Marseille, France ; ;Service de Neurologie et de Neuropsychologie, C.H .U . Throne, Marseille,
France; and pistituto di Clinica Neurologica, University di Milano, Italy
(Received 8 January 1993 ; accepted 23 April 1993)
Abstract-Route description was investigated in two patients suffering from left unilateral neglect,
Both had evident difficulty with left turns . This finding suggests that the topological correspondence
between represented environment and representational mechanisms in the brain is not confined to
frozen (picture-like) perspectives .

IT HAS OI-rEN been found that patients suffering from unilateral neglect have difficulty with the contralesional side of

familiar visual arrays when asked to describe them from memory from a particular vantage point . In the case studies
so far reported they were requested to describe town prospects [8, 10. 15, 16, l8], interiors [l0 . 18], or maps [2, 17 .
19] . Defective forward and backward oral spelling of either the initial or terminal segment of words, depending on
the side of the lesion, has also been observed in neglect pa tients [2, 3,1 1 ] and is likely to be due to local im pairment of
an orthographic representation organized in much the same way as visual images . It is claimed that these findings
support an analogue theory of mental representation [4 . 6, 7] . Imaginal neglect in the description of well-known
itineraries was first mentioned, though tangentially, by DUHAMFI . and BRomICH17N [14J . In consideration of its
theoretical interest, it has been specifically investigated in the two cases reported in this note .
M .M . 54-year-old right-handed male with highest educational level . CVA on 25 February 1989 . CT scan
(November 1989) and MR[ (October 1990) : Large infarct in the territories of the right middleand posterior cerebral
arteries . An early clinical report mentioned left hemiplegia, hemianopia and hypoaesthesia ; total left-ear extinction
on dichotic examination ; severe unilateral neglect on unspecified routine tests ; spatial dysgrapltia and
constructional apraxia .
The patient was re-examined during the first days of January 1991 . His neurological impairment was unchanged .
except for a very slight improvement in the hemiplegia, to the extent that he could walk, though with marked
difficulty . He was totally anosognosie with respect to his constructional apraxia, which was still very severe . By
contrast, he had become perfectly aware of his unilateral neglect . Actually. he claimed to have formed his own theory
of the disorder ; in his opinion this should not he defined as an inability to conceive the left side of his body and outer
space, but as extreme difficulty in directing attention to that side, a difficulty that could only be overcome by
strenuous voluntary effort . There was in fact an amazing dissociation between his normal performance on formal
tests, such as line bisection and cancellation tasks, on which he knew he would fail, short of sustained self-control,
and spontaneous, relaxed behaviour in everyday lift . His wile reported, for example, that he often neglected food on
the left side of his plate . Neglect was also dramatically revealed by a very simple task that he was given for the first
time : on being asked to pick up a handful of coins spread over the table while keeping his eyes closed . he only
collected coins from the right side . When one of the examiners asked him whether he had completed the task, he
answered : "If you ask that, then I probably have not", and resumed his search up to the last coin . His description
from memory of a landscape that was very familiar to him, i .e . the Marseille Vieux port as seen from La Canebiere,
was totally defective on the left (east) side of the imagined perspective . By contrast, he correctly reported from the
right (west) side, and in the appropriate order, Rue de la Republique, "les beaux immeuhles construits sur le Vieux
port par Pouil Ion", the sown hall and Fort-St .-Jean . He went on adding details-a famous church and the Evechethat could only be seen by turning right at the end ofthe harbour . As usual, mental reversal of the first perspective
lead to recovery of previously omitted details from the east side of the harbour and neglect of those that had been
*Address for correspondence : Professor Edoardo Bisiach, 22070 Lurago Marinone (Como). Italy .
1255

1256

Note

reported from the opposite side in the first description, with the only exception of the town hall . In describing
well-known itineraries in Marseille, he often failed when left turns were'ncluded . Here are two examples . (Numbers
and letters refer to figures and their details, respectively) .
From Ohelisque de Nfazargues (la) to La 7lmone Hospital (11b)

I go in the direction of the traffic lights of Rd . Michelet (to) and continue . Al a certain point I find Bd . Rabatau
(ld) . I take Bd . Rabatau and go straight ahead to La Timonc ; that is . without having to turn .
Front La Ttruone Hospital to Mazargues

I leave La Timone and take Bd . Baille (lei, I go down to Castellane (lf) . After Castellane I take the Prado ; I go
down the Prado (1g) and arrive at Mazargues .
Flout Luminy (2a) to the David (2b)

I came from Luminy and have to cross the road that leads to Cassis . I go down to the Obelisque de Mazargues
12c) . Once I am at the Ohelisque de Mazargues, . . . what shall I do? Let me think it over . The Ohelisque de
Mazargues is at the beginning of Rd . Michelet (2d) . I go down Rd . Michelet, and on and on . I arrive to the David .
(One of the examiners points out that the last part of the description is not accurate enough and asks the patient to
imagine himself giving directions to another examiner, who was a foreigner.) From Bd . Michelet you arrive at the rendpoint an Prado (2c)-There you arrive at the Prado itself . You continue down the Prado until gnu find a statuc
disfigured by Medicine students : the David . (The patient is asked whether there are any turns in the lost part of the
route . He re .suines his description whit evident unease .) You turn into the Petit Prado . . . no, no it's still Bd . Michelet.
Keep straight on . You arrive at the rond-point dot Prado . . . , let etc think it over . . . . there is a sense giratoire . You
must take the sense giratoire and at a certain point, on your left, there is the Petit Prado (2f) . This will take you
straight to David . OK! I t is surprising how unnatural all that is . I don't think it was Like that before my illness . Now I
must think hard to make out places where I have spent my whole Life! It is not spontaneous . It has nothing to do with
the hemiplegia . It must he something else, but I don't know what .
From David to Luminr

I am at David . I continue along the cormche (2g) . I go past the Restaurant La Met ; past la Vieille Chapelle (2h) . I
go up and up towards Bonneveine (2i) . From Bonneveine I arrive at Bd . de Hamhourg (2j) . I go up Rd . do
Hamhourg . There is a rond-point . I go to Bonneveine and then to the Avenue de Mazargues (2k) . Once I am at
Mazargues, I go till the end . I turn into l
id . d e la Concorde (211,1 arrive to the Obefisque de Mazargues, et 16 je suis
sauoe' I turn right and arrive straight to LuminyA .S .76-gear-old right-handed woman . CVA on 16 November 1990 . (T scan : large ischaenua in thedislr ict (,[the
right middle cerebral artery, with partial sparing of the parietal region and basal ganglia . Left motor impairment
with transitory anosognosla ; left somatosensory deficit and hemianopia . Severe left neglect on cancellation tasks
1575 left-sided emissions on Dict .rn and WLNoei w test [13] ; 57.5 left-sided omissions on Albert's test [I]) . The
following is an abstract from an interview that took place on 15 January 1991 . AL that time, she had almost
completely recovered from her motor impairment . but neglect was still present . In fact, she participated as an
outpatient in several investig_ationsin which she was very willing tocooperalee tier description of Milan itineraries
that did not involve left turns was fluent and flawless, hot when left turns were included, her performance was
variable . In some instances, especially with short routes starting from her residence, she was perfectly accurate, while
on some occasions site would hesitate before making the correct choice, or postpone the left turn until it was
unavoidable, suggesting less appropriate alternatives . On other occasions, she would lose track of the route she was
describing and get confused . Sometimes, her preference for right turns starting from the very beginning of tier report
resulted in the sane phenomenon already observed in M .M . : if, after having described an itinerary from point a to
point b she then had to describe one going from b to a, the latter was not the reversed replica of the former and the
two paths, taken together, formed a roughly quadrangular itinerary .
From I'm Ricordi (3a) to Piaea delta Repubhhca ( 3b)
I walk from Via Andrea Flat it (3c) in Viale Brianza (3d) and from there to the Stazione Cent rate (3c) . . . . Then
. . there is a street . . . . Through Vials Brianza to the Stazione Centritle ; . . . at that point . . . (One of the examiners
asks whether at that point she has to hen left or right) I turn left . I place mvselfso a, to have the front of Starione
Centrale at my hack and from there I take Via Vittor Pisani (3f) . There I am!
Frorn Piaeca dells Rot uhhhe'a to Via Rienrdi

I go to the Slazione Cent rate along Via Viltor Pisani . From the Stazione Centrale, I go to Via Vitruvio (3g) .. up to
Corso Buenos Aires (311) and on . There is Piazza Argentina (3i) . I cross Piazzale Loreto (3j) and arrive at Via
Ricordi .
Front inside the Duorno (4a), through the main door of the c athedral . t o the Ospedale Pofidinleo (4h)
I turn into Cost, Vittorio Emmmele 14c) and walk in the direction of Piazza San Babila (4d ) . Then I turn right into
Corso Monforte . At the cross-roads 14e), I turn right and walk towards Via Franceco Sforza (4f) until I get to the
Policlinico .

Nr,n

Fig . 2 . Route connecting Luminy and David .

Fig. 3 . Route connecting Via Ricordi and Piazza della Repubblica .

0911

NOTE

1261

From the Ospedole Policlinico to the Duomo

I take Via Francesco Sforza . Then I leave it . . . . I don't remember . . .(she mutters incomprehensibly) . . . . Once
again in San Bahila . (One of the examiners oaks how she pet a to Piozzn .Son Bahila .) . . . I pass there . . . I find Piazza
Fontana (4g) . Then I crass Piazza Fontana and find thyself at the Duomo .
Recognizing a definite preference for right turns in the descriptions of itineraries given by neglect patients is far
from easy . due to the high frequency of more or less pronounced topographical disorientation of these patients[ 12] .
However, the two cases reported in this note are, in our opinion . more than merely suggestive . Their
'disorientation' only emerged when left turns had to be reported . Note that IO normal subjects asked, as M .M ., to
describe the itinerary front Mazar_uues to La Timone never omitted the left turn at the end of Bd . Rabatau . The left
turn required at the, and-paint (in Fr ado (2c) to get to David coming from Bd . VI ichele t was mentioned by M .M . only
after prompting by the examiner . However. much more impressive is his Illation] rightward departure from David
and his entanglement in the labyrinth of streets on the left side of his intended direction in his attempt to make for
tuminy . He appeared totally oblivious of the much more convenient path along the main roads he had previously
reported while describing the reverse itinerary . His exclamation on arrival at the reassuring landmark constituted by
the Obeliaque de Mazargues, was very indicative of his relief front distress : no further left turns were required from
there to his destination ! As for A .S . it must he noted that the stretch from Via Ricordi to Piazza della Repubblica is in
her immediate neighbourhood . Nonetheless, after her first correct choice . i .e . Via Doita, she made an illogical right
turn towards Viale Brianza . thus emerging on the side of the Stazione Centrale . Then she hesitated . After prompting
she could remember that a left turn was required, but seemed to need to anchor herself momentarily to a landmark
oil her right (the front of the Stazione Centralcl before resuming her report . Her description of the route from the
Duomo to the Policlinico was perfectly accurate bin absurd . Indeed, the Milanese would laugh at such directions .
Twenty control subjects, interviewed in deference to formality, only described routes through either Via La_getto or
the University Statale (see Fig . 4) . A .S .'s fluent and unhesitating report of the itinerary from the Duomo to the
Policlinico was in sharp contrast with the report of the itinerary connecting those two landmarks in the apposite
direction . Like M .M . . she got lost as soon as she was confronted with the necessity of a left turn .
The inability of neglect patients to make an accurate description from memory of the contralesional side of a
stationary visual array suggests that man's production of pictorial representations such as drawings originates in an
inner representation the mechanism of which is itself characterized by analogue spatial features . It must be her lie in
mind that the phenomenon is not due to the fact that patients describe the visual array as they would ply ceir -a it given
their disorder . Indeed, with few exceptions, of which M . M . is an example, neglect patients are totally unaware of this
disorder . In spite of his keen introspection and self-analysis . M .M . was quite satisfied with his incomplete description of
the Vieux Port and would nevereomment that, of course . lie knew pretty well what he had left out nn order to smtulate
his difficulty in directing attention leftwards . Mental representations implemented in topological neural maps similar
to those known to implement early stages of sensory processing . however . might constitute the last step before the
cxlerimlization of the mind's IepresentationaI activity by means of drawingsinstrucions relative to the imaginary
vantage point . or in the case of country maps, the canonical orientation of what has to be described from memory,
might force the generation of a quasi-externalized representation of this kind . Up-stream Ior in parallel) with respect to
t his type of i epresentation, or whenever this type of representation is not induced by pa rticular task demands, cognitive
representation Oft hings such as landscapes, interiors, etc . . might be thought to he organized in a non-analogue, i .c,
linguistic or "abstract' code (whatever the latter might mean) . The putative push towards a pictorial representation of
a stationary array when a subject is asked to describe it from memory under the constraints of a used vantage point is
arguably much weaken when the patient's task is to give cerhul directions about how w go from our point Of ;I town to
another. Nonetheless . the behaviour of M .MI and ASS suggests that their verbalization too was mediated by a
representation in which analogue properties could be recognized and that representation with such properties,
therefore, are unlikely to he special-purpose and located at the periphery of the cognitive machinery .
Further investigation is needed to ascertain whether phenomena such as those reported here arc as reliable as
those upon which the notion of imaginal neglect has so far been grounded . Furthermore, it remains unsettled
whether the erratic reports given by our two patients when they had to deal with an area lying to the left of [lie
starting direction of the itinerary they had to describe . indicates resort to acquired verbal routines in an al tempt to
compensate far the circumscribed inaccessibility of ore side of an analogue visuospatial representation . The
question of the extent to which any inference drawn from cases of imaginal neglect as regards the structure of
cognitive processes can be generalized across individuals also remains open .
M .M also showed neglect of the left side of a stationary perspective (Vieux port) . Regrettably, we omitted to lost
A . S . 's performance on a similar task . This was anfortunate, sotceiuraginal neglect of leftward turns inightdissociate
from imaginal neglect of the left side of unchanging perspectives . The farmer, but perhaps not the latter, might
indeed depend on "premotor" rather than on "perceptual" neglect . Whatever might be the validity of such a
distinction [9, 30], however, it is worth noting that whereas M .M . had tic) neglect on Tegncr and Levande's mirrorreversed line cancellation task [20] . A .S, displayed on this task a very consistent "perceptual' neglect [5] .
Aeknovledgemems--l'his study was largely prompted by remarks made by Prof . Daniel Dennell during a

discussion on imaginal neglect at an informal symposium held in Parma, June 1990 . The lass paragraph of the

1262

NOTE

Discussion was written in response to comments made with insight by an anonymous reviewer . M .M . and A .S . have
been much more than subjects of a netiropsychological investigation : the incentive provided by their cooperation as
persons is gratefully acknowledged . The investigation was supported by C .K .R. and M .U .R .S .T. grants to the first
author .

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