when space merges into language

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Neuropsychologia 44 (2006) 556–565 When space merges into language M. Cristina Rinaldi a,, Luigi Pizzamiglio a,b a Centro Ricerche di Neuropsicologia, Fondazione I.R.C.C.S. Santa Lucia, Via Ardeatina 306, 00179 Rome, Italy b Dipartimento di Psicologia Universit` a “La Sapienza”, Rome, Italy Received 10 January 2005; received in revised form 25 May 2005; accepted 7 July 2005 Available online 30 August 2005 Abstract We present data from right brain-damaged patients, with and without spatial heminattention, which show the influence of hemispatial deficits on spoken language processing. We explored the findings of a previous study, which used an emphatic stress detection task and suggested spatial transcoding of a spoken active sentence in a ‘language line’. This transcoding was impaired in its initial portion (the subject- word) when the neglect syndrome was present. By expanding the original methodology, the present study provides a deeper understanding of the level of spoken language processing involved in the heminattentional bias. To ascertain the role played by syntactic structure, active and passive sentences were compared. Sentences comprised of musical notes and of a sequence of unrelated nouns were also compared to determine whether the bias was manifest with any sequence of events (not only linguistic ones) deployed over time, and with a sequence of linguistic events not embedded in a structured syntactic frame. Results showed that heminattention exerted an influence only when a syntactically structured linguistic input (=sentence with agent of action, action and recipient of action) was processed, and that it did not interfere when a sequence of non-linguistic sounds or unrelated words was presented. Furthermore, when passing from active to passive sentences, the heminattentional bias was inverted, suggesting that heminattention primarily involves the logical subject of the sentence, which has an inverted position in passive sentences. These results strongly suggest that heminattention acts on the spatial transcoding of the deep structure of spoken language. © 2005 Elsevier Ltd. All rights reserved. Keywords: Space; Language; Neglect 1. Introduction The spatial dimension has been so relevant in the evo- lution of the nervous system that sensory and motor pro- cessing cannot take place unless their spatial co-ordinates are coded. Coslett (1999) claimed that the influence of space also holds for higher-order more abstract functions (including language), which are less obviously related to space. Coslett’s (Coslett, Schwartz, Goldberg, Haas, & Perkins, 1993) considerations originated from clinical observations carried out on an aphasic patient, J.F., whose anomia became more or less severe depending on the hemifield stimuli were presented to. According to Coslett (1999), the importance of Corresponding author. E-mail address: [email protected] (M.C. Rinaldi). spatial information for every action we perform is so strong that each stimulus we perceive is automatically marked with reference to its co-ordinates in the egocentric space, even if spatial information does not seem relevant for the task at hand (“Spatial Registration Hypothesis”). Following this rea- soning, any stimulus presented in the contralesional field (for patient J.F., the right hemispace) should activate the left hemi- sphere attentional system for the impaired right hemispace. This explains J.F.’s worse performance with stimuli in the contralesional field, while his performance in the left hemis- pace was supported by his intact right hemisphere (Coslett et al., 1993). This interpretation stresses the importance of the extra- personal, egocentric space linguistic stimuli arise from (Coslett, 1999). Other authors hypothesize that any event expressed through language, whether spoken or written, auto- matically activates an “internal” spatial representation. 0028-3932/$ – see front matter © 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.neuropsychologia.2005.07.007

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Page 1: When space merges into language

Neuropsychologia 44 (2006) 556–565

When space merges into language

M. Cristina Rinaldia,∗, Luigi Pizzamiglioa,b

a Centro Ricerche di Neuropsicologia, Fondazione I.R.C.C.S. Santa Lucia, Via Ardeatina 306, 00179 Rome, Italyb Dipartimento di Psicologia Universita “La Sapienza”, Rome, Italy

Received 10 January 2005; received in revised form 25 May 2005; accepted 7 July 2005Available online 30 August 2005

Abstract

We present data from right brain-damaged patients, with and without spatial heminattention, which show the influence of hemispatialdeficits on spoken language processing. We explored the findings of a previous study, which used an emphatic stress detection task andsuggested spatial transcoding of a spoken active sentence in a ‘language line’. This transcoding was impaired in its initial portion (the subject-word) when the neglect syndrome was present. By expanding the original methodology, the present study provides a deeper understandingof the level of spoken language processing involved in the heminattentional bias. To ascertain the role played by syntactic structure, activea o compared tod a sequenceo nly when as t it did noti e to passives ence, whichh g of the deeps©

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nd passive sentences were compared. Sentences comprised of musical notes and of a sequence of unrelated nouns were alsetermine whether the bias was manifest with any sequence of events (not only linguistic ones) deployed over time, and withf linguistic events not embedded in a structured syntactic frame. Results showed that heminattention exerted an influence oyntactically structured linguistic input (=sentence with agent of action, action and recipient of action) was processed, and thanterfere when a sequence of non-linguistic sounds or unrelated words was presented. Furthermore, when passing from activentences, the heminattentional bias was inverted, suggesting that heminattention primarily involves the logical subject of the sentas an inverted position in passive sentences. These results strongly suggest that heminattention acts on the spatial transcodintructure of spoken language.2005 Elsevier Ltd. All rights reserved.

eywords: Space; Language; Neglect

. Introduction

The spatial dimension has been so relevant in the evo-ution of the nervous system that sensory and motor pro-essing cannot take place unless their spatial co-ordinatesre coded.Coslett (1999)claimed that the influence of spacelso holds for higher-order more abstract functions (including

anguage), which are less obviously related to space.Coslett’s (Coslett, Schwartz, Goldberg, Haas, & Perkins,

993) considerations originated from clinical observationsarried out on an aphasic patient, J.F., whose anomia becameore or less severe depending on the hemifield stimuli wereresented to. According toCoslett (1999), the importance of

∗ Corresponding author.E-mail address: [email protected] (M.C. Rinaldi).

spatial information for every action we perform is so strthat each stimulus we perceive is automatically markedreference to its co-ordinates in the egocentric space,if spatial information does not seem relevant for the tashand (“Spatial Registration Hypothesis”). Following this rsoning, any stimulus presented in the contralesional fieldpatient J.F., the right hemispace) should activate the left hsphere attentional system for the impaired right hemispThis explains J.F.’s worse performance with stimuli incontralesional field, while his performance in the left hempace was supported by his intact right hemisphere (Coslett eal., 1993).

This interpretation stresses the importance of the epersonal, egocentric space linguistic stimuli arise f(Coslett, 1999). Other authors hypothesize that any evexpressed through language, whether spoken or written,matically activates an “internal” spatial representation.

028-3932/$ – see front matter © 2005 Elsevier Ltd. All rights reserved.oi:10.1016/j.neuropsychologia.2005.07.007

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M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565 557

The latter explanation is postulated byChatterjee, Maher,Gonzalez Rothi, and Heilman (1995b). They described anagrammatic patient, W.H., who assigned the thematic rolesof agent and recipient of a given action on the basis of a spa-tial or temporal strategy. For example, in describing a picture,this patient was asked to report who did something to whom(agent and recipient of action). He tended to consider the fig-ure located on the left as the agent of action (spatial strategy),or to match the first noun he heard with the figure located onthe left (temporal strategy) (Chatterjee et al., 1995b).

According toChatterjee et al. (1995b), conceptual knowl-edge of thematic roles is actually independent of language,and is matched with linguistic content only subsequently, bymeans of the grammatical and syntactic algorithms specificto one’s own language. Due to a brain lesion, these linguisticalgorithms were impaired in their agrammatic patient. There-fore, he based his thematic role detection exclusively on theautomatic spatial representation of events, which proceedsnaturally from left (agent of action) to right (recipient ofaction), with the verb being the vector defining the thematicroles and supporting the whole event frame.

To further support this idea,Chatterjee, Maher, andHeilman (1995a) and Chatterjee, Southwood, and Basilico(1999)asked non brain-damaged subjects to draw an assignedthematic role. Their reasoning was that if there is a spatial rep-resentation underlying a spoken sentence, and an “implicitp leftt ep-r ctionp rityo f thep rgino

patialr prim-i nts, aw ted—d lan-g ene-s ingl ptuals imen-s

ifiedl neda ionala mod-i ingl neso

asicpb hef ect,o rb

Patient O.R.F., described byBaxter and Warrington(1983), underwent two consecutive vascular accidents withina short period of time. The first parietal lesion caused con-duction aphasia (the patient was left-handed), phonologicaldyslexia, and mild neglect dyslexia, without other signs ofspatial neglect; the second vascular event, again strikingthe right parietal region, produced an additional impairmentof word-spelling abilities that was not present before. Theword–spelling deficit was observed only for letters at thebeginning of words; for example, if the examiner spelled theword “b-e-g-g-a-r” aurally letter by letter, the patient reported“vinegar” (Baxter, & Warrington, 1983).

Interestingly, this bias was manifested when spelling pro-ceeded either from the beginning to the end of the word,or from the end to the beginning of the word.Baxter andWarrington (1983)hypothesized that the patient was repre-senting the stimulus on an inner screen, and the symptomsresulted from an interaction between representational neglectand neglect dyslexia. The authors affirmed that the patientreported “reading” the aurally spelled words on an “innerscreen”.

Instead, patient N.J., described byCaramazza and Hillis(1990), exhibited severe neglect affecting the right half ofspace after a lesion to the left hemisphere; he had no lan-guage deficits. N.J. was submitted to several reading andspelling tests: horizontal reading, vertical reading, mirror-r itiono tens ivelya ver-t lingt (N.J.r -s“),i thei ardsi l ofr . Att sin-g lesso e tot ands i-n

hav-i ng ofs goest patials

thei g, butw age:s nyr Thisi ficitd phic

ropensity” to conceive events as traversing space fromo right, with the agent of the action on the left of this resentational space, the subjects should draw a given aroceeding from left to right. They showed that the majof subjects located the agent closer to the left margin oage, and the recipient of the action closer to the right maf the page (Chatterjee et al., 1995a, 1999).

For Chatterjee and colleagues, the presence of a sepresentation underlying spoken language reflects thetive way the mind conceptualizes and represents eveay that has been successively obscured—but not deleuring the course of development by the evolution ofuage. Analogously, passing from phylogenesis to ontogis,Mandler (1996)observed that in the young child emerginguistic concepts are mapped on a pre-existing conceystem, which has space as a fundamental constituent dion.

If space and language interact at some still unidentevel, forming the spatio-linguistic representation outlibove, it is theoretically possible to observe representatbnormalities as a consequence of (1) a brain lesion

fying spatial processing and (2) a brain lesion modifyinguistic processing in two opposite, but converging, lif action.

Some evidence for the latter is provided by the two aphatients described above, i.e., byCoslett et al. (1993)andy Chatterjee et al. (1995b). Instead, some evidence for t

ormer is provided by two patients with hemispatial neglne described byBaxter and Warrington (1983)and the othey Caramazza and Hillis (1990).

everted reading, delayed copy, aural spelling, recognf aural spelling, written spelling and backwards writpelling. When reading, the patient made errors exclust the end of words, irrespective of the form of the input (

ical, horizontal or mirror reversed). Also, on the spelasks errors appeared only at the right end of a wordeported “exceed” after the examiner spelled “e-x-c-e-srrespective—also for spelling—of the form or order ofnput (written and aural spelling, forward and backwpelling). According toCaramazza and Hillis (1990), read-ng and spelling both involve a common pre-lexical leveepresentation, which they call “grapheme description”his level of representation, the abstract identity of thele letters compounding the word is computed, regardf the form/orientation of the input; therefore, damag

his format-independent level would impair both readingpelling in a similar way and in conformity with the hemattentional deficit.

Since the spelling tasks were performed aurally, the beor of both patients strongly suggests a spatial transcodipoken language which, given its spatial format, underhe same bias observed in neglected patients for visuo-stimuli in the contralesional hemispace.

The clinical reports of these two patients documentnfluence of hemineglect on spoken language processinith reference to a very peculiar type of spoken langupelling. Although spelling is performed aurally, in maespects it is actually very close to written language.s probably why Baxter and Warrington defined the deescribed in their patient as a rare type of “dysgra

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558 M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565

syndrome”, highlighting with the term “dysgraphic” theaffinity of spelling and written language.

With regard to the effects of hemineglect on genuine spo-ken language, a neglect patient -J.L.- was reported byBarbutand Gazzaniga (1987). As a consequence of a right parietallesion, in addition to errors affecting the most leftward lettersof words in reading, writing and spelling, J.L. also producederrors in spontaneous speech. For example, he often omit-ted the beginning of a word, saying “bulance” instead of“ambulance”, or “portant” instead of “important”. Most ofhis errors were omissions, but the examiner also observedthat the patient often made substitutions, forming semanti-cally unrelated words. According toBarbut and Gazzaniga(1987), the pattern of errors exhibited by their patient wasconsistent with the hypothesis that some aspects of languageprocessing involve some spatial mechanisms responsible forthe representation of what they call “conceptual space”.

Recently, a decade after the literature reported above, apaper byRinaldi, Marangolo, and Pizzamiglio (2003)addedanother piece of evidence to this field of investigation. Theauthors described a different type of hemineglect effecton the processing of spoken language than that previouslyobserved. When asked to compare two spoken sentences(subject/verb/object) with regard to their emphatic stress,patients with right hemisphere lesions and spatial neglectmade significantly more errors when the stress was placeda . Theb ordo guagei kens alogw henb wayt h iso t thew sideo fore,n n isn

rigi-n tionb g theo

ernst ture.T andp ethert itorys

f thes hem-i , orw istics s, ift whent nces

the effect can be attributed exclusively to the need to locatea target stimulus in a sequence of events spaced over time.

Third, do the stimuli need to be meaningful sentences orcan the same effect of neglect be observed with a sequenceof non-related words? Does neglect affect the representationof the event expressed in the spoken sentence, where a verbsupports the event frame and defines the thematic roles, ordoes it affect any sequence of three nouns, independently ofthe presence of a verb?

2. Methods

2.1. Subjects

This study was carried out on 26 right brain-damaged sub-jects admitted to the Santa Lucia Foundation I.R.C.C.S. inRome for rehabilitation (mean age 61.7 years, S.D. 11.37;education 9.7 years, S.D. 4.19) (seeTable 1for individualpatients’ data).

For each patient, unilaterality of the brain lesion wasdocumented by a CT or an MR scan. Each patient admit-ted to the hospital underwent a standard neuropsycholog-ical examination, which included a battery for the diag-nosis of hemispatial neglect for personal and peripersonalspace. The following tests comprised the battery: Cancella-te ,1 ,At ,1 s forh glect.A wos eana 4.31)a e6 07).

ane ermmT ryw atials ine-g incen tientss

as“ ain-d addedl ed( duca-t ears,S

wl-e were

t the beginning of the sentence (on the subject-word)ias exhibited by neglected patients towards the initial wf the sentence suggests a transcoding of spoken lan

nto a spatial format. The auditory trace left by the spoentence would be automatically transformed into an anith an intrinsic spatial component. This analog would te affected by the presence of hemineglect in the same

his deficit affects spatial information processing, whicn the contralesional side. In other terms, it appears thaord at the beginning of the sentence falls on the “left”f the spatial transcoding of the sentence and is, thereeglected similar to the way left visuo-spatial informatioeglected by these patients in the external space.

The present investigation aims at expanding the oal methodology and qualifying the nature of the interacetween the spatial and linguistic mechanisms underlyinbserved effect.

As in the previous experiment, the first question conche use of a unique format, i.e., active sentence struche replication or the change in the results using activeassive sentences will contribute to understanding wh

he effect is related to the position of the stress in the audtring of words or, instead, to its syntactic structure.

The second question is whether the comparison otress location in the two sentences produces a bias inneglect patients only when linguistic strings are usedhether, instead, it takes place also when two non-lingutrings of acoustic events are compared. In other wordhe bias in hemineglect patients can also be observedhey compare the stress embedded in two musical sente

,

ion Test (Albert, 1973), the Letter Cancellation Test (Dillert al., 1974), the Sentence Reading Test (Pizzamiglio et al.992), the Wundt–Jastrow Area Illusion Test (Massironintonucci, Pizzamiglio, Vitale & Zoccolotti, 1988), and

he Personal Neglect Test (Zoccolotti, Antonucci, & Judica992). Patients who failed on at least three of the five testeminattention were classified as having hemispatial neccording to this criterion, patients were divided into tub-groups, 12 patients with hemineglect (N+ Group: mge 62 years, S.D. 8.33; mean education years 10, S.D.nd 14 patients without hemineglect (N− Group: mean ag2 years, S.D. 13.44; mean education years 10, S.D. 4.

The neuropsychological examination also includedvaluation of phonological and visuo-spatial short-temory (Wais Digit Span Test,Orsini et al., 1987; Corsi Span

est,Orsini et al., 1987). Phonological short-term memoas intact in all subjects examined, whereas visuo-sphort-term memory, unimpaired in patients without hemlect, was impaired in 4 of the 11 patients with neglect (seglect was in part responsible for the fact that these pacored below the cut-off).

For the experimental condition described belowSequence of Three Nouns”, a different group of right bramaged patients was tested, since this condition was

ater. Respectively, 11 N− and 13 N+ patients were testN− group: mean age 63.6 years, S.D. 12.69; mean eion years 10.53, S.D. 3.86; N+ group: mean age 60.3 y.D. 13.8; mean education years 10.61, S.D. 4.09).Patients with hearing deficits not previously ackno

dged but manifested during the experimental sessions

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M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565 559

Table 1Individual data of N− and N+ patients for sex, years of education, time post onset and locus of lesion

Subjects (N = 26) Age Sex Education (years) Time post-onset (months) Lesion site

N− group1 74 F 12 2 Right cortico-subcortical fronto-parietal lesion2 58 M 10 3 Right internal capsula + lateral thalamic lesion3 52 M 5 8 Right extern caps + nucl caud + white matt periventric parietal lesion4 62 M 17 1 Right temporo-parietal lesion5 48 M 13 30 Right subcortico- temporal lesion6 57 M 11 2 Right occipital lesion7 52 F 8 360 Right fronto-parietal lesion8 39 M 8 4.5 Right cortico-subcortical fronto-temporal + internal capsula9 57 M 17 6 Right parietal lesion

10 52 M 13 7 Right thalamic lesion11 76 M 8 3 Right cortico-subcortico temporal lesion12 79 F 5 6 Right semioval center + frontal lobe lesion13 71 M 5 4 Right pons lesion14 82 M 5 1.5 Right temporal lesion

N+ group1 60 M 7 2 Right parietal lesion2 62 F 3 6 Right fronto-temporo-parietal lesion3 71 F 11 3.5 Right cortico-subcortical fronto-temporal lesion4 43 M 8 5 Right internal capsula lesion5 64 M 10 7 Right frontal lesion6 54 M 7 2 Right temporo-parietal lesion7 59 M 13 2 Right cortico-subcortical temporo-fronto-parietal lesion8 75 F 5 2 Right temporo-fronto-parietal lesion9 53 F 16 1 Right temporo-fronto-parietal lesion

10 68 M 13 4.5 Right insular + temporo-parietal lesion11 63 M 17 3 Right parieto-temporal lesion12 75 M 5 1.5 Right insula + frontal lesion

excluded from the study. The research was approved bythe Ethical Committee and all patients gave their writtenconsent.

2.2. Stimulus material

Patients were requested to judge two spoken sentencesemitted from a tape recorder in four different experimentalconditions:

(1) Active versus passive linguistic condition.(2) Musical condition.(3) Sequence of unrelated nouns condition.

2.2.1. Active–passive linguistic conditionStimuli consisted of spoken sentences recorded by a tape

recorder; all sentences were in Italian and in the active or pas-sive form, and only high frequency and highly familiar wordswere used. Each sentence was comprised of three elements: asubject, a verb and an object (e.g., “The boy reads the book”).The following description refers to the active sentences andit will be replicated for the passive sentences. Each item con-sisted of a pair of linguistically identical sentences, and withemphatic stress placed on the same or on a different wordin each of the two sentences. The two sentences of the pairwere separated by a two-second time interval. The emphatic

stress could be placed either on the subject-, the verb- or onthe object-word. Following is an example of stress placedon the same elements of a sentence pair: “The boy reads thebook”/“The boy reads the book”; here, instead, are examplesof stress placed on different elements of a sentence pair: “Thewolf attacks the sheep”/”The wolf attacksthe sheep”; “Thethunderbolt struck the house”/“The thunderbolt struck thehouse”.

The patients were asked to listen to each sentence pairand to judge whether the two sentences were stressed inthe same way or not, or, more simply, if their intonation“sounded the same or not” (answer: “yes”/“no”). Each pairof sentences was preceded by an acoustic warning signal,and no time-limit for the answer was set by the examiner.Two separate sets of active and passive sentences (comprisingtwo practice trials + 48 test trials each) were included in thetest.

For each experimental condition, a different set of 48 + 2stimuli was used; however, in each condition the whole setof 48 stimuli was balanced according to the same schema,with half of the sentences requiring a “yes” answer and half a“no” answer. Most importantly, the whole set of stimuli wasdivided into two sub-groups according to the position of theemphatic stress: Type I, including all sentence pairs with theempathic stress on the subject word in at least one of the twosentences of the pair (e.g., “The boy reads the book” / “The

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560 M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565

Fig. 1. Schematic representation of item types and their separation into Type I and Type II.

boy reads the book”); and Type II, including all sentencepairs in which the emphatic stress was never on the subjectword, but rather on the verb or the object word (e.g., “Theteacherwrites a letter” / “The teacher writesa letter”) (seeFig. 1).

In each set of 48 stimuli, half of the sentence pairs wereType I and the other half, Type II. The set of 48 passivesentences had exactly the same characteristics as the activeset. Here, too, there were 24 “same”sentence pairs with thestress located on the same element (e.g., “The ball is hit bythe boy” / “The ball is hit by the boy”), and 24 “different”sentence pairs, with the stress located on different elements

(e.g., “The window is closed by the man” / “The window isclosedby the man”). In the passive sentences set, the positionof emphatic stress, the balancing and the separation of stimuliinto Type I and Type II sub-groups were exactly the same asdescribed for the active sentences.

The two blocks of active and passive sentences werealways presented in the active-first, passive-second sequence.

2.2.2. Musical conditionIn this condition, sentences formed by a sequence of

musical notes instead of words were used. We substituted lin-guistic with musical stimulus material to ascertain whether

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M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565 561

the bias of neglect on the spatial representation underlyingspoken language affects (1) not language per se, but ratherany sequence of elements deployed over time regardless oftheir linguistic nature, and (2) the so-called suprasegmen-tal features of language, which include sentence stress asa component of linguistic prosody (in a musical sentence,the structure is analogous to the melodic contour of lan-guage). A professional musician played notes on a pianoand they were recorded on a tape-recorder. We did not makethe musical sentences by assembling the notes at random,which, according to the musician, would have been the sameas meaningless linguistic babbling, but instead by takingfragments of real pieces of music which had an underlyingstructure with a meaning. Specifically, sentences consistedof one-voice thematic fragments extracted from a thematiccatalogue of J.S. Bach (1685–1750). To form the musicalsentences, only fragments with a ternary structure were cho-sen, so that the structure would be analogous to the three-element structure of the linguistic sentences; therefore, alsoin the musical sentences an initial, a central and a finalpart of the sentence was detectable. Emphatic stress couldbe placed on each of these three components since, in thiscase, the stress was made by means of a marked increase inthe loudness of the notes played on the keyboard. All sen-tences had been previously administered to a group of nonbrain-damaged control subjects to verify that the variationsi earchp

. Then samea atics sicalr otherc yingw

2ce of

t erb +n ordert ack-ed spa-t thev tationu spo-k sent.N rdst ar-c elC irsw nounsi thes hatics nouns

Fig. 2. Comparison of the means and S.D.s of correct answers of N+ patientsin the active linguistic vs. passive linguistic condition. Score ranges areshown under each histogram.

3. Results

3.1. Active–passive linguistic condition

An ANOVA 2 × 2× 2 was computed to compare the per-formance of the two groups of patients on the two sentencetypes, active and passive; factors used were “Group” (N−/N+patients), “Sentence Type” (Type I/Type II) and “Condi-tion” (active/passive). “Group” and “Condition” showed nomain effects (p = 0.20 andp = 0.53); however, “SentenceType” was significant (Type I: mean 19.16, S.D. 3.54;Type II: mean 18.34, S.D. 3.54) (F1,24= 10.52,p = 0.003).The “Group”× “Sentence Type” interaction was not signifi-cant (p = 0.16), whereas the “Group”× “Condition” (interac-tion (p = 0.02) was significant; the “Condition”× “SentenceType” interaction was also significant (p = 0.000); finally, thethree-way “Group”× “Sentence Type”× “Condition” inter-action was significant (p = 0.02). A Duncan post-hoc analysisrevealed that: (a) the processing of Type I sentences by N+patients differed significantly in the active versus the passivelinguistic condition (p = 0.0001); (b) on the contrary, the pro-cessing of Type I sentences by N− patients did not differ inthe two linguistic conditions (p = 0.24); N+ patients’ process-ing of Type II sentences also differed in the active versus thepassive linguistic condition (p = 0.04).

Therefore, as also shown inFigs. 2 and 3, N+ patients’d d thep pas-s tientsm of thes mosto nd oft

Fi s ares

n emphasis could be detected, as foreseen by the resrotocol.

Here, too, sentences were presented in pairs (48 + 2)otes comprising the two sentences of the pair were thend the only variable element was the position of emphtress. So, apart from the nature of the stimuli, i.e., muather than verbal, the task was exactly the same as theonditions described: listening to two “sentences” and sahether they sounded the same or not.

.2.3. Sequence of three nouns conditionIn this condition, sentences comprised of a sequen

hree nouns were used instead of the canonical noun + voun sentences. The verb was purposely excluded in

o ascertain its relevance—as claimed by linguists like Jndoff and Gruber (quoted inChatterjee et al., 1999)—inefining thematic roles and in supporting the whole

ial representation of linguistic events. In other words, iferb is the element responsible for the spatial represennderlying spoken language, the effect of neglect onen language should not occur when the verb is not preouns used were high frequency bi- and tri-syllabic wo

aken from the frequency lexicon of the Italian language “Bellona Corpus” (Istituto di Linguistica Computazionale dNR di Pisa, 1989). For this condition, 48 + 2 sentence paere created as well. Each sentence comprised three

n sequence, i.e. “dog–apple–pen”, repeated twice withame or with a different emphatic stress (the same emptress balancing used for the canonical noun + verb +entences).

ifferential processing of Type I sentences distinguisheerformance of the two groups of patients in active versusive sentences. Specifically, in active sentences N+ paade more errors when the stress was at the beginning

entence (Type I), and in passive sentences they madef their errors when the stress was at the center or the e

he sentence (Type II).

ig. 3. Comparison of the means and S.D.s of correct answers of N− patientsn the active linguistic vs. passive linguistic condition. Score rangehown under each histogram.

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562 M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565

Fig. 4. Means and S.D.s of correct answers of patients with and withoutneglect in the two sentence types of the musical condition. Score ranges areshown under each histogram.

3.2. Musical condition

The means of the correct answers obtained by N+ and N−patients in the musical condition are reported inFig. 4.

As shown by the graph, this condition proved to be quitedifficult for both groups of patients compared to the otherexperimental conditions employed in this study. As before,the performance of the two groups of patients on the two typesof musical sentences was compared by an ANOVA 2× 2,with “Group” (N−/N+ patients) and “Sentence Type” (Type I,Type II) as factors. The results showed a main “Group” effect(F1,20= 8.83, p = 0.007), since the N+ patients were moreimpaired than the N− patients on this task (mean of correctanswers: N+ group = 28.2, S.D. 6.74; N− group = 36, S.D.5.75). “Sentence Type” was also significant (F1,20= 12.06,p = 0.002) because all patients tested found the Type II sen-tence type more difficult to process than the Type I sen-tence type (mean of correct answers: Type I = 17.27, S.D.3.93; Type II = 15.18, S.D. 3.77). But, most importantly, the“Group” × “Sentence Type” interaction was not significant(F1,20= 0.2,p = 0.64). This means that neglected patients donot process a sequence of non-linguistic sounds stressed inthe initial part differently from sequences stressed in the cen-tral or final part. More specifically, this result suggests thatthe bias related to the presence of neglect does not affect(1) any sequence of events deployed over time, regardless ofi ntalf

3

andN n arer

izedb dif-fi of a2 da fc 2;N not( en-t D.4 n

Fig. 5. Means and S.D.s of correct answers of patients with and withoutneglect in the two sentence types of the sequence of three nouns condition.Score ranges are shown under each histogram.

was not significant (F1,20= 0.05,p = 0.82). Therefore, we candeduce that when there is no verb in the sentence the linguis-tic task is quite difficult for neglect patients. However, this isnot due to greater impairment for the initial part of the lin-guistic string but seems to affect the different sections of thestring in a similar way.

An additional point concerns the possible relationshipbetween the measures of neglect and the effect producedby the experimental manipulations (influence of stress onsentence comparison). We computed a correlation matrixbetween each test for neglect and the number of correctresponses in our emphatic stress tasks. No correlations weresignificant: the highest correlations were found between theactive/passive condition with the Wundt–Jastrow Illusion test(range from 0.32 to 0.52). The lowest correlations for theexperimental conditions were found for the Personal neglecttest and the Sentence reading test (range from 0.05 to 0.37).

An overall measure of neglect severity was computed tak-ing the averagez-scores (computed on an independent pool of120 N+ patients) of the five neglect tests. In this case, the cor-relation with the Passive linguistic condition was significant(−0.57,p < 0.05).

4. Discussion

4

r therc enti ionalb note-w thea hichi Thisr nor-mts ctureh N+p

ts nature (linguistic or non-linguistic), (2) a suprasegmeeature of language as prosody.

.3. Sequence of unrelated nouns condition

The means of the correct answers obtained by N+− patients in the sequence of unrelated nouns conditio

eported inFig. 5.As shown by the graph, this condition—character

y the absence of the verb—proved to be particularlycult for the N+ group of patients. Based on the results× 2 ANOVA (“Group” × “Sentence Type”), “Group” hasignificant main effect (F1,20= 22.44,p = 0.0001) (mean o

orrect answers for “Group”: N− group = 40.45, S.D. 6.1+ group = 29, S.D. 7.01), while “Sentence Type” did

F1,20= 1.24,p = 0.27) (mean of correct answers for “Sence Type”: TypeI = 17.73, S.D. 4.05; Type II = 18.41, S..33); finally, the “Group”× “Sentence Type” interactio

.1. Active versus passive linguistic condition

First, the present results provide additional support foesults obtained in our previous study (Rinaldi et al., 2003),onfirming that neglect patients have a specific impairmn processing the initial part of an active sentence (positias), namely, the subject-word. In the present study, aorthy additional result emerged from a comparison ofctive versus the newly introduced passive condition, w

n neglect patients is the inversion of the positional bias.esult goes beyond the reduction of the bias obtained inal subjects byChatterjee et al. (1995a, 1995b)passing from

he active to the passive condition, since we observed aninver-ion, not a reduction, of the bias. Therefore, sentence struas a role in determining the positional bias observed inatients’ processing of spoken sentences.

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M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565 563

An attempt to account for this inversion can be made byconsidering the distinction between the grammatical subjectand the logical subject of a sentence. The grammatical sub-ject is the one indicated by syntactic rules, and the logicalsubject is the one who actually performs the action in a sen-tence, i.e., the doer of the action. Although these two subjectscoincide in active sentences (“The dog chases the ball” –logical/grammatical subject: “dog”), in passive sentences,instead, the logical subject appears at the end of the sen-tence under the grammatical guise of agent (e.g., “The ballis chased by the dog” – logical subject: “dog”; grammaticalsubject “ball”). Therefore, the inversion of the bias passingfrom active to passive structures suggests that the compo-nent specifically compromised by the presence of neglect is,namely, the doer of the action, the logical subject of the sen-tence. But, to reconnect this to the selective involvement ofneglect for the left hemispace, we need an additional step, i.e.,the consideration that active and passive sentences, thoughdifferent in their “surface structures”, share the same “deepstructure”, in Chomsky’s terms. In the deep structure, thelogical subject (the doer of the action) always appears at thebeginning, which means “on the left” in terms of the spatialtranscoding of the spoken sentence hypothesized.

In support of this view, that of an intrinsically spatial natureof the deep structure of language, as noted byO’Keefe (1996),has a long tradition in linguistics. According to this view,n in ap s.

4

e usw e theb ess-i s notp sicaln elyt entalf by thr ointt

s int ly ina ethert haves pro-cT sionh s nos at thea hicha bero

a ofo side

of space and verbal auditory stimuli towards the right. It isalso possible that the attentional bias generated by musicalstimuli towards the left hemispace makes up for neglect of thesame hemispace, which characterizes heminattention, thusexplaining the absence of a bias for Type I sentences in thisexperimental condition.

4.3. Sequence of unrelated nouns condition

As in the case of the musical condition, this experimen-tal condition also proved to be more difficult than expected,especially for our N+ patients, though not in terms of a dif-ferential error distribution (no bias for Type I sentences). Thefact that when no verb was present in the linguistic string nopositional bias emerged in N+ patients adds further supportto the hypothesis (reported inChatterjee et al., 1999) that theverb is the element responsible for genesis of the spatial rep-resentation underlying a spoken sentence (no verb = no event,no thematic roles defined, no elements to build a spatial rep-resentation).

Therefore, without a verb the three nouns given are justunrelated concepts without any unifying structure. Thus, thepresence of a left-to-right “vector-for-action”, represented bythe verb and claimed byChatterjee et al. (1999)to be thebasis for the representation of events expressed by means oflanguage, seems to be indispensable for manifestation of thep agep

p-r is ag task,t sted.

4

andt eralli tion,r ct isn uirest eglecti atest epa-r ionsw stingc

sksu im-u d ind atialt

ofn als.T tionh herea ow

on-spatial propositions would be subsequently locatedarasitic way on intrinsically spatial prototypic structure

.2. Musical condition

The results obtained in the musical condition providith important cues about the mechanisms that underliias under investigation and the level of linguistic proc

ng involved, because they show that the neglect bias iresent with any type/sequence of acoustic event (muotes) utilized over time. Consequently, it is highly unlik

hat the neglect bias acts at the level of the suprasegmeatures of language such as prosody, as also suggestedesults of the active/passive condition, which, instead, po a semantic involvement.

Although both groups of patients made many errorhis condition, the errors were not distributed preferentialny sentence type. Different factors may have acted tog

o determine this result. For instance, various studieshown that the melodic contour of language is primarilyessed by the right hemisphere (Bloomstein & Cooper, 1974).herefore, the fact that patients with a right hemisphere leave major problems on a melodic comparison task iurprise. Secondly, these studies have also shown thbsence of “segmental” cues in the acoustic input, wlso characterized our stimuli, determined a higher numf errors.

Third, in a study conducted on normal subjectsSegalowitznd Plantery (1985)found that musical stimuli (piecesrchestral music) orientated attention towards the left

e

ositional bias exhibited by N+ patients in spoken langurocessing.

Apart from the impossibility of building a structured reesentation of the “event”, this could also mean therereater demand on memory resources to carry out this

hus explaining the lower performance of the patients te

.4. Correlational results

The low correlations between the experimental taskshe measures of neglect, with the exception of the ovndex of neglect severity and the Passive linguistic condiequire a final comment. First of all, it is known that negleot a unitary syndrome; for this reason, its diagnosis req

he use of more than one test since a patient may show nn one test but not in another. This clinical evidence indiche existence of multiple spatial dimensions that can be sately or jointly affected by the neglect syndrome, dimenshich are not necessarily covered completely by the exilinical tests, such as the ones used in our research.

Additionally, it must be considered that while the tased to identify neglect deal with explicit visuo-spatial stli, the effect involved by the emphatic stress, inserteifferent strings of acoustic signals, depends on a sp

ranscoding of auditory traces.This transcoding, although effective in the group

eglect patients, may not be activated in all individuhese individual differences in a related field of investigaave been described in research on the “number-line”, wsignificant proportion of normal subjects did not sh

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564 M.C. Rinaldi, L. Pizzamiglio / Neuropsychologia 44 (2006) 556–565

the activation of spatial transcoding in different kinds ofnumerical processing (Dehaene, Bossini, & Giraux, 1993,for instance, found the number-line effects to be significantin students of scientific, but not always of literary studies).It may be suggested that although the presence of a spatialbias in neglect patients influences the activation of a “spatiallanguage-line”, the use of spatial transcoding is associatedmore with individual differences and less with the intensityof neglect disorders.

5. General discussion

Our data show that in brain-damaged patients an interac-tion exists between the presence of neglect and the type of taskadministered. The task consisted of comparing the stress posi-tions in two heard sentences, a comparison, which directlyinvolved the acoustic traces left by the spoken sentences inthe working memory. When they were given two sequencesof words to compare, patients with unilateral neglect mademore errors when the cue (the stress) appeared in the ini-tial part than in the central or the final part of the sentence.This type of effect exerted by neglect on the task employedis strongly suggestive of a spatial transcoding of the auditorytraces left in the working memory by the heard sentence, asalready postulated in our previous study.

sug-g uagel hist wayb tionas

tob takep nlyi hada tion,b alsof ion,t ctivet

lecti nceo ce”,d inter-a put( udi-t s ap spa-t aticr sen-t of thes s withs glecta guis-t does

something to whom”, and in its spatial transcoding the logi-cal subject –the agent of the action, the “who”—consequentlyappears “on the left” (in both active and passive sentences).

We see, therefore, that the absence of a structure underly-ing linguistic input, determined by the absence of the verb,was a critical factor, and this absence characterized both thethree-noun and the musical condition employed in this studyin which the neglect bias was not observed.

In the musical condition, it can be objected that the stimuliemployed were pieces of real music, with an actual underly-ing structure. However, since none of the subjects tested inour study had had any previous musical education, it is highlyunlikely they could have perceived the underlying structure.It is possible that a different result would have emerged withprofessional musicians; but, unfortunately, very few musi-cians with neglect are described in the literature (we know ofonly one case reported byLandi et al., 1997).

In the case of the three-noun sequence, instead, stimuliwere actually processed as linguistic and had a semantic con-tent (each noun is a concept). But, also here, semantic contentper se did not seem to be enough for the neglect bias to appear.Semantic content must, in fact, be engraved into a carryingstructure, defined by the verb, which establishes which con-cept acts as agent and which as recipient of action within thewhole sentence frame.

To conclude, we would like to present some considerationsa okenl biasw ents,a

agew thera uagea of hise valu-a antlyp page( ta nal-y lyi be,i , note uaged cod-i thisrt sted(

then wing,a of ad enceo ardstP r,2

Our data from the previous and the present studyest that spoken language may activate a “spatial lang

ine’, which is a spatial transcoding of linguistic input. Transcoding is then perturbed in a spatially predictabley the presence of a spatial bias such as the heminattenyndrome.

With respect to our previous work, we are now ableetter define the conditions required for the effect tolace. The effect is not found for all auditory input, but o

n specific circumstances. In fact, we found that neglectn effect on the linguistic task in the active/passive condiut not in the musical or in the three-noun condition. Weound that the effect was inverted in the positive condithe active /passive condition, when passing from the ao the passive sentence structure.

These results mainly suggest the following: (1) negnteracts with auditory linguistic input; e.g. a sequef musical notes, although forming a “musical sentenoes not produce the same spatial bias; (2) neglectcts with a syntactically structured auditory linguistic inagent/action/recipient of action), and not with just any aory linguistic input (noun /noun/ noun); (3) the verb harimary role in determining the presence of a structured

ial representation in linguistic input, defining the themoles and providing the frame for the event narrated in theence; (4) neglect acts at the level of the deep structureentence, which in the case of active sentences coincideurface structures. More exactly, we hypothesize that nects on the spatial transcoding of the deep structure of lin

ic input; the deep structure is a representation of “who

l

bout the entity of the bias exerted by neglect on spanguage. As estimated from the active sentences, theas not present in every N+ patient tested but in 8/12 patind in a different strength in each one.

The fact that the effect of neglect on spoken languas not universal conforms well to results obtained by outhors who investigated the relationship between langnd space. Chatterjee, for instance, admits that in somexperiments with normal subjects the spatial bias was eted only in the limited percentage of subjects who constlaced the agent of the action on the same side of thein one experiment, only 37% of the subjects) (Chatterjee el., 1999), and that the others were not included in the asis. Also,Coslett (1999)found his hemifield effects onn patients with a specific lobe involvement (parietal londependently of the presence of neglect); but, here toovery patient exhibited these effects. Leaving the langomain, other authors who investigated the spatial trans

ng of numerical quantities (the number-line) did not findelationship to be ubiquitous (Dehaene et al., 1993). A. Kimoo found the number-line in only 63% of the subjects teA. Kim, personal communication).

This spatial transcoding of numerical quantities, i.e.,umber-line, represents a good piece of evidence shos in the study we described, how spatial transcodingifferent domain (numbers) can be affected by the presf a spatial deficit, i.e., neglect, undergoing a shift tow

he ipsilesional side when this syndrome is present (Zorzi,riftis, & Umilta, 2002; Vuilleumier, Ortigue, & Brugge004).

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Acknowledgement

This research has been supported by grant of MinisteroItaliano della Sanita.

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