English. We report a picture-word interference (PWI) experiment conducted in Italian where target verbs were used to name pictures in presence of semantically related and unrelated distracters. The congruency of grammatical class between targets and distracters was manipulated and nouns and verbs were used as distracters. Consistently with previous studies, an expected semantic interference effect was observed but, interestingly, such an effect does not equally apply to target-distracter pairs sharing or not grammatical class information. This outcome seems to corroborate the hypothesis of the intervention of grammatical constraints in word production as explored in the PWI task.
Italiano. Questo lavoro descrive un esperimento di interferenza figura-parola sull’ italiano in cui le figure dovevano essere denominate usando verbi in presenza di distrattori semanticamente collegati o non collegati alla figura. È stata manipolata anche la congruenza di classe grammaticale tra target e distrattori; questi ultimi nella metà dei casi erano nomi e nell’altra verbi. In linea con studi precedenti, abbiamo ottenuto un effetto di interferenza semantica; il dato interessante è che quest’ultimo effetto interessa in modo differente le coppie targetdistrattore congruenti o non congruenti per classe grammaticale. Questo risultato sembra corroborare l’ipotesi che nella di produzione di parole esplorata attraverso il compito di interferenza figuraparola giochino un ruolo le proprietà grammaticali delle parole.
Models of lexical access share the assumption
that different kinds of linguistic information
(semantic, orthographic-phonological,
syntacticgrammatical, and so on) have different levels of
lexical representation
Scholars have also tried to investigate the
activation of grammatical information in speech
production through the PWI paradigm but
conflicting evidence has been collected. For
instance,
As a consequence, the intervention of grammatical constraints during production processes, as explored in PWI tasks, is still debated.
In this study on Italian we aimed at exploring the problem by trying to avoid possible confounds existing in previous studies.
Participants: Thirty-six undergraduate students
(28 females) from University of Salerno
voluntarily took part in the experiment. They were all
native speakers of Italian and they all had normal
or corrected-to-normal vision. Their age ranged
from 20 to 30 years (mean=22; sd=2.5). They
served for a session lasting about 45 minutes.
Materials: Thirty-five black-and-white line
drawings depicting actions were used as
experimental items. Participants were instructed to
name these pictures by using inflected verb
forms (either present indicative, or 3rd singular
person). These verbs constituted the target items.
For each target-verb a semantically related
distracter-verb and a semantically related
distracternoun were selected, so that a list of 35
distracterverbs and a list of 35 distracter-nouns were built.
The selected nouns and verbs were not affected
by the semantic bias due to the object/action
dichotomy. The semantic relatedness between
targets and distracters was calculated on the basis of
2 measures: corpus-based automatic semantic
metrics
The same distracters were differently paired
with the target verbs so that two lists of unrelated
nominal (related-noun and unrelated-noun
experimental conditions) and verbal (related-verb and
unrelated-verb experimental conditions)
distracters were created. Distracters in the four
experimental conditions were matched for the main
psycholinguistics variables: imageability,
writ1 The first measure provided objective values, based on
distributional estimates, for the semantic distance between
each target-word and its distracter. The second measure
allowed us to ascertain to what extent the specific word
sense evoked by the picture was related to the
distracterword.
ten form frequency
The experimental list was composed of 140 trials where the 35 target-verbs were accompanied by 70 verb-distracters (35 semantically related and 35 unrelated) and by 70 noun-distracters (35 semantically related and 35 unrelated). Two additional distracters were used as filler trials: for each target a related and an unrelated word were provided; these filler distracters differed from experimental distracters since they were wordclass ambiguous items. Instances of all experimental conditions are reported in Table 2 and an example of experimental item is reported in Figure 1.
Semantically related pairs
Semantically unrelated pairs length written form frequency imageability shared letters between targets and distracters subjective semantic relatedness
ratings WEISS metrics noun 7.1 (1.6) 79.3 (92.3) 3.5 (0.6)
2 (1.1) 3.3 (0.9) 0.7 (0.1) verb 6.3 (1.4) 75.3 (97.7) 3.7 (0.6)
2 (1.1) 3.5 (1.03) 0.6 (0.2) noun 7.1 (1.6) 79.3 (92.3) 3.5 (0.6) 2 (1.1) 1.4 (0.4) 0.9 (0.1) verb 6.3 (1.4) 75.3 (97.7) 3.7 (0.6) 1.6 (1.0) 1.4 (0.4) 0.9 (0.1)
In order to prevent any strategic bias due to semantic and/or grammatical relationships among targets and distracters, 15 additional pictures were used as filler targets and were presented with 6 different distracters. The whole list of both experimental and filler target-distracter pairs was composed of 300 trials: 33% were semantically related trials and 67% were unrelated trials.
Procedure: The participants were tested individually; an experimental session consisted of three parts: a familiarization, a practice and an experimental phase. The E-Prime software 2.0 (Psychology Software Tools, Inc., Pittsburgh, PA) was used.
At the beginning of the experiment, each participant was familiarized with the whole set of experimental and filler pictures in an untimed picture naming session. In this phase, the pictures were presented on the computer screen with a superimposed row of Xs to simulate the distracter word. Participants learned to produce the targets upon presentation of the corresponding pictures. If participants named a picture with a verb that differed from the one designed as the target by experimenters, a feedback was given: the expected verb was provided to participants and they were invited to use it in the experimental session.
Following the familiarization phase, a practice block was administered where participants were asked to name each picture as inflected verb forms (present indicative 3rd singular person, e.g. beve, he/she drinks) and were instructed to respond as quickly and accurately as possible, while ignoring the distracter word. The experimenter was seated behind the participant and recorded errors and equipment failures. The stimuli presented in the training phase were part of the filler set.
The stimuli appeared on a video display unit controlled by a personal computer. Reaction times from the appearance of the stimuli to the onset of articulation were collected by a voice key connected to the computer and participant responses were recorded. Upon a response, the picture and the distracter disappeared from the screen. Both the presentation of the stimuli and the recording of the responses were managed by the E-Prime software 2.0. The responses of the participants were checked for accuracy by an experimenter.
Each single trial consisted of the following events: a fixation cross presented at the center of the screen for 300 ms; the stimulus until the response or for a maximum of 2.5 seconds; a feedback mask signaling the activation of the voice key of 500ms, a blank interval of 500 ms. The SOA between pictures and distracter-words was 0 ms.
Words pronounced incorrectly, non-expected picture names, hesitations in giving the responses, word fragments, omissions, verbal dysfluencies and responses given after the deadline were scored as errors. Invalid responses (e.g., trials in which the voice key was triggered by external noise) and responses shorter than 400 ms were considered as missing data.
At the end of the practice phase, the experiment started and 6 experimental blocks of 50 trials (35 experimental items and 15 filler items) were presented, for a total of 300 trials. An equal number of items from each experimental condition was included in every block. Blocks were counterbalanced across participants. In each block, stimuli underwent a randomization governed by the EPrime software 2.0.
An analysis of variance (ANOVA) was performed on naming latencies and accuracy rates by subjects (F1) and by items (F2) with the distractor type (four levels) as a variable. For the sake of conciseness only the statistically significant analyses will be reported and discussed.
A main effect of semantic relatedness has been observed both in the ANOVA by participants (F1(1, 35) = 4.56, p< .05) and by items (F2(1, 30) = 4.46, p< .05) on response latencies. Responses to target verbs were slower when they were accompanied by semantically related distracters (+17 ms).
Neither effects of grammatical class nor interaction between grammatical class and semantic relation were found.
Two-tailed t tests comparing the semantic interference effect within the grammatical class congruent and non-congruent target/distracter pairs revealed that the semantic interference effect reaches the statistical significance with noun-distracters (+24 ms, p = .02) but not with verb-distracters (+9 ms, p = .43). The results are graphically shown in Table 3.
Related Unrelated
Noun distracters
One of the aim of the present experiment was
to overcome some limitations of previous
investigations. The following constraints were
adopted:
1. We contrasted the production of verbs
when presented with semantically related
and unrelated distracters: the expected
semantic interference effect guaranteed
for the reliability of the paradigm.
2. We selected experimental materials
where the differences between
grammatical classes in terms of their semantic
domain (objects (nouns) vs. actions
(verbs)) was kept under control.
3. Word-class ambiguous items were
excluded by experimental materials.
4. Inflected finite verbal-forms were used
both as targets and distracters: these
verbal forms allow to maximize the
difference between nouns and verbs2.
Actual2 The distinction between finite and non-finite moods is
motivated on morphological and syntactic grounds:
finiteforms are inflected for person and in syntactic context they
are used as verbal predicates. Conversely, non-finite forms
lack for person inflection and are used in periphrastic
construction or in combination with auxiliary verbs to assemble
the “composed tenses” of the paradigm. Under certain
circumstances, non-finite forms undergo syntactic
transcategorization and behave as nouns or adjectives: “mi piace
ballare [infinitive]”, (I love dancing). “I partecipanti
[present participle], sono pronti” (participants are ready); “tre
gare vinte [past participle, from “vincere”] e cinque perse
[past participle, from “perdere”], (three competitions won
and five lost).
ly, the Italian inflected form “amavo”
(indicative, imperfect, 1st singular
person, I used to love), is composed of a
stem, “am-”, which conveys the core
meaning of the verb, the vowel “-a-”,
which specifies the inflectional pattern
compatible with the verbal stem, the
segment “–v-”, which encodes mood and
tense information, and the segment ”-o”
which encodes person and number
information. None of these features, with
the exception of meaning and number
features, can be part of the lexical
representation of noun-forms. This latter
manipulation has relevant consequences on
the detection of grammatical class effect
in PWI, since it has been demonstrated
that, when finite verbs have to be
produced, the naming context sets the
response-relevant criterion on the
grammatical class of verbs and then
noundistracters tend to interfere significantly
more than verb-distracters
Consistently with previous PWI evidence, our experiment replicated a reliable semantic interference effect. This finding confirms that the selection of an oral target response is slowed-down by the activation of a semantically-related distracter because the lexical system has to manage the level of activation of target lexical competitors, including the highly activated semantically related distracter word. Interestingly, we observed that, at least when pictures have to be named by using inflected verb forms, such an effect does not equally affect all semantically related target-distracter pairs: related pairs sharing grammatical class information do not exhibit significant semantic interference but grammatical-class incongruent pairs do.
In conclusion, our data suggest that the PWI task is sensitive to the manipulation of grammatical class information. In other words, such a pattern of results is compatible with the intervention of grammatical constraints during production processes, as explored in the PWI task. 3 This result was obtained regardless of semantic relation between targets and distracters. dell’Italiano Scritto http://linguistica.sns.it/CoLFIS/Home.htm and
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