Fitch and Hauser
(2004) have tested monkeys and humans with artificial grammars in both
FSG and PSG categories. They have shown that humans can easily learn
both structures but monkeys fail to learn sentences which have
recursive structure. They use (AB) n sentences as FSG and AnBn as PSG
grammar where A’s are CV syllables pronounced by a man speaker and B’s
are CV syllables pronounced by a woman speaker. This is very easy for
humans to learn because they can just listen to the transitions between
man voice and woman voice. We have tested the same structures on human
adults but using more difficult materials. In our experiments A
group is consisted of Cv syllables and B group is consisted of CVC
syllables. If humans own a system to detect dependencies in recursive
structures they should also learn sentences of our experiments.
Serially ordered consonants (Cs) of an
artificial language stream constituted exclusively by CV syllables are
used to segment speech on the basis of their transitional probabilities
(TPs), see Newport et Aslin (2004) and Bonatti et al (in press). Here
we explore more extensively this claim.
First, we show that the TPs among
consonants are also employed to parse an artificial speech stream when
more complex syllables than CV (i.e., CCV, CVC) are used. Then we
explore the relative importance of syllables and consonants to extract
the constituent items in an artificial speech stream. We demonstrate
that the TPs between Cs are useful only if the Cs of test items
maintain the same syllabic position they occupy in the habituation
stream.
We show that syllables act as
organizing structures, determining which consonants are used to compute
statistical dependencies during segmentation.
The results of two
ERP experiments with
semantic and syntactic violations in Croatian sentences will be
presented. In the first experiment subjects were presented with
semantically correct and semantically incorrect sentences such as "The
dog ate a question." In the second experiment there was a syntactic
violation in the target stimuli - the target word violated the
agreement in gender, e.g. "The nurse (f) is nice (m)."
The results were
similar to the results
in similar experiments in other languages. The N400 component was
observed in sentences with semantic violation while both left anterior
negativity (LAN) and P600 was elicited in sentences with agreement
error.
In comparison to other languages the N400 component showed delayed
latency preceded by another negative wave that could reflect
morphosyntactic processing of the target word.
Finally, Croatian specific formal features such as aspect will be
discussed in light of finding electrophysiological evidence in favor of
particular models of language comprehension.
- Judit Gervain et al.: "Learning the categories and the order of
morphemes in an artificial grammar: cross-linguistic comparisons"
Universal to human language is the
distinction between function words (e.g. the, he, up etc.) and content words (e.g. table, dog, run, nice etc.). These two major
categories play different roles in language. The former encode
syntactic relations, while the latter carry semantic meaning. Moreover,
languages seem to show a tendency to prefer either of the two possible
relative orders of the two categories. In English, for instance,
auxiliaries precede main verbs (will
go), prespositions precede noun phrases (under the table) etc., whereas in
Hungarian, the opposite is true (menni
fog 'go will'; az asztal
alatt 'the table under'). It is, therefore, essential for
language learning infants to distinguish these two broad categories.
They are aided in this task by a number of "low level" cues, available
from the speech signal, that the two categories differ in. First,
function word tokens seem to be universally more frequent than content
word tokens. Secondly, the former appear to be shorter, typically
monosyllabic, and phonologically more reduced than the latter.
Werker and colleagues have shown in a series of experiments that young
infants are able to tell the two major categories apart on the basis of
these phonological cues.
In a series of artificial grammar experiments, we asked, as a first
step, whether adult subjects are able to do the required classification
on the basis on the first kind of cue, i.e. the difference in
frequency. The evidence suggests that the answer to this question is
positive. As a second step, we investigated whether there are native
language-related differences in what subjects take to be the
basic order of the two categories. We tested speakers of five
typologically different languages: Italian, French, Hungarian, Japanese
and Basque.
- Agnes Kovacs: "Bilinguals’ advantage in understanding
other minds. What does this benefit mean?"
The studies investigate how bilingual
and monolingual children understand situations that involve mental
states of others. We explore whether bilingualism promotes success in
theory of mind tasks. This may be possible because bilingual children
switch between their languages as a function of the addressee’s
language. According to our proposal this language selection requires an
insight into the others’ mind. If this is the case, bilinguals develop
a theory of mind earlier than matched monolinguals. In the first study
3 years old bilingual and monolingual children performed a standard
theory of mind task, a modified theory of mind task and a control task
for general information processing. Results show that success in theory
of mind develops faster in bilinguals than in monolinguals while they
do not differ in the control task. The second study investigates the
mechanisms, which might underlie the observed phenomena. The questions
we address are the following: 1.Are bilinguals really better in ToM or
they are just better in inhibiting a prepotent response (the reality
bias)? In order to study this, in addition to the standard ToM tasks we
used tasks that lack the strong bias by decreasing the saliency of last
event or increasing the saliency of previous event. 2. Are the
differences in ToM ability due to better grammatical abilities of the
bilinguals? We measured performance in understanding tensed complements
that involved mental or communication verbs, with or without a
prepotent response. 3. How long does the bilingual advantage last?
(comparing 3 and 4 years old) The results show that the bilingual
advantage is not due to better grammatical abilities and the
differences between monolinguals and bilinguals disappear at the age of
four. Furthermore, it seems that the young bilingual advantage is only
restricted to the standard ToM tasks, which involve a prepotent
response.
- Damir Kovacic, Marcela Pena,
Hifumi Tsubokura, Atsushi Maki, Jacques Mehler: "Optical topography study of speech
perception changes following cochlear implantation: a case study"
Restoration of hearing after cochlear
implantation is based principally on two factors: i) degree of
bypassing damaged structures in the inner ear by the surgical insertion
of a neuroprosthetic device and ii) intrinsic properties of the
cerebral cortex to process novel auditory sensory input (plasticity).
Animal studies show that after frequency-selective deafening at the
sensory periphery by a partial cochlear ablation, auditory cortex
reorganizes its tonotopic maps (Schwaber et al, 1993). Namely, after
some adaptation period, deprived parts of the cortex become responsive
to intact cochlear regions. However, little is known about the
mechanisms and timeline of the adaptation to the new stimuli in both
adults and children cochlear implant (CI) users.
This study explores the outcome over 5 months of the changes in the
regional brain activity associated with a language discrimination task,
in a profoundly deaf adult following cochlear implantation, using
Optical Topography (OT). OT is a novel non-invasive neuroimaging
technique that records the hemodynamic (vascular) response of the
superficial areas of the brain in response to sensory stimulation and
cognitive tasks.
- Valerie Lesk and Stephen Womble: "Phonological priming of tip of the tongues:
Effect of prime time"
A study was performed involving
phonological priming and tip of the tongue states (TOTs) where
participants took either 200mg of caffeine, or a placebo. Results show
a clear positive priming effect produced for the caffeine group when
primed with phonologically related words. When primed with unrelated
words the caffeine subgroup produced a significant increase in the
number of TOTs. This contrasting effect provides evidence that
the
positive priming of caffeine was not because of caffeine's well-known
alertness effects. For placebo, a significant negative effect occurred
with the related word priming condition. The results support the novel
hypothesis that the blocking of A1 adenosine receptors by caffeine
induces an increased short-term plasticity (STP) effect within the
phonological retrieval system. To test further the time dependent
STP-caffeine hypothesis, in this study the prime-target interval is
lengthened. We show that when the prime-target interval is
increased,
the priming effect is weaker.
- Pines Nuku et al.: "Joint attention in action observation and
action execution"
‘Joint attention’ refers to changes in
one’s own action potentials after observing somebody else’s actions.
Observing spatially directed but non-predictive intentional postures,
have attentional consequences for an observer. There is some evidence
that perceived gaze leads to attention shifts (Friesen & Kingstone,
1998; Langton & Bruce, 1999; Ristic Friesen & Kingstone, 2002)
or that perceived grasping movements induces preparation of similar
actions (Fadiga et al., 1995; Craighero et al., 2002). While a recent
study (Fischer & Szymkowiak, 2004) showed that posture (grasping,
pointing) cueing triggers other’s attention only when it conveys the
intention of another’s action, but not when the to-be-performed action
has already been performed.
In our study we wanted to know whether pointing and grasping postures
alone might trigger others' attention. We also wanted to see whether
the intentions of another’s action do have beneficiary effects on the
observers' attentional allocation. Our question of whether motor
priming is influenced by inferential processes that select targets when
the observed action is a meaningful/intended one, or whether we can
distinguish between intentional (meaningful) and non-intentional
(non-intended) but attention-triggering actions, are answered in three
different experiments.
In the first experiment we showed that when presented with grasping
postures, implying an already-performed action, observers were
inhibited in their responses as when compared with pointing postures
where the action was not yet being performed. In the second experiment
we give an alternative explanation to this effect, while in the third
experiment we show that by giving the posture cueing a causal
relationship with the manipulated target ie., when there is a perceived
sensory consequence between posture and action outcome, we did invert
the inhibitory effects seen for the grasping posture.
Take together the data give an alternative explanation to the effects
of intentions' observation reported in Fischer & Szymkowiak. The
data also show that perceived sensory consequences are a prerequisite
for understanding the intention of another’s action while postures
alone might be not automatically trigger the observers’ reallocation of
attention.
- Mohinish Shukla et al.: "Cross-linguistic
interaction between prosody and statistics in segmenting fluent speech"
Research into segmenting fluent speech
has revealed that infants and adults can use the transition
probabilities (TPs) between syllables in order to achieve segmentation;
syllabic sequences with high internal TPs are treated as possible
word-like units, while 'dips' in TP are taken as evidence for
segmentation points.
In theories of prosodic phonology, words are invariably aligned to
larger prosodic constituents in speech. Thus, phonological phrase and
intonational phrase boundaries are invariably also word boundaries.
In previous research we asked if Italian subjects would be sensitive to
such segmentation information inherent in Italian IP characteristics.
More precisely, we asked if artificial, trisyllabic 'words' that span
IP contours are equally well accepted as similar 'words' that lie
internal to IP contours. We found that contour-straddling 'words' were
significantly dispreferred. In addition, we found evidence supporting
the view that even in such artificial speech streams, subjects perceive
'chunks': 'words' that occurred at the leading edges of prosodically
defined chunks were better recognized than 'words' in the middles of
such chunks.
Here we ask if the result we obtained was due to Italian IPs being used
with Italian subjects. In order to establish the potential universality
of such a segmentation strategy, we examined the effect on the
segmentation of statistically well-formed 'words' as in the previous
experiments, but using Japanese IP characteristics instead of Italian.
The results suggest that even with Japanese IPs, subjects continue to
reject 'words' with high internal TPs if they straddle IP boundaries,
even though the IPs are from a foreign language.
- Alessia Tessari et al.: "Use of strategies in imitation of
meaningful and meaningless actions in brain damaged patients"
We tested a group of patients with
unilateral left- or right- hemisphere damage on an action imitation
test. Actions were either meaningful (MF) or meaningless (ML) and were
presented either in separated blocks or intermingled. Overall patients’
performance was worse than that of controls. No difference between MF
and ML actions emerged when presented intermingled. However, the
blocked presentation allowed dissociations between MF and ML actions to
emerge in some patients. Results are interpreted based on a two-route
model. In the mixed condition patients used the non-semantic route to
imitate both kind of stimuli whereas in the blocked condition they
applied the semantic route for MF and the direct route for ML actions.