Blog Archives

Contribution of frontal cortex to the spatial representation of number

Neuropsychological and neurophysiological studies have suggested that prefrontal cortex may be involved in non-verbal number processing, when relevant for current behavioural goals. More precisely, it has been suggested that an intact right inferior frontal gyrus (rIFG) in humans may be necessary to the use of a spatial representation of numbers, also known as mental number line. In a popular model of spatial functions (e.g., Corbetta et al., 2008), rIFG is part of a right-lateralised ventral fronto-parietal network that conveys signals to a dorsal network supporting attentional orienting in contralateral space. Within the dorsal network, the frontal eye fields (FEF) are known to contribute to visual scene analysis and visual conjunction search tasks when eye movement commands are not required. In the present study, we hypothesised they might also be involved in exploring a conceptual space, such as the mental number line. We examined the proposed functions of the human rIFG and right Frontal Eye Field (rFEF) by interfering with their normal functioning with repetitive Transcranial Magnetic Stimulation (rTMS) while participants performed numerical tasks. The results suggest that, when number magnitude is relevant to the task, rIFG supports orienting to the entire mental number line while rFEF are crucial for contralateral orienting (that is towards small numbers).

from Cortex

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Do English and Mandarin speakers think about time differently?

Time is a fundamental domain of experience. In this paper we ask whether aspects of language and culture affect how people think about this domain. Specifically, we consider whether English and Mandarin speakers think about time differently. We review all of the available evidence both for and against this hypothesis, and report new data that further support and refine it. The results demonstrate that English and Mandarin speakers do think about time differently. As predicted by patterns in language, Mandarin speakers are more likely than English speakers to think about time vertically (with earlier time-points above and later time-points below).

from Cognition

Event categorisation and language: A cross-linguistic study of motion

It is well known that languages differ in how they encode motion. Languages such as English use verbs that communicate the manner of motion (e.g., slide, skip), while languages such as Greek regularly encode motion paths in verbs (e.g., enter, ascend). Here we ask how such cross-linguistic encoding patterns interface with event cognition by comparing labelling and categorisation preferences for motion events by English- and Greek-speaking adults and 5-year-olds. Our studies show that, despite cross-linguistic encoding differences, the categorisation of dynamically unfolding motion events proceeds in identical ways in members of these two linguistic communities. Nevertheless, language-congruent categorisation preferences emerge in tasks that implicitly encourage the use of linguistic stimuli during event apprehension. These data have implications for the relationship between language and event categorisation.

from Language and Cognitive Processes

An Expanded Role for the Dorsal Auditory Pathway in Sensorimotor Control and Integration

The dual-pathway model of auditory cortical processing assumes that two largely segregated processing streams originating in the lateral belt subserve the two main functions of hearing: identification of auditory “objects”, including speech; and localization of sounds in space (Rauschecker and Tian, 2000). Evidence has accumulated, chiefly from work in humans and nonhuman primates, that an antero-ventral pathway supports the former function, whereas a postero-dorsal stream supports the latter, i.e. processing of space and motion-in-space. In addition, the postero-dorsal stream has also been postulated to subserve some functions of speech and language in humans. A recent review (Rauschecker and Scott, 2009) has proposed the possibility that both functions of the postero-dorsal pathway can be subsumed under the same structural forward model: an efference copy sent from prefrontal and premotor cortex provides the basis for “optimal state estimation” in the inferior parietal lobe and in sensory areas of the posterior auditory cortex. The current article corroborates this model by adding and discussing recent evidence.<p><p>from <a href=”http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T73-511R9MF-1&_user=108452&_coverDate=09%2F17%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000059732&_version=1&_urlVersion=0&_userid=108452&md5=92012beacc6d889b84df16a876e066bc&searchtype=a”><em>Hearing Research</em></a></p>

Processing time shifts affects the execution of motor responses

We explore whether time shifts in text comprehension are represented spatially. Participants read sentences involving past or future events and made sensibility judgment responses in one of two ways: (1) moving toward or away from their body and (2) pressing the toward or away buttons without moving. Previous work suggests that spatial compatibility effects should be observed, where the future is mapped onto responses away from the body, and the past is mapped onto responses toward the body. These effects were observed, but only when participants were moving to make their responses, and only for larger time shifts (e.g., a month).

from Brain and Language

Children’s verbalizations of motion events in German

Recent studies in language acquisition have paid much attention to linguistic diversity and have begun to show that language properties may have an impact on how children construct and organize their representations. With respect to motion events, Talmy (Towards a cognitive semantics: Concept structuring systems, Cambridge University Press, 2000) has proposed a typological distinction between satellite-framed (S) languages that encode path in satellites, leaving the verb root free for the expression of manner, and verb-framed (V) languages that encode path in the verb, requiring manner to be expressed in the periphery of the sentence. This distinction has lead to the hypothesis (Slobin, From “thought and language” to “thinking for speaking”, Cambridge University Press, 1996) that manner should be more salient for children learning S-languages, who should have no difficulty combining it with path, as compared to those learning V-languages. This hypothesis was tested in a corpus elicited from German children and adults who had to verbalize short animated cartoons showing motion events, and the results are compared with previous analyses of French and English corpora elicited in an identical situation (Hickmann et al., Journal of Child Language, 36: 705–741, 2009). As predicted, and as previously found for English, German children from three years on systematically express both manner (in the verb root) and path (in particles), in sharp contrast to French children, who rarely package manner and path together. These results suggest that, when they are engaged in communication, children construct spatial representations in accordance with the particular properties of their mother tongue. Future research is necessary to determine the extent to which cross-linguistic differences in production may reflect deeper differences in the allocation of attention and in conceptual organization.

from Cognitive Linguistics

Auditory Attentional Control and Selection during Cocktail Party Listening

In realistic auditory environments, people rely on both attentional control and attentional selection to extract intelligible signals from a cluttered background. We used functional magnetic resonance imaging to examine auditory attention to natural speech under such high processing-load conditions. Participants attended to a single talker in a group of 3, identified by the target talker’s pitch or spatial location. A catch-trial design allowed us to distinguish activity due to top-down control of attention versus attentional selection of bottom-up information in both the spatial and spectral (pitch) feature domains. For attentional control, we found a left-dominant fronto-parietal network with a bias toward spatial processing in dorsal precentral sulcus and superior parietal lobule, and a bias toward pitch in inferior frontal gyrus. During selection of the talker, attention modulated activity in left intraparietal sulcus when using talker location and in bilateral but right-dominant superior temporal sulcus when using talker pitch. We argue that these networks represent the sources and targets of selective attention in rich auditory environments.

from Cerebral Cortex

Event categorisation and language: A cross-linguistic study of motion

It is well known that languages differ in how they encode motion. Languages such as English use verbs that communicate the manner of motion (e.g., slide, skip), while languages such as Greek regularly encode motion paths in verbs (e.g., enter, ascend). Here we ask how such cross-linguistic encoding patterns interface with event cognition by comparing labelling and categorisation preferences for motion events by English- and Greek-speaking adults and 5-year-olds. Our studies show that, despite cross-linguistic encoding differences, the categorisation of dynamically unfolding motion events proceeds in identical ways in members of these two linguistic communities. Nevertheless, language-congruent categorisation preferences emerge in tasks that implicitly encourage the use of linguistic stimuli during event apprehension. These data have implications for the relationship between language and event categorisation.

from Language and Cognitive Processes

Competing conceptual representations trigger co-speech representational gestures

Abstract
Various interconnections between the processing of speech and gesture have been demonstrated in the literature. However, it is not well understood what cognitive factors influence intra-speaker variation of the gesture frequency. This study investigates the hypothesis that provides a unifying explanation for the previous findings on this issue; namely, competing representations in the conceptualisation process for speaking trigger representational gestures. Twenty adult participants described complex geometric figures. In the easy condition, the organisation of the lines necessary for conceptualisation were highlighted by making some lines darker, but in the hard condition, unnecessary competitor conceptualisations were highlighted. The descriptions in the two conditions were lexically comparable. However, the rate of representational gestures (but not that of beat gestures) was higher in the hard condition than in the easy condition. This finding is compatible with the idea that gestures may play a role in the conceptualisation process for speaking.

from Language and Cognitive Processes

Competing conceptual representations trigger co-speech representational gestures

Various interconnections between the processing of speech and gesture have been demonstrated in the literature. However, it is not well understood what cognitive factors influence intra-speaker variation of the gesture frequency. This study investigates the hypothesis that provides a unifying explanation for the previous findings on this issue; namely, competing representations in the conceptualisation process for speaking trigger representational gestures. Twenty adult participants described complex geometric figures. In the easy condition, the organisation of the lines necessary for conceptualisation were highlighted by making some lines darker, but in the hard condition, unnecessary competitor conceptualisations were highlighted. The descriptions in the two conditions were lexically comparable. However, the rate of representational gestures (but not that of beat gestures) was higher in the hard condition than in the easy condition. This finding is compatible with the idea that gestures may play a role in the conceptualisation process for speaking.

from Language and Cognitive Processes

Cross-cultural variation of speech-accompanying gesture: A review

This article reviews the literature on cross-cultural variation of gestures. Four factors governing the variation were identified. The first factor is the culture-specific convention for form-meaning associations. This factor is involved in well-known cross-cultural differences in emblem gestures (e.g., the OK-sign), as well as pointing gestures. The second factor is culture-specific spatial cognition. Representational gestures (i.e., iconic and deictic gestures) that express spatial contents or metaphorically express temporal concepts differ across cultures, reflecting the cognitive differences in how direction, relative location and different axes in space are conceptualised and processed. The third factor is linguistic differences. Languages have different lexical and syntactic resources to express spatial information. This linguistic difference is reflected in how gestures express spatial information. The fourth factor is culture-specific gestural pragmatics, namely the principles under which gesture is used in communication. The culture-specificity in politeness of gesture use, the role of nodding in conversation, and the use of gesture space are discussed.

from Language and Cognitive Processes