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Whether grocery shopping or choosing words to express a thought, selecting between options can be challenging, especially for people with anxiety. We investigate the neural mechanisms supporting selection during language processing and its breakdown in anxiety. Our neural network simulations demonstrate a critical role for competitive, inhibitory dynamics supported by GABAergic interneurons. As predicted by our model, we find that anxiety (associated with reduced neural inhibition) impairs selection among options and associated prefrontal cortical activity, even in a simple, nonaffective verb-generation task, and the GABA agonist midazolam (which increases neural inhibition) improves selection, whereas retrieval from semantic memory is unaffected when selection demands are low. Neural inhibition is key to choosing our words. anxiety | choice | midazolam | ventrolateral prefrontal cortex | neural network model doi/ 10.1073/pnas.1002291107

Verbal communication is a joint activity; however, speech production and comprehension have primarily been analyzed as independent processes within the boundaries of individual brains. Here, we applied fMRI to record brain activity from both speakers and listeners during natural verbal communication. We used the speaker's spatiotemporal brain activity to model listeners' brain activity and found that the speaker's activity is spatially and temporally coupled with the listener's activity. This coupling vanishes when participants fail to communicate. Moreover, though on average the listener's brain activity mirrors the speaker's activity with a delay, we also find areas that exhibit predictive anticipatory responses. We connected the extent of neural coupling to a quantitative measure of story comprehension and find that the greater the anticipatory speaker--listener coupling, the greater the understanding. We argue that the observed alignment of production- and comprehension-based processes serves as a mechanism by which brains convey information. functional MRI | intersubject correlation | language production | language comprehension doi/ 10.1073/pnas.1008662107

Tuberous sclerosis (TSC) is an autosomally dominant neurocutaneous disease notable for its high comorbidity with autism in human patients. Studies of murine models of tuberous sclerosis have found defects in cognition and learning, but thus far have not uncovered deficits in social behaviors relevant to autism. To explore social communication and interaction in TSC2 heterozygous mice, we recorded ultrasonic vocalizations (USV) and found that although both wild-type (WT) and heterozygous pups born to WT dams showed similar call rates and patterns, baseline vocalization rates were elevated in pups born to heterozygous dams. Further analysis revealed several robust features of maternal potentiation in all but WT pups born to heterozygous dams. This lack of potentiation is suggestive of defects in mother-pup social interaction during or before the reunion period between WT pups and heterozygous dams. Intriguingly, male pups of both genotypes born to heterozygous dams showed particularly heightened call rates and burst patterns. Because our maternal retrieval experiments revealed that [TSC2.sup.+/-] dams exhibited improved defensive reactions against intruders and highly efficient pup retrieval performance, the alterations in their pups' USVs and maternal potentiation do not appear to result from poor maternal care. These findings suggest that a pup's interaction with its mother strongly influences the pup's vocal communication, revealing an intriguing dependence of this social behavior on TSC2 gene dosage of both parties involved. Our study of this murine model thus uncovers social abnormalities that arise from TSC haploinsufficiency and are suggestive of autism. usv | TSC | mTOR | maternal care | social communication doi/ 10.1073/pnas.1005620107

An important question in understanding language processing is whether there are distinct neural mechanisms for processing specific types of grammatical structure, such as syntax versus morphology, and, if so, what the basis of the specialization might be. However, this question is difficult to study: A given language typically conveys its grammatical information in one way (e.g., English marks 'who did what to whom' using word order, and German uses inflectional morphology). American Sign Language permits either device, enabling a direct within-language comparison. During functional (f)MRI, native signers viewed sentences that used only word order and sentences that included inflectional morphology. The two sentence types activated an overlapping network of brain regions, but with differential patterns. Word order sentences activated left-lateralized areas involved in working memory and lexical access, including the dorsolateral prefrontal cortex, the inferior frontal gyrus, the inferior parietal lobe, and the middle temporal gyrus. In contrast, inflectional morphology sentences activated areas involved in building and analyzing combinatorial structure, including bilateral inferior frontal and anterior temporal regions as well as the basal ganglia and medial temporal/limbic areas. These findings suggest that for a given linguistic function, neural recruitment may depend upon on the cognitive resources required to process specific types of linguistic cues. brain | language | sign language | syntax | neuroimaging doi/ 10.1073/pnas.1003174107

Purpose: This study investigated the network of brain regions involved in overt production of vowels, monosyllables, and bisyllables to test hypotheses derived from the Directions Into Velocities of Articulators (DIVA) [...]

Purpose: This study examined alterations in ventilation and speech characteristics as well as perceived dyspnea during submaximal aerobic exercise tasks. Method: Twelve healthy participants completed aerobic exercise-only and simultaneous speaking [...]

Purpose: This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task [...]

Speech and conversational hand gestures were recorded during interviews of 23 younger (M = 21 years) and 19 older adults (M= 70 years). Three kinds of questions were used in order to activate either visual images, motor images, or no mental image (abstract topics). On average, the rate of gesture production did not differ in younger and older adults, but it was significantly influenced by imagery conditions. Gesture production was higher in the motor than in the visual imagery condition, and lowest in the abstract condition. A significant interaction between age and imagery conditions influenced the proportion of representational gestures, which were relatively less frequent in older adults, especially in the visual imagery condition. Content analysis of verbal responses showed that imagery values did not differ in younger and older adults, but that concrete words were less frequent in responses to abstract questions than in the two other conditions. The implications of these results concerning the mechanisms of gesture production and the age-related changes in conversational behavior are discussed.

Neuromuscular and sociolinguistic hypotheses were proposed to explore and account for the nature of individuals' idiosyncratic speech rates. One hundred subjects (50 males and 50 females) read the Farm Script passage at both habitual and maximum rates. FAST and SLOW subgroups of subjects were selected for both genders based on their overall speaking rates. The articulation rate data derived from 30 selected subjects (SLOW and FAST) revealed the following findings: (a) a significant linear regression function existed between the habitual and maximum rates, (b) significantly different maximum rates were found for the SLOW and the FAST groups, (c) roughly equivalent relative changes from habitual to maximum rate for both SLOW and FAST groups. No significant gender differences were found across different speech tasks and measures of speech rates. The weight of the evidence seems to suggest that neuromuscular constraints play a role in the determination of an individual's habitual speaking rate. Nevertheless, the study did not suggest that either neuromuscular hypotheses or sociolinguistic hypotheses alone can account for the control of individuals' speaking rates due to the unusual ability demonstrated by a few subjects in the SLOW group, to speak at very fast maximum rates. KEY WORDS: speaking rate, neuromuscular constraints, sociolinguistic considerations.

It has been hypothesized that typical speech movements do not involve large muscular forces and that normal speakers use less than 20% of the maximum orofacial muscle contractile forces that are available (e.g., Amerman, 1993; Barlow & Abbs, 1984; Barlow & Netsell, 1986; DePaul & Brooks, 1993). However, no direct evidence for this hypothesis has been provided. This study investigated the percentage of maximum interlabial contact pressures (force per unit area) typically used during speech production. The primary conclusion of this study is that normal speakers typically use less than 20% of the available interlabial contact pressure, whether or not the jaw contributes to bilabial closure. Production of the phone [p] at conversational rate and intensity generated an average of 10.56% of maximum available interlabial pressure (MILP) when jaw movement was not restricted and 14.62% when jaw movement was eliminated. KEY WORDS: interlabial contact pressure, bilabial closure, speech production

Arousal has become a central variable within much of communication research from deception to emotional communication. Specifically, several communication theories attempting to explain how one interactant's unexpected involvement changes affect another's posit arousal as a central variable directly or indirectly influencing the behavioral changes. Similar to these theories, which place emphasis on expectancies (anticipatory sets concerning typical interaction behaviors), psychophysiology literature posits that neuronal models (similar to expectancies) exist for consistently presented patterns and that mismatched stimuli cause an orienting response. This two-part study explores the applicability of the 'orienting response' to these interpersonal communication theories explaining violations of expectancies. In study one, four levels of involvement changes (very high, high, low, and very low) were manipulated to examine the physiological manifestation of arousal through heart rate, skin temperature, and pulse volume changes - measured every 5 seconds. All involvement changes were followed by arousal changes in the opposite directions of orienting responses - increases in heart rate, skin temperature, and pulse volume. Because the physiological measurement may have been too tonic, a second study was completed. In study two, the two levels of involvement that were the most arousing (very high and very low) were manipulated, and heart rate, skin temperature, and pulse volume were measured every .5 seconds. The results of the second investigation indicate that the orientation response did manifest itself in significant decreases in heart rate and increases followed by decreases in pulse volume.

Correlations of EMG activity among paired sites surrounding the lips were examined as a measure of muscle coupling during oral movements. Twenty-two young women (M = 22 years old) and 22 older women (M = 75 years old) performed lip protrusion, chewing, conversational speech, and reading aloud tasks. Surface EMG was recorded from the right and left sides of both the upper and lower lips during 20 s of task performance. Signals from each site, representing the sum of activity from muscle fibers present in the underlying tissue, were correlated with signals from every other site. Positive correlations were pervasive, but the range of values extended from .96 to -.19. Correlation values tended to be high across the upper lip and across the lower lip, regardless of the task. Other sites (right side, left side, and diagonal pairs) were also highly correlated for the protrusion and chewing tasks, but were less highly correlated for the speech tasks. Younger women showed significantly lower correlation values for speech tasks than older women. Results imply an increase in muscle coupling for speech as an effect of the aging process, perhaps reflecting a reduction in flexibility of fine oral motor control. Limits of the correlation technique and issues concerning speech production ability in old age are discussed. KEY WORDS: aging, electromyography, lip, oral motor control, perioral

This study investigates the extent to which the use of a face mask conveys linguopalatal contact changes during speech production. Electropalatographic data from five Catalan speakers were collected for different consonants, i.e., the alveolar stop [n], the alveolopalatal stop [n] and the palatal approximant [j], in the sequences [iCi] and [aCe]. Results for [n] indicate more closure retraction in the mask versus nonmask condition occurring presumably when the mask is pressed forcefully against the face in front of the mouth. The use of the mask for [n] and [j] causes an increase in dorsopalatal contact, which reflects most likely a strategy of articulatory and/or perceptual compensation.

Spectra of vowels were analyzed to determine whether differences exist between the spectral slope of vowels produced by tracheoesophageal (TE) speakers and normal speakers and, if so, to quantify such differences. The linear predictive autocorrelation method was used to calculate smoothed spectra and the spectra were normalized with respect to a low frequency component. Comparisons between normalized spectral energy within a selected high frequency range revealed that energy within this frequency range for vowels produced by TE speakers was significantly higher than that produced by normal speakers. A least-square distance matching procedure was used to quantify speaker group differences in the spectral slope of vowels. Average spectra of vowels produced by the normal speakers could be matched to average spectra of vowels produced by the TE speakers by decreasing the spectral slope of their vowels by 2-3 dB/octave.

The following questions are addressed concerning how a theory of lexical access can be realized in the brain: (1) Can a brainlike device function without inhibitory mechanisms? (2) Where in the brain can one expect to find processes underlying access to word semantics, syntactic word properties, phonological word forms, and their phonetic gestures? (3) If large neuron ensembles are the basis of such processes, how can one expect these populations to be connected? (4) In particular, how could one-way, reciprocal, and numbered connections be realized? and, (5) How can a neuroscientific approach for multiple access to the same word in the course of the production of a sentence?

Speaking is a communication task that requires the transmission of intelligible signals from a speaker to a listener. At the same time, speaking is also a skilled, complex, and rapid [...], This study tests the hypothesis that the relative timing, or coarticulation, of articulatory movements at VC and CV boundaries is influenced by both the listener's requirement for clarity and the speaker's strategy to economize effort. Movement and acoustic data were collected from 7 subjects who spoke in three conditions: normal, clear, and fast. It was predicted that fast speech would show more coarticulation and clear speech would show less coarticulation than normal speech. The speech materials were designed to investigate coarticulation in the movements of the upper lip and tongue. They consisted of repetitions of [i[C.sub.n]u] utterances embedded in carrier phrases, where the number of consonants, n, ranged from 1 to 3. Analyses focused on kinematic measures and the amount of coarticulation (overlap) of the /i-u/ transition movement with the acoustic interval of the /i/. The consonant-string duration was longest in the clear speaking condition and shortest in the fast condition. Compared to the normal condition, peak velocities were higher in the fast and clear speaking conditions, indicating increased effort. The influences of speaking condition on coarticulation and on the formants of the /i/ were small. Thus, even though there was evidence of increased effort in the clear and fast conditions, the hypothesized effects of a trade-off between clarity and economy of effort were minimally evident in formant values for /i/ and measures of coarticulation. KEY WORDS: coarticulation, speaking rate, clarity, speech motor control, articulatory measurement

During speaking, the breathing apparatus generates pressure to drive the larynx and upper airway structures to create the sounds of speech, while at the same time serving to meet gas [...], This study was conducted to explore the influence of speaking on ventilation. Twenty healthy young men were studied during periods of quiet breathing and prolonged speaking using noninvasive methods to measure chest wall surface motions and expired gas composition. Results indicated that all subjects ventilated more during speaking than during quiet breathing, usually by augmenting both tidal volume and breathing frequency. Ventilation did not change across repeated speaking trials. Quiet breathing was altered from its usual behavior following speaking, often for several minutes. Speaking-related increases in ventilation were found to be strongly correlated with lung volume expenditures per syllable. These findings have clinical implications for the respiratory care practitioner and the speech-language pathologist. KEY WORDS: hyperventilation, end-tidal [Pco.sub.2], breathing, respiratory kinematics, magnetometers

Psychology professor Uri Hasson discusses findings that the brain waves of a speaker and a listener become similar as the listener's comprehension increases.

(1) Reaction time (RT) studies give only a partial picture of language processing, hence it may be risky to use the output of the computational model to inspire neurophysiological investigations instead of seeking further neurophysiological data to adjust the RT based theory. (2) There is neurophysiological evidence for differences in the cortical representation of different word categories; this could be integrated into a future version of the Levelt model. (3) EEG/MEG coherence analysis allows the monitoring of synchronous electrical activity in large groups of neurons in the cortex; this is especially interesting for activation based network models.