The role of right and left parietal lobes in the conceptual processing of numbers

Neuropsychological and functional imaging studies have associated the conceptual processing of numbers with bilateral parietal regions (including intraparietal sulcus). However, the processes driving these effects remain unclear because both left and right posterior parietal regions are activated by many other conceptual, perceptual, attention, and response-selection processes. To dissociate parietal activation that is number-selective from parietal activation related to other stimulus or response-selection processes, we used fMRI to compare numbers and object names during exactly the same conceptual and perceptual tasks while factoring out activations correlating with response times. We found that right parietal activation was higher for conceptual decisions on numbers relative to the same tasks on object names, even when response time effects were fully factored out. In contrast, left parietal activation for numbers was equally involved in conceptual processing of object names. We suggest that left parietal activation for numbers reflects a range of processes, including the retrieval of learnt facts that are also involved in conceptual decisions on object names. In contrast, number selectivity in right parietal cortex reflects processes that are more involved in conceptual decisions on numbers than object names. Our results generate a new set of hypotheses that have implications for the design of future behavioral and functional imaging studies of patients with left and right parietal damage

Neural overlap of L1 and L2 semantic representations across visual and auditory modalities : a decoding approach/

This study investigated whether brain activity in Dutch-French bilinguals during semantic access to concepts from one language could be used to predict neural activation during access to the same concepts from another language, in different language modalities/tasks. This was tested using multi-voxel pattern analysis (MVPA), within and across language comprehension (word listening and word reading) and production (picture naming). It was possible to identify the picture or word named, read or heard in one language (e.g. maan, meaning moon) based on the brain activity in a distributed bilateral brain network while, respectively, naming, reading or listening to the picture or word in the other language (e.g. lune). The brain regions identified differed across tasks. During picture naming, brain activation in the occipital and temporal regions allowed concepts to be predicted across languages. During word listening and word reading, across-language predictions were observed in the rolandic operculum and several motor-related areas (pre- and postcentral, the cerebellum). In addition, across-language predictions during reading were identified in regions typically associated with semantic processing (left inferior frontal, middle temporal cortex, right cerebellum and precuneus) and visual processing (inferior and middle occipital regions and calcarine sulcus). Furthermore, across modalities and languages, the left lingual gyrus showed semantic overlap across production and word reading. These findings support the idea of at least partially language- and modality-independent semantic neural representations

Impulse

Features:[Page 2-3] SDSU College of Engineering listens to industry needs[Page 3-4] Rosco owner helps SDSU stay tuned to industry needs[Page 4] Engineering Extension helps companies\u27 safety[Page 5] Motorgrader removes snow with a wing and a plow[Page 6-7] Task force studies how Engineering can boost economic development[Page 8-9] EROS/SDSU connection \u27heavenly\u27[Page 9] Program helps meet manufacturing needs[Page 10-11] Industries support, supply SDSU Ground Source Heat Pump Laboratory[Page 11] Ground Source Heat Pump Laboratory moves toward accreditation[Page 11] Remund takes over as director of Prairie Heat Pump Association[Page 12-13] Mechanical engineering programs assist regional businesses[Page 13] Internships, other collaborations benefit SDSU students, industry[Page 14] Students gain real-world experience working for Raven, Aerostar[Page 15] EERC does GIS projects for Aberdeen, Sioux Falls[Page 16] Mission to Planet Earth proposes ways to benefit Upper Midwest[Page 17] Welding program creates opportunities, helps industry[Page 17] Waste reduction now part of SDSU industrial programDepartments:Faculty:[Page 18] Professor returns to NASA[Page 18] Professor edits international journal[Page 19] Students important to new faculty members[Page 19] SDSU co-hosts Regional Ag Engineering ConferenceStudents:[Page 20] IBM speaker/SDSU student discuss communications in engineering[Page 20] SWE takes young women down \u27The Road Less Traveled\u27[Page 21] Space Grant students launch high-altitude balloon[Page 22] Nuclear aspect of Navy appeals to SDSU grads[Page 22] Student computer programmers winners at ACM contest site[Page 23] World Wide Web helps SDSU students[Page 23] Graduate engineering students receive $6,000 ISHM grants[Page 24] SDSU offers students VLSI Lab experience[Page 24] Software grant to help SDSU engineering studentsContributors:[Page 25] Scholarship established in memory of Brad Schultz[Page 26] Donation of Cummins Engine provides learning experience[Page 27] Hohbach to establish chair in engineering[Page 28] Herther family, friends establish scholarship[Page 28] Electrical Engineering Department receives equipment grant[Page 29] Large private donation enables update of electrical engineering labALUMNI[Page 30] Mittan improves airline auto-pilot compass[Page 31] Espeland has diverse, distinguished career[Page 33-40] College of Engineering donorsAlumni notes inside back coverhttps://openprairie.sdstate.edu/coe_impulse/1027/thumbnail.jp

Impulse

Features: [Page 2-4] Sports and engineering important to student-athletes[Page 5-9] Senior engineering design conference prepares students for the industry[Page 10] Students stir science excitement in second graders[Page 11] SDSU team introduces area students to engineeringDepartments:Student news:[Page 11] Conde native named outstanding sophomore[Page 12] Bridge building: athletic competition[Page 13] Students receive Space Grants[Page 13] Clean water priority of civil engineering student[Page 13] Engineering students tour two South Dakota industries[Page 14] ME student makes your name his business[Page 16] Clifton awarded space grad assistantship at SDSU[Page 16] Channeling through RDTNFFaculty news:[Page 17] Gritzner wins faculty summer research grant at EROS[Page 17] Math professor\u27s program helps South Dakota businesses[Page 18] Quality is part of industrial management program[Page 18] Galipeau chairs Society of Plastics Engineers session[Page 19] SS Lacertae: SDSU professor writes of \u27Cosmic Billiards\u27[Page 19] Electric Council names Knabacb Person of the Year[Page 20] Grant to enable study of advanced electronic ceramics materials[Page 21] SDSU professor named to prestigious NASA science team[Page 21] Professor, students investigate ferroelectric nylon[Page 22] Bergum edits international journal on Fibonacci numbers[Page 22] Friedrich named College of Engineering computer specialistCampus news:[Page 23] Top ENTRE business plans win awards[Page 24] IMPULSE magazines goes on-line[Page 25] EED. Inventors Congress successful due to student involvement[Page 26] SDSU participates in second annual Space Day[Page 26] Industrial program receives environmental award[Page 27] Manufacturing engineering technology major to start this fall[Page 27] Vocational technical degree programs to change at SDSU[Page 28] Students, industry benefit from construction management major[Page 28] SDSU lecture series gives overview of EROS Data CenterAlumni news:[Page 29] SDSU education rates high with engineering alumnus[Page 29] Welding classes help graduate get design job[Page 30] \u27Dynamic Dakotans\u27 make their mark in Detroit[Page 30] National engineering society president speaks at SDSU[Page 31] Two former Brookings men named SDSU Distinguished Engineershttps://openprairie.sdstate.edu/coe_impulse/1026/thumbnail.jp

A tutorial on group effective connectivity analysis, part 2: second level analysis with PEB

This tutorial provides a worked example of using Dynamic Causal Modelling (DCM) and Parametric Empirical Bayes (PEB) to characterise inter-subject variability in neural circuitry (effective connectivity). This involves specifying a hierarchical model with two or more levels. At the first level, state space models (DCMs) are used to infer the effective connectivity that best explains a subject's neuroimaging timeseries (e.g. fMRI, MEG, EEG). Subject-specific connectivity parameters are then taken to the group level, where they are modelled using a General Linear Model (GLM) that partitions between-subject variability into designed effects and additive random effects. The ensuing (Bayesian) hierarchical model conveys both the estimated connection strengths and their uncertainty (i.e., posterior covariance) from the subject to the group level; enabling hypotheses to be tested about the commonalities and differences across subjects. This approach can also finesse parameter estimation at the subject level, by using the group-level parameters as empirical priors. We walk through this approach in detail, using data from a published fMRI experiment that characterised individual differences in hemispheric lateralization in a semantic processing task. The preliminary subject specific DCM analysis is covered in detail in a companion paper. This tutorial is accompanied by the example dataset and step-by-step instructions to reproduce the analyses

Impulse

Features: [Page 2-4] College of Engineering impact felt throughout the state [Page 5] Welding binds SDSU with community, industry [Page 6] Engineering students create moving sign [Page 7] Galipeau devises new humidity sensor [Page 7] Alumnus heads engineering building project [Page 8] South Dakota’s space involvement highlighted at Space Day [Page 9] Grad students coordinate Space Grant Consortium balloon project [Page 10] Andrawis, Flippin spend summer researching at NASA [Page 11] Landscape architect wins summer faculty fellowship at EROS [Page 12-13] NASA funds undergraduate research assistantships [Page 14] Volga student assists ACE CampDepartments:Faculty:[Page 15] Engineering professor Ritchie Mikesell retires [Page 16-17] Knabach retires after nearly 40 years at SDSU [Page 18] Tiltrum honored for work as adviser [Page 19] Vandever recognized for service to Alpha Lambda Delta [Page 20] Rufer, Monnens step up at SDSU [Page 20] Durland retires after 40 years as extension ag engineer [Page 21] New civil engineering professor Reid knows concrete explosives [Page 21] Brown to serve on technical program committee for workshop [Page 21] Clarke begins new position with SDSU [Page 22] Dalsted studies cropland use intensity in Niger Students:[Page 23] Ag engineering students design new egg carton [Page 24-25] EED, South Dakota Inventors Congress [Page 25] Eberlein, Knabach honored as SDSU Distinguished Engineers [Page 26] Seniors present design projects at conference [Page 27] Sebert strives for success [Page 27] ASCE chapter wins certificate of commendation [Page 28] South African enjoys SDSU [Page 28] Schultz, Sikkink write outstanding research papers [Page 29] Regional electric companies support SDSU engineering students Alumni:[Page 30] Chen receives National Science Foundation fellowship [Page 31] SDSU graduates win Engineer of the Year [Page 31] Engineering alumni named SDSU Family of the Year [Page 32] Anderson contracts to clean up Arizona water Alumni notes inside back coverhttps://openprairie.sdstate.edu/coe_impulse/1028/thumbnail.jp

A Generative Model of Speech Production in Broca’s and Wernicke’s Areas

Speech production involves the generation of an auditory signal from the articulators and vocal tract. When the intended auditory signal does not match the produced sounds, subsequent articulatory commands can be adjusted to reduce the difference between the intended and produced sounds. This requires an internal model of the intended speech output that can be compared to the produced speech. The aim of this functional imaging study was to identify brain activation related to the internal model of speech production after activation related to vocalization, auditory feedback, and movement in the articulators had been controlled. There were four conditions: silent articulation of speech, non-speech mouth movements, finger tapping, and visual fixation. In the speech conditions, participants produced the mouth movements associated with the words “one” and “three.” We eliminated auditory feedback from the spoken output by instructing participants to articulate these words without producing any sound. The non-speech mouth movement conditions involved lip pursing and tongue protrusions to control for movement in the articulators. The main difference between our speech and non-speech mouth movement conditions is that prior experience producing speech sounds leads to the automatic and covert generation of auditory and phonological associations that may play a role in predicting auditory feedback. We found that, relative to non-speech mouth movements, silent speech activated Broca’s area in the left dorsal pars opercularis and Wernicke’s area in the left posterior superior temporal sulcus. We discuss these results in the context of a generative model of speech production and propose that Broca’s and Wernicke’s areas may be involved in predicting the speech output that follows articulation. These predictions could provide a mechanism by which rapid movement of the articulators is precisely matched to the intended speech outputs during future articulations

Where Bottom-up Meets Top-down: Neuronal Interactions during Perception and Imagery

Functional magnetic resonance imaging (fMRI) studies have identified category-selective regions in ventral occipito-temporal cortex that respond preferentially to faces and other objects. The extent to which these patterns of activation are modulated by bottom-up or top-down mechanisms is currently unknown. We combined fMRI and dynamic causal modelling to investigate neuronal interactions between occipito-temporal, parietal and frontal regions, during visual perception and visual imagery of faces, houses and chairs. Our results indicate that, during visual perception, category-selective patterns of activation in extrastriate cortex are mediated by content-sensitive forward connections from early visual areas. In contrast, during visual imagery, category-selective activation is mediated by content-sensitive backward connections from prefrontal cortex. Additionally, we report content-unrelated connectivity between parietal cortex and the category-selective regions, during both perception and imagery. Thus, our investigation revealed that neuronal interactions between occipito-temporal, parietal and frontal regions are task- and stimulus-dependent. Sensory representations of faces and objects are mediated by bottom-up mechanisms arising in early visual areas and top-down mechanisms arising in prefrontal cortex, during perception and imagery respectively. Additionally non-selective, top-down processes, originating in superior parietal areas, contribute to the generation of mental images, regardless of their content, and their maintenance in the ‘mind's eye

MODELING FISH LENGTH DISTRIBUTION USING A MIXTURE TECHNIQUE

In fisheries science, length and age are important aspects of fish life history. Length is a function of growth, which provides an integrated measure of the environmental and endogenous conditions, e.g. genetics, affecting individuals and populations. Length at age data can be used to assess quality and quantity of habitat, food availability, or the need for and influence of management activities. Statistical mixture techniques may be used as a means to effectively model fish length distribution. A three-component mixture model, based on normal variates, was employed to describe length distribution in mountain whitefish species. The resulting model provided parameter estimates with meaningful biological interpretations, which were in turn used for inferential and comparative purposes. The technique will be demonstrated with reference to seven years of bio-monitoring data collected from the Kootenai River in Northern Idaho prior to and post nutrient addition treatment