198,668 research outputs found
On the Parametrization of Clapping
No full textvan Welbergen H, Ruttkay Z. On the Parametrization of Clapping. In: Sales Dias M, Gibet S, Wanderley MM, Bastos R, eds. Gesture-Based Human-Computer Interaction and Simulation. Lecture Notes in Computer Science. Vol 5085. Berlin, Heidelberg: Springer Berlin Heidelberg; 2009: 36-47
Ameroglossum alatum E. M. Almeida, A. M. Wanderley & L. P. Felix 2021, sp. nov.
No full textAmeroglossum alatum E.M.Almeida, A.M.Wanderley & L.P.Felix sp. nov. urn:lsid:ipni.org:names:77216325-1 Figs 2A, 3a–e Diagnosis A species morphologically similar to A. manoelfelixii because it has glabrous to glabrescent, lustrous vegetative parts and inflorescences. However, A. alatum sp. nov. differs from this and other species of Ameroglossum, by having conspicuous membranous wings on the stem extending to the peduncle of the inflorescence and the pedicel (vs not or sparsely winged). Because of its green stems and leaves, A. alatum sp. nov. may also appear similar to A. bicolor sp. nov., although it differs by having its inflorescence in a simple dichasium (vs compound dichasium), winged peduncles and pedicels (vs partially winged) and the sepals not overlapping (vs sepals overlapping). Etymology The name is derived from the Latin adjective ʻ alatus ʼ, ʻwingedʼ, referring to the conspicuous wings on the branches, peduncles and pedicels. Material examined Type BRAZIL – Alagoas • Maravilha; 09°14ʹ39ʺ S, 37°19ʹ33ʺ W; 792 m a.s.l.; 21 Aug. 2012; E.M. Almeida & A.M. Wanderley 461; holotype: EAN!; isotype: K!. Description Saxicolous chamaephyte up to 80 cm, with secondary branching in the medial portion. Young branches greenish to slightly purplish, lustrous, quadrangular, conspicuously winged, glabrous; brownish when mature, slightly inclined, subquadrangular. Leaves opposite, decussate; leaf blade 3.5–6.0 × 1.5–2.5 cm, green with purplish margins, lustrous, elliptic to narrowly elliptic, slightly bullate; adaxial side glabrous; abaxial side with venation occasionally purplish, glabrescent with papillose trichomes, rarely aciculate; apex acute, rarely slightly caudate, reflexed; margin flat, occasionally revolute, ciliate. Inflorescence a simple dichasium. Peduncle purplish, frequently bifacial, subcylindrical, conspicuously winged, glabrescent, with papillose trichomes; primary peduncle 0.60–1.70 × 0.10–0.12 cm, secondary peduncle 0.20–0.80 × 0.06–0.07 cm. Pedicel 0.60–1.40 × 0.09–0.13 cm, greenish, frequently bifacial, glabrescent, with papillose trichomes; dorsal side conspicuously winged, ventral side with base slightly winged. Bracts 0.25–0.40 × 0.06 cm, slightly purplish, glabrescent, with papillose trichomes, margin glabrous. Calyx greenish, occasionally with reddish apex, abaxial side glabrous, adaxial side densely covered by papillose trichomes, margin glabrous; sepals lanceolate, dorsal ones 1.10–1.20 × 0.30–0.35 cm; lateral ones ca 1.0 × 0.2 cm; ventral ones ca 1.0 × 0.3 cm. Corolla 4.0– 4.5 cm long, orangish, externally pubescent, with papillose trichomes and/or glandular, internally glabrous; tube 2.8–3.3 cm long; upper lip 1.2–1.3 × 0.6 cm, slightly bilobate; lower lip 1.0–1.2 × 0.5 cm, inner perianth with filiform trichomes, white, lobes revolute, median lobe ca 0.10 × 0.13 cm. Stamens included, adnate to the middle of the corolla tube; filaments violet, ca 2.0 cm long; capsule ca 0.1 cm diam.; staminodium ca 0.6 cm long, adnate to the middle of the corolla tube, glabrous. Ovary 0.6–0.7 × 0.3 cm; style ca 4.6 cm long, exserted, glabrous. Capsule 1.5–1.7 × 0.7–0.9 cm, green. Seeds 0.10 × 0.05 cm. Distribution Currently known only from a single population on a granite outcrop near the city of Maravilha, in the Sertão Alagoano mesoregion, Alagoas State, Brazil. Elevation ca 790 m. Ecology As for the other taxa of Ameroglossum, A. alatum sp. nov. is restricted to granite outcrops, where it is probably pollinated by hummingbirds. Flowering and fruiting were recorded in August. Population and threats The population is composed of approximately 20 adult individuals, restricted to an area of approximately 3000 m ² on one of the tops of this granite outcrop. The small population demonstrates elevated homozygosity, suggesting a low genetic diversity, probably caused by a founder and/or a genetic bottleneck effect (Wanderley et al. 2018).Published as part of Almeida, Erton M., Christenhusz, Maarten J. M., Wanderley, Artur Maia, Cordeiro, Joel Maciel P., Melo, José Iranildo Miranda De, Batista, Fabiane Rabelo Da Costa & Felix, Leonardo P., 2021, An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species, pp. 1-25 in European Journal of Taxonomy 746 on pages 6-7, DOI: 10.5852/ejt.2021.746.1313, http://zenodo.org/record/469584
Ameroglossum fulniorum E. M. Almeida, A. M. Wanderley & L. P. Felix 2021, sp. nov.
No full textAmeroglossum fulniorum E.M.Almeida, A.M.Wanderley & L.P.Felix sp. nov. urn:lsid:ipni.org:names:77216328-1 Figs 2D, 4d–g Diagnosis This species is similar to A. manoelfelixii in having lustrous, purple-tinged vegetative parts and scarlet flowers, but it differs in having inflorescences in simple dichasia (vs compound dichasia), peduncle winged (vs peduncle not winged) and white trichomes on the lower lip of the corolla (vs trichomes violet). It differs from the other species of Ameroglossum by the deep vinaceous colour of its vegetative parts. Etymology The specific epithet is dedicated to the Fulni-ô Amerindians whose territories are located in the Serra do Comunaty where the type material was collected. Members of the Fulni-ô ethnic group have conserved many of their traditional cultural values, being one of the few indigenous groups in north-eastern Brazil that have conserved their original language, Yaathe or Ia-tê, from the Macro-Jê linguistic branch. Material examined Type BRAZIL – Pernambuco • Águas Belas, Quilombo; 09°04ʹ11ʺ S, 37°00ʹ43ʺ W; 903 m a.s.l.; 21 Aug. 2012; E.M. Almeida & A.M. Wanderley 439; holotype: EAN!; isotype K!. Description Saxicolous chamaephyte up to 80 cm, occasionally with secondary branching along the stem. Young branches purplish, lustrous, quadrangular, not winged, glabrescent, trichomes aciculate; brownish when mature, slightly inclined to incumbent, subquadrangular. Leaves opposite, decussate; leaf blade 6.0– 14.5 × 1.2–3.9 cm, purplish when young, later greenish, lustrous, narrowly elliptic to elliptic, rarely narrowly trullate, slightly bullate; adaxial side glabrous; abaxial side glabrescent with papillose trichomes, principally the youngest leaves, rarely with recurved trichomes; apex sharply acuminate, flat to reflexed; margin flat to revolute, ciliate. Inflorescences in simple dichasia. Peduncle purplish, subcylindrical, winged, glabrescent, with papillose trichomes; primary peduncle 0.70–1.80 × 0.10–0.14 cm, secondary peduncle 0.3–0.8 × 0.1 cm. Pedicel 0.50–1.20 × 0.10–0.15 cm, purplish, glabrescent, with papillose trichomes, ventral side without wings. Bracts 0.10–0.30 × 0.05–0.08 cm, purplish, glabrescent, with papillose trichomes, margin glabrous. Calyx purplish, abaxial side glabrescent, with trichomes recurved and papillose, adaxial side densely covered by papillose trichomes, margin glabrous; sepals lanceolate, dorsal sepal 1.2–1.7 × 0.3 cm, lateral ones 1.0–1.3 × 0.2 cm, ventral ones 1.0–1.2 × 0.2–0.3 cm. Corolla 5.0– 5.6 cm long, scarlet, externally glabrescent, with trichomes glandular and papillose, internally glabrous; tube 4.0– 4.2 cm long; upper lip 1.3–1.8 × 0.9–1.1 cm; lower lip 1.3–1.5 × 0.4–0.5 cm, inner perianth with trichomes filiform, white; lobes revolute, median lobe 0.2–0.3 × 0.1 cm. Stamens included, adnate to the median third of the corolla tube; filaments violet, dorsal ones 2.00–2.70 × 0.08 cm, ventral ones 2.20–2.60 × 0.08 cm; thecae 0.15 cm diam.; staminodium 0.2–0.5 cm, adnate to the proximal third of the corolla tube, glabrous. Ovary 0.60–0.80 × 0.24–0.30 cm; style 4.2–5.1 cm, occasionally exserted, glabrous. Capsule 1.5–2.1 × 0.7–1.0 cm, purplish. Seeds 0.10 × 0.04 cm. Distribution Only two populations of A. fulniorum sp. nov. are known growing near Águas Belas, Serra do Comunaty, in the Agreste mesoregion of Pernambuco State, Brazil. Elevation ca 900 m. Ecology Like other species of Ameroglossum, the occurrence of A. fulniorum sp. nov. is restricted to granite outcrops. Flowering and fruiting in August. Population and threats Only two populations of A. fulniorum sp. nov. are currently known, which together comprise approximately 40 widely spaced adult individuals. Due to the isolation of those populations and their restricted distributions, together with environmental pressure from trampling by domestic animals and the occasional passage of wildfires, this species is highly threatened.Published as part of Almeida, Erton M., Christenhusz, Maarten J. M., Wanderley, Artur Maia, Cordeiro, Joel Maciel P., Melo, José Iranildo Miranda De, Batista, Fabiane Rabelo Da Costa & Felix, Leonardo P., 2021, An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species, pp. 1-25 in European Journal of Taxonomy 746 on pages 13-14, DOI: 10.5852/ejt.2021.746.1313, http://zenodo.org/record/469584
Ameroglossum bicolor E. M. Almeida, A. M. Wanderley & L. P. Felix 2021, sp. nov.
No full text<p> <i>Ameroglossum bicolor</i> E.M.Almeida, A.M.Wanderley & L.P.Felix sp. nov.</p> <p>urn:lsid:ipni.org:names:77216327-1</p> <p>Figs 2C, 4a–c</p> Diagnosis <p> This species is morphologically similar to <i>A. alatum</i> sp. nov. in having lustrous branches and leaves, winged pedicels, and white trichomes on the lower lip of the corolla tube. It differs in having green or slightly purplish vegetative portions (vs completely green), wings not evident (vs strongly winged), inflorescence usually a compound dichasium (vs simple dichasium) and the dorsal sepal partially covering the lateral sepals (vs the sepals not overlapping).</p> Etymology <p> The specific epithet is the Latin adjective ʻ <i>bicolor</i> ʼ, ʻtwo-coloredʼ, referring to the vegetative variation observed in its populations. Among the four populations described here, it was possible to encounter green or purplish, almost wine-coloured, plants in the same population, a characteristic only observed in this species.</p> Material examined <p> <b>Type</b> BRAZIL <b>– Pernambuco</b> • Agrestina, Lajedo do Boi; 08°28ʹ08ʺ S, 35°55ʹ06ʺ W; 428 m a.s.l.; 21 Aug. 2014; <i>E.M. Almeida, E.M. Almeida & M. Fernandes 1229</i>; holotype: EAN!; isotypes: IPA!, K!, RB!, UFP!.</p> <p> <b>Paratypes</b> BRAZIL <b>– Pernambuco</b> • Caruaru, Pedra do Guariba; 29 Jul. 2005; <i>Y. Melo, M. Alves, P. Santos, A. Araújo, J. Rodrigues, J. Gomes, S. Martins & B. Maciel 43</i>; UFP[41,995]! • Pedra do Guariba; 08°22ʹ55ʺ S, 35°50ʹ38ʺ W; 685 m a.s.l.; 22 Jul. 2007; <i>M. Sobral-Leite, B. Maciel & P. Gomes 359</i>; UFP[46,440]! • “ Pedra do Guariba ”; 08°22ʹ55ʺ S, 35°50ʹ38ʺ W; 685 m a.s.l.; 22 Jul. 2007; <i>M. Sobral- Leite, B. Maciel & P. Gomes 382</i>; IPA[80,821]! • Divisa entre os municípios de Caruaru e Agrestina, Serra da Quitéria, Sítio flexeira, “ Pedra do Urubu ”; 08°23ʹ43ʺ S, 35°59ʹ33ʺ W; 540 m a.s.l.; 24 Jul. 2009; <i>M. Sobral-Leite, B. Maciel & P. Gomes 916</i>; UFP[57,163]! • “ Pedra do Urubu ”; 08°23ʹ43ʺ S, 35°59ʹ33ʺ W; 540 m a.s.l.; 24 Jul. 2009; <i>M. Sobral-Leite, B. Maciel & P. Gomes 916</i>; IPA[83,689]! • Agrestina, Distrito de Terra Vermelha, Pedra do Urubu; ca 700 m a.s.l.; 2 Aug. 2009; <i>A.M.Wanderley 1</i>; UFP[58,598]!• Bonito; 08°29ʹ10ʺ S, 35°43ʹ42ʺ W; 446 m a.s.l.; 3 Jul. 2015; <i>L.P. Felix, E.M. Almeida & J.P. Araújo 15758</i>; EAN[22,895]! • Quipapá; 12 Mar. 1958; <i>Dárdano de Andrade-Lima 50-600</i>; IPA!.</p> Description <p>Saxicolous chamaephyte up to 80 cm, with frequent secondary branching along the stem.Young branches purplish or greenish, lustrous, quadrangular, not winged, glabrescent, trichomes aciculate and papillose, principally near the insertion of the young leaves; branches brownish when mature, slightly inclined to incumbent, subquadrangular. Leaves opposite, decussate; leaf blade 3.4–9.1 × 1.0– 3.8 cm, green and tinged with purple when young, bullate, later green to greenish, smooth, lustrous, elliptic, rarely narrowly elliptic; adaxial side glabrous; abaxial side glabrescent, trichomes recurved and/or papillose; apex acute, rarely acuminate, flat; margin flat, occasionally revolute, ciliate. Inflorescence a compound dichasium, occasionally simple. Peduncle green or slightly purplish, subcylindrical, winged to the median third, glabrescent, with papillose trichomes; primary peduncle 0.9–3.0 × 0.1–0.2 cm, secondary peduncle 0.45–1.40 × 0.06–0.15 cm, tertiary peduncle 0.36–0.80 × 0.06–0.09 cm. Pedicel 0.6–1.3 × 0.06–0.10 cm, green or tinged purple, ventral portion not winged, glabrous. Bracts 0.20–0.60 × 0.05– 0.10 cm, green or tinged purple, glabrescent, with papillose trichomes, margin glabrous. Calyx greenish to slightly purplish, abaxial side glabrescent, with trichomes papillose, rarely aciculate, adaxial side densely covered by papillose trichomes, margin glabrous; dorsal sepal 1.5–2.1 × 0.5–0.7 cm, broadly lanceolate to ovate, partially covering the lateral sepals; lateral sepals 1.2–1.6 × 0.2–0.3 cm, lanceolate; ventral ones 1.5–1.3 × 0.3–0.4 cm, lanceolate. Corolla 4.4–5.2 cm long, yellow-orange or scarlet, externally pubescent, with trichomes glandular and/or papillose, internally glabrous; tube 3.2–4.0 cm long; upper lip 1.2–1.4 × 0.8–0.9 cm, slightly bilobate; lower lip 0.9–1.3 × 0.4–0.5 cm, inner perianth with trichomes filiform, white; lobes revolute, median lobe 0.13–0.15 × 0.06–0.07 cm. Ventral pair of stamens sometimes exserted, adnate until the median third of the corolla tube; filaments violet, dorsal ones 1.70–2.40 × 0.08 cm, ventral ones 2.00–2.50 × 0.08 cm; thecae 0.15 cm diam.; staminodium 0.5– 1.1 cm, adnate until the middle third of the corolla tube, glabrous. Ovary 0.5 × 0.2 cm; style 4.0– 5.5 cm, sometimes exserted, glabrous. Capsule 1.5–1.7 × 0.7–1.0 cm, green or tinged purple. Seeds 0.10 × 0.04 cm.</p> Distribution <p> Three populations of <i>Ameroglossum bicolor</i> sp. nov. are known from granite outcrops in the municipalities of Agrestina, Bonito and Caruaru in the Agreste mesoregion of Pernambuco State, Brazil. It grows at elevations between 425 and 700 m.</p> Ecology <p> <i>Ameroglossum bicolor</i> sp. nov. has been collected in flower from May to October, with high inter- and intrapopulational synchrony (Wanderley <i>et al.</i> 2014a).</p> Population and threats <p> A population of 70 adult individuals is known from a granite outcrop known as Lajedo do Boi in the municipality of Agrestina; at least 40 individuals are known from the Pedra do Guariba granite outcrop in the municipality of Caruaru (Wanderley <i>et al.</i> 2014a); four other individuals were also located in Caruaru at Serra da Quitéria; 50 adult individuals are estimated to compose the population in the municipality of Bonito, all in Pernambuco State, Brazil. Main threats to these populations are habitat destruction through trampling by domestic animals, burning and other agricultural activity.</p>Published as part of <i>Almeida, Erton M., Christenhusz, Maarten J. M., Wanderley, Artur Maia, Cordeiro, Joel Maciel P., Melo, José Iranildo Miranda De, Batista, Fabiane Rabelo Da Costa & Felix, Leonardo P., 2021, An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species, pp. 1-25 in European Journal of Taxonomy 746</i> on pages 11-13, DOI: 10.5852/ejt.2021.746.1313, <a href="http://zenodo.org/record/4695849">http://zenodo.org/record/4695849</a>
Evaluation of Input Devices for Musical Expression: Borrowing Tools from HCI
No full textThis article addresses the evaluation of input devices for musical expression. The comparison and evaluation of input devices is a well-developed topic in Human-Computer Interaction (HCI) research area, a multidisciplinary field that presents several similarities (and many differences) to computer music. We here introduce an overview of various developments from HCI and discuss possible applications of this knowledge to the musical context. Results from previous experiments are commented and a set of musical tasks is suggested and discussed as a first step toward the evaluation of input devices for musical expression
Ameroglossum intermedium E. M. Almeida, A. M. Wanderley & L. P. Felix 2021, sp. nov.
No full textAmeroglossum intermedium E.M.Almeida, A.M.Wanderley & L.P.Felix sp. nov. urn:lsid:ipni.org:names:77216330-1 Figs 2F, 5e–h Diagnosis Ameroglossum intermedium sp. nov. combines characters of both A. manoelfelixii and A. pernambucense. It can be distinguished from A. manoelfelixii by its puberulent branches and leaves (vs glabrousglabrescent leaves), with acicular trichomes recurved at the apex (vs papillose trichomes), and from A. pernambucense by its compound dichasial inflorescence (vs a simple dichasium) and the revolute lower lip (vs involute). Etymology The specific epithet is derived from the Latin adjectives ʻ inter ʼ, ʻbetweenʼ, and ʻ medius ʼ, ʻmiddleʼ, referring to the morphological characteristics of the new species that are intermediate between A. manoelfelixii and A. pernambucense. Material examined Type BRAZIL – Alagoas • Quebrangulo; 09°18′17″ S, 36°31′13″W; 502 m a.s.l.; 23Aug. 2012; E.M.Almeida & A.M. Wanderley 478; holotype: EAN!; isotypes: IMA!, IPA!, K!, RB!. Other material BRAZIL – Alagoas • Quebrangulo, estrada para Bom Retiro; 09°17ʹ56ʺ S, 36°30ʹ33ʺ W; 25 Aug. 2013; L.P. Felix & E.M. Almeida 14,339; EAN[19,860]!. Description Saxicolous chamaephyte up to 150 cm, frequently with secondary branching along the stem. Young branches green to slightly purplish, bifacial, dull, quadrangular or hexangular, often narrowly winged, pubescent, with recurved trichomes; brown cinereous when mature, slightly inclined to decumbent, subquadrangular. Leaves opposite, decussate, occasionally verticillate and then up to three leaves per node; leaf blade 5.1–14.0 × 1.4–3.9 cm, green, lustrous, elliptic to narrowly elliptic, rarely trullate, bullate when young, later smooth; adaxial side glabrous, abaxial side pubescent, with recurved trichomes; apex acute, rarely acuminate, flat to reflexed; margin revolute when young, later flat, ciliate. Inflorescence a compound dichasium, occasionally simple. Peduncle green or tinged purple, subcylindrical, winged, pubescent, with recurved trichomes; primary peduncle 0.7–4.0 × 0.1–0.2 cm, secondary peduncle 0.30– 1.80 × 0.13–0.15 cm, tertiary peduncle 0.30–1.20 × 0.07–0.10 cm. Pedicel 0.6–2.5 × 0.1–0.2 cm, green to slightly purplish, pubescent, with recurved trichomes; ventral side winged up to the proximal third. Bracts 0.20–0.60 × 0.03–0.08 cm, green, abaxial side glabrous, adaxial side glabrescent with papillose trichomes, margin ciliate with recurved trichomes. Calyx green, abaxial side glabrescent, with recurved and/or papillose trichomes, adaxial side covered by papillose trichomes, margin ciliate with recurved trichomes; sepals lanceolate, dorsal one 1.2–1.5 × 0.3–0.5 cm, lateral ones 1.0–1.2 × 0.2 cm, ventral ones 0.8–1.1 × 0.2–0.3 cm. Corolla 4.5–5.6 cm long, orangish, with proximal third yellowish, external side pubescent, trichomes glandular, rarely recurved and/or papillose; tube 3.5–4.4 cm long; upper lip 1.2–1.8 × 0.6–0.8 cm, slightly bilobate; lower lip 1.1–1.4 × 0.35–0.50 cm, inner perianth with white filiform trichomes; lobes revolute, median lobe 0.1 × 0.2 cm. Stamens occasionally with the ventral pair exserted, adnate to the median third of the corolla tube; filaments violet, dorsal ones 1.6–2.6 × 0.8 cm, ventral ones 1.9–2.9 × 0.8 cm; thecae ca 0.2 cm diam.; staminodium 0.3–0.4 cm, adnate to the median third of the corolla tube, glabrous. Ovary 0.4–0.7 × 0.2–0.3 cm; style 3.6–5.6 cm, occasionally exserted. Capsule 1.2–1.6 × 0.6–0.8 cm, greenish. Seeds 0.10 × 0.05 cm. Distribution Only two populations of Ameroglossum intermedium sp. nov. are currently known, both in the municipality of Quebrangulo, Agreste mesoregion of Alagoas State. Elevation ca 500 m. Ecology This species occurs exclusively on granite outcrops. Flowering and fruiting recorded in August and like all other Ameroglossum species it is pollinated by hummingbirds. The surrounding vegetation was probably originally composed of deciduous forest, but this has now been replaced by natural pasture. Population and threats Only two rock outcrops separated by pasture in a single municipality in Alagoas State are known to harbour this species. Approximately 200 adult individuals can be found in the first population, whereas the other comprises approximately 30 individuals. The main threat to these populations are farming and grazing of the site by stray animals. Taxonomic notes Among the species of Ameroglossum with quadrangular stems, A. intermedium sp. nov. stands out by having reproductive and vegetative structures covered in trichomes, a characteristic otherwise typically observed in A. pernambucense. However, A. intermedium sp. nov. differs by having leaves that are principally opposite and decussate, inflorescences of compound dichasia and the revolute lower lip.Published as part of Almeida, Erton M., Christenhusz, Maarten J. M., Wanderley, Artur Maia, Cordeiro, Joel Maciel P., Melo, José Iranildo Miranda De, Batista, Fabiane Rabelo Da Costa & Felix, Leonardo P., 2021, An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species, pp. 1-25 in European Journal of Taxonomy 746 on pages 16-17, DOI: 10.5852/ejt.2021.746.1313, http://zenodo.org/record/469584
Input Devices for Musical Expression: Borrowing Tools from HCI
No full textThe paper draws a parallel between the research in human-computer interaction and the results in gestural control of electronic music performance
Integrating nonspatial, nontemporal multisensory information in action-based perception
No full textThe study of multisensory perception has traditionally emphasized the integration of temporal and spatial aspects of events in nonaction settings. We adopted an action-based paradigm to investigate the factors affecting how nonspatial and nontemporal multisensory information is integrated. On a trial, participants struck a virtual object with a constant velocity and received feedback on correctness. When a performance criterion was reached, feedback was eliminated, the properties of the stimulus were changed, and the effects on striking velocity and performance were measured.
In Experiment 1, we studied the effects of the congruence of multisensory information and of a participant's expertise in the task. We studied a unimodal or a multisensory audio-haptic display in which the haptic and sound hardness of the object were manipulated. In multisensory trials, the audio-haptic changes could be congruent (e.g., both increased in hardness) or incongruent. We recruited participants with different levels of expertise with the task: percussionists, nonpercussionist musicians and nonmusicians. Overall, striking velocity decreased with an increase in both haptic and sound hardness. The level of expertise influenced the effects of haptic, but not of sound, hardness, where only percussionists struck harder haptic objects faster. For all participants, striking velocity in the multisensory trials was most strongly affected by changes in haptic hardness. Further, the effects of hardness were much more similar across participants in the auditory than in the haptic modality. Multisensory congruence modulated the effects of sound but not haptic hardness: whereas in congruent trials the effects of audio hardness were the same as in the unimodal condition, audio hardness was behaviorally irrelevant when it varied in opposition to haptic hardness. Overall, performance did not improve from the unimodal to the multisensory context. Only for nonmusicians, performance was significantly better in the audio-only condition. In summary, the effects of the least relevant modality, audition, were more similar across individuals, were independent of expertise and were modulated by multisensory congruence. On the contrary, the effects of the primary modality, haptics, varied more across individuals, were influenced by expertise, and were independent of multisensory congruence.
In Experiment 2, we assessed the behavioral relevance of a visual property of the display. Nonmusicians were presented with either a visual or a visual-audio-haptic stimulus. We manipulated the speed of the visual striking object, and, in multisensory congruent trials, also the sound and haptic hardness. Participants wore a head mounted display. Striking velocity decreased for increasing haptic and sound hardness, and for decreasing speeds of the striking object. Future investigations will extend the results of Experiment 1 to visual-audio-haptic contexts
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