| 1. |
- Larsson, Matz, 1955-, et al.
(författare)
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Bipedal Steps in the Development of Rhythmic Behavior in Humans
- 2019
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Ingår i: Music & Science. - : Sage Publications. - 2059-2043. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- We contrast two related hypotheses of the evolution of dance: H1: Maternal bipedal walking influenced the fetal experience of sound and associated movement patterns; H2: The human transition to bipedal gait produced more isochronous/predictable locomotion sound resulting in early music-like behavior associated with the acoustic advantages conferred by moving bipedally in pace. The cadence of walking is around 120 beats per minute, similar to the tempo of dance and music. Human walking displays long-term constancies. Dyads often subconsciously synchronize steps. The major amplitude component of the step is a distinctly produced beat. Human locomotion influences, and interacts with, emotions, and passive listening to music activates brain motor areas. Across dance-genres the footwork is most often performed in time to the musical beat. Brain development is largely shaped by early sensory experience, with hearing developed from week 18 of gestation. Newborns reacts to sounds, melodies, and rhythmic poems to which they have been exposed in utero. If the sound and vibrations produced by footfalls of a walking mother are transmitted to the fetus in coordination with the cadence of the motion, a connection between isochronous sound and rhythmical movement may be developed. Rhythmical sounds of the human mother locomotion differ substantially from that of nonhuman primates, while the maternal heartbeat heard is likely to have a similar isochronous character across primates, suggesting a relatively more influential role of footfall in the development of rhythmic/musical abilities in humans. Associations of gait, music, and dance are numerous. The apparent absence of musical and rhythmic abilities in nonhuman primates, which display little bipedal locomotion, corroborates that bipedal gait may be linked to the development of rhythmic abilities in humans. Bipedal stimuli in utero may primarily boost the ontogenetic development. The acoustical advantage hypothesis proposes a mechanism in the phylogenetic development.
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| 2. |
- Larsson, Matz, 1955-
(författare)
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Did heart asymmetry play a role in the evolution of human handedness?
- 2017
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Ingår i: Journal of Cultural Cognitive Science. - Heidelberg, Germany : Springer. - 2520-100X .- 2520-1018. ; 1:2, s. 65-76
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Tidskriftsartikel (refereegranskat)abstract
- Almost 90% of humans are right handed, but why is unclear. It has been suggested that right handedness evolved in the context of escalating motor and cognitive demands related to tool use. Literature indicates that homicide may have been common in early hominins. Since, in combat with sharp implements, handedness may influence the relative level of exposure of left and right thorax, the hypothesis presented here is that thoracic anatomic asymmetry resulted in a survival advantage for right handed individuals. While fighting with sharp tools, a left hand unilateral grip will rotate the left hemi-thorax towards an opponent. The aims of this study were to quantify the degree of thoracic/cardiac asymmetry in humans and to estimate any difference in risk of injury from a sharp implement attack to the left and the right human thorax. CT-scans of 37 men showed a mean of 73% (SD 7%) of the heart volume to be situated in the left hemi-thorax. Nineteen physicians unaware of the hypothesis estimated the outcome of weapons penetrating the left and right thorax/abdomen at random points. The difference in estimated mortality for left and right thorax was significant, p\0.001 (Wilcoxon- signed-ranks-test for two related samples). These results suggest greater vulnerability of the left side of the body in combat, and, accordingly, an adaptive value of right-handedness. Thoracic asymmetry may have contributed to the development of right hand preference in humans.
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| 3. |
- Larsson, Matz, 1955-, et al.
(författare)
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Effects of sounds of locomotion on speech perception
- 2015
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Ingår i: Noise & Health. - : Medknow. - 1463-1741 .- 1998-4030. ; 17:77, s. 227-232
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Tidskriftsartikel (refereegranskat)abstract
- Human locomotion typically creates noise, a possible consequence of which is the masking of sound signals originating in the surroundings. When walking side by side, people often subconsciously synchronize their steps. The neurophysiological and evolutionary background of this behavior is unclear. The present study investigated the potential of sound created by walking to mask perception of speech and compared the masking produced by walking in step with that produced by unsynchronized walking. The masking sound (footsteps on gravel) and the target sound (speech) were presented through the same speaker to 15 normal-hearing subjects. The original recorded walking sound was modified to mimic the sound of two individuals walking in pace or walking out of synchrony. The participants were instructed to adjust the sound level of the target sound until they could just comprehend the speech signal ("just follow conversation" or JFC level) when presented simultaneously with synchronized or unsynchronized walking sound at 40 dBA, 50 dBA, 60 dBA, or 70 dBA. Synchronized walking sounds produced slightly less masking of speech than did unsynchronized sound. The median JFC threshold in the synchronized condition was 38.5 dBA, while the corresponding value for the unsynchronized condition was 41.2 dBA. Combined results at all sound pressure levels showed an improvement in the signal-to-noise ratio (SNR) for synchronized footsteps; the median difference was 2.7 dB and the mean difference was 1.2 dB [P < 0.001, repeated-measures analysis of variance (RM-ANOVA)]. The difference was significant for masker levels of 50 dBA and 60 dBA, but not for 40 dBA or 70 dBA. This study provides evidence that synchronized walking may reduce the masking potential of footsteps.
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| 4. |
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| 5. |
- Larsson, Matz, 1955-, et al.
(författare)
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Is the Capacity for Vocal Learning in Vertebrates Rooted in Fish Schooling Behavior?
- 2018
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Ingår i: Evolutionary biology. - : Springer. - 0071-3260 .- 1934-2845. ; 45:4, s. 359-373
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Forskningsöversikt (refereegranskat)abstract
- The capacity to learn and reproduce vocal sounds has evolved in phylogenetically distant tetrapod lineages. Vocal learners in all these lineages express similar neural circuitry and genetic factors when perceiving, processing, and reproducing vocalization, suggesting that brain pathways for vocal learning evolved within strong constraints from a common ancestor, potentially fish. We hypothesize that the auditory-motor circuits and genes involved in entrainment have their origins in fish schooling behavior and respiratory-motor coupling. In this acoustic advantages hypothesis, aural costs and benefits played a key role in shaping a wide variety of traits, which could readily be exapted for entrainment and vocal learning, including social grouping, group movement, and respiratory-motor coupling. Specifically, incidental sounds of locomotion and respiration (ISLR) may have reinforced synchronization by communicating important spatial and temporal information between school-members and extending windows of silence to improve situational awareness. This process would be mutually reinforcing. Neurons in the telencephalon, which were initially involved in linking ISLR with forelimbs, could have switched functions to serve vocal machinery (e.g. mouth, beak, tongue, larynx, syrinx). While previous vocal learning hypotheses invoke transmission of neurons from visual tasks (gestures) to the auditory channel, this hypothesis involves the auditory channel from the onset. Acoustic benefits of locomotor-respiratory coordination in fish may have selected for genetic factors and brain circuitry capable of synchronizing respiratory and limb movements, predisposing tetrapod lines to synchronized movement, vocalization, and vocal learning. We discuss how the capacity to entrain is manifest in fish, amphibians, birds, and mammals, and propose predictions to test our acoustic advantages hypothesis.
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| 6. |
- Larsson, Matz, 1955-
(författare)
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Samtal om tobak och kvalificerad rökavvänjning : sjukdomsförebyggande arbete i klinisk praxis
- 2017
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Ingår i: Socialmedicinsk Tidskrift. - Stockholm : Socialmedicinsk tidskrift. - 0037-833X. ; 94:2, s. 147-155
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Tidskriftsartikel (refereegranskat)abstract
- Smoking-cessation support and anti-tobacco-legislation have the potential to generate substantial health improvements, and reduce socioeconomic differences. It is exceedingly cost-effective. Current smoking is an important risk-indicator, influencing prognosis and treatment e.g. in patients with rheumatoid arthritis, heart disease, air-way diseases, and before elective surgery. Raising the question timely, empathy and professional support are crucial factors. It is essential to ask and document tobacco habits of all patients, including ex-smokers and never users. Behavioral counseling and pharmacotherapy, given in combination, significantly increase long-term abstinence rates. First-line pharmacotherapy to support quit attempts are nicotine replacement therapy, bupropion and varenicline. Health-care professionals are trusted and have unique possibilities to raise the tobacco issue in meetings with patients and in the society debate.
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| 7. |
- Larsson, Matz, 1955-, et al.
(författare)
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Tobaksberoende
- 2017
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Ingår i: Läkemedelsboken. - : Läkemedelsverket.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Larsson, Matz, 1955-
(författare)
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Tool-use-associated sound in the evolution of language
- 2015
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Ingår i: Animal Cognition. - : Springer Science and Business Media LLC. - 1435-9448 .- 1435-9456. ; 18:5, s. 993-1005
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Forskningsöversikt (refereegranskat)abstract
- Proponents of the motor theory of language evolution have primarily focused on the visual domain and communication through observation of movements. In the present paper, it is hypothesized that the production and perception of sound, particularly of incidental sound of locomotion (ISOL) and tool-use sound (TUS), also contributed. Human bipedalism resulted in rhythmic and more predictable ISOL. It has been proposed that this stimulated the evolution of musical abilities, auditory working memory, and abilities to produce complex vocalizations and to mimic natural sounds. Since the human brain proficiently extracts information about objects and events from the sounds they produce, TUS, and mimicry of TUS, might have achieved an iconic function. The prevalence of sound symbolism in many extant languages supports this idea. Self-produced TUS activates multimodal brain processing (motor neurons, hearing, proprioception, touch, vision), and TUS stimulates primate audiovisual mirror neurons, which is likely to stimulate the development of association chains. Tool use and auditory gestures involve motor processing of the forelimbs, which is associated with the evolution of vertebrate vocal communication. The production, perception, and mimicry of TUS may have resulted in a limited number of vocalizations or protowords that were associated with tool use. A new way to communicate about tools, especially when out of sight, would have had selective advantage. A gradual change in acoustic properties and/or meaning could have resulted in arbitrariness and an expanded repertoire of words. Humans have been increasingly exposed to TUS over millions of years, coinciding with the period during which spoken language evolved. ISOL and tool-use-related sound are worth further exploration.
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| 9. |
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| 10. |
- Lassmann-Klee, Paul, et al.
(författare)
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Differences of FENO in adult general populations of Nordic regions
- 2019
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 54:Suppl. 63
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Eventual differences of expiratory nitric oxide (FENO) levels in general populations of Nordic countries may reflect differences in eosinophilic inflammation at population level.Aim: To study the differences in FENO of Nordic regions and their epidemiological associations.Methods: From 1997 to 2003 we measured FENO (ppb) and conducted skin prick-tests for a random sample of adults (n=1498), aged 20-60 years from Finland (Helsinki), Sweden (Stockholm and Örebro) and Estonia (Narva and Saaremaa). We compared differences between regions by estimating odds ratios (OR) and 95% confidence intervals (CIs) for high FENO (>25 ppb) using logistic regression adjusted for gender, smoking and allergy. Finally, we estimated crude ORs and 95% CIs for high FENO and for asthma, rhinitis, current asthma symptoms and asthma medication.Results: The mean and standard deviation (SD) for FENO was 19(14) in Finland, 18(12) in Sweden and 16(15) in Estonia (p<0.001). Estonia had a lower mean FENO than other countries, with no differences between Finland and Sweden. Compared to Helsinki, the adjusted OR (95%CI) for high FENO was 0.42(0.21-0.81) in Stockholm, 0.65(0.43-0.98) in Örebro, 0.53(0.32-0.84) in Narva and 0.45(0.28-0.71) in Saaremaa. In Estonia, high FENO was associated with asthma, allergy, rhinitis, current asthma, and asthma medication; in Finland with rhinitis and use of short acting β-agonist; in Sweden with asthma and asthma medication. Smoking was associated with low FENO. Mean FENO in asthmatics was 24(19) in Finland, 20(12) in Sweden, and 43(49) in Estonia (p=0.07).Conclusions: We observed a higher mean FENO in Finland and Sweden compared to Estonia, and found no overall differences of FENO levels in asthmatics.
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