Audition Day 8

1. AuditionDay 8 Music Cognition MUSC 495.02, NSCI 466, NSCI 710.03 Harry Howard Barbara Jazwinski Tulane University

2. Course administration • Spend provost's money Music Cognition - Jazwinski & Howard - Tulane University

3. Macrostructure of the brain The parts of the brain that you can see with the naked eye

4. Questions • What are the axes of the brain? • What are the lobes of the brain and what do they do? • What are the main connections between parts of the brain? • What are the three ways of referring to areas of the brain? Music Cognition - Jazwinski & Howard - Tulane University

5. Macrostructure overview • Three axes of the brain • Vertical • Horizontal • Longitudinal • Lateral • Connections • Naming conventions • Gyrii ~ sulcii • Brodmann’s areas • Stereotaxic (“Talairach”) coordinates Music Cognition - Jazwinski & Howard - Tulane University

6. Vertical axis: ventral/dorsal • Orientation of picture • Which way is forward? • to the left: cerebellum at back • Which hemisphere do we see? • medial side of right; left is cut away > sagittal view • Vertical axis • Dorsal is up, like dorsal fin (dorsal comes from Latin word for back) • Ventral is down (ventral comes from Latin word for belly) • Cortical vs. subcortical division • Cerebrum vs. cerebellum • Cerebral cortex (neocortex) vs. cerebellar cortex Music Cognition - Jazwinski & Howard - Tulane University

7. Longitudinal axis: anterior/posterior • Lobes • Sylvian fissure • Perisylvian area Music Cognition - Jazwinski & Howard - Tulane University

8. Longitudinal axis, functions Music Cognition - Jazwinski & Howard - Tulane University

9. Lateral axis: left/right Music Cognition - Jazwinski & Howard - Tulane University

10. Lateral axis • General • Which way is anterior? • Motor and sensory organs are crossed • Ipsilateral, contralateral • LH • Language • Math • Logic • RH • Spatial abilities • Face recognition • Visual imagery • Music Music Cognition - Jazwinski & Howard - Tulane University

11. Corpus callosum Arcuate fasciculus Connections Music Cognition - Jazwinski & Howard - Tulane University

12. Naming conventions How to refer to specific areas of the brain

13. Gyrii • AnG - angular gyrus • FP - frontal pole • IFG - inferior frontal gyrus • IOG - inferior occipital gyrus • ITG - inferior temporal gyrus • LOG - lateral occipital gyrus • MFG - middle frontal gyrus • MTG - middle temporal gyrus • OG - orbital gyrus • oper - pars opercularis (IFG) • orb - pars orbitalis (IFG) • tri - pars triangularis (IFG) • poCG - postcentral gyrus • preCG - precentral gyrus • SFG - superior frontal gyrus • SOG - superior occipital gyrus • SPL - superior parietal lobe • STG - superior temporal gyrus • SmG - supramarginal gyrus • TP - temporal pole Music Cognition - Jazwinski & Howard - Tulane University

14. Sulcii • cs - central sulcus (Rolandic) • hr - horizontal ramus • ifs - inferior frontal sulcus • ios - inferior occipital sulcus • ips - intraparietal sulcus • syl - lateral fissure (Sylvian) • los - lateral occipital sulcus • ls - lunate sulcus • pof - parieto-occipital fissure • pocs - postcentral sulcus • precs - precentral sulcus • sfs - superior frontal sulcus • tos - transoccipital sulcus • vr - vertical ramus Music Cognition - Jazwinski & Howard - Tulane University

15. Brodmann’s areas Music Cognition - Jazwinski & Howard - Tulane University

16. Brodmann’s areas, functions Music Cognition - Jazwinski & Howard - Tulane University

17. Frequency

18. Sound creation • Sound creation is created in most instruments, including the voice, by turbulent oscillation between phases in which air is compressed and phases in which it is rarefied. • The following figure depicts such a transition, in which increasing darkness symbolizes increasing compression of the airflow. • The heavy line represents the pressure of airflow as a single quantity between a minimum and a maximum. • as air is compressed, its pressure rises; • as air is rarefied, its pressure falls. • A single cycle of compression and rarefication is defined by the distance between two peaks, marked by dotted white lines. Music Cognition - Jazwinski & Howard - Tulane University

19. Graph of turbulent oscillation (of vocal air) Music Cognition - Jazwinski & Howard - Tulane University

20. Frequency • This cycling of airflow has a certain frequency • the frequency of a phenomenon refers to the number of units that occur during some fixed extent of measurement. • The basic unit of frequency, the hertz (Hz), is defined as one cycle per second. Music Cognition - Jazwinski & Howard - Tulane University

21. Two sine functions with different frequencies • A simple illustration can be found in the next diagram. It consists of the graphs of two sine functions. • The one marked with o’s, like beads on a necklace, completes an entire cycle in 0.628 s, which gives it a frequency of 1.59 Hz. • The other wave, marked with x’s so that it looks like barbed wire, completes two cycles in this period. Thus, its frequency is twice as much, 3.18 Hz. Music Cognition - Jazwinski & Howard - Tulane University

22. Graph of two sine functions with different frequencies Music Cognition - Jazwinski & Howard - Tulane University

23. Fundamental frequency • The pitchof an instrument corresponds to the lowest frequency of oscillation, called fundamentalfrequency or F0. • Fundamental frequency & gender • the fundamental frequency of a man’s voice averages 125 Hz, • the fundamental frequency of a woman’s voice averages 200 Hz • This 60% increase in the pitch of a woman’s voice can be accounted for entirely by the fact that a man’s vocal folds are on average 60% longer than a woman’s. Music Cognition - Jazwinski & Howard - Tulane University

24. The fundamental & higher frequencies • This brief introduction to frequency leads one to believe that an instrument vibrates at a single frequency, that of its fundamental frequency, much as the schematic string on the left side of the next diagram is shown vibrating at its fundamental frequency. Music Cognition - Jazwinski & Howard - Tulane University

25. Higher frequencies • However, this is but a idealization for the sake of simplification of a rather complex subject. • In reality, instruments vibrate at a variety of frequencies that are multiples of the fundamental. • The diagram depicts how this is possible – a string can vibrate at a frequency higher than its fundamental because smaller lengths of the string complete a cycle in a shorter period of time. • In the particular case of the central diagram, each half of the string completes a cycle in half the time. Music Cognition - Jazwinski & Howard - Tulane University

26. Superposition of frequencies • This figure displays the outcome of superimposing both frequencies on the string and the waveform. • The result is that a pulse of vibration created by the vocal folds projects an abundance of different frequencies in whole-number multiples of the fundamental. • If we could hear just this pulse, it would sound, as Loritz (1999:93) says, “more like a quick, dull thud than a ringing bell”. Music Cognition - Jazwinski & Howard - Tulane University

27. Audition

28. Overview of the auditory pathway Music Cognition - Jazwinski & Howard - Tulane University

29. Auditory transduction: the cochlea • The cochlea is filled with a watery liquid, which moves in response to vibrations coming from the middle ear via the oval window. • As the fluid moves, thousands of "hair cells" are set in motion, and convert that motion to electrical signals that are communicated via neurotransmitters to many thousands of nerve cells. • These primary auditory neurons transform the signals into electrical impulses known as action potentials, which travel along the auditory nerve to structures in the brainstem for further processing. Music Cognition - Jazwinski & Howard - Tulane University

30. Cross section of the cochlea • The basilar membrane within the cochlea is a stiff structural element that separates two liquid-filled tubes that run along the coil of the cochlea. • The tubes transduce the movement of air that causes the tympanic membrane and the ossicles to vibrate into movement of liquid and the basilar membrane. • This movement is conveyed to the organ of Corti, composed of hair cells attached to the basilar membrane and their stereocilia embedded in the tectorial membrane. • The movement of the basilar membrane compared to the tectorial membrane causes the sterocilia to bend. • They then depolarise and send impulses to the brain via the cochlear nerve. Music Cognition - Jazwinski & Howard - Tulane University

31. Frequency dispersion • The basilar membrane is a pseudo-resonant structure that, like the strings on an instrument, varies in width and stiffness, which causes sound input of a certain frequency to vibrate some locations of the membrane more than others and thus ‘maps’ the frequency domain that humans can hear. • High frequencies lead to maximum vibrations at the basal end of the cochlear coil (narrow, stiff membrane) • Low frequencies lead to maximum vibrations at the apical end of the cochlear coil (wide, more compliant membrane). Music Cognition - Jazwinski & Howard - Tulane University

32. The cochlea & basilar membrane Music Cognition - Jazwinski & Howard - Tulane University

33. More recent auditory pathway- note complexity Music Cognition - Jazwinski & Howard - Tulane University

34. Schematic auditory pathway Music Cognition - Jazwinski & Howard - Tulane University

35. Auditory regions of the brain A lateral view of the cerebral cortex that highlights the prominent neural regions for auditory perception. The temporal lobe is shaded and the numbers refer to the Brodmann areas of primary auditory cortex (area 41) and secondary auditory cortex (areas 22 and 42). The right hemisphere contains homologous regions. Music Cognition - Jazwinski & Howard - Tulane University

36. Auditory cortex Music Cognition - Jazwinski & Howard - Tulane University

37. Primary auditory cortex (A1) tonotopic map Music Cognition - Jazwinski & Howard - Tulane University

38. Absolute vs. relative pitch • Thus A1 represents absolute pitch • We do not know how relative pitch is represented Music Cognition - Jazwinski & Howard - Tulane University

39. Timbre • Different parts of a musical instrument vibrate • with different onsets (attack) • See Levitin’s discussion of Schaeffer’s perceptual experiments on onset (attack), pp. 53-4. • at different frequencies (steady state) • for different durations (flux or decay) Music Cognition - Jazwinski & Howard - Tulane University

40. The timbre of the human voice Supralaryngeal Laryngeal Respiratory Music Cognition - Jazwinski & Howard - Tulane University

41. Back to our regularly scheduled program

42. Ingredients of music cognition mostly receptive, mostly from Levitin Music Cognition - Jazwinski & Howard - Tulane University

43. Next Monday Go over other musical perceptual attributes §1-2 of Levitin