Perception Study Guide 3

Important Terms/Concepts

Movement perception: structure from motion 
Biological moition

            Distinguishing characteristics

            Human/infant sensitivity

            Brain areas involved

Visual guidance of locomotion.

Flow fields: global visual field changes in periphery 
            focus of flow 
            exponential retinal image size increase 
            amusement park rides 

Movement and eye movement 

Saccadic eye movements

Visual masking – forward and backward
            Eye movements and perceived motion

Corollary discharge hypothesis  
                    eyes paralyzed: yes/no 
                    voluntary eye movement; object remains stationary  
                    pushing on eyeball: yes/no 
                    eye following object: yes/no

Tracking movements

Information need to smoothing track objects

Success and limits of tracking movements 

Motion sensitive cells

How to design? Importance of delay lines

Role of MT lobe in extracting motion information

Apparent motion
        Why?: building an movement detector in the eye 
            horizonal inhibitory connections 
            direction specific detectors 
            fooling direction specific detectors (DS cells) 

Motion after affects 
        selective fatigue of interacting DS detectors 

Sound 
    Three requirements for sound 
        vibrating body 
        elastic medium 
        receptive organ

Physics of sound

            Sound pressure waves 
            point of maximum compression 
            point of maximum expansion (or rarefaction) 
            travelling wave 

Wavelength/frequency/CPS/Hz; correspondence to pitch

            Amplitude/dB/loudness

            Overtones/harmonics/sound quality/timbre 

Acoustics 
    echoes: reflected sounds 
        reverberation time 
        absorption vs. reflective properties of different surfaces 
            muddle sound vs. dead sound 
        impedance 
        speed of sound 

The ear 
    Three major parts 
        outer 
            pinna 
                gross sound localization 
            auditory canal 
                resonance frequency 
            tympanic membrane (ear drum) 
        middle ear 
            ossicles: mallus, incus, stapes 
                impedance matching device 
                surface area difference between tympanic membrane and oval window 
                conduction hearing loss 
                sensori-neural hearing loss 
        Inner ear 
            Cochlea 
                vestibular canal 
                cochlear duct 
                tympanic canal 
                round window 
                traveling wave within the cochlea 
                organ of corti 
                organ of corti hair cells 
                inner and outer hair cells 
                basilar membrane 
                Reissner's membrane 
                tectorial membrane 
                point of maximal displacement 
Theories of pitch perception 
    place theory 
        basilar membrane/keyboard analogy 
        note: amount of basilar membrane dedicated to various frequencies 
        problem of missing fundamental 
    frequency theory 
        firing of auditory nerve fibers 
        volley principle 
   duplex compromise 
        20-500 Hz frequency only 
        500-4000 Hz frequency and place 
        4000-20,000 Hz place only

Response of auditory nerve fibers

Locations of connections to IHC

Importance of variations in spontaneous firing rates

Frequency tuning of auditory nerve fibers

Auditory pathways beyond cochlea: from monaural to binaural processing 
Localizing sounds: two important cues 
    interaural amplitude differences: better for high frequencies 
    interaural time differences: better for low frequencies 

    Shadowing effect

Auditory cortex

            Tonotopic organization

            Frequency magnification

            Meaningful/categorical processing

Audiogram or Audibility Function

            Changes across ages/species

            Indicator of presbycusis

            Indicator of hearing deficits: sensory-neural and conduction

Otitis media

Otosclerosis

Hearing aids vs. cochlear implants

Auditory masking and the crucial band

Asymmetry of masking: two reasons why 
    action of basilar membrane to high and low frequencies 
    patterns of response for frequency tuned nerve fibers 
Loudness perception

Magnitude estimation 
            equal loudness contours 
Neural basis of loudness perception

Response of high vs. low spontaneous activity AN

Response of frequency tuned AN

Pitch perception

Fundamental frequency vs. harmonic overtones

Missing fundamental

Role of place and frequency theories in explaining missing fundamental

Sound localization

Interaural time and intensity cues

Cone of confusion

Duplex theory

Speech perception 
            Vocal anatomy; vocal folds, vocal tract (parts and functions)

            Descended larynx

 

Sound spectragram and neurogram

            Invariance problem with phonemic signals

            Un-segmented nature of signal

Speech and the brain

            Primary auditory cortex

            Wernicke’s and Broca’s areas

            Role of analogue areas in right hemisphere

            phonagnosia   

            auditory pathways from PAC

Motor information in identifying phonemic signal

            McGurk effect

            Context effects: phonemic restoration effect

Music perception

            Aspects of melody

                        Absolute vs. relative pitch intervals

                        pitch contour

Absolute  pitch

Brain areas associated with music perception

            RH anterior superior temporal

            Superior posterior temporal

            Left anterior temporal

            Limbic areas:  hippocampus, amygdala