lecture 14 – sensory systems review how do we really sense … · 2015-02-21 · bio 354 -...
TRANSCRIPT
![Page 1: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/1.jpg)
1
Lecture 14 – Sensory systems reviewHow do we really sense things?
Raghav RajanBio 354 – Neurobiology 2
February 19th 2015
All lecture material from the following links unless otherwise mentioned:1. Research papers or other links mentioned on slide
![Page 2: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/2.jpg)
2
From earlier classes ...!!
● Vishnu
![Page 3: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/3.jpg)
BIO 354 - Neurobiology 2 3
General principles of sensory systems
● All sensory systems convey 4 basic types of information
– What is the stimulus (modality) – Different sensory systems
– Where is the stimulus (location) – Different subsets of neurons
– How strong is it (intensity) – Firing patterns (rate and timing)
– When did it come on, when did it go off (timing) – Firing patterns (rate and timing)
● The brain BUILDS a picture of the external world
● Constrained by the architecture and functioning of networks of neurons
● Understanding the basic anatomy and functioning is necessary for going further
![Page 4: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/4.jpg)
BIO 354 - Neurobiology 2 4
Studying perception
● Illusions
![Page 5: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/5.jpg)
BIO 354 - Neurobiology 2 5
Object perception - shadows
● Shadows imply a light source
● We assume there is only one light source
● Second figure perceived as bumps and depressions
http://www.ib.cnea.gov.ar/~redneu/2013/BOOKS/Principles%20of%20Neural%20Science%20-%20Kandel/gateway.ut.ovid.com/gw2/ovidweb.cgisidnjhkoalgmeho00dbookimagebookdb_7c_2fc~31.htm
![Page 6: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/6.jpg)
BIO 354 - Neurobiology 2 6
Studying perception
● Illusions
● Psychophysics
![Page 7: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/7.jpg)
BIO 354 - Neurobiology 2 7
Psychophysics
● Outer psychophysics – the relationship between physical stimulus and sensation
● Inner psychophysics – theoretical idea of the internal neuronal representation resulting in sensation – largely inferred from outer pscyhophysics
● Importantly, can be compared between humans and animals
http://www.uni-leipzig.de/~isp/isp/history/texts/PSYPHY-M.PDF
![Page 8: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/8.jpg)
BIO 354 - Neurobiology 2 8
Comparing vibration amplitude discrimination thresholds in humans and macaques
http://jn.physiology.org/content/jn/38/3/539
![Page 9: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/9.jpg)
BIO 354 - Neurobiology 2 9
Comparing vibration amplitude discrimination thresholds in humans and macaques
http://jn.physiology.org/content/jn/38/3/539
● Standard vibration – 30Hz and 102 μm amplitude
● Comparison stimuli – 30Hz and 61-143 μm amplitude
![Page 10: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/10.jpg)
BIO 354 - Neurobiology 2 10
Comparing vibration frequency discrimination thresholds in humans and macaques
http://jn.physiology.org/content/jn/38/3/539
● Standard vibration – 30Hz
● Comparison stimuli – 24 – 36 Hz
![Page 11: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/11.jpg)
11
What do we perceive, what do neurons perceive and how are the two related?
● Neurophysiology – relationship between neuronal activity and the stimulus
![Page 12: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/12.jpg)
12
Frequency discrimination of vibration stimuli (flutter – 5-50Hz) by macaque monkeys
● Monkeys learn to discriminate the frequency of two vibratory stimuli on their fingers
http://www.cns.nyu.edu/~david/courses/sm12/Readings/Romo_Salinas%20nrn2003.pdf
![Page 13: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/13.jpg)
13
Recording neuronal
activity during the task -
correlation● What aspect
of the neuron's response carries information about the stimulus
● About the behavior
● Firing rate?
● Firing pattern?
http://www.cns.nyu.edu/~david/courses/sm12/Readings/Romo_Salinas%20nrn2003.pdf
![Page 14: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/14.jpg)
14
● Caveats
Microstimulation can evoke perception of a
real stimulus
http://www.cns.nyu.edu/~david/courses/sm12/Readings/Romo_Salinas%20nrn2003.pdf
![Page 15: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/15.jpg)
15
Studying the relationship between neural activity and perception in humans – different spatiotemporal scales
● fMRI
● PET
●
http://www.bobblum.com/ESSAYS/NEUROPSYCH/BAM.html
![Page 16: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/16.jpg)
16
Studying the relationship between neural activity and perception in humans - Causation
● Damage due to injury
● TMS
● Caloric vestibular stimulation
●
![Page 17: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/17.jpg)
17
Looking at the role of two hemispheres in binocular rivalry
http://www.uq.edu.au/nuq/jack/CBrivalry.pdf
![Page 18: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/18.jpg)
18
Labelled line vs. distributed representations – Grandmother cell debate
● Could ultimately be a combination of both
![Page 19: Lecture 14 – Sensory systems review How do we really sense … · 2015-02-21 · BIO 354 - Neurobiology 2 3 General principles of sensory systems All sensory systems convey 4 basic](https://reader035.vdocuments.us/reader035/viewer/2022070921/5fba1b6f2db8be73ad343ef8/html5/thumbnails/19.jpg)
BIO 354 - Neurobiology 2 19
General principles of sensory systems
● All sensory systems convey 4 basic types of information
– What is the stimulus (modality) – Different sensory systems
– Where is the stimulus (location) – Different subsets of neurons
– How strong is it (intensity) – Firing patterns (rate and timing)
– When did it come on, when did it go off (timing) – Firing patterns (rate and timing)
● The brain BUILDS a picture of the external world
● Constrained by the architecture and functioning of networks of neurons
● Understanding the basic anatomy and functioning is necessary for going further