Exam 1: Chapter 1

Question 1

“The function of structure is the structure of function”

meaning and 2 examples

Answer 1

• The molecular shape (configuration) determines the biological function- structures change shape to change function
• Meissner’s and Pacinian Corpuscle embedded at different levels in skin
• Reduction in surface area increases force in middle ear

Question 2

theme: Top-down processing vs. Bottom-up processing

Answer 2

top-down processing: Intelligent perception. The stimulus input is somehow enhanced/modified by neural processes to make the perceptual experience. changing over time (example: edges are so important that mother nature has enhanced them).
–examples: Mach bands, Certain illusions and constancies require previous experience with a stimulus

bottom-up processing: Direct perception. The complete perceptual experience is given from the stimulus itself

Question 3

theme: Vision is dominate sense in humans

why? (4)

Answer 3

Eye is more complicated: only sense organ to originate from brain

• More cortical tissue devoted to vision (more brain area)
• Most studied of senses
• Depth perception appears to be innate
• Certain illusions and constancies require previous experience with a stimulus – top-down processing

Question 4

Sir Francis Bacon (1561-1626)

Answer 4

“Man, being the servant and interpreter of nature, can do and understand so much and so much only as he has observed in fact or in thought of the course of nature: beyond this he neither knows anything nor can do anything ”

“By far the best proof is experience”

Question 5

Importance [of sensation and perception?] (5)

Answer 5

Obtain knowledge: Satisfy curiosity
Test theories: through experiments
Pleasure in existence: Sensory deprivation studies
Treatment of disease states: Save money and increase quality of life
Understand developmental characteristics: Age appropriate stimuli and tasks

Question 6

t/f equipment like microscopes and PET scans do NOT involve human perception

Answer 6

False! Even when using equipment like microscope or PET scans, ultimately involves human perception
example: professor has cataracs- looking through a microscope

Question 7

are we limited by our sensory capabilities? why or why not?

Answer 7

We are limited by our sensory capabilities. Your world is what your senses tell you. The limitations of your senses set the boundaries of your conscious existence and experience.
-example: dogs can hear high pitch, but humans cannot detect at all - this is likely because it would be costly (a waste of resources) to be able to hear all levels of noise/pitch

Question 8

why is it that sensory capabilities are influenced greatly
by the environment during evolution?
-examples

Answer 8

Sensory capabilities of animals influenced greatly by what was required to survive in a competitive environment. (Sensory capabilities evolved to maximize survival in competitive environment)

-examples: Ultraviolet light detected by insects, but not humans. Ultrahigh frequencies of sound heard by dogs and rats but not humans.

Question 9

Emphasis of Human Perception in regards to environment and evolution: provide examples and reasonings for vision, audition, touch, taste

Answer 9

Vision: What effect would being color blind have on survival in a modern human world? But what about early in the course of evolution? Would a color blind individual find ripe fruit to eat? Know which snakes to avoid? Most color blindness is not complete.

• duplex theory: day and night vision <= beneficial for humans
• fovea over periphery (acuity and color)
• color vision: green, red, yellow, blue

Audition: midrange frequencies- speech <= has survival value

Touch: head and hands (objects and sensory organs)= important for grip strength or force when strike things; a lot of brain tissue is given to controlled forced (can be used as a measurement)

Taste: bitter and sweets -using metabotropic => uses 2nd messenger system even though while 1 neurotransmitter binds more slowly it
-sour/salt using ionictropic (ex:GABA)=> a faster response but only 1 channel opening

Question 10

Emphasis of Human Perception in regards to environment and evolution:
What was emphasized?

Answer 10

Correlated with survival in evolutionary environment. Note evolutionary environment may not be the same as current environment.

Question 11

_____ is an example of something that is usually regulated by the unconscious bran but can be brought to conscious awareness when necessary.

Answer 11

The vestibular sense

Question 12

the myth of the 5 senses

Answer 12

there are more sensory systems than the traditional five.
examples:
-we have a vestibular system to help keep our balance and a proprioception system to allow us to monitor the position of our bodies.
- Our sense of touch is composed of multiple physiological systems designed to sense different features of the environment. Heat, cold, pain, itchiness, and soft touch are all implemented by separable systems. Indeed, the receptors for the “itch” experience are a unique kind of receptor different from those that sense touch and those that sense pain. Thus, depending on how the different touch systems are counted, it is more realistic to say that human beings have anywhere from 7 to 12 different sensory systems (see Table 1.1).
-Indeed, some have even argued that hunger and thirst should be counted as senses. We leave them out, as they deal strictly with internal states that are not directly linked to perception of the external world.

Question 13

the majority of the functions of the sense in the human body are due to external stimuli: what are 2 examples of internal stimuli?

Answer 13

Function, organ, stimuli

pain: skin/viscera; extenal/internal
proprioception: muscles; internal

Question 14

The Basics of Perception

-what is important ?

Answer 14

stimulus (many: sight, sound, touch, etc) => (many arrows) sensation => (Only attended stimuli get fully processed) perception

All sensory systems are sending in information to the brain. What we pay attention to is what gets processed further. SELECTIVE ATTENTION IS VERY IMPORTANT IN WHAT WE PERCEIVE. IF UNATTENDED, MINIMAL PERCEPTION.
-so we do not get overloaded

Question 15

To our conscious selves, the process of perceiving a photo of Russian dolls is seamless

explain

Answer 15

However- To understand this photograph, you must sense the colors and images, but cognitive processes aid in understanding what it is you are looking at. Without some cultural knowledge, the sensation makes little sense.

Question 16

Transduction

-give examples of energies detected by human sensory systems.

Answer 16

Transduction is the term used when energy in the environment activates a sensory organ and an electrical signal is sent to the brain.
Transduction: the process of converting a physical stimulus into an electrochemical signal.

examples: Light energy (vision), mechanical energy (audition, touch), and chemical energy (taste, smell) are all detected by human sensory systems.

Question 17

Receptors:

Answer 17

Receptors: specialized sensory neurons that convert physical stimuli into neural responses.

Question 18

Neural response:

Answer 18

Neural response: the signal produced by receptor cells that can then be sent to the brain.

(neurons are very picky about what they respond to)

Question 19

Perception

give 2 examples of Converting Energy Into a Neural Signal

Answer 19

Perception is the process of converting physical stimuli, such as light and sound energy, into neural signals within our sensory organs.

(a) Light is reflected off the petals of the flowers and into the eyes. The eyes then transduce this light into a neural signal to be sent to the brain.
(b) Sound is produced by the bird and reaches our ears. Special hair cells in the cochlea of the ear transduce the sound into a neural signal to be sent to the brain.

Question 20

The Aristotle Illusion

In the illustration:

Answer 20

we see two crossed fingers and a pencil touching in the middle. In this illusion, we feel as if we have been touched by two pencils rather than one.
FIGURE 1.9

Question 21

motion aftereffect

Answer 21

A motion aftereffect is a sensory experience that occurs after prolonged experience of visual motion in one particular direction. After watching the constant downward motion of a waterfall, the motion detectors in our brains adapt or tire in response to the downward motion. When we look away from the waterfall, upward motion detectors become active, and we experience the illusion that whatever stationary object we are looking at is moving upward.

FIGURE 1.10 Waterfall Illusion
The second illusion discussed by Aristotle is known as the motion aftereffect, also known as the waterfall illusion (Verstraten, 1996; Wade, 1996).

Question 22

The doctrine of specific nerve energies

what animal have we studied and what did it tell us?

Answer 22

Doctrine of Specific Nerve Energies: perception is defined by the pathway over which the sensory information is carried

What would happen if we could magically rewire the brain such that the visual system was rerouted to the auditory area?
=>Frog experiments can help with the answer: the vision of frogs, can see where axons and such go in the brain

(maybe related to synthesia?)

Question 23

Hermann von Helmholtz (1821–1894)

Answer 23

was a German physician, physicist, and sensory physiologist. He is credited with developing a theory of color vision and promoting the constructivist view of sensory perception.

top down

Question 24

Ewald Hering (1834–1918)

Answer 24

was a German physiologist who introduced the opponent theory of color vision. He was also interested in binocular vision. He disagreed with Helmholtz on constructivism. Hering argued that stimuli themselves had sufficient information to allow for direct perception.

Hering viewed environmental inputs and our sensory apparatus as sufficient for us to grasp the structure of the perceived world, without the need for internal unconscious inferences. That is, stimuli themselves contain adequate information for the viewer to perceive the world. In Hering’s view, the perceptual processes in the brain do not need to make sense of the perceptual world; the brain simply needs to register it.
Whereas Helmholtz’s view is more popular with most experimental psychologists as well as physiologists, Hering’s view influenced the development of Gestalt psychology and later, direct perception theory (also known as the Gibsonian view).

bottom up

Question 25

Constructivist approach:

Answer 25

(Intelligent perception)

the idea that perceptions are constructed using information from our senses and cognitive processes

The constructivist view is that the brain further enhances aspects of the stimulus which results in a complete perception

Unconscious inference

take best advantage of prior experience (i think ???)

Question 26

Unconscious inference:

Answer 26

Perception is not adequately determined by sensory information, so an inference or educated guess is part of the process; this inference is not the result of active problem solving but rather a nonconscious cognitive process

Question 27

Do the senses provide exact representation of external world?

Answer 27

No. Some aspects of the stimuli are enhanced and some aspects are ignored.

we do not see exactly what is there = top-down processing

Question 28

Mach Bands

Answer 28

The neural output from the retina in enhanced near the edges which emphasizes the edges over the middle areas. Hence the apparent brightness appears to change within a band.

Result: The brain enhances edges

is due to the nervous system (wiring)

-the actual luminance is a step function but the perceived lightness is not that

Question 29

Gustav Fechner (1801–1887)

Answer 29

is considered the “father of psychophysics.” His landmark work on the relation between physical stimuli and perception established sensory psychology as a unique discipline separate from physiology. His work inspired the beginning of scientific psychology.

Question 30

(1795 – 1878) Ernst Heinrich Weber

Answer 30

was a famous German physician. He was considered one of the founders of experimental psychology. Weber was the influential scientist in the sphere of physiology and psychology.

Weber’s law states that a just-noticeable difference between two stimuli is related to the magnitude or strength of the stimuli. By virtue of the Weber’s law states that a “just-noticeable difference” (JND) between two stimuli is related to the magnitude or strength of the stimuli.

k= delta I/ I

delta I = the difference threshold
I = the initial stimulus intensity
k= a constant

Question 31

webers law

Answer 31

JND is a proportion which is like a percentage
If original stimulus value is small then the JND can be smaller but if the original stimulus value is large then the JND will be larger

Example: if 10% change is needed for a JND, when starting at 10 lbs then 1 lb of change will be noticed. But if starting at 100 lbs then 10 lbs of change will be needed before the change is noticed.

k= delta I/ I

delta I = the difference threshold
I = the initial stimulus intensity
k= a constant

Question 32

Gestalt psychology:

Answer 32

A school of thought claiming that we view the world in terms of general patterns and well-organized structures rather than separable individual elements

The Gestalt view is unique in that it non reductionist in its approach. “The whole is greater than the sum of its parts”

top-down processing!

ex: Kanizga’s triangle;

1.16 Kanizsa Triangle
When most people look at this figure, they see a bright white triangle lying on top of a background consisting of a less bright triangle and some odd-shaped “Pac-Man” figures. The bright white triangle is illusory. The triangle is suggested by the pattern of figures, and our perceptual systems enhance the perceived brightness of the figure, but close inspection of the figure will convince you that there is no actual change in brightness.

an A made up of “x”

To see the A, one must order the individual elements into a pattern. Just by examining the individual elements, we would never see the A. Gestalt psychologists considered patterns such as these the rule rather than the exception.

grouping principle (5)

Question 33

Direct perception

Answer 33

(Gibsonian approach): the approach to perception that claims that information in the sensory world is complex and abundant, and therefore the perceptual systems need only directly perceive such complexity.

Question 34

Information-processing approach:

Answer 34

the view that perceptual and cognitive systems can be viewed as the flow of information from one process to another.

“thinking”

-we now realize the brain has a lot of parallel processing : all at the same time = faster

Question 35

Computational approach:

type of processing?

Answer 35

an approach to the study of perception in which the necessary computations the brain would need to carry out to perceive the world are specified

top-down approach!

David Marr first developed theory (1982), heavily influenced by computer science and artificial intelligence theories
He viewed the brain as an incredibly complicated computer and sought a mathematical explanation for perceptual processes

Current researchers: trying to develop mathematical models predicting perceptual phenomena

Mathematical models: based on neural networks, computer simulations of how nervous systems work (Venrooij et al., 2013)
—-we canNOT model a brain; only a few neurons

Question 36

neuroscience

Answer 36

Neuroscience: The study of the structures and processes in the nervous system and brain

The goal of neuroscience is to understand sensation and perception in terms of the structures and processes in the nervous system that produce it. The neuroscience approach starts with examining the physiological processes whereby a physical signal is transduced into a neural signal.

Question 37

Microelectrode:

Answer 37

A device so small that it can penetrate a single neuron in the mammalian center

Question 38

Agnosia:

Answer 38

A deficit in some aspect of perception as a result of brain damage

Question 39

Prosopagnosia:

Answer 39

Face agnosia, resulting in a deficit in perceiving faces

Question 40

Amusia:

Answer 40

A person’s loss of appreciation of music because of certain areas of the right temporal lobe

Question 41

Neuroimaging:

Answer 41

Technologies that allow us to map living intact brains as they engage in ongoing tasks

Question 42

Functional magnetic resonance imaging (fMRI):

Answer 42

A neuroimaging technique that generates an image of the brain on the basis of the blood levels in different areas of the brain, which correlate with activity levels in those regions

MRI research: started in the 1990s
Areas of the brain critical in odor perception, such as piriform cortex in the temporal lobe

-NOT all areas of the brain are always active- vary depending on waht doing (listening, watching: depednign on the task at hand)

People use more than 10% of their brain !!!

Question 43

Neuropsychology:

Answer 43

The study of the relation of brain damage to changes in behavior

Question 44

Cognitive penetration:

2 examples

an application

Answer 44

The view that cognitive and emotional factors influence the phenomenology of perception and reflects top-down processing

• emotions DO effect
• develops through experience

Muller Lyer illusion: subjects judge the bottom center line as longer than the top center line. Only subjects that developed (grew up) in regions with square buildings experience the Muller Lyer illusion.

Red-associated objects (e.g., the apple) required more red in the background to be judged a match than did the objects that were not associated with the color red.

Application: Avoiding collisions
There is an interaction between size of an object and estimates of contact times when driving. Subjects estimate that they will contact larger items sooner than they would smaller items. Hence be careful when riding a bike!
The automobile driver must estimate the time to collision with the bicyclist. If the driver determines that a collision is imminent, he or she must apply the brakes immediately, in this case, to spare the bicyclist major injury.

Time to collision: the estimate that an approaching object will contact another.

Size-arrival effect: Bigger approaching objects are seen as being more likely to collide with the viewer than smaller approaching objects

Question 45

Cognitive impenetrability:

Answer 45

Perception is not affected by cognitive factors (bottom-up processing), only our reporting of them is affected

Question 46

Ewald Hering (1834–1918)

Answer 46

Direct perception: the direct view is that the stimulus itself, without any ongoing brain activity enhancement, is sufficient for a complete perception