PPVK - Attention, Percp, Visual cog

Question 1

Sensation

Answer 1

the ability to detect a stimulus

Question 2

Perception

Answer 2

the act of giving meaning to a detected sensation

Question 3

Attention

Answer 3

any of the very large set of selective processes in the brain

Question 4

Selective attention

Answer 4

when processing is restricted to a subset of the possible stimuli

Question 5

PPVK (interdisciplinary field of which?

Answer 5

psychologists, biologists, computer scientists, medical doctors, neuroscientists…

Question 6

Name scientific methods and explain them:

Answer 6

1.Ecological approach –observe and draw some conclussions
2.Psychophysics -use of carefully controlled laboratory stimuli →measuring behaviour
→Thresholds: finding the limits of what can be perceived
→Scaling: measuring private experience
→Signal detection theory: measuring difficult decisions
3.Neurophysiology -use of carefully controlled laboratory stimuli →measuring neural responses
→Sensory neuroscience: the biology of cognitive processes
→Neuroimaging: an image of the mind
4.Computational models: using math and computation to understand cognition

Question 7

Gustav Fechner (explain why he was important)

Answer 7

• invented “psychophysics”
• the true founder of experimental psychology
• Fechner –from a degree in medicine, to biological science to physics and mathematics
  -Damaged his eyes by staring at the sun while performing vision experiments

Question 8

Psychophysics

Answer 8

the science of defining quantitative relationships between physical and psychological (subjective) events

Question 9

Absolute threshold

Answer 9

minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time

Question 10

Just noticeable difference (JND; difference threshold)

Answer 10

the smallest detectable difference between two stimuli, or the minimum change in a stimulus that can be correctly judged as different from a reference stimulus

Question 11

Absolute treshold (vision, hearing, vestibular, taste,smell, touch)

Answer 11

Stars at night, or a candle flame 30 miles away on a dark, clear night
A ticking watch 20 feet away, with no other noises
A tilt of less than half a minute on a clock face
A teaspoon of sugar in 7.5 liters of water
A drop of perfume in 3 rooms
The wing of a fly falling on your cheek from a height of 3 inches
Psychophysics and Thresholds

Question 12

Weber’s law

Answer 12

the JND is a constant fraction of the comparison stimulus
larger stimulus values have larger JNDs and smaller stimulus values have smaller JNDs

Question 13

Who extended Weber’s law?

Answer 13

Fechner

Question 14

Fechner’s law

Answer 14

*the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity
*An attempt to equate mind and matter

Question 15

What are psychophysical methods?

Answer 15

*Method of constant stimuli
→ many stimuli, ranging from rarely to almost always perceivable, are presented one at a time
*Method of limits
→ the magnitude of a single stimulus or the difference between two stimuli is varied incrementally until the participant responds differently
*Method of adjustment
→ similar to the method of limits, but the participant controls the stimulus directly

Question 16

Name scaling methods

Answer 16

Magnitude estimation, Cross-modality matching

Question 17

Magnitude estimation

Answer 17

→the participant assigns values according to perceived magnitudes of the stimuli
→the method of adjustment → magnitude estimation on a finer scale
→magnitude estimates are well described by Stevens’ power law:
S = aIb
(S) is related to stimulus intensity (I) by an exponent (b)

Question 18

Cross-modality matching

Answer 18

→matching the intensity of a sensation in one sensory modality with the intensity of a sensation in another
→bitter propylthiouracilPROP

Question 19

SDT

Answer 19

A psychophysical theory - response of an observer to the presentation of a signal in the presence of noise
SDT makes a distinction between:
*observers’ ability to perceive a signal
*observers’ willingness to report a signal

Question 20

Sensitivity

Answer 20

observers’ ability to perceive a signal

Question 21

Criterion

Answer 21

observers’ willingness to report a signal

Question 22

Cranial nerves

Answer 22

12 pairs of nerves (one for each side of the body) that originate in the brain stem and reach sense organs and muscles

Question 23

Name cranial nerves for sensory information

Answer 23

*Olfactory (I)
*Optic (II)
*Auditory (VIII)

Question 24

Muscles that move the eyes (cranial nerves)

Answer 24

*Oculomotor (III)
*Trochlear (IV) nerves
*Abducens (VI) nerves

Question 25

Parts of neuron?

Answer 25

dendrites, soma, axon, myelin sheath, nodes of ranvier, axon(synaptic) terminals, schwann cells

Question 26

Dendrites

Answer 26

Branch-like structures that receive signals from other neurons and transmit them to the cell body.

Question 27

Cell body (soma)

Answer 27

The main part of the neuron containing the nucleus, which processes incoming signals.

Question 28

Axon

Answer 28

A long, tube-like structure that carries electrical impulses away from the cell body toward other neurons or muscles.

Question 29

Myelin Sheath

Answer 29

A fatty layer that covers the axon, insulating it and speeding up signal transmission.

Question 30

Nodes of ranvier

Answer 30

Gaps in the myelin sheath that help speed up the transmission of nerve impulses.

Question 31

Axon terminals

Answer 31

The ends of the axon that release neurotransmitters to communicate with other neurons or target cells.

Question 32

Schwann cells

Answer 32

support neurons, especially in forming the myelin sheath around axons

Question 33

Which nerves are dedicated to specific sensory and motor tasks?

Answer 33

Cranial nerves

Question 34

Polysensory brain areas

Answer 34

→ information from several senses is combined → sensory integration (multisensory integration): the process of combining different sensory signals

Question 35

Electroencephalography (EEG)

Answer 35

A technique that measures electrical activity from populations of many neurons in the brain

Question 36

Event-related potential (ERP):

Answer 36

A measure of electrical activity from a subpopulation of neurons in response to particular stimuli that requires averaging many EEG recordings

Question 37

Magnetoencephalography (MEG)

Answer 37

→similar to EEG →measures changes in magnetic activity across populations of many neurons in the brain →has the same high temporal resolution as EEG, but better spatial resolution

Question 38

Computerized tomography (CT)

Answer 38

→an imaging technology that uses X-rays →creates images of slices through volumes of material (e.g., the human body)

Question 39

Magnetic resonance imaging (MRI)

Answer 39

→an imaging technology that uses the responses of atoms to strong magnetic fields →forms images of structures like the brain

Question 40

Functional magnetic resonance imaging (fMRI)

Answer 40

→variant of MRI →measures localized patterns of brain activity →activated neurons provoke increased blood flow, which can be quantified by measuring changes of oxygenated and deoxygenated blood to strong magnetic fields -> BOLD signal

Question 41

blood oxygen level-dependent (BOLD) signal

Answer 41

→the ratio of oxygenated to deoxygenated hemoglobin →permits the localization of brain neurons that are most involved in a task

Question 42

Positron emission tomography (PET)

Answer 42

→measures the metabolism of brain cells using safe radioactive isotopes →allows us to define locations in the brain where neurons are especially active

Question 43

What comupational models aim to simulate?

Answer 43

the steps in psychological and/or neural processes in a computer using mathematical language and equations.

Question 44

Efficient coding models

Answer 44

models that discover structure in sensory input to efficiently encode the world

Question 45

Bayesian models

Answer 45

models that make predictions (predictive coding) based on prior knowledge about the world

Question 46

Artificial Neural Networks

Answer 46

models that simulate biological neurons with layers of input units massively interconnected with output units that can excite or inhibit each other

Question 47

Deep neural nets (DNNs)

Answer 47

artificial neural networks with a very large number of layers of nodes with millions of connections between the input and output layers.