Chapter 1/2

Question 1

How can we qualitatively measure perception?

Answer 1

introspection, describing and recognizing

Question 2

how can we quantitatively measure perception?

Answer 2

detecting, judging magnitude and response measures

Question 3

what is introspection?

Answer 3

its about what you think. ex: why do i lose my sense of taste when i have a cold? why does the world appear stationary when i move my eyes? etc.

Question 4

what is description?

Answer 4

how i describe what’s out there, what i am perceiving.

Question 5

What is recognition ?

Answer 5

includes categorization. what is the identity of the stimulus? ex: that picture is a woman!

Question 6

psychophysics is used to ___

Answer 6

study the relationship between the physical qualities of stimuli and the subjective perceptions of those stimuli.

Question 7

before psychophysics (i.e. pre-Fechner), it was thought that you perceived with ____

Answer 7

your soul

Question 8

what were fechners 3 ways of detecting thresholds (just name them, dont explain)?

Answer 8

1. method of limits
2. method of adjustment
3. method of constant stimuli`

Question 9

describe the method of constant limits.

Answer 9

bring stimulus down until detected. then bring stimulus up until detected. repeat.

issue: habituation/anticipation

Question 10

describe the method of adjustment

Answer 10

stimulus intensity adjusted until observer detects it.

Fastest but lease accurate measurement

Question 11

describe the method of constant stimuli.

Answer 11

stimuli of varying intensities presented in random order. Threshold = intensity that results in detection in 50% of trials.

most time consuming but also most accurate threshold detection method.

Question 12

what’s Ernst Weber known for?

Answer 12

just noticeable difference, i.e. difference threshold (DL).

DL/s=k
where s= standard stimulus and k= Weber fraction

Question 13

what’s S.S. Steven known for?

Answer 13

magnitude estimation.

Question 14

what is response compression?

Answer 14

as intensity increases, the perceived magnitude increases more slowly than the intensity (0<n<1).

Question 15

what is response expansion?

Answer 15

as the intensity increases, the perceived magnitude increases more quickly than the intensity (n>1).

Question 16

do perception and recognition always go together?

Answer 16

no. ex: visual agnosia (when someone can see but cant recognize or interpret what they’re seeing - parietal lobe defect).

Question 17

what is judging magnitudes and is it a qualitative or quantitative method of measuring perception?

Answer 17

quantitative.

what;s the magnitude of a stimulus (given a comparator).

Question 18

what is response measures and is it a qualitative or quantitative method of measuring perception?

Answer 18

quantitative

how quickly can I react to a stimulus?

Question 19

neurons process and transmit ____ signals

Answer 19

bioelectric signals

Question 20

action potentials propagate when axon becomes ____ to ions.

Answer 20

selectively permeable.

Question 21

chemical neurotransmitters are released from the sending neuron’s _____

Answer 21

terminal boutons

Question 22

neurotransmitters bind to receptors of the receiving neuron’s ____ and _____

Answer 22

dendrites and cell body

Question 23

ACh is a ___ neurotransmitter

Answer 23

excitatory - helps cell become less negatively charged (Depolarization).

Question 24

what does it mean when we say that action potentials are “non-attenuating”?

Answer 24

it means that they remain the same size as it propagates from the cell body to the terminal boutons.

Question 25

what's the upper limit of a neuron firing? why is there a limit?

Answer 25

around 500-800 spikes/second. Refractory period causes limit.

Question 26

Absolute refractory period

Answer 26

right after AP, Na+ channels inactivate, so no new AP can be generated, regardless of the stimulus

Question 27

relative refractory period

Answer 27

Na+ channels recovering and K+ channels still open. Membrane is hyperpolarised, so AP can only be generated if stimulus > normal

Question 28

describe the principle of representation.

Answer 28

the external world is encoded by patterns of neural activity in the brain. So your brain doesnt experience the world directly, it experiences electrical and chemical signals to create a model of the world.

Question 29

specificity coding is also called ___

Answer 29

the grandmother cell hypothesis

Question 30

what is specificity coding?

Answer 30

Specificity coding is the idea that a single neuron (or a very small group of neurons) is responsible for recognizing or representing one specific stimulus — such as your grandmother’s face, your dog, or the Eiffel Tower.

Question 31

according to _____ hypothesis, each distinct concept or object is represented by its own dedicated neuron

Answer 31

specificity coding (aka the grandmother hypothesis)

Question 32

what are the two modern alternatives to specificity coding?

Answer 32

population coding nad sparse coding

Question 33

define population coding

Answer 33

Definition: Information about a stimulus is represented by the pattern of activity across a large group (population) of neurons, rather than by one specific neuron. Key idea: Each neuron responds broadly to many stimuli, but in different degrees, and the brain interprets the overall pattern across the population. Analogy: Like an orchestra — each instrument (neuron) plays a part, but the whole symphony (pattern) is what carries the meaning.

Question 34

define sparse coding

Answer 34

Definition: A small subset of neurons (not just one, but not the whole population) responds strongly to a particular stimulus, while most others remain silent. Key idea: It’s a middle ground between specificity and population coding — → Fewer neurons than population coding → More neurons than the single “grandmother cell” idea. Example: A handful of neurons fire whenever you see your grandmother, and some of those same neurons might also respond to other elderly women or family members. So the representation is distributed, but sparse. Analogy: Like a few musicians playing a recognizable tune — not a soloist (specificity), not a full orchestra (population), but a small ensemble.

Question 35

what's phrenology?

Answer 35

Phrenology was a 19th-century pseudoscience that claimed a person’s personality traits and mental abilities could be determined by the shape and bumps of their skull. It introduced the idea of localization of function in the brain, but its specific claims were scientifically invalid.

Question 36

structural MRI measures what?

Answer 36

structural connectivity - just the anatomy of the brain

Question 37

fMRI measures what?

Answer 37

specificity of brain activation and functional connectivity (NETWORKS) via measuring blood level oxygenation (difference between active and non-active parts of the brain) Combines anatomy and physiology