Exam 3 Flashcards
Why do we need attention?
Because we can’t pay attention to everything so we have to pick and choose what parts of the world we process more and what we process less
What does the attentional filter do
It blocks undesired information (usually like in a dichotic listening test)
What is inattentional blindness
You don’t see something even if you are looking at it. You only see it if you attend to it
What is an attentional blink
“closing” attention. Task experiment where you get worse at finding one thing if you also have to look for the other thing
What is change blindness
You don’t notice changes
What were the main results from the moran and desimone study
Cells have preferential responses in area V4 based on what is being paid attention to. More activity depends on where you are focusing. Attention changes the activity in the brain
What did O’Craven et al find
That our attentional system is active to motion in MT areas when things are moving
What does the inferemporal cortex pay special attention to
Object recognition and form/color
What does the parietal cortex pay special attention to
“Where” and motion
How does attention solve the binding problem
Feature integration theory
What is the preattentive stage
It is where primitives (lines and circles) automatically and effortlessly pop outW
What is the focused attention stage
Where the primitives are combined. These require effort and attention
What is a feature search
In the preattentive stage. Stimuli not bound together
What is a conjunction search
In the focused attention stage. Attention binds object features together
What is the biased competition model
Stimuli compete for attention. This competition can be biased, often toward the object that is currently attended in the visual field, or alternatively toward the object most relevant to behavior.
Attentional capture
New objects attract attention
Value driven attention
Highest value color is most distracting
Does attention stay stagant?
No, it spreads through an object
What are some brain areas involved in attentional control
Frontal eye field
Posterior Parietal Cortex (damage produces unilateral spatial neglect)
How are pure tones plotted
In a sine wave
What does the amplitude represent on a sine wave
How much pressure changes
What does the wavelength represent on a sine wave
Time/distance
Frequency/hz (pitch)
What range of sounds can humans hear
20 hz to 10,000,000 hz
What is the difference in the charts of a pure tone and a complex tone
Pure tone is true sine wave
Complex tone is not
What is a fundemental frequency
The lowest frequency that you can hear in a complex tone. Has the highest amp
What kinds of frequencies does noise canceling work for
Lower frequencies
What is a fourier spectrum
a complex waveform made up of multiple waves
What is a harmonic
Its the higher frequencies after the fundamental freq.
What do different instruments make different sounds if they are playing the same note
Because the note is being held differently. it either drops off or is sustained
How does distance relate to dB
you HAVE to keep distance in mind or else your measurements will get screwed uo
what is the equation for sound pressure and amp
pressure/p (sub)O
20 log (P/pO
What happens if you add together two sounds with the same dB
It will increase by 6dB
ex: 80dB + 80dB = 86dB
Frequency
pitch
Amplitude
Loudness
Waveform
Timbre
What does loudness depend on
Amplitude and frequency
What is an audibility curve
The abs. threshold of the tones
Can you still hear at 0dB
YES! It is just how its defined.
Where does human speech fall in hz
~1,000 - 10,000
Where is greatest displacement caused on the basilar membrane
At he apex where low frequency pressure waves are
What is the envelope of traveling waves
A chance in the attack rate over time
What signals do inner hair cells send
release of neurotransmitters
What signals do outer hair cells send
a motile responses
What is place coding for frequency
That hair cells signal different frequencies depending on location
What does a frequency tuning curve represent
It gives evidence for place coding by showing the frequencies that hair cells respond to
Sharper curves are higher freq
More rounded curves are lower freq
What frequencies does the apex stimulate
Low freq
What freq does the base/stapes stimulate
High freq
What frequency does white noise have
Equal energy at all freq
Where does the effect of masking extend
It extends more to higher freq so may be harder to hear masked high freq notes
How high can phase locking extend to
can etexnd to 4000-5000 hz
What is phase locking
In a sound wave, hair cells can’t fire at every single peak because its too much energy so instead, seperately fibers peak at different times and if you listen to them all TOGETHER it becomes the same initial sound wave. The timing is a certain amount of milliseconds apart and its locked to that time
What is timbre
an example of the tone envelope. its why musical instruments all sound different
What is tone chroma
Pitch class (like middle C)
What is the tritone paradox
It is hard to tell if a C is higher than F# (a half octave). Some say this depends on where you grew up
What does periodicity pitch tell us
That we perceive the fundemental frequency to be there even if it is not
Why do things sound different when played backwards
Because of the tone envelope since attack and decay rates would be reversed
The anterior ROI responds to ______ tasks
What
The posterior ROI responds to ______ tasks
Where
What is azimuth
Its the left/right plane of things we can hear
What is interaural level difference (ILD)
An acoutsic shadow is cased from our head that shadows one ear. It’s about the different sound levels entering the ear
What is interaural time difference (ITD)
I helps us localize sound because whatever reaches the ear faster must be closer to us
What does having our head straight looking forward do to ITD
It makes it very hard to tell where the sound is coming from so you have to rotate your head
Do we notice echoes
Not really. They reflect off the room on everything that isn’t the sound source
How does elevation help us localize sound
We can detect changes in elevation through the pinna. Experiment where the pinna was artificially blocked and couldn’t perceive elevation but could perceive azimuth. got better over time
Would putting on headphones effect auditory localization
It would destroy elevation cues but not azimuth
What do we do where there are audio cues and visual cues at the same time
we go with the visual cue
Do audio cues effect our visual perception
Yes. Sound can alter perceived motion
What is grouping by harmonic coherence
All multiples of the fundemental freq. are perceived a s a unit and not seperate sound waves
What is group by synchronous change
We group together sounds that move together
What is auditory stream segreation or pitch streaming
When tones are close in frequency they sound like a galloping pattern of one sound stream. but when the freq are far apart it sounds like two different sound streams
What is grouping by similiary
We group tones that sound the same together. If there is a flank tone it will mess up our perception
What is grouping by temporal proximity
Grouping together based on speech and being close together in time. in slow speeds the sounds sound like one wave.
What is perceptual completion of occluded sounds
We image a sound being there even if it’s not actually there because another sound is playing “over” it
What is a formant
Its a clump on a graph indicating the sound wave emerging from the mouth. Dif vowels have dif formants @ dif freq
What do formant transitions depict
Consonants
what is coarticulation
One phoneme can influence the acoustic properties of another. basically our words flow right into one another
What is the segementing problem
We don’t have gaps between words
How do we solve the segmenting problem
With phoneme transition probabilities. We know which phonemes probably end a word
What is the variability problem
Children and men would sound different
What is categorical perception
Voice onset time is a cue to voicing
What is voice onset time
The interval between the initial bursts of frequencies and the onset of voicing. difference between Pa (longer voice onset time) and Ba
What is phonemic restoration effect
We use knowledge of the language to augment our perception. We will in gaps. We do this better when we can lip read
What is the effect of context on speech perception
It’s easy to misperceive sound if there is conflicting context (like the cat example). When we don’t segment correctly, speech perception becomes very hard
What are the effects of syntax and semantics on perception in noise
When the sentence is grammatically correct and follows a clear meaning, it is much easier to pick out the words. When it’s not, it’s very hard
