Chapter 4 Flashcards
In a dichotic listening paradigm what attribute of the unattended stream can participants identify?
Physical attributes; whether its human speech, music or silence. Whether the voice is male/female, loud or quiet, high or low
They can NOThowever identify any semantic content
explain the experiment that demonstrated the same effects shown in the dichotic listening paradigm using visual inputs?
Subjects were told to focus on the white team passing a ball and ignore the black team. They did this successfully but failed to notice that a gorilla walked through the scene.
What’s the cocktail party effect?
When salient information in the unattended channel can leak through and be noticed. Similar to when you’re at a party and someone in another conversation you weren’t listening to says your name and catches your attention.
explain the bottleneck theory of attention
People erect a filter to block out potential distractors while allowing desired information to go on and receive further processing
What is a mask
Meaningless jumble designed to interrupt further processing
What is inattentional blindness and which experiment first demonstrated it?
The inability to see something directly in front of you because you aren’t paying attention to it
> first shown in an experiment by Mack and Rock where participants fixated on a target but were told to make judgements about a + elsewhere on the screen, on the 4th trial the target changed into a shape. Participants with no warning of this change didn’t notice it.
What is a real life example of inattentional blindness
Not being able to find the ketchup even though it’s right in front of you
What do Mack and Rock argue about attention?
There is no conscious perception without attention
explain the experiment that proved unconscious perception is possible without attention?
Subjects had to identify which of 2 lines was longer. On the 4th trial the dots in the background created the Muller-lyer illusion. Subjects did not perceive the pattern however they were still influenced by the illusion and said the line with the outward fins was longer although the lines were actually identical
Define change blindness and give examples
Observer’s inability to detect changes in scenes they’re looking at directly
ex. changes in two pictures, in different angles of a film, in real life (the door switch)
What are the two ways to think about inattentional blindness and change blindness
- they reveal genuine limits on perception (people don’t see the stimulus)
- they reveal limits on memory (people see it but immediately forget)
explain the early and late selection hypotheses
Early selection: Attended input is identified and privileged from the start
Late selection: All inputs receive relatively complete analysis and selection is done after
Evidence for late selection
the muller lyer inattentional blindness experiment
Evidence for early selection
- Brain activity for attended vs. unattended inputs are distinguishable 80ms after presentation while early sensory processing is underway
- Neurons in V4 are more responsive to attended inputs vs. unattended inputs
What does the evidence supporting early selection tell us about attention and perception?
Attention doesn’t change what we remember it can literally change what we percieve
How can we explain the mixed results supporting both early and late selection?
If the attended stimuli is complex fewer resources are left to process unattended stimulus showing the pattern for early selection, if the stimulus is simples more resources are available to process unattended info and the late selection pattern emerges.
How can detectors be used to explain inattentional blindness, selective listening and leaking of info from the unattended stream
inattentional blindness: If we not primed (warned) that a change will occur the detectors are unprepared and thus do not fire
Selective listening: the detectors for the distractor stream recieve no resources and are thus unprimed
Leakage: The detectors for personally salient info (ie. your name) are already primed, the activation level is higher so they will fire although your attention is elsewhere
Perception requires primed detectors, What are the two types of primes
- Stimulus based: Stimulus you’ve already encountered (recently/frequently) not under conscious control.
- Fast (immediate)
- Free (can prime one detector without taking activation from another) - Expectation Based: You can deliberately prime detectors for stimuli you are expecting
- Slower (half a second)
- Has a cost when mislead (priming the wrong detector takes something away from the others)
What does expectation based priming reveal (as shown my Posner and Snyder)?
The presence of a limited capacity system (perceiving requires work, work requires limited mental resources)
Define spatial attention
Ability to focus on a particular position in space and be better prepared for any stimulus that appears there
In Posner and snyder’s letter detection task what was revealed
Even in simple tasks, being primed to focus attention to one side of the screen means they devote less attention to the right and thus have slower RTs. = further evidence of limited capacity system
How can we be sure it’ attention moving and not the eyes?
Because eye movements require 180-200ms and benefits of primes are detected within 150ms
What group of brain areas control attention
A network of brain sites in the frontal and parietal cortexs
What area of the brain controls memory allowing you to focus on remembered events
The parietal cortex
