Video Module 8: Selective Attention

Question 1

attention

Answer 1

The cognitive and neuropsychological mechanisms that allow us to select what enters our conscious awareness (relevant perceptual input)

Question 2

selective attention

Answer 2

attending to certain aspects of our environment/stimuli while choosing to ignore others

Question 3

divided attention

Answer 3

attending to multiple different stimuli or multiple tasks at once; dividing our attention between tasks
- e.g. multitasking

Question 4

Why is it important that we have the capability for selective attention?

Answer 4

We have a limited capacity to process and respond to stimuli; it is important that we are able to decide which stimuli are relevant and which are irrelevant to avoid cognitive overload.

Question 5

control (mechanism of attention)

Answer 5

inhibiting irrelevant stimuli

Question 6

How does attention work as a filter?

Answer 6

We are able to perceive what we attend to, but not perceive the rest of the information that we are sensing.
e.g. cocktail party effect

Question 7

priming (mechanism of attention)

Answer 7

facilitation of relevant stimuli

Question 8

What is a dichotic listening task (shadowing) and how does it help us study attention?

Answer 8

A dichotic listening task is when participants wear headphones in which one audio plays in one ear, and a different audio plays in the other ear. Participants are typically instructed to repeat the message in one ear and ignore the message in their other ear. They help us study attention and how we process information.

Question 9

What kinds of unattended stimuli are participants aware of in dichotic listening tasks?

Answer 9

For the audio in the unattended ear, participants are typically aware of low-level information:
- Non-speech sounds
- The gender of a speaker and if the gender switches
- Human vs. robot voice
- Words that are highly relevant to them (e.g. their own name)

Question 10

What kinds of unattended stimuli are participants not aware of in dichotic listening tasks?

Answer 10

For the audio in the unattended ear, participants typically unaware of higher-level information:
- Semantic info (meaning)
- Syntax (sentences vs. random words)
- The language of the speaker (if the speaker switches languages)

Question 11

What is the early selection theory for attention?

Answer 11

Early selection theory proposes that filtering occurs between sensory analysis (sensory input) and semantic analysis (examining input for meaning).
- Explains why we recognize low-level information in our unattended ear, but why we aren’t able to tell what a speaker is talking about
- failure to perceive; no interpretation

Question 12

What is the late selection theory for attention?

Answer 12

Late selection theory proposes that filtering happens at the semantic level, between semantic analysis and registering information into our conscious awareness (working memory). This suggests that our brain understands the meaning of input, but we’re only choosing to be aware of certain information.
- interpretation; failure to remember

Question 13

What is supporting evidence for early selection? What are the issues with early selection?

Answer 13

evidence: EEG data show that unattended stimuli receive less processing than attended stimuli in primary sensory areas. There is a greater voltage change across the hemisphere connected to the attended ear.
issues: Subjects sometimes become aware of semantic information. For example, they are very likely to notice their own name or words personally relevant to them. Additionally, they sometimes accidentally switch between the audio in the attended and unattended ear.

Question 13

What is supporting evidence for late selection? What are the issues with late selection?

Answer 13

evidence: a study was conducted in which participants were shown stimuli of grey boxes with lines, in which dots were flashed below their conscious awareness to create the Muller Lyer illusion. Participants consistently reported not seeing the dots, yet also consistently reported one line being longer than the other.
issues: it cannot be the case that all semantic information in the unattended ear is perceived.

Question 14

attenuation model for attention

Answer 14

proposes that there is a filter that allows some information through and some analysis in the unattended ear, but there is a greater level of analysis in the attended ear.
- The attended channel is “enhanced” and the unattended channel is “reduced”, but info from both channels is processed.
Attenuation works through attention as priming; in other words, things that have a lowered response threshold may fire even if the signal (from the unattended channel) is weak.

Question 15

expectation based priming (attention)

Answer 15

in which the detectors we expect to use are primed.
- top-down activation of detectors
- requires effort (anticipation) and draws on a limited resource (attention)
- expectation based priming is what we use for selective attention

Question 16

stimulus driven priming (attention)

Answer 16

in which the detectors exposed to a certain stimulus more recently or frequently are more sensitive to that stimulus
- bottom-up activation of detectors based on the features in the stimulus
- does not require effort nor attention

Question 17

What is the difference between stimulus-driven and expectation-based priming?

Answer 17

stimulus-driven: incurs no cost; benefits from priming but not as much as EB priming
expectation-based: incurs a cost (the cost of being misled/having false expectations makes us less accurate); benefits from priming at an even greater level than SD priming
For example, we are much faster at recognizing a stimulus if we have the expectation that it will appear, however if our expectation is wrong then our response time slows down. However, if we have no expectation, we are faster at recognizing a more common stimulus (if it occurs frequently), however our response time doesn’t slow down because we do not expect it to show up.