NEUR2020 Final Exam

What is attention?

Attention is the recruitment and focusing of perceptual or cognitive resources onto selected information so that it is processed more fully than unattended information.

Why is attention necessary?

Because the brain has limited processing capacity and cannot deeply process all available sensory information at once.

What are the two major properties of attention discussed in the lecture?

Capacity Selectivity

What does capacity mean in attention?

The limited amount of perceptual or cognitive resources available for a task.

What does selectivity mean in attention?

The ability to allocate limited resources to some information while reducing processing of other information.

Does attention completely block unattended information?

No. It usually attenuates unattended information rather than fully blocking it.

What is overt attention?

Attention directed where the eyes are looking.

What is covert attention?

Attention shifted without moving the eyes.

Give an example of covert attention.

Looking at a friend while actually listening to another conversation nearby.

Why does covert attention show that attention is not the same as eye position?

Because you can keep your eyes fixed while mentally attending to another location.

What is the early selection problem?

If selection happens too early the brain must choose what to attend before it has processed meaningfully what the information is.

What is the late selection problem?

If everything is already deeply processed before selection then it is unclear why attention is needed at all.

What is the attentional bottleneck?

A processing limit where resources become exhausted preventing all information from being processed deeply.

What determines where the attentional bottleneck occurs?

The perceptual load of the task.

What happens when perceptual load is high?

Resources are exhausted early so only basic information from unattended input is processed.

What happens when perceptual load is low?

More information can pass through to later perceptual and semantic processing.

What is the cocktail party phenomenon?

The ability to focus on one conversation while still noticing personally relevant information like your name in unattended speech.

What does the cocktail party phenomenon suggest about unattended information?

It is not completely blocked. Some basic or personally relevant information can still get through.

What is a shadowing task?

A task where participants repeat speech presented to one ear while ignoring different speech in the other ear.

What did shadowing tasks show about unattended speech?

Participants could detect basic features like speaker gender or native language but usually not semantic content.

What is inattentional blindness?

Failing to notice an obvious stimulus because attention is focused elsewhere.

What does the colour-changing card trick demonstrate?

That large visual changes can be missed when attention is focused on a specific task.

What does the moonwalking bear or gorilla-style demonstration show?

People can miss unexpected events when they are focused on counting or attending to another task.

Why does inattentional blindness occur?

Because attention is capacity-limited and task-relevant information uses most of the available resources.

What task did participants perform in the Mack and Rock-style inattentional blindness experiment?

They judged whether the horizontal or vertical line of a cross was longer.

Why was the cross-judgement task perceptually demanding?

The lines were very similar in length so participants had to scrutinise the stimulus carefully.

What happened on the surprise trial in the inattentional blindness experiment?

A new object appeared while participants were focused on the line-judgement task.

Which properties of the unexpected object were detected best?

Basic features such as location and colour.

Which properties of the unexpected object were detected poorly?

More detailed features such as shape and number.

What does the inattentional blindness experiment suggest about visual processing?

Basic features may be processed earlier while detailed object processing requires more attention.

What is the spotlight metaphor of attention?

Attention works like a spotlight that enhances processing in a selected region of space.

What is the zoom lens metaphor of attention?

Attention can be narrowly focused for high detail or spread broadly for coarser processing.

What happens when attention is spread over a broad area?

Processing becomes more diffuse and less detailed.

What happens when attention is narrowly focused?

Processing becomes more detailed and higher-resolution.

What is the Posner cueing paradigm used to study?

How attention shifts across space and how valid or invalid cues affect reaction time.

What is a valid cue in the Posner paradigm?

A cue that correctly indicates where the target will appear.

What is an invalid cue in the Posner paradigm?

A cue that directs attention to the wrong location.

What happens on valid cue trials?

Reaction times are faster because attention is already in the correct location.

What happens on invalid cue trials?

Reaction times are slower because attention must disengage move and re-engage elsewhere.

Why are invalid cue trials slower?

Because attention is initially directed to the wrong side and must shift to the target location.

What is endogenous attention?

Voluntary internally controlled attention often guided by symbolic cues like arrows.

What is exogenous attention?

Involuntary attention captured by external events such as flashes movement or loud sounds.

Which type of attention is faster: endogenous or exogenous?

Exogenous attention is faster.

Which type of attention lasts longer: endogenous or exogenous?

Endogenous attention lasts longer.

Give an example of an exogenous cue.

A sudden flash loud bang or unexpected movement.

Give an example of an endogenous cue.

An arrow telling you to attend to the left or right side of a display.

What are the three components of shifting attention?

Disengage Move Engage

What does disengagement of attention mean?

Releasing attention from its current object or location.

What does movement of attention mean?

Directing attention from one location to another.

What does engagement of attention mean?

Locking attention onto the new object or location.

Which brain region is linked to disengaging attention?

The parietal lobe especially the right parietal lobe.

Which brain region is linked to moving attention?

The superior colliculus.

Which brain region is linked to engaging attention?

The thalamus especially the pulvinar.

What is parallel search?

A search process where the target pops out and can be detected quickly regardless of the number of distractors.

What kind of features produce pop-out in parallel search?

Simple features such as a different colour or orientation.

What is serial search?

A search process where items must be inspected one by one.

What kind of task produces serial search?

A conjunction search where the target is defined by more than one feature.

What is a conjunction search?

A search where the target is defined by a combination of features such as colour plus orientation.

How does increasing distractors affect parallel search?

It has little effect on reaction time.

How does increasing distractors affect serial search?

Reaction time increases because more items must be checked.

Why are target-absent serial search trials slower?

Because the person must search the whole display before deciding the target is absent.

What are local-global stimuli?

Large global shapes made from smaller local elements such as a big H made of small Ts.

What does global processing refer to?

Processing the overall larger shape.

What does local processing refer to?

Processing the smaller elements that make up the larger shape.

What is EEG useful for in attention research?

Measuring the timing of brain responses with high temporal resolution.

What is an event-related potential (ERP)?

An averaged EEG response time-locked to a specific event or stimulus.

What does the P1 ERP component roughly reflect?

Early sensory processing around 100 ms after stimulus onset.

What happens to P1 and N1 when attention is validly directed to a stimulus?

They are enhanced showing increased sensory processing.

What does ERP evidence show about attention?

Attention can amplify early sensory responses in visual cortex.

What does fMRI evidence show about attention in visual cortex?

Directing attention to a region can increase BOLD activity in the corresponding visual cortex area even when the stimulus is absent.

What does the correlation between BOLD response and d′ suggest?

Stronger visual cortex activation is associated with better stimulus detection sensitivity.

What does attention do to primary visual cortex activity?

It heightens or amplifies activity in the relevant visual cortex region.

Can attention be directed to objects as well as locations?

Yes. Attention can be directed to objects not just spatial regions.

What did the house/face attention study demonstrate?

Attention can enhance processing of the attended object category such as houses or faces even when stimuli overlap spatially.

What is spatial neglect?

A disorder where a person fails to attend to one side of space usually the side opposite a brain lesion.

What is hemineglect?

Neglect of one half of visual space.

Which brain region is strongly linked to spatial neglect?

The posterior parietal lobe.

Spatial neglect is usually contralateral to what?

The side of the brain lesion.

Right parietal damage most often causes neglect of which side?

The left side of space.

Why is right parietal damage usually more debilitating than left parietal damage?

Because the right parietal lobe appears to deploy attention to both visual fields while the left parietal lobe mainly deploys attention to the right visual field.

What is the line bisection task?

A clinical test where a person marks the midpoint of a line. Neglect patients often mark too far to the right.

What does a rightward mark in line bisection suggest?

Possible left-sided spatial neglect.

What happens in the clock drawing task with spatial neglect?

Numbers may be clustered on one side of the clock often the right side.

What happens in copying tasks with spatial neglect?

The patient may copy only one side of the object or scene.

What is multisensory integration?

The process where the brain combines information from different sensory modalities.

What types of sensory information can be integrated?

Light sound mechanical stimulation and chemical information.

Why is redundancy across senses useful?

If one sense is unreliable or unavailable another sense can provide information.

How can multisensory integration improve perception?

It can speed responses improve perceptual accuracy and resolve ambiguity.

What is multisensory enhancement?

Improved perception or faster responses when information from multiple senses is combined.

What is multisensory conflict?

A situation where different senses provide conflicting information.

What is visual dominance?

The classic idea that vision tends to dominate other sensory modalities when information conflicts.

What are three examples of visual dominance discussed in the tutorial?

Spatial ventriloquism effect Colavita effect McGurk effect

What is the spatial ventriloquism effect?

A visual stimulus shifts the perceived location of a sound.

Why does the ventriloquism effect happen?

Visual and auditory information conflict spatially but match temporally and semantically so the brain assumes the visual location is correct.

In a movie theatre why do voices seem to come from actors mouths?

Because vision shifts the perceived sound location toward the actors on screen even though sound comes from speakers.

What happens when the visual-auditory spatial mismatch is small?

The perceived sound location may shift almost completely toward the visual stimulus.

What happens when the visual-auditory spatial mismatch is larger?

Integration becomes partial rather than complete.

What is the Colavita visual dominance effect?

When visual auditory and audiovisual stimuli are presented people often underreport the auditory component of audiovisual stimuli.

In the Colavita effect what modality is usually favoured?

Vision.

Does the Colavita effect reflect integration or competition?

Competition. Vision and audition compete for attention and vision tends to dominate the response.