Understanding Attention and Selection

What is Attention?

• Attention refers to the cognitive processes that help us to sustain focus on some things at the expense of other things
• A cognitive system needs attention to avoid being overwhelmed by the vast amount of information arriving at our senses
• At each moment, there is vastly more information at our senses than our minds can process, so we need a cognitive filter

Attentional Selection

• Attention selects some information for further processing and filters out other information
• This selection happens in different ways:
• Sensory attention focuses on a specific sensory modality as a whole
• Feature-based attention is attention based on different low-level sensory features
• Object-based attention is attention to an object as a whole

Sensory Attention

• Attention can select for one sensory modality over another
• We usually attend to information coming in from vision

Feature-Based Attention

• We can pay attention to the same feature across multiple different spatial locations
• Examples of visual features include colour, shape, direction of motion, orientation, spatial frequency, etc.
• Examples of auditory features are pitch and timbre
• When concentrating on a song's bassline, one is using auditory feature-based attention
• Attending to 'citrus notes' in wine tasting is feature based attention
• When searching for an app on a smartphone, most people use feature-based attention as their first strategy
• Searching for the calendar by looking for apps that are white with a number on them is feature based
• Problems can occur when two apps share features

Object-Based Attention

• We can pay attention to a single visual 'object', even when it overlaps with another object in space
• Paying attention to one feature of an object enhances cognitive and neural processing of the rest of the object
• Paying attention to the direction of motion of the face enhances processing of the face's other features, like expression and orientation

Dichotomies of Attention

• Dichotomies help to understand the different kinds of attention and what they all have in common
• Attention operates by selecting some things for further cognitive processing at the expense of other things

External vs. Internal Attention

• External attention selects things in the external world, like stopping and listening to sounds in a room
• Internal attention selects things in your internal world of thoughts, feelings, and memories, like recalling how many rooms were in the house that you lived in when you were a child
• You drop a hammer on your toe and for a moment your mind focuses on the pain in your foot, this is an example of the distinction being not perfect, is it internal or external attention?

Overt vs. Covert Attention

• Overt attention is when external visual information is selected via movements of the eyes
• Information is foveated with overt attention
• Covert attention is when external visual information is selected without eye movements
• Both are kinds of external attention

Voluntary vs. Reflexive Attention

• Voluntary attention is when we direct attention to an object by conscious volition
• Relaxing by paying attention to the feeling of the breath going in and out of your lungs is an example of voluntary attention
• Reflexive attention is when something captures our attention because of unconscious processes
• Both voluntary and reflexive attention can be either internal or external
• For visual stimuli, reflexive external attention is usually overt unless effort is exerted

Sustained vs Divided Attention

• Sustained attention is when attention selects a single stimulus for subsequent processing
• Complete focus on your notes while studying is sustained attention
• Divided attention is when attention selects multiple stimuli for processing at the same time
• Note all attention is capacity-limited with an upper limit on how many things we can attend to at the same time
• There are also capacity limits for other cognitive processes in the mind which is the reason why we need attention in the first place
• When we divide our attention across multiple tasks, performance on those tasks suffers
• Texting while driving is an example of divided attention, so it is dangerous

Summary of Attention

• Attention is a family of capacity-limited processes by which certain information is prioritised for processing (or 'selected') over other information
• There are different ways that we 'select' information to attend to (sensory, feature-based, object-based)
• The information that is selected may be external (in our environment) or internal (like memories or feelings)
• External attention may or may not involve moving your eyes to look at something directly
• Attention can be directed to a thing voluntarily, or can be reflexively captured
• A single thing might be selected (sustained attention), or multiple things might be selected at the same time (divided attention)
• There are capacity limitations on attention, meaning that here is an upper limit on how many things we can attend to at the one time

When Does Attention Happen?

• Early selection theories propose that attention operates after low-level features are extracted, but before stimuli are processed to the level of semantic meaning
• Evidence comes from dichotic listening experiments
  • Participants are presented with different audio in their left vs. right ear
• They are instructed to pay attention to one ear only
• They typically cannot answer questions accurately about information from the unattended ear

Early Selection Theory: Broadbent's Filter Model

• Broadbent proposed that attention is a filter that selects a single message and screens all other messages out
• Filtering is based on low-level sensory features, such as high pitch versus low pitch

The 'Dear Aunt Jane' Experiment (Gray & Wedderburn, 1960)

• If participants were attending solely to the left ear, they should report "Dear 7 Jane"
• Instead, they are more likely to report "Dear Aunt Jane"

Early Attentional Selection Theory: Treisman's Attenuator Model

• Anne Treisman proposed that attention should be thought of as an attenuator rather than a filter (attenuate = weaken, reduce, lessen)
• Attention is not all-or-nothing. Instead, it amplifies the selected message and attenuates others
• The attenuator operates before semantic information is extracted, so this is still an early-selection model
• The attenuated information is then passed to a 'dictionary unit' that analyses meaning
• Some words in the dictionary have a higher threshold for activation, which means it takes more input for them to be passed on
• A person's own name has a very low threshold for activation

Late Attentional Selection Theories

• Late-selection models place a filter after the extraction of semantic memory
• The meaning of all stimuli is analysed fully
• These models have a hard time accounting for data from dichotic listening experiments

Flexible Attentional Selection

• Nilli Lavie's load theory showed that semantic processing of unattended information depends on the cognitive load of the attended task
• Cognitive load can be how easy or automatic a task is
• Under low cognitive load, there are spare attentional resources that are automatically used for semantic processing of unattended stimuli
• This resembles late selection models
• Under high cognitive load, there are no spare attentional resources, and so unattended stimuli receive no semantic processing
  • This resembles early selection models
• The more automatic a task is, the more capacity is left over for processing distracting information
• This predicts that phone-based distractions will affect experienced drivers more than learners

Feature Extraction and Binding

• The extraction of low-level sensory features is pre-attentive
• Feature integration theory proposes that the act of attending to a stimulus binds its various features together into a coherent percept
• If we do not attend to a stimulus, its features are not bound together
• Some individuals with brain damage in the parietal lobe show impaired feature binding
• Before we attend to an object, it is represented in our minds as a set of unconnected features
• Visual objects consist of colour, shape, motion, location, etc
• Auditory objects consist of pitch, direction, loudness, etc
• By attending to an object, those different features are bound together or 'integrated'
• Another way of saying this is that attention helps our minds to solve the binding problem
• We can't consciously perceive these free-floating features
• Treisman would say that this is because feature integration happens prior to conscious awareness

Illusory Conjunctions

• The first piece of evidence that features are free-floating before we attend to them comes from illusory conjunction experiments
• Features from two different objects are erroneously bound together into a single percept

Feature Search vs. Conjunction Search

• Conjunction search requires feature binding by attention, whereas feature search does not

How Can Attention Go Wrong?

• Attention to things we don't want to pay attention to is distractibility
• Not attending to things we might want to pay attention to is attentional blindness

Distraction

• Distraction is when attention to a primary task is interrupted by another task or stimulus
• Distraction can be good if the interrupting task or stimulus is important
• We usually use the term distraction when the interrupting task or stimulus is less important than the primary task

Stimuli and Attention

• Recall that earlier we drew a distinction between reflexive attention and voluntary attention
• Attentional capture is the process by which a stimulus attracts reflexive attention
• If a stimulus is very good at capturing attention, we say that the stimulus is highly salient

Factors Influencing Stimulus Salience

• Stimuli can acquire salience if they do not share many perceptual features with the stimuli around them
• Stimuli that are very personally meaningful, tend to capture attention
• Stimuli with strong positive or negative associations are highly salient
• In the "dot probe" task, stimuli that follow a very positive or very negative image are detected more quickly than stimuli that follow a neutral image
• This effect is particularly strong for negative images in individuals with an anxiety disorder

ADHD

• Attention deficit hyperactivity disorder (ADHD) is frequently misunderstood
• Inattention and hyperactivity are two different components of ADHD
• Increased distractibility is one of the key aspects of the inattention component of ADHD
• Individuals with ADHD are more easily pulled off task by external/internal stimuli.
• Increased distractibility is often explained by a heightened sensitivity to reflexive attention
• In ADHD, reflexive capture seems to be stronger and more easily triggered by a wider range of stimuli.
• The way individuals with ADHD perceive the salience of different stimuli, might be different
• Things that might not readily capture the attention of someone without ADHD could be much more salient and attention-grabbing for someone with ADHD

Attentional Blindness

• Attentional blindness involves situations where we don't attend to things we perhaps should or might want to notice

Inattentional Blindness

• a class of phenomena that show we are unconscious of perfectly visible (or audible) stimuli unless we pay attention to those stimuli
• Simons & Chabris' 'gorilla experiment' is an example of inattentional blindness

Change Blindness

• We are incapable of detecting changes to stimuli unless we are paying attention to the relevant part of the stimulus