Attention

Function of attention

Signal detection and vigilance
• Keep an eye out for what you need
Search
• Find signal among distracters
Selective attention
• Attend to some stimuli and ignore others
Divided attention
• Manage attention to coordinate work

Metaphor 1: The Spotlight

• Attention acts like a spotlight

• it 'illuminates' selected information

• Enhances processing of whatever falls within the beam

• Attended objects are processed faster & more accuratel

• Spotlight can move (covertly, without eye movement)

Endogenous

Top-down / voluntary
• Internally driven
• You decide to focus
• Examples: studying, proofreading,
searching for a friend in a crowd
• Slower to deploy, but precise

Exogenous

• Bottom-up / reflexive
• Externally driven
• Stimulus captures you
• Examples: loud bang, flashing notification,
someone calling your name
• Rapid & automatic, hard to suppress

Signal detection theory

A signal is the important information we are trying to notice. REQUIRES:

• Attention: focusing on possible signals.

• Perception: interpreting what you sense.

• Memory: comparing the signal to past experiences.

• Decision-making: deciding whether the signal is real.

Vigilance

• Waits for a signal that may come at unknown time

• Watching clock hand jumps, miss rates rise over time

• Training helps, but rest produces quicker results

• Expectation of stimulus location affects efficiency

Metaphor 2: The Filter

• Attention acts like a filter that gates information flow

• Unwanted input is blocked before reaching higher processing

• Broadbent's early filter model (1958): filter selects by physical features (pitch, loudness, location)

• Problem: we still notice our own name in an unattended channel → selective filter / late-filter models

• Key debate: Where in processing does selection happen?

CONTROLLED

Effortful and deliberate

Requires awareness

Serial (one thing at a time)

Resource-limited — draws heavily on working memory

Best for novel or complex tasks

AUTOMATIC

Effortless; requires little conscious attention

Fast, parallel (many things at once)

Involuntary — hard to stop

Develops through extensive practice

Examples: driving a familiar route, reading words

Similarity theory

Similarity of target to distracters reduces detection

Degree of disparity of targets and distracters important

Difference between distracters also plays a role

Dissimilar distracters make object easier to find

Selective Attention: Ignoring the Irrelevant

the ability to focus on task-relevant information while filtering out task-irrelevant information

Broadbent's Early Filter

Physical features (pitch, location) gate information before it's processed semantically. Unattended channel is completely blocked.

Treisman's Attenuation

Rather than blocking, the filter weakens non-target channels. Personally significant info (own name) can still break through

Late Selection Models

All info is fully processed for meaning; selection happens after semantic analysis. Explains how we can detect our name.

Vigilance Decrement

Sustained attention tasks show miss rates rise over time. The brain's alerting system fatigues — even for trained professionals (air traffic control, radiology).

Improving Vigilance

Rest & breaks restore performance faster than training. Knowing signal location helps. Moderate arousal is optimal (Yerkes-Dodson law).

Single Pool Model

One shared pool of limited cognitive resources

Any two tasks draw from same pool

Performance degrades as tasks compete

Explains: difficulty driving while in deep conversation

Multiple Resources Model

Separate pools for different modalities & stages

Tasks using DIFFERENT resources interfere less

Example: jogging + listening to a podcast (fine); jogging + reading (hard)

Explains: you can sometimes successfully dual-task if modalities differ

Automatization: From Novice to Expert

With practice, controlled processes become automatic — freeing up resources for higher-level tasks.

Capture errors:

Auto-pilot overrides new intention (drive home when meaning to stop at store

Perseveration

Repeat a completed step (add sugar twice to coffee)

Loss of activation:

Forget goal mid-routine (why did I open the fridge?)

A L E R T I N G

OR I E N T I N G

E XE C U T I V E C ON T R OL

🔄 Change Blindness

Fail to notice large changes in scenes when there's an interruption (cut, blink, flicker). Real-world risk: missing important changes in medical imagery or traffic.

👁 Inattentional Blindness

Fail to see clearly visible objects when attention is occupied elsewhere. The gorilla experiment (Simons & Chabris 1999) — ~50% miss it.

🗺 Spatial Neglect

After lesion (often right parietal/frontal lobe), patients ignore the contralateral hemifield. Draw only right side of a clock. Not blindness — attention deficit

Habituation

We give decreasing attention to repeated stimuli — a conscious process tied to episode count.

Sensory adaptation:

The senses themselves diminish response to constant stimuli (smell, touch) — unconscious, tied to stimulus intensity.

Dishabituation

A change in the habituated stimulus captures attention again — the basis of 'contrast effects' in advertising and alarm design.

Attention to Action: Norman & Shallice's Model

Supervisory Attentional System (SAS)

Top-down executive control that overrides contention scheduling for novel, dangerous, or complex situations — the prefrontal cortex in action.