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Broadbent's Filter Model of Attention
Designed to explain selective attention, based on Colin Cherry's dichotic listening experiments. These experiments presented different stimuli to each ear, with participants shadowing (repeating aloud) the message in the attended ear.
Cherry found participants could identify the gender of the voice in the unattended ear but not its content. This confirmed people are generally unaware of unattended information.
Neville Moray (1959) Dichotic Listening Experiment
Showed participants were unaware of a word repeated 35 times in the unattended ear.
Introduced the "cocktail party effect": the ability to focus on one conversation amid many.
Moray's key finding: about a third of participants detected their name in the unattended ear, suggesting meaning can bypass Broadbent's filter.
Gary and Wedderburn (1960) "Dear Aunt Jane" Experiment
Participants shadowing "Dear 7 Jane" in one ear and hearing "9 Aunt 6" in the other, reported "Dear Aunt Jane."
This demonstrated attention can switch channels based on semantic meaning (top-down processing).
Anne Treisman's Attenuation Model
A modification of Broadbent's model, proposing selection occurs in two stages.
Replaced Broadbent's filter with an attenuator, which analyzes messages based on: (1) physical characteristics (pitch, speed), (2) language (syllables, words), and (3) meaning.
The attenuator weakens unattended messages rather than completely blocking them, leading to its nickname, the "leaky filter model."
Dictionary Unit (Treisman's Model)
The second stage where messages are analyzed.
Contains words stored in memory, each with a threshold for activation. Words with low thresholds (e.g., one's own name) are easily detected even when attenuated.
Treisman's is still an early selection model as it proposes filtering before full semantic processing.
Donald MacKay (1973) Late Selection Model
Experiment: Participants shadowed ambiguous sentences (e.g., "They were throwing stones at the Bank") in one ear, while biasing words ("river" or "money") were presented to the unattended ear.
Participants' interpretation of the ambiguous sentence was influenced by the unattended biasing word, even though they reported no awareness of it.
This led to the late selection model of attention: selection for final processing occurs after the meaning of messages has been analyzed.
Behavior is connected to priming, specifically lexical priming (meaning-based priming).
Ignoring Distracting Stimuli (2 Factors)
Processing capacity: The limited amount of information a person can handle.
Perceptual load: The difficulty of a task. Low-load tasks leave capacity for distractors; high-load tasks use most capacity, reducing distraction.
Load theory of Attention
Explains that high-load tasks consume most processing capacity, leaving no resources for irrelevant stimuli, thus reducing distraction. Low-load tasks leave residual capacity, allowing distractors to be processed and affect performance.
Types of Attention
Endogenous attention: Voluntary, goal-driven focus (e.g., studying while ignoring coffee shop noise).
Exogenous attention: Involuntary, transient focus toward a sudden stimulus (e.g., startled by a loud siren).
Stroop Effect
Difficulty responding to one aspect of a stimulus (e.g., ink color) while ignoring another (e.g., the word's meaning), especially when they conflict (e.g., the word "RED" printed in blue ink).
Scanning a Scene with Eye Movements
Central vision: Foremost region of visual field, containing the fovea (high detail vision).
Peripheral vision: Surrounds central vision.
Fixation: Pausing eyes on points of interest.
Saccadic eye movements: Rapid, jerky eye movements between fixations.
Overt and Covert Attention
Overt attention: Shifting attention by moving the eyes.
Stimulus Salience: Physical properties (color, contrast, movement) capturing attention. This is a bottom-up process, analyzed via saliency maps.
Scene Schema: Observer's knowledge about typical scenes guiding attention (top-down process).
Covert Attention: Shifting attention without moving the eyes (e.g., "looking out of the corner of your eye").
Michael Posner's pre-cueing experiment showed that information processing is more effective at locations where attention is directed.
This illustrates the "spotlight" or "zoom lens" idea of attention.
Same-Object Advantage
Attention to one part of an object enhances processing for other parts of the same object.
Attention and Perception
Attention enhances perception, making attended objects seem bigger, faster, more richly colored, and with better contrast.
Experiments by Datta and DeYoe used fMRI to create "attention maps," demonstrating that directing attention to specific areas activates specific brain regions.
Tolga Cuker and colleagues described Attentional Warping: the brain's categorical map changes to prioritize categories being searched for, even if they're not present.
Divided Attention, Task Switching, and Multitasking
Divided attention: Paying attention to multiple things simultaneously by allocating cognitive resources (e.g., listening to music while driving).
Task switching: Rapidly shifting attention and cognitive resources between tasks (e.g., texting and driving).
Multitasking: Attempting to consciously divide attention and switch between multiple tasks. People often overestimate their multitasking ability.
Automatic Processing and Choking
Automatic Processing (Schneider & Shiffrin):
Occurs without intention.
Uses limited cognitive resources.
Choking: A decline in performance due to increased conscious awareness or intended control of a task, often under pressure.
Productivity Illusion: Multitasking drivers feel productive but rely on error-prone memory processes, increasing risk and reducing effectiveness on all tasks.
Mind Wandering
Thoughts originating internally (daydreaming) that detract from task performance, like "mindless reading."
Associated with activation in the default mode network (DMN), which is active when not engaged in a task.
Inattentional Blindness and Deafness
Inattentional blindness: Failure to notice a visible stimulus when attention is directed elsewhere.
Inattentional deafness (Raveh & Lavie):
Occurs when inattention causes a person to miss an auditory stimulus.
High-load visual tasks make it harder to detect tones, supporting Lavie's load theory across modalities.
Change Detection and Blindness
Change detection: Detecting differences between sequentially presented pictures.
Change blindness: Difficulty detecting obvious changes in scenes when attention is not directed to them (e.g., Rensink's experiments with blank fields between images).
Continuity errors: Unnoticed discrepancies in film scenes across cuts.
Binding and Feature Integration Theory (FIT)
Binding: The process of combining individual features (color, form, motion, location) to perceive a coherent object.
Binding Problem: How the brain achieves this combination.
Feature Integration Theory (FIT) (Anne Treisman): Proposes two stages:
Pre-attentive stage: Automatic, unconscious, and effortless analysis of object features independently (e.g., redness, roundness, movement are processed separately).
Focused attention stage: Attention is focused on an object, combining its independent features to create a conscious perception of the whole object.
Illusory Conjunctions
Experiments showed participants combining features from different objects (e.g., reporting a red circle and green triangle after seeing a red triangle and green circle), especially when attention was divided.
Balint's Syndrome
Parietal lobe damage causing inability to focus attention on individual objects.
Patients often report illusory conjunctions, supporting FIT's idea that focused attention is crucial for feature binding.
Visual Search
Conjunction search: Searching for a target defined by two or more features (e.g., a "horizontal" and "green" object among distractors).