Attention and Selective Attention

• Attention is the ability to focus on specific stimuli or locations
• Selective: attending to one thing and ignoring others
• Divided: paying attention to more than one thing at a time
• Capacity and timing are limited.
• Overt and covert: consciously attend to information, but some information grabs attention

Selective Attention

• Selective attention focuses on one message while ignoring others
• Humans do not attend to a large fraction of environmental information
• Information is filtered out and promoting other information for processing

Research Method: Dichotic Listening

• Presenting one message to one ear, and another to the other
• Participants "shadow" one message to ensure attendance
• Participants cannot report the content of the message in the ear they are not attending to.
• Participants know there is a message and what the gender the speaker is
• The unattended information is processed at some level
• Cocktail party effect happens when people respond to their name in a conversation around them
• Changes in gender or tones are noticed

Models of Selective Attention

• An attention filter occurs either early or later in processing

Early selection model

• It uses Broadbent's filter model

Intermediate selection model

• It uses Treisman's attenuation model

Late selection model

• MacKay (1973) is an example of this

Broadbent's Filter Model

• Filters the message before incoming information is analyzed
• Sensory memory holds all incoming information for a fraction of a second before transferring to the next stage
• A filter identifies the attended message based on physical characteristics
• Only the attended message is passed onto the next stage
• The detector processes all information to determine higher-level characteristics of the message
• Short-term memory receives output of detector, and holds information for 10–15 seconds, and may transfer it to long-term memory

Broadbent's Model Limitations

• The model cannot explain why participant's name gets through during the cocktail party phenomenon.
• The model cannot explain why participants shadow meaningful messages that switch from one ear to another in the "Dear Aunt Jane" experiment (Gray & Wedderburn, 1960).

Treisman's Attenuation Model

• Attended messages can be separated early in the information processing system
• Selection can occur later
• An attenuator analyzes incoming messages in terms of physical characteristics, language, and meaning
• Attended messages are let through the attenuator at full strength
• Unattended messages go through at much weaker strength than the attended message
• A dictionary unit contains words that each have a threshold for being activated.
• Words that are common or important have low thresholds
• Uncommon words have high thresholds

Late Selection Models

• Selection of stimuli for final processing does not occur until after information has been analyzed for meaning
• In MacKay's 1973 study participants heard ambiguous sentences in one ear.
• They heard either "river” or “money” in the unattended ear
• Participants chose which was closest to the meaning of attended message
• "They threw stones toward the side of the river yesterday."
• "They threw stones at the savings and loan association yesterday."
• Meaning of the biasing word affected participants' choice
• Participants were unaware of the presentation of the biasing words

Load Theory of Attention

• Processing capacity is the amount of information a person can handle at any given moment.
• Perceptual load is the difficulty of a given task
• High-load tasks require higher amounts of processing capacity
• Low-load tasks use lower amounts of processing capacity

Overt Attention

• It involves eye movements, attention, and perception
• Saccades are rapid eye movements from one place to another
• Fixations are short pauses on points of interest.
• Eye trackers are used to study this

Bottom-up Determinants of Eye Movement

• Stimulus salience are areas that stand out and capture attention
• Depends on characteristics of the stimulus like color and motion

Top-Down Determinants of Eye Movements

• Scene schema is knowledge about what is contained in typical scenes
• this helps guide fixations in a scene
• Eye movements are determined by task
• eye movements preceded motor actions

Covert Attention

• Precueing directs attention without moving the eyes
• Participants respond faster to a light at an expected location
• Participants respond even when eyes are kept fixed

The Stroop Test

• There is interference when the name of a word makes it difficult to name the ink color
• It is difficult to avoid paying attention to the meanings of the words

Divided Attention

• Practice enables people to simultaneously do two things that were difficult at first.
• Attention is divided between remembering and monitoring rapidly presented stimuli in Schneider and Shiffrin's (1977) study
• A memory set of one to four characters are called the target stimuli
• Test frames could contain random dot patterns, a target, and distractors.
• Automatic processing occurs without intention, using few cognitive resources.

Distractions: Cell Phone Use

• In a 100-Car Naturalistic Driving Study, accident risk is 4X higher when using a cell phone
• Strayer and Johnston's (2001) study simulated driving
• They found that participants on the phone missed twice as many red lights and took longer to apply the brakes
• The result was the same using "hands-free" phones

Attention and Visual Perception

• Inattentional blindness: Stimulus is not attended, even when a person is looking directly at it

Object-Based Visual Attention

• Attention is either location or object-based
• Location-based attention moves from one place to another
• Object-based attention is directed to one place on an object
• Egly 1994 found that participants saw two side-by-side rectangles followed by a target cue
• They found that reaction time was fastest when target appeared where indicated
• Reaction time was also faster when the target appeared in the same rectangle
• Enhancing effect of attention spreads throughout the object
• Attention can be based on the environment, specific objects, static scenes, or dynamic events

Change Detection

• Change blindness occurs when shown two versions of a picture and differences are not immediately apparent
• Identifying differences requires concentrated attention and search

Attention and Experiencing a Coherent World

• Binding combines features like color, form, motion, and location to create perception of an object

Feature Integration Theory

• Objects are analyzed into features in the preattentive stage, and the features are later combined with attention
• The preattentive stage is automatic, requires no effort or attention, is unaware of process, and analyzes objects into features
• In a 1982 study, Treisman and Schmidt found participants combine features from different stimuli.
• There were illusory conjunctions because features are "free floating"
• The focused attention stage means attention plays a key role to get correct answers
• In a 1982 study, Treisman and Schmidt told participants to ignore black numbers and focus on objects
• Then participants correctly paired shapes and colors

Balint's Syndrome

• R.M., a patient with Balint's syndrome, was studied in 1982 by Treisman and Schmidt
• Balint's syndrome involves the inability to focus attention on individual objects
• Balint's syndrome involves a high number of illusory conjunctions being reported
• The feature integration theory is mostly bottom-up processing.
• Top-down processing influences accuracy in identifying an object
• Top-down processing combines with feature analysis

Physiology of Attention

• Attention enhances neural responses, and is distributed across the brain
• fMRI detects cortical activity during a search
• Attention to an expected direction of motion caused brain activity to increase in a number of brain areas
• In a Datta and DeYoe (2009) study, participants directed their attention to different areas of a circular display while keeping their eyes fixed
• Researchers activated different brain areas by shifting what the participants were focusing on
• They found a yellow "hot spot" in the brain that had the highest activation from focusing attention

Explanation of attention, including selective and divided attention. Discusses overt and covert attention mechanisms and limitations in capacity and timing. Describes dichotic listening research method and cocktail party effect.