Perceptual Processes: Attention & Consciousness Dr. Claudia J. Stanny EXP 4507 Memory & Cognition Spring 2009

What do we mean when we say we are “paying attention?” Focus on one task to exclusion of others Selectivity Inhibition of irrelevant information Ability to shift attention (disengage from one task and engage with another task) Maintaining focus Vigilance – sustained attention to one task Division of effort across multiple tasks Multitasking Allocation of resources to multiple tasks 2Claudia J. Stanny

Defining Attention Vigilance (Sustained attention) Selective Attention (Focus on one task) Division of Attention (Multitasking) Attention as processing capacity or mental effort Controlled Processing (Attentional Processing) Automatic Processing 3Claudia J. Stanny

Vigilance Sustained attention Example: Radar screen operators Problems with boredom and distractibility Lapses Missed signals Observers periodically disengage from tasks to monitor the environment Neurological aspects of periodicities in attention (Aue, Arruda, Kass, & Stanny in review) Claudia J. Stanny4

Selective Attention Tasks Ability to focus attention Dichotic Listening Task Shadowing Task Stroop Task Selection of one stimulus source, task, or response Inhibition of other stimulus sources, tasks, or responses Claudia J. Stanny5

Selective Attention: Shadowing Tasks Cocktail Party Phenomenon Two distinct messages arrive at each ear Task is to repeat (shadow) the message in one ear 6Claudia J. Stanny

Selective Attention: Dichotic Listening Tasks Two sets of digits Report by time of arrival Report by location (left ear, right ear) Relative cost of reporting by location or switching channels to report by time of arrival 7Claudia J. Stanny

Selective Attention: Dichotic Listening Tasks Sometimes the cost of switching from one channel to another is less than predicted by an early selection model 8Claudia J. Stanny

Stroop Task Stimulus activates competing responses Color name (generated by reading) Color name (generated by perception of color) Two possible task demands: Read the word Name the ink color Must inhibit one response to make the correct response for the task demands Claudia J. Stanny9

Demonstration of the Stroop Task Claudia J. Stanny10

Divided Attention Division of attention across multiple tasks Questions: To what extent can attention be divided without loss in quality of performance on tasks? To what extent does practice change our ability to maintain task performance when attention is divided? Claudia J. Stanny11

What is the effect of practice? Automatic & Controlled Processing Schneider & Shiffrin, 1977; Shiffrin & Schneider, 1977 Controlled Processing Attentional processing Sequential, slow, flexible, requires resources Bottlenecks likely to occur during multi-tasking Automatic Processing Distributed processing Parallel, fast, inflexible, requires few resources May be able to multi-task automatic processes Claudia J. Stanny12

Demonstration of Automatic and Controlled Processing in the Shiffrin & Schneider Task Claudia J. Stanny13

Theories of Attention Bottleneck theories Resource theories Feature integration theory Claudia J. Stanny14

Bottleneck Theories Where in the stream of information processing does the bottleneck (selectivity) occur? Filter Theory (Broadbent, 1958) Attenuation Theory (Treisman, 1960) Late Selection Theory (Deutsch & Deutsch, 1963) Claudia J. Stanny15

Attention as Processing Resource Attention as an allocation of capacity or resources for processing information Kahneman (1973) Attention and Effort Role of arousal Effects of practice Potential for multitasking 16Claudia J. Stanny

Implications for Multitasking Development of automaticity can reduce demands on processing resource Automatic processing can enable the division of attention and multitasking Possible for simple, highly practiced tasks Errors appear when one or more tasks become more demanding Claudia J. Stanny17

Costs of Automaticity Costs of rapid switching between tasks Task analysis : Evaluate the specific demands of each task Automatic processes are inflexible and lead to errors when situation requires a new response Example in the Schneider & Shiffrin task: Attentional Capture Example in the Stroop task: Difficulty in inhibiting rapid but irrelevant responses 18Claudia J. Stanny

Multitasking Application: Driving while talking on a cell phone Claudia J. Stanny19 Cole, Kass, & Stanny (2007)

Consequences of Divided Attention: Other Applications Response times are slower when we are engaged in a cell phone conversation Distracting effects of advertising on web pages Web pages with ads take longer to read and comprehend than those without ads Added effects of animated ads Memory and understanding of main points in text is worse when textbooks include irrelevant cartoons and side bars to generate interest Relevant photos, cartoons, and other materials aid learning; irrelevant materials just distract Claudia J. Stanny20

Visual Search Feature present searches Target identified by a single feature Rapid, parallel searches (target “pops out”) Feature absent searches Target identified by the absence of a single feature Slow, serial examination of each stimulus We process positive information (feature present) more rapidly than negative information (feature absent) Claudia J. Stanny21

Demonstration: Visual Search Tasks Claudia J. Stanny22

Conjunction Searches Target is a combination of features Non-targets have only one of the features Slow, serial search process Focused attention to a location required to detect integrations of features When attention is distracted, illusory combinations of features might occur Claudia J. Stanny23

Demonstration: Searches involving Feature Conjunctions Claudia J. Stanny24

Feature Integration Theory Treisman & Gelade (1980) Distributed attention Process stimuli in parallel Processing is distributed across the spatial array Process dominated by feature detection Focused attention Process stimuli serially Attention is allocated to a specific spatial location to accurately integrate the features for that stimulus Claudia J. Stanny25

Neurological Correlates of Attention Orienting attention network Parietal lobe; active during visual search tasks & when attending to spatial locations Visual neglect when this area is damaged Executive attention network Frontal lobe; inhibits automatic responses when task produces conflicting responses (e.g., Stroop) Top-down control of attention Alerting attention network Orienting responses to novel stimuli Claudia J. Stanny26

Unilateral Neglect Lesions of posterior parietal lobe Some role of frontal lobe Hemineglect Usually seen with right parietal lesions 27Claudia J. Stanny

Visual Search in Unilateral Neglect Visual search strategies are biased to one side of the visual field in neglect Severity of neglect is exaggerated with increased visual clutter Claudia J. Stanny28 Husain, M (2008). Scholarpedia, 3(2):3681.

Attention and Consciousness Role of subjective awareness Awareness of products of mental processing Level of awareness of mental processes themselves Rapidity of some processes (e.g., retrieval) make them inaccessible to awareness or conscious examination Role of self-report as valid data about some processes (e.g., problem solving, metamemory, metacognition) Claudia J. Stanny29

Disorders of Attention Obsessive-Compulsive Disorder Attentional Deficit Disorder Blindsight Damage to visual cortex, sub-cortical visual areas intact Claudia J. Stanny30