Attention Selects Stimuli for Processing

• Attention—or selective attention—is the process of selecting or focusing on one or more stimuli for enhanced processing and analysis.

• Arousal is the global level of alertness in an individual.

• Overt attention occurs when the focus coincides with the sensory orientation.

• In covert attention, the focus is independent of sensory orientation.

• Cocktail party effect—selectively enhanced attention to filter out distracting stimuli.

Covert Attention

Selective Attention Videos

The "Door" Study demonstrating "change blindness"

Did You see the Gorilla

The Monkey Business Illusion

Attention Selects Stimuli for Processing

• Inattentional blindness • can occur in a shadowing task using two sources of visual stimuli.

• Subjects fail to perceive nonattended stimuli.

• Change blindness • is the failure to notice changes when comparing two alternating static

visual scenes.

• Change-detection• For objects that have evolutionary importance such as other animals

Bottlenecks in Attention

The Stroop Effect

Attention May Be Endogenous or Exogenous

• Endogenous attention—or voluntary attention—is directed toward aspects of the environment in keeping with interests and goals.

• In this top-down process, higher-order cognitive processes control lower-order systems, often with conscious control.

• The symbolic cuing task measures reaction time to a stimulus that is preceded by a hint as to the location it will appear.

• The cues presented may be valid, or invalid.

Measuring the Effects of Endogenous Shifts of Attention

ERP Changes in Endogenous Visual Attention

Attention May Be Endogenous or Exogenous

• Exogenous attention—or reflexive attention—is the involuntary reorienting of attention toward a stimulus source, cued by an unexpected object or event.

• In this bottom-up process, lower-order sensory inputs trigger processing by higher-order systems.

• A peripheral spatial cuing task measures latency to detect a visual stimulus, when it is preceded by an irrelevant stimulus in the same location.

• Due to inhibition of return, longer intervals (200 ms or more) interfere with processing of valid cues.

Exogenous Attention and Inhibition of Return

Early Television Exposure and Subsequent Attentional Problems in Children

• Television viewing is correlated with decreased attention spans in children

• Television watched daily at ages 1 and 3 years• Ten percent of children had attentional problems at age 7• A 1-SD increase in the number of hours of television watched at

age 1 is associated with a 28% increase in the probability of having attentional problems at age 7.

• Is this part of the environmental factors that influence the development of ADHD?

Extensive Television Viewing and the Development of Attention and Learning Difficulties During Adolescence

• Frequent television viewing during adolescence– is correlated with an elevated risk for subsequent attention and learning

difficulties after family characteristics and prior cognitive difficulties were controlled.

– 1 or more hours of television per day at age 14 had more

• poor homework completion, negative attitudes toward school, poor grades, and long-term academic failure.

– 3 or more hours of television per day increased these problems

– 3 or more hours of television per day also showed

• attention problems • Less likely to finish college.

– Not because of reciprocal effects between television viewing and learning difficulties

Development of Attention

• Development of attentional networks – alerting network matures throughout adolescence and into

adulthood

– orienting network seems to be formed as early as 4 years of age

– executive attention network develops from 4 to 7 years of age• executive attention might not change much past the age of 7 • however, inhibitory control and emotional regulation development into

adolescence• between 8 and 12 years of age reduced brain activation

– right-sided frontal-midbrain regions during alerting

– right-sided temporoparietal junction during orienting

– dorsolateral prefrontal cortex during executive control of attention

• children also showed more activation in several regions compared with the adults

– superior frontal gyrus during orienting

– superior temporal gyrus during executive control of attention

The Immediate Impact of Different Types of Televisionon Young Children’s Executive Function

• 4-year-olds watched 9 minutes of either– Fast paced television cartoon (Sponge Bob)– http://spongebob.nick.com/videos/clip/spongebob-173b-mrs-puffs-plan-clip.html

– Educational cartoon (PBS of young boy) – Or drew for 9 minutes

• Immediately tested on 4 tasks assessing executive function– Tower of Hanoi– HTKS task– Delay-of-gratification– Backward digit span

• Children who watched the fast-paced television cartoon performed significantly worse on the executive function tasks than children in the other 2 groups

Disorders Provide Clues about the Organization of Attention

Attention-deficit hyperactivity disorder (ADHD) is a syndrome of distractibility, impulsiveness, and hyperactivity that, in about 5% of all children, interferes with school performance.

These children tend to have overall brain volumes reduced about 3–4%, with reductions most evident in the cerebellum and in the frontal lobes.

Attention and awareness are behavioral and experiential manifestations of consciousness but are not synonymous.

Consciousness may be defined as being aware that we are conscious and perceiving what is going on in our minds and around us.

Disorders Provide Clues about the Organization of Attention• Damage to the attentional system in the right hemisphere can

cause behavioral changes.• Hemispatial neglect is a syndrome in which no attention is paid

to one side of the body or to things presented to that side.• Hemispatial neglect results from damage to the right inferior

parietal cortex.

• Extinction—or extinction of simultaneous double stimulation—is the inability to recognize stimuli presented to both sides that can occur with right inferior parietal lesions.

• Anosognosia is the denial of illness, and patients may not recognize signs of their unilateral neglect, even disclaiming ownership of their limbs.

ERP Maps in Exogenous Visual Attention

Exogenous and Endogenous Attention Are Complementary

Visual Search

Effects of Attentional Spotlights on fMRI Activation in Visual Cortex

Effect of Selective Attention on the Activity of Single Visual Neurons

Attentional Remodeling of a Neuron’s Receptive Field

Shifts of attention between cued locations cause shifts in peak sensitivity within a receptive field map of one neuron.

Attention can also apparently cause the overall size of receptive fields to shrink, sharpening the receptive field

Many Brain Regions Are Involved in Processes of Attention

Several cortical regions are associated with the source or control of attention.

The lateral intraparietal area—or LIP—is involved in the top-down control of attention in monkeys.

The human homolog to this region is the intraparietal sulcus (IPS).

Both encode a salience map (or priority map) controlling the voluntary shifts of attention.

The frontal eye field (FEF) establishes gaze in accordance with cognitive goals (top-down processes) rather than with characteristics of stimuli.

The temporoparietal junction (TPJ) helps shift attention to a new location after target onset.

Cortical Regions Implicated in the Top-Level Control of Attention

A Frontoparietal Attentional Control Network

A Right Temporoparietal System Responds to Novel Stimuli

The Cortical Attentional Control Network

Diagnostic Test for Hemispatial Neglect

Brain Damage in Hemispatial Neglect