Attention and Consciousness

Chapter 3

Outline

1. The Nature of Attention and Consciousness

2. Attention1. Vigilance and Signal Detection2. Search 3. Selective Attention4. Divided Attention

3. Cognitive Neuroscientific Approaches to Attention

1.The Nature of Attention and Consciousness

• Attention– Is the means by which we actively process a limited

amount of information from the enormous amount of information available through our senses, our stored memories, and our other cognitive processes

• Consciousness– More directly concerned with awareness – it includes

both the feeling of awareness and the content of awareness, some of which may be under the focus of attention

1.The Nature of Attention and Consciousness

Different conceptions of consciousness:• Biopsychological

– different levels of arousal (sleep, coma, hyperactivity)• Meta-cognitive

– Reflection on your own cognitive processes– Being aware of cognitive processes

• Psychoanalytic– Unconscious information – we do not have access to

it in normal awakened state• Phenomenological

– What it is like to have an experience of something– Individual, subjective aspects of experience

1.The Nature of Attention and Consciousness

Relationship between attention and consciousness

• Attention + Consciousness• No attention + No Consciousness• Attention + No Consciousness• No attention + Consciousness

?

Can you provide an example of each of the possible relationships between attention

and consciousness?

1.The Nature of Attention and Consciousness

1. Preconscious Processing

• Information that is available for cognitive processing but that currently lies outside of conscious awareness exists at the preconscious level of awareness

1.The Nature of Attention and Consciousness

1. Preconscious Processing

• Priming– Processing of certain stimuli is facilitated by

prior presentation of the same or similar stimuli

– Sometimes we are aware of the prime sometimes we are not

– Even when we are not aware of the prime, the prime will influence the processing of the target

1.The Nature of Attention and Consciousness

1. Preconscious Processing

Antony Marcel (1983)• Participants had to classify series of words into

various categories (e.g. pine-plant)• Primes where words with two meanings such

as palm followed by target word (tree or hand)• Task outline:

Is this a plant?Prime – PALMTarget - TREE

1.The Nature of Attention and Consciousness

1. Preconscious Processing

Antony Marcel (1983) (cont.)- If the participant was consciously aware of

seeing the word “palm”, the mental pathway for only one meaning was activated

- If the word “palm” was presented so briefly that the person was unaware of seeing the word, both meanings of the word appeared to be activated

1.The Nature of Attention and Consciousness

1. Preconscious Processing

Tip-of-the-tongue phenomenon• We try to remember something that is known

to be stored in memory but that cannot quite be retrieved

• People who can not come up with the word, but who thought they knew it, could identify the first letter, indicate the number of syllables, or approximate the word’s sounds

1.The Nature of Attention and Consciousness

1. Preconscious processing

Blindsight• Lesions in some areas of the visual cortex• Patients claim to be blind• When forced to guess about a stimulus in the

“blind” region, they correctly guess locations and orientations of objects at above-chance levels

1.The Nature of Attention and Consciousness

2. Controlled Versus Automatic Processes• Controlled processes

– Require intentional effort; full conscious awareness; consume many attentional resources; performed serially; relatively slow

• Automatic Processes– Little or no intention or effort; occur outside of

conscious awareness; do not require a lot of attention, performed by parallel processing; fast

1.The Nature of Attention and Consciousness

2. Controlled Versus Automatic Processes

• Many tasks that start off as controlled processes eventually become automatic ones

• Automatization – The process by which a procedure changes

from being highly conscious to being relatively automatic

?

Can you provide some examples

of automatic and controlled processes?

1.The Nature of Attention and Consciousness

3. Habituation• Habituation

– We become accustomed to a stimulus, we gradually notice it less and less (e.g. music and studying)

• Dishabituation– A change in a familiar stimulus prompts us to start

noticing the stimulus again

• Sensory adaptation– Physiological phenomenon; not subject to conscious

control; occurs directly in the sense organ, not in the brain

2. Attention

1. Vigilance and Signal Detection• We vigilantly try to detect whether we did or did

not sense a signal (a particular target stimulus of interest)

• Vigilance– A person’s ability to attend to a field of stimulation

over a prolonged period, during which the person seeks to detect the appearance of a particular target stimulus

– Example – (Mackworth, 1948) • Participants were watching when a clock hand took a double

step• Substantial deterioration after half an hour of observation• Vigilance can be increased with training

2. Attention

2. Search• Search

– Scan the environment for particular features– Whereas vigilance involves passively waiting for a

signal stimulus to appear, search involves actively seeking out the target

• Distracters– Nontarget stimuli that divert our attention away from

the target stimuli– Can cause false alarm

2. Attention

2. Search2 kinds of search:• Feature search

– When we can look for some distinctive features of a target we simply scan the environment for those features (e.g. T vs. O)

• Conjunction search– We look for a particular combination of

features (e.g. T vs. L, p. 85)

2. Attention

2. Search• Feature-Integration Theory (Anne Treisman)

– Each of us has mental map for representing the given set of features for a particular item (shape, size, color features)

– During feature searches we monitor the relevant feature map for the presence of any activation in the visual field

– During conjunction searches, we can simply use the map of features, we must conjoin two or more features into an object representation at a particular location

2. Attention

2. Search

• Similarity theory (Duncan and Humphreys)– As the similarity between target and distracter

increases, so does the difficulty in detecting the target stimuli

– Factors influencing search• Similarity between the target and the distracters• Similarity among distracters (p. 86, 87)

2. Attention2. Search

• Guided search theory (Cave and Wolfe)– All searches involve two consecutive stages

• Parallel stage – simultaneous activation of all the potential targets

• Serial stage – sequential evaluation of each of the activated elements

• Movement-Filter theory (McLeod at al.)– Movement-filter – can direct attention to stimuli with a

common movement characteristics– Movement can both enhance and inhibit visual search

2. Attention

3. Selective Attention• Stroop effect (Stroop, 1935)

– Demonstrates the psychological difficulty in selectively attending to the color of the ink and trying to ignore the word that is printed with the ink of that color

– Since reading is an automatic process (not readily subject to your conscious control) you find it difficult intentionally to refrain from reading and instead to concentrate on identifying the color of the ink

2. Attention

3. Selective Attention• The cocktail party problem (Cherry, 1953)

– The process of tracking one conversation in the face of the distraction of other conversations

• Shadowing– Listening to two different messages and repeating

back only one of the messages as soon as possible after you hear it

• Dichotic presentation– Listening to two different messages (presenting a

different message to each ear) and attending to only one of them

2. Attention

3. Selective Attention

Filter and Bottleneck Theories• Broadbent’s Model

– We filter information right after it is registered at the sensory level

• Moray’s Selective Filter Model– The selective filter blocks out most information at the

sensory level, but some highly salient messages are so powerful that they burst through the filtering mechanism (e.g. your name)

2. Attention

3. Selective Attention

Filter an Bottleneck Theories (cont.)• Treisman’s Attenuation Model

1. We preattentively analyze the physical properties of a stimulus (stimuli with target properties)

2. We analyze whether a given stimulus has a pattern, such as speech or music

3. We sequentially evaluate the incoming messages, assigning appropriate meanings to the selected stimuli messages

2. Attention3. Selective Attention

Filter and Bottleneck Theories (cont.)• Deutsch and Deutsch’s Late Filter Model

– Placed the signal-blocking filter later in the process, after sensory analysis and also after some perceptual and conceptual analysis of input had taken place

• Neisser’s Synthesis– Two processes governing attention

• Preattentive processes (rapid, automatic, parallel)• Attentive processes (controlled, occur later, serial)

2. Attention

3. Selective Attention

Attentional-Resource Theories

• We have attentional resources specific to a given modality– Explains why we can study and listen to a

music but not listen to news

2. Attention

4. Divided Attention

• The attentional system must perform two or more discrete tasks at the same time– much better performance at two or more

automatic tasks (driving a car and speaking) than controlled tasks (writing and comprehending read text)

3. Cognitive Neuroscientific Approaches to Attention

• Hemineglect (Martha Farah)– Patients ignore half of their visual field

• Attention deficits have been linked to lesions in – The frontal lobe– The basal ganglia

Stroop Effect

Read through this list of color names as quickly as possible. Read from right to left

across each line

Red Yellow Blue Green

Blue Red Green Yellow

Yellow Green Red Blue

Stroop Effect

Name as quickly as possible the color of ink in which each word is printed. Name from

left to right across each line.

Red Blue Green Yellow

Yellow Red Blue Green

Blue Yellow Green Red