Transcript Attention
Attention
What Is Attention?
Attention is the process by which the mind chooses from among the various stimuli that strike the senses at any given moment
allows only some info to enter into consciousness
Sternberg (1999): ‘Attention acts as a means of focusing
limited mental resources on the information and cognitive processes that are most salient at a given moment’
Related Concepts: Alertness Concentration Selectivity Control
Attention
Types of attention: Vigilance Focused Auditory Visual Divided
Vigilance
‘Person’s ability to attend to a field of stimulation over a prolonged period of time… person seeks to detect the appearance of a particular target …’
(Sternberg, 1999) A vigilance task usually involves waiting for something unpredictable to happen e.g. radar operator
Big Issues in Attention
Facts that drive attention research We are bombarded by more information than we can attend to
Selective Attention
Shiftability Sustainability
Divided Attention
Some tasks can be performed with little, if any, attention
Cocktail Party Effect
Focused Auditory Attention
Illustrated by the cocktail party phenomenon (Cherry, 1953) Ability to listen selectively to one conversation during a party while ignoring the noise going on around you Questions: what happens to the ‘excluded’ message? To what extent is it processed?
Dichotic Listening Task
Focused Auditory Attention
Dichotic listening task Different messages are presented to each of a participant’s ears S/he is asked to shadow or repeat one of the messages ‘on-line’ Questions about the message in the
un
attended ear Only the physical characteristics of unattended message could be reported e.g. gender of voice (Cherry, 1953)
Shadowing Results
Physical attributes of unattended channel are detected Male vs. female voice Human vs. musical instruments Semantic attributes of unattended channel were missed Don’t notice foreign language Don’t notice repeated items
Theories to explain Attention
Bottleneck Theories
Capacity Theories
Bottleneck Theories
All information gets into sensory register Somewhere along the way, information is filtered or selected for attention Early at perceptual level Late at response level Only selected information makes it into awareness and long-term memory
Filter Theory (Broadbent)
Focused Auditory Attention
Broadbent’s model (1958) An
early selection
model Sensory characteristics of all messages are processed A filter, under conscious control, selects one message Selection on the basis of physical characteristics, e.g. gender of voice All other messages excluded
Focused Auditory Attention
Broadbent’s Model (cont’d) But counter evidence suggests that the meaning of the unattended message, not just its physical characteristics, were being processed e.g. Moray (1959) – you always detect your name in the ‘excluded’ message e.g. Treisman (1964a) – bilingual participants able to recognise the identity of two messages in different languages
Attenuation Model (Treisman)
Present a story in dichotic listening task Story switches from attended ear to unattended ear Participant mistakenly shadows from attended ear to unattended ear Attended Ear:
She had peanut butter
you keep using that word
sandwiches
Unattended Ear: freaking laser beams
and jelly
Focused Auditory Attention
Treisman’s Model (1964) An
early selection
model All messages are processed beyond the sensory stage All messages are processed but unattended messages are
attenuated
Important stimuli (own name) have low thresholds so attenuated form is enough to activate name
Late Selection (Deutsch & Deutsch)
Focused Auditory Attention
Deutsch & Deutsch (1963)
Response selection
model
All
messages processed perceptually and for meaning. No filtering, no attenuation Bottleneck comes at the response stage, when only one of the messages can be responded to
Early Filtering (Broadbent): Filter Input Detection Recognition Attenuation (Treisman): Attenuator Input Detection Recognition Late Filtering (Deutsch & Deutsch): Filter Input Detection Recognition
Problems with Early Models
Memory for unattended channel may depend on familiarity or importance Cocktail party effect There are effects of practice There is implicit memory for the unattended channel even when there isn’t explicit memory Shock study People can shadow meaningful message that switch from ear to ear Treisman Memory for unattended channel affected by similarity to attended channel
Context Effects
Attended ear: “They were standing near the bank” Unattended ear: One of the following was presented “river” “money” Participants interpreted “bank” as a riverbank if they heard “river” a financial bank if they heard “money”
Problems with Late Models
Even if pertinence is controlled for We are more likely to notice effects in the attended channel (87%) We are less likely to notice effects in the unattended channel (8%) If selection is late Why do we feel like we’re consciously selecting early?
Neuro evidence Enhanced neural processing at early stages
Multi-mode Theory (Johnston and Heinz)
We may decide which stage we do the selection Late selection loads capacity
Focused Visual Attention
Attentional shifts from one target to another can be achieved: Overtly: overt movement of head and/or eyes Covertly: internal shift, in conditions where there is no time for eye movements
Focused Visual Attention
Analogies for covert attention The
spotlight
analogy Attention is like an internal spotlight. The area within the spotlight is attended to, the area outside is not The
zoom lens
analogy Experimental subjects can control whether they focus on a specific target (the middle letter of a five letter word) or spread their attention (across all the letters) (La Berge, 1983)
Focused Visual Attention
Treisman's
feature integration model
(Treisman & Gelade, 1980) Describes the role of attention in perceptual processing Detecting the features (colour, size, corners, lines) of a stimulus is done in parallel (simultaneously) and needs no attention Integrating these features into a percept is done serially (one after the other) and needs attention
Divided Attention
Focused attention asks about the extent to which we can focus on one task and ignore others Divided attention asks about the extent to which we can do more than one task at the same time
Divided Attention
There is a general assumption of limited capacity: i.e. resources available to process information are limited Two models: Central resource theory: a central bank of resources which is available for all tasks requiring mental effort Multiple resource theory: several banks of specialised resources, e.g. specific to a modality
Divided Attention
Strategic Control: the degree to which attention can be allocated, relatively, to competing tasks is under strategic control (Wickens & Gopher, 1977) Practice: improves the ability to do simultaneous tasks because practice leads to automaticity (Anderson). Automatic tasks need very little attention
Divided Attention
Central vs. multiple resource theory Doing two similar tasks is harder than doing two dissimilar tasks e.g. Segal & Fusella (1970) doing a visual imagery task with a visual detection task is harder than with an auditory detection task This suggests that there are separate resources for vision and audition, i.e. supports multiple resource theory
Divided Attention
Dual task experiments Get people to perform multiple tasks and look at the effects on performance Often find that performance suffers This breakdown of performance when two tasks are combined sheds light on the limitations and nature of the human information processing system
Dual Task Performance
Divided attention is difficult when: Tasks are similar Tasks are difficult When both tasks require conscious attention Divided attention is easier when: Tasks are dissimilar Tasks are simple When at least one of the tasks does not require conscious attention Tasks are practiced
Capacity Theories
Tasks take mental effort We have limited mental effort to allocate to all demands on our attention Conscious control of allocation Some tasks require more attention than others
Resource Allocation Model (Kahneman)
What Affects Allocation?
Resources Arousal Available Capacity Other Effects Enduring Dispositions Momentary Intentions
Different Processes
Some tasks are easier to perform than others and don’t seem to affect attention Especially tasks that are well practiced Other tasks are tedious and require our conscious attention Two types of processing: Automatic or pre-attentive processing Controlled or attentive processing
When Attention Is Lost
Visual Neglect
Their Visual Experience
Writing Reading
Bisect All the Lines
…