Attention

Attention

Ability to select behaviourally relevant input and ignore the rest

Exogenous attention

Involuntary, stimulus driven, caused by external sensory input

Endogenous attention

Voluntary, goal-driven, controlled by internal thoughts

Spatial attention

Often described as a ‘spotlight’ that enhances information at a specific location in the visual field

Feature-based attention

Enhances the representation of low-level features such as colour, motion, orientation

Object-based attention

Attention selects a coherent object, rather than just a chunk of space

Focused attention

One target

Divided attention

Multiple targets

Overt attention

With eye-movement

Covert attention

Without eye-movement

Selective attention

Filtering through necessary informationS

Sustained attention

Prolonged focus

Top-down attention

Selective attention, goal-directed, driven by internal priorities, expectations and task demands

Bottom-up attention

Information that catches attention, stimulus-driven by salient or unexpected features in the environment.

How do top-down and bottom-up attention work together?

In a continuous and parallel manner, allowing us to focus on what is necessary while also scanning the environment for what may be important

Cherry’s Cocktail Party (1953)

Used a dichotic listening task, where the voices’ features were manipulated. It was found the more different the physical characteristics of the voices, the easier the tasl was, and that unattended information is filtered out very early in sensory processing

Broadbent’s filter theory (1958)

Suggests a selective filter interrupts the access of irrelevant input to the STM. Selection based on physical characteristics of the input, for example pitch and tonality. Excluded input remains briefly in sensory register, and is reected unless attended to rapidly.

What is the purpose of the selective filter in Broadbent’s model?

To prevent the information-processing system from becoming overloadedL

Limitations of Broadbent’s filter theory

Existence of opposing evidence, unable to explain when participants report unattended information when it semantically matches the attended stream

Treismans’s Attentuation theory (1964)

Suggests existence of ‘attentuator’ that reduces, but does not eliminate, unattended material. The information is only analysed if it’s activation exceeds a threshold affected by context, subjecive importance, saliency and priming.

Evaluation of Treisman’s Attentuation theory

More flexible early-selection model than Broadbents, however maintains that unattended information decays in sensory register and therefore have no effect on behaviour

Deutsch & Deutsch’s Late selection model (1963)

Suggests all stimuli are fully analysed for meaning and only then does filtering take place, based on physical properites and meaning.

Subliminal stimuli

Sensory inputs conveyed below the threshold of conscious awareness that can affect behaviour, supporting the claim that all information is processed for meaning.

How did Normal (1968) build on Deutsch & Deutsch’s late selection model?

Added ‘input power’ as an important factor - strength of input can be elaborated by stimulating any sensory system (auditory, tactile, visual, olfactory)

Limitations of the later late selection model

Very uneconomical (resource demanding), opposing research has shown breakthrough od unattended material is infrequent, not supported by more recent neuropsychological evidence.

Hillyard et al.’s ERP study (1973)

Provides neurophysiological evidence showing that the N1 component is larger for attended than unattended auditory stimuli before any semantic processing could occur

Lavie’s Load theory (2005)

Provides evidence of both early and late selecting, suggesting the brain adopts one of the two systems depending on the perceptual load

How do cognitive resources affect the load theory?

The amount of cognitive resources that remain as a person carries out a task determines how well they can avoid the task-irrelecant stimuli.

Limitations of Lavie’s Load theory (2005)

‘Load’ is often defined by whether distractor interference occurs, making the theory circular. Manipulations intended to increase load often change other things simultaneously.