Attention

- The brain has a limited capacity

- We need a way to select certain information for further processing 

- "Everyone knows what attention is. It is the taking possession by the mind in clear and vivid form one our of what seem several similtaneous objects or trains of thought" - William James 

External:

- External sensory stimuli

- Specific locations, features, objects 

Internal:

- Internally-generated information

- Task rules, working memory, LTM

Exogenous 

- Bottom-up

- A stimulus captures your attention

Endogenous 

- Top-down

- Your attention or goals direct your attention

Overt 

- Attention directed to a fixation point

- Eyes move to focus on the source of information

Covert

- Attention directed away from fixation point 

- Does not involve eye movements 

Focused/Selective

- Focused on one source of information

Divided 

- Focusing on several things at once

- Multitasking

The Cocktail Party Effect:

- "How do we recognise what one person is saying when others are speaking at the same time" (Cherry, 1953)

Dichotic Listening Task 

- Different voices played in each ear - ppts must focus on one 

- Very little awareness of information in the unattended ear

- Listeners distingushed the two inputs based on physical features 

Broadbent's Filter Theory (1958) 

- Filters out unimportant information based on physical characteristics before deeper processing occurs 

- Early selection model 

Deutsch & Deutsch Pertinence Model (1963)

- All incoming information is processed fully, but only the content of the attented information is later available in consious awareness 

- Late selection model

Treisman's Attenuator Theory (1964)

- Attenuates unimportant information when there is insufficient processing capacity

- Intermediate selection model

- Visual Attention as a spotlight (Posner,1980)

- Goodhew et al.(2016)

      - Temporal attention task: ppts detected whether disc was presented once or twice

      - Spotlight size was manipulated by a pre-trial inducer (large or small)

       - Supports spotlught account over a zoom lens 

- Visual attention as a zoom lens (Erikson & St. James, 1986)

- Optimal zoom setting "includes all possible target locations and excludes possible distractor locations" (Chen & Cave, 2016)

- Split Visual attention as a multiple spotlight (Awh & Pashler, 2000)

- May only apply when attended stimuli are presented in different hemifields 

Endogenous:

- Dorsal attention network 

- Goal-directed 

Exogenous:

- Ventral attention network

- Stimulus-driven  

- Behavioural Syndrome occuring after brain injury 

- It is defined as the inability to detect, attend or respond to stimuli in spatial locations contralateral to cerebral damage 

- People with spatial neglect after a cerebral injury on the right side of their brain would have issues processing information on their left side.

- If shown a picture of 2 houses where one is burning and one is fine and the burning one was on the left they would process no differences in the two houses.

- Patients in trials chose the house that wasnt on fire 9/11 when asked which one they would prefer to live in 

- Neglected information processed unconsiously

- The failure to consiously percieve otherwise salient events when they are not attended (Ward & Scholl, 2015)

- Also observed in relation to sound (inattentional deafness) and touch (inattentional numbness)

- When asked to make a judgement about a shape, a large proportion of participants do not notice a change in the fixation cross (Mack & Rock, 1998)

- The failure to detect changes in visual scenes (Ball et al., 2015)

- The door study (Simons & Levin, 1998)

        - Unwitting ppts approached by a confederate and asked for directions 

         - Mid-conversation the confedersate switches with another person while obscured by a door 

        - 50% of people did not notice the change

Attention given to more than one task at a time 

  - using a phone while driving or walking 

  - listening to music whilst writing an essay

Most University students multitask whilst studying 

  - 99% of self-directed computer sessions involved some form of multi-tasking (Judd, 2014)

Results in a cost of performance

  -Greater cost associated with similar tasks 

  -May improve with practice

Strayer & Johnston, 2001

- The probablity of missing a red light more than doubled when speaking on a cell phone 

- This happened even more when the phone was hands-free

Scattered Attentional Hypothesis

- Multitasking impairs cognitive control becasue attentional resources are allocated too widely 

- Frequent multitaskers are more easily distracted 

- Also show greater pre-frontal cortex activity during the distractor task (Moisala et al., 2016)

Trained Attention Hypothesis

- Multitasking enhances cogntive control as a result of practice 

- Evidence is more mixed 

- More efficient task-switching (Alzahabi & Becker, 2013)

- Cannot establish causal relationships from these studies alone

- Everyday environment is multisensory 

- We co-ordinate attention across different sensory modalities 

McGurk & MacDonald (1976)

- If someone made the sound "Ba-ba" but moved their mouth as if they said "Ga-ga" we do not percieve them to have made a "Ba-ba" sound 

- This is because the audiotory and visual information do not match up so we may instead hear "Da-da"