Attention 2 Flashcards
What is the term used to describe the failure to acknowledge stimuli on the contralesional side of the lesion and only acknowledge stimuli on the ipsilesional side of the lesion?
(Hemispatial) Neglect
Explain Hemispatial Neglect
The failure to acknowledge stimuli on the contralesional side of the lesion and only acknowledge stimuli on the ipsilesional side of the lesion
What causes Neglect?
Lesion/damage on the right hemisphere of the brain
What lesion specifically causes Neglect?
Right parietal damage to the brain, following a stroke (blockage in brain rather than a bleed out)
What do Neglect patients do?
- They only acknowledge things/surroundings on the right side, which is the same side of the brain as their lesion
- e.g. They only eat on the right side of the plate
- e.g. They only draw on the right side of the papar
What is a patient with hemispatial neglect likely to do when presented with a line-bisection task?
Bisect the lines to the RIGHT of the centre
Describe 3 features of the border between neglected space and non-neglected space
1) It’s a gradient, not sharp and fuzzy (not entirely black as it is a loss of attention, not vision)
2) Does not necessarily align with the middle of the stimulus (vertical midline, it depends on the display)
3) Can vary with the number of distractors in the display
Is anything processed when there’s neglect?
Yes - Some unwanted semantic information (info with meaning)
But - Patients may not be consciously aware of the neglected stimuli
Marshall and Halligan
Who conducted the Piazza Del Duomo experiment for Neglect?
Bisiach and Luzzatti
Describe the Piazza Del Duomo experiment for Neglect
- Patients were told to picture themselves standing on one side of the Piazza Del Duomo
- Patients were asked to describe what they remember of the Piazza
- They described the right side of the Piazza only
- Patients were told to “walk over” to the other end of the Piazza and describe their surroundings
- Again, they described the right side of the Piazza, only now it was based on what they saw on the other end of the Piazza
What is a visual search?
Looking for something in a clustered visual environment
What are the 2 types of visual search?
Serial and Parallel search
What is a Parallel Visual search?
Visual search process that focuses on multiple items at once
What is a Serial Visual search?
Visual search process that focuses on one item at a time
If reaction time is affected by display size, it is a … (parallel/serial) visual search
Serial
If reaction time is not affected by display size, it is a … (parallel/serial) visual search
Parallel
If there are no effects of display size at all it is a …
Pop out
Why is it that if the reaction time is affected by display size, it is a serial visual search?
- Because if the display size is large, you would have to go through each item one by one
Why is it that if the reaction time is not affected by display size, it is a parallel visual search?
- Because no matter the display size, if the distractors share similar traits that contrast with the attended/target item, you can attend to all items at the same time
What is the term used to describe when there is no effect of display size at all?
Pop out
Who proposed the Feature Integration Theory (FIT)?
Triesman and Gelade
What does the Feature Integration Theory (FIT) suggest?
The visual search is a two-stage process
List the 2 stages of the Feature Integration Theory (FIT)
1) Preattentive stage
2) Focused attention stage
Feature Integration Theory (FIT) suggests that visual search is a two-stage process. What is the role of the preattentive stage?
Process physical and basic characteristics of the search items
The Feature Integration Theory (FIT) involves 2 processes. Which process is fast and which is slower?
1) The first stage (Preattentive) is fast
2) The second stage (Focused Attention) is slower
Describe the results of the Feature Integration Theory (FIT) study
- Conjunctive targets (when targets share one of their traits with the distractors) require more attention
- Illusory conjunctions occur due to problems in combining features at a late stage
- The set size affects conjunction target search but not single target search
What are conjunctive targets?
When targets share one of their traits with the distractors (e.g. Target is the letter ‘T’ but it shares the colour ‘Green’ with the distractor letters
Which stage of the FIT requires focused attention?
Focused attention stage
Which stage of the FIT does not require focused attention?
Preattentive stage
Which stage of the FIT is faster than the other?
Preattentive stage
Which stage of the FIT initially follows a parallel process?
Preattentive stage
Which stage of the FIT is used when the targets have a combination of features?
Focused attention stage
Which stage of the FIT allows illusory conjunctions to occur?
Focused attention stage
Which stage of the FIT is required only when searching for targets defined relative to distractors by a conjunction of features?
Focused attention stage
What is the Threat Superiority Effect?
When people are quicker at noticing something potentially threatening compared to something positive or neutral
What is divided attention also known as?
Multitasking
What is divided attention dependent on? (List 3)
1) Task difficulty
2) Task similarity
3) Practice
The more difficult the task, the (more/fewer) targets detected
Fewer
Fewer targets are detected when the task is (more/less) difficult
More
The more similar the task, the (more/fewer) targets detected
Fewer
Fewer targets are detected when the tasks are more (similar/different)
Similar
The more practice you have at dividing your attention, the (better/worse) you are at multitasking
Better
What did Triesman and Davies suggest about task similarity?
Two tasks interfered much more when both tasks are in the same modality
Who claimed that two tasks interfered much more when both tasks are in the same modality
Triesman and Davies
Who attempted to measure similarity?
Segal and Fusella
How is task similarity measured?
- Participants were asked to multitask, either by performing 2 tasks in the same modality or 2 tasks in different modalities
- e.g. Auditory task + Auditory task OR Visual task + Auditory task
- The study found that the more similar the task, the worse the performance
Who proposed evidence that practice improves multitasking?
Spelke, Hirst and Neisser
What did Spelke, Hirst and Neisser do to investigate the effects of practice on improving divided attention?
- Participants read a short story whilst writing down dictated words
- 2 participants, 5 hours training per week for 4 months
What did Spelke, Hirst and Neisser discover about practising to improve divided attention?
- After 6 weeks, participants improved but recall and semantic processing of dictated words were still poor
- Later could write down categories to which words belonged
What are the limitations of Spelke, Hirst and Neisser’s practice study?
- Focused on accuracy rather than speed (less sensitive)
- Reading task could be done flexibly according to demands of secondary task
What are the 2 ways to explain divided attention?
1) Central capacity
2) Multiple resources
What is the central capacity model?
- It has limited attention resources
- The success of multitasking depends on the drain of each task on resources
- Multitasking may require more resources than available
Who proposed the central capacity model theory?
Bourke et al.
What did the central capacity model theory suggest?
- There are 4 tasks which need different amounts of central capacity
1) Random letter generation
2) Pattern learning
3) Manual task
4) Tone detection
- Findings suggest tasks with the most requirement for central capacity interfered the most and had poor multitasking performance
Who proposed the multiple resources model theory?
Wickens
What does the multiple resources model theory suggest?
- Separate sources of capacity may be specialised for certain processes
- More interference occurs when tasks share a modality or a type of response
What are the 3 successive stages of processing in Wicken’s multiple resources model?
1) Encoding (perceptual processes; visual or auditory)
2) Central processing (spatial or verbal codes)
3) Response (vocal or manual
What is selective interference?
- Type of resources that tasks require that determines whether they will interfere
- e.g. secondary tasks are interference sources for primary tasks when the 2 tasks are similar
What are the limitations of the multiple resources model?
- Models focus on auditory and visual inputs but tasks could also be presented in other modalities
- Coordination between tasks is not considered
What causes cognitive delay?
Psychological refractory period (PRP)
How does Psychological refractory period (PRP) work?
- 2 stimuli
- 2 responses
- Respond to each stimulus as quickly as possible
- Second stimulus presented shortly after the first
- Response to the second stimulus slows down and both stimuli are presented together closely in time
What did Pashler suggest about cognitive delay?
- Response to the 2nd stimulus is slowed because participants are still processing the 1st stimulus
- Results is delayed response time when asked to divide attention
What is the Stroop effect?
- When there are 2 competing processes (e.g. naming colour + reading a word)
- The automatic processing of reading a word interferes with the instructions
- Participants that take longer to name the colours of the emotional words than neutral words have an attentional bias
Who introduced the automatic vs. controlled response theory?
Shiffrin and Schneider
List 7 features of an automatic response
- Fast
- No attention is required
- No reduced capacity when multitasking
- Parallel process
- Unavailable to the conscious brain
- Unavoidable
- Hard to modify once learnt
List 5 features of a controlled response
- Slower
- Attention is needed
- Serial process
- Available to the conscious brain
- Can be used flexibly in changing circumstances
Who introduced the Supervisory Attentional System (SAS)?
Norman and Shallice
What are the different levels of automaticity according to Norman and Shallice?
1) Fully automatic (controlled by schemas)
2) Partially automatic (resolve conflict between schemas without conscious control)
3) Deliberate control by SAS
What is SAS?
- Involve frontal lobes
- To induce non-routine, goal-oriented behaviour by guiding the selection of goal-oriented task schema
- SAS controls when there is the need for deliberate planning, problem-solving or when a strong habitual response has to be prevented
What term is used to describe patients who struggle with planning, organising and controlling actions?
Dysexcutive syndrome
What is Dysexcutive syndrome often associated with?
- Frontal lobe damage
- Cognitive, emotional and behavioural symptoms
- Struggle with planning, organising and controlling actions
Who found and defined Utilization behaviour?
Lhermitte
What term is used to describe patients who grasp and utilise any object in front of them, even if the behaviour is inappropriate?
Utilisation behaviour
What is Utilisation behaviour associated with
- Medial frontal lesions
- Patients often grasp and utilise any object in front of them, even if the behaviour is inappropriate
- Patients are unable to control their behaviour
What does the Homunculus problem refer to?
- “Who controls the brain?” argument
- Some claim there is a small entity in the mind in which does the controlling of brain and behaviour
- Proposing a brain area/ mechanism leads to an infinite recursion (rerunning of a procedure/loop)
