Flashbulb memory

Shockingly and emotionally charged events tend to be remembered more vividly and in more detail than other events.

Brown and Kulik (1977) Said that flashbulb memories are accurate and are immune from being forgotten. They said that this is because there is an activation of a special neural mechanism that 'prints' details permanently in the memory. For this to happen, there must be high emotionality and consequentiality. There is some evidence for this 'special mechanism'. Conway et al. in 1994 found that flashbulb memories are not simple stronger versions of normal memories. They tested this by looking at the resignation of Margaret Thatcher, and seeing how many brits and non brits remembered it after 11 months. A higher proportion of brits remembered as it had high consequentiality for them. Wright, Gaskell and Muircheartaigh however found that only 12% remembered the event vividly after 18 months.

Difficulties with the 'special mechanism'

• Winningham, Hyman and Dinnel (2000). They tested the memory for the O.J. Simpson acquittal. People were tested both immediately, after 1 week and then 8 weeks later. Those who showed high consistency should be regarded as having flashback memories.
• Memories change over the first few days. Forgetting is initially rapid, then there is further learning post-event.
• Talarico and Rubin (2003). Few studies have assessed the retention for both flashback and everyday memories. On the 12th september 2001, students memories of september 11th and of a recent everyday event was tested. This was repeated 3 times: 7, 42 and 224 days later. Vividness of flashback memories was retained for 32 weeks. This was measured on a 7 point scale. Flashback memories showed no more consistency than everyday memories with regard to the number of details recalled however.
• There is therefore some discrepancy between beliefs in strength of flashback memories and accuracy.

Prospective memory

Most of the research into memory had been focussed in retrospective memory. Prospective however is the memory which allows you to remember to carry out intended actions. This can be time or event based. The attentional demand depends upon the importance and complexity of the task or memory, and involves the activation of the frontal lobes.

Studies:

1. Marsh, Hicks and Landau (1998). People reported an average of 15 plans for the week, 25% f which were not completed. Reasons were given for most of these, only 3% was due to forgetting.
2. McDaniel et al. (1998). Prospective Memory is under full or divided attention. Performance is much better however when full attention is used.
3. Hermann & Gruneberg (1993) said that people are most likely to forget to do something when they are distracted or preoccupied.

Attention and Prospective Memory

1. Marsh and Hicks (1998). Tasks involving the central executive impaired event based prospective memory performance relative to the control condition. Tasks involving the phonological loop or the visuo-spatial sketchpad however did not impair performance.
2. McDaniel and Einstein (2000). The performance of an additional ongoing task was impaired by the prospective memory task being carried out at the same time.

Frontal Lobes and prospective memory.

The prospective memory attentional system is located in the frontal lobes.

Burgess et al. (2000) looked at 65 brain damaged patients with prospective memory problems and found that there is an association between the dorsolateral prefrontal cortex and the activity of planning and creating intentions. He also associated the Brodman's area 10 with maintaining intentions. By contrast with this, retrospective memory tasks involve anterior and posterior cingulates. Burgess et al. did another study in 2001 using PET on prospective memory in intact individuals which supported these findings. They also found evidence for different processes and structures being involved in retrospective and prospective memory.

False Memories

These can be created in the laboratory.

Loftus and Pickrel (1995) asked young adults to recall four childhood experiences that were reported by a relative. One of these was false. 25% of participants recalled false events at two follow up interviews.

Ceci (1995) asked children to think about both real and fictitious events for 10 weeks. Approximately 60% of them confused the fictitious and real events by the end of the study.

Eyewitness Testimony and the misinformation effect.

Confirmation bias and the eyewitness testimony are event memories that are influenced by the observers expectations. This was tested by Valentine et al. in 2003, who studied identity parades.

The misinformation effect is when memories are modified by post-event information which can be misleading. This was shown by Loftus and Palmer in 1974 by people a video of a multiple car accident.

Autobiographical Memory

There are two forms of autobiographical memory proposed by Williams in 1999. These are:

1. Personal Semantic Memory: These are the facts one knows about oneself
2. Episodic Memory: These are memories of the event from ones life. Episodic memory includes information about the emotional experience as well as the factual details of the event.

Hierachical Structure of the autobiographical memory self-memory system:

(Conway 2000; Conway and Pleydell-Pearce, 2000)

1. General: These are about lifetime periods, for example 'when i was a t university'
2. Intermediate: This refers to general events and can include extended or single events such as a specific holiday, or categorical or repeated events such as shopping.
3. Specific: This relates to event specific knowledge including images, feelings. These are in temporal order.

Routes of retrieval of autobiographical memories - Berntsen, 1998

There are two routes of retrieval for autobiographical memories. These are

1. Direct. These are involuntary recalls of memories and can be assessed by diary records. Some cues may spontaneously lead to the direct activation of specific event memories.
2. General. This is a voluntary process which can be assessed by presenting cues. It is a strategic process that is mediated by the central executive. Williams (1996) suggested the process by which this happens:

a. An intermediate Description is created that describes the information that is to be recalled.

b. The ID/intermediate description is used to search for a specific autobiographical memory.

c. Contextual Information is added to the memory search. This requires the inhibition of the intermediate description.

d. This voluntary retrieval is disrupted by depression.

Lifetime memories

These are types of memory from different life stages:

• Retention function: this is for memories up to 20 years old. Older memories are less likely to be recalled than recent ones.
• Infantile amnesia: These is almost a total lack of memories from the first 3 years of life.
• Reminiscence Bump: This describes memories from age 10 to 30. There is a particularly large amount of these, especially from age 15 to 25

Infantile Amnesia

Howe and Courage (1997) related infantile amnesia to the emergence of a 'cognitive self'. They said that advances in cognitive development occur at around 20 to 24 months. This is when visual self recognition takes place through touching and smiling, as well as the use of personal pronouns. This is when there is an emergence in autobiographical memory, and signals the end of infantile amnesia. This also assumes that there are very few autobiographical memories between age 2 and 5, as rehearsal must take place.

Rubin, in 2000, supported this theory, and found that only 22% of the autobiographical memories from the first 10 years, came from ages 2-5

Reminiscence Bump

Rubin et al., in 1998 identified novelty and stability as being important factors in determining the strength of memories

• Novelty - first time experiences. These are often distinctive and accessible memories. They have less or lowered proactive interference.
• Stability - These memories are usually from early adulthood and stable periods.

Conway and Pleydell-Pearce (2000) said that 'the reminiscence bump reflects the preferential retention of events from a period of consolidation of the self'. They considered that the self and personal goals do not change very much after age 30.

Everyday memory overview

Areas of research:

• Autobiographical Memory
• Eyewitness testimony, misinformation effect and false memory
• Prospective memory (time and event based)
• Flashbulb memory
• Links with remaining lectures and cognition on cognition and emotion.

How do we study everyday memory?

• Everyday experiences
• Real-life applicability; importance of ecological validity
• should it be studied only in naturalistic settings?

Ecological validity is the extent to which experimental findings are applicable to everyday settings.

There are three assumptions proposed by Neisser in 1996 about everyday memory. These are that it is:

• Purposeful
• personal
• influenced by situational demands and motivations

This approach to memory understands the differences between traditional memory research which encouraged accuracy, and everyday memory research which is more purposeful and focusses on personal interpretations of memories.

Types of Problem solving

There are two types of transfer, positive and negative.

1. Positive: This is when performance is improved based on previous experience
2. Negative: This is when performance is impaired due to previous experience

Isomorphs and Homomorphs.

These describe the type of task that might be carried out.

1. Isomorph: this describes tasks with identical underlying states or problem spaces, but no superficial similarities. (They have difference physical details). A Move in one task is functionally identical to a move in another task.
2. Homomorph: This is when tasks have similar but not identical underlying states or problem spaces. Some of the moves are prohibited in one of the tasks.

Two examples of these tasks are missionaries and cannibals, and the Jealous husbands which is a homomorph of the m & c, as is follows a similar structure but has different rules.

Analogical Problem Solving

This is learning by analogy, when there are similarities between current and previous problems. These similarities have been defined by Chen (2002):

1. Superficial similarities (eg objects)
2. Structural Similarities (casual relations)
3. Procedural Similarities (concrete operations)

Dunker's Radiation Problem (1945)

• a ray of sufficient strength to destroy a tumour will also destroy healthy tissue.
• a ray that will not destroy healthy tissue will be too weak to destroy tumour.
• when given the problem on its own, only 10% people solved it.

Gick and Holyoak (1980;1983)

• They gave participants a story that was structurally similar. When they were told that it was relevant to the radiation problem, 80% solved the problem.
• In this example, they were unlikely to make use of analogy because there was no superficial similarity between the story and the problem. (Keane, 1987)
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Problem Solving

The areas of research in problem solving include:

• problem solving tasks
• transfer of knowledge
• expertise (development of skills, from controlled to automatic processing

Problem solving is:

1. Goal Directed
2. Cognitive - not an automatic process
3. There is only a problem to solve with the individual lacks the relevant knowledge

Gestalt approach

• this distinguishes between reproductive problem solving which involves the use of experience, and productive problem solving which involves novel restructuring.
• Restructuring and insight was tested by Maier (1931) using the two string problem. Participants were given the problem of two strings hanging from the ceiling too far apart to hold at the same time. Maier observed how they overcame this problem
• Evaluation: concepts of insight and restructuring are quite vague and hard to measure, particularly as we dont know the processes underlying them,
• Novick and Sherman 2003, suggested that insight may be based on the accumulation of knowledge, Gestaltists did not use problems such as skilled games which involve this however.

Functional Fixedness

• Past experience does not always help to find a solution to a problem
• eg Duncker (1945) used the candle problem. The task is to attach a candle to the wall next to a table so that the wax doesnt drip onto the table below.

Computational Approach: Newell and Simon's (1972) General Problem Solver (GPS)

• This involved a systematic computer simulation of human problem solving.
• It had several assumptions about the human mind however, for example, serial processing, limited short term memory capacity and the ability to retrieve information from long term memory
• They investigated the strategies that are used by asking people to think aloud while solving problems
• In the GPS a problem is represented as a problem space
• Initial state --> intermediate states --> Goal State
• The towers of Hanio/London are an example of a problem state. They give the participant a starting position and a goal position which they must rearrange the blocks into
• Newell and Simon concluded from their observations that we select manual operators (moves) by relying on the 'rules of thumb'. This is also known as heuristics
• Means-end analysis: this requires the difference between the goal state and the initial state to be observed. A sub-goal is then formed to reduce this difference. Then, a mental operator or move is selected to reach the sub-goal. This is a contrast with algorithms which are complex methods that are guaranteed to solve problems
• Evaluation: Newell and Simon applied the general problem solver (GPS) to 11 different problems. It managed to solve all of them, but not necessarily in the same way as humans. The computational model allows us to see when and how performance deviates from the ideal. FInally, GPS is consistent with knowledge of human information processing, eg limited working memory capacity.
• Limitations of the computational approach: the general problem solver is better than humans at remembering previous moves, but worse at planning future moves.
• Everyday problems are ill-defined and so some solutions might cause other problems. Specific knowledge might be needed. The problems used as examples in the computational model are well defined and have a clearly specified initial state, goal state and range of moves
• Computational models are best suited to serial processing tasks, and not so well suited to insight.

Brain Regions association with working memory

The working memory, as seen in Baddeley's model, is divided into several components. Each is associated with a different region of the brain.

Phonological Loop

• The phonological store is located in the parietal lobe
• The Articulatory rehearsal component is in both the frontal lobe and the cerebellum
• The speech production area associated with articulatory rehearsal is also known as Broca's area

Visuospatial Sketchpad

• This involves the dorsal and ventral streams
• The visual cache - storage takes place in the occipital and visual cortex
• The inner scribe - spatial rehearsal takes place in the inferior parietal lobe.

Central Executive

• The prefrontal cortex is associated with this component.
• This is the brain region that deals with higher level cognitive tasks.
• Evidence has found activation particularly in the dorsolateral region of the prefrontal cortex.

Episodic buffer

• There is little information available about the anatomical location of the episodic buffer.
• Similarly to the other three components, it is likely to be associated with multiple locations

Evaluation of the original working memory model

There are some advantages to the original model, and some evidence to support it. Dual task studies for example support the idea of having two specialised subcomponents. There is also neuropsychological and neuroimaging evidence that different brain regions are associated with the phonological loop and the visuospatial sketchpad and its subcomponents. Finally, there is strong evidence for an executive control system.

There are some difficulties with the original three component model however. Problems arise from the poor specification of interaction with the long term memory. There is evidence that the central executive is more than simply an attentional system, as an amenesiac patient with impaired long term memory was still found to have immediate memory for passages of prose that extend beyond the capacity of the PL and VSS. Another problem is that there is no system that allows for 'chunking'. Chunking allows for the information in the longterm memory to supplement immediate recall. If stimuli is a meaningful sentence then the memory span is increased. The model does not account for this however .

A further criticism of the original model is that there is no mechanism proposed for the interaction between the phonological loop and the visuospatial sketchpad, as well as no mechanism for the role of working memory in conscious awareness . The central executive was originally proposed to assist in binding this but how could it do this without a multimodal short term store to integrate the information.

Because of these criticisms and flaws with the model, Baddeley, in 2000, added in a 4th component to the model to account for the problems.

• Episodic Buffer: This hold on to and integrates diverse information
• It has limited capacity to temporarily store information
• it has a binding role and acts as a common multidimensional code.
• It has a temporary interface with the slave systems (VSS and PL)
• it is accessible to conscious awareness
• It links the working memory with the longterm memory more explicitly
• The information held in this buffer interacts with the visual semantics and language components and gets converted to the long term memory

The Central Executive

This is the interface between the two subsystems and long term memory. It is more similar to an attentional system than a memory store, as is allocates resources to the visuospatial sketchpad and the phonological loop. Baddeley (1996) suggested that the model of attentional control proposed by Norman and Shallice (1980; 1986) could provide a good model of the central executive. The functions of the central executive, as suggested by Baddeley are listed below

• Retrieval strategies,
• timesharing in dual-task performance
• selecting attention
• temporary activation of the long term memory
• suppression of habitual, automatic responses and actions

Impairments to the central executive occur in a syndrome called 'Dysexecutive syndrome' or 'frontal lobe syndrome'. These result in effects which seem as if there is no system to allocate processing resources. Individuals with the syndrome have disturbed attention and are easily distractable, making it difficult for them to learn new tasks.

Evidence for the central executive can be seen through a test involving the random generation of digits or letters:

• The participant is required to hold 1-8 digits in their memory while generating a random sequence of digits of letters.
• Close attention is needed to prevent the repetition of digits or the production of stereotyped responses (non random)
• The results show that as the digit memory load increases, the randomness decreases and the responses become more stereotyped.
• There is an implication that during the production of novel schema (made up random digits) the dominant schema (non-random sequences) must be constantly inhibited by the SAS .

The Visuospatial Sketchpad and Phonological/Articulatory Loop

Baddeley and Hitch 1974 & Baddeley 1986

They separated memory into two forms, which with rehearsal work into the central executive (which is modality free). The two forms are:

• The visuo-spatial sketchpad (inner eye) which is specialized for spatial and/or visual coding
• Phonological/articulatory loop (inner voice) which holds information in a speech-based form

• All three of the components have limited capacity, and are relatively independent.
• The theory has implications for dual task processing:
• If 2 tasks are performed simultaneously and use the same component, they cannot be performed successfully.
• If the two tasks are performed simultaneously using different components it should be possible to perform them equally well.
• This theory was tested by giving participants a primary task and asking them to carry out a second task simultaneously.
• To use the phonological/articulatory loop, participants carried out an articulatory rehearsal at the same time as being asked to produce irrelevant speech.
• The visuo-spatial sketchpad was used through carrying out through spatial rehearsal. Participants were simultaneously asked to generate irrelevant hand movements.

Phonological Loop

• This stores verbal information in a speech based form
• Information is maintained by articulatory rehearsal
• Information enters the phonological store through articulatory word presentation and visual word presentation.
• Henson Burgess and Frith 2000 identified the areas associated with the PL.
• Storage: left inferior parietal
• Rehearsal: left prefrontal

Phonological similarity effect

• This asks participants to serially recall a word list. When these are phonologically similar, this proves to be more difficult than when they are dissimilar. eg knee, he, lee, she, me is more difficult than odd, shy, up, bay, hoe
• This was tested by Larsen, Baddeley and Andrade in 2000. They found that similar word recall was 25% worse than dissimilar recall.

Word Length Effect

• The ability to reproduce a series of words is better with short words than long words
• Baddeley et al.. 1975: Articulatory suppression eliminates the word length effect, which suggests that word length effect depends on the phonological loop.
• Baddeley et al. 2002: There is still a word length effect when the output delay is controlled by using recognition memory rather than recall

Articulatory Suppression

• Phonological loop is disrupted if there is performance of overt or covert articulatory rehearsal of irrelevant items
• Articulatory suppression removes the word length effect and also the phonological similarity effect.
• Articulatory suppression process dominates the articulatory control process component of the phonological loop.

Evidence for the two components and the distinction between phonological store and the articulatory control process comes from brain damaged patients...

• Individuals with damage to the PS but not the ACP seem to have poor short term memory for auditory-verbal material but they still have normal speech production. These individuals have lesions in the left temporo-parietal cortex
• Individuals with the opposite; damage to the ACP but intact PS tend to have lesions to thepremotor, frotal paraventricular and anterior insula of left hemisphere

Visuospatial Sketchpad

• This area provides temporary storage and manipulation of visual and spatial information
• Info is maintained by spatial rehearsal
• Logie (1995) said that there are two components:
• The visual cache - this stores info about form and colour.
• The inner scribe - this contains spacial and movement information. It rehearses information in the visual cache.

Evidence for the visuospatial sketchpad:

• Quinn and McConnel 1996
• Participants had to learn a word list by one of 2 methods. While they did this there was visual or spatial interference tasks.
• Method 1: Method of loci. In this example, memory performance was interrupted by the visual task, but not the spatial task, suggesting that learning is dependent on visual cache.
• Method 2: Pegword. This method used a linked word with the item t aid memory. The memory performance observed was affected by both the visual and spatial interference tasks, suggesting that learning requires both visual and spatial components.

Evidence for both components from brain damaged patients:

• Unilateral presentational neglect (Beschin et al. 1997)
• Patient found it hard to describe details from the left side of scenes in visual imagery unless a visual stimulus is available
• No problems were found in perceiving the left sides of scenes so visual perception is therefore intact
• This suggests that damage to the visual cache where there are stores about form and colour

Evidence for both components of visuospatial sketchpad from imaging studies

• PET - Smith and Jonides 1997
• They found that a spatial task produced activity in the right hemisphere, particularly the prefrontal, premotor, occipital and parietal cortices.
• The visual task however produced activation in the left hemisphere, particularly the parietal and inferotemporal cortices.
• There was also further evidence for the visual 'what' pathway (ventral PFC) and the spatial 'where' pathway (dorsal PFC)
• There is support for the separation of visual cache and inner scribe components from the fact that there is no interference between visual and spatial tasks when they are performed together (Quinn and McConnell 1986)
• Brain damaged patients can also have damage to the visual but not the spatial component
• Imaging data suggests that VC and IS are associated with the activation of different brain regions
• Functions = geographical orientation and the planning of spatial tasks

Articulatory Suppression

the rapid repetition of some simple sound which uses the articulatory control process of the phonological loop

Memory Overview

• History - The distinction between long term and short term memory was made (STM/LTM)
• Memory refers to the retention of learning or experience. Our memory retains all the things that we learn and would have no content without learning.
• Memory consists of 3 interrelated processes:

1. Encoding (registration/reception)
2. Storage
3. Retrieval

• Encoding is necessary for storage and retrieval. There is not sufficient availability/accessibility distinction.

The distinction between STM and LTM - William James (1890)

• Primary memory: psychologically present, conscious experience, retrieval is effortless
• Secondary memory: Psychologically past, unconscious, retrieval is effortful

Atkinson and Shriffin's (1968) multi-store model

Input -> Sensory stores ->(attention) -> Short term store -> (rehearsal)-> Long term store

• Sensory stores holds information briefly. It is modality specific however, and the information decays quickly.
• Short term store has a limited capacity and duration and information is easily displaced.
• Long term store has a large capacity and is held for a long time. There can be interference with the information however over time.

fMRI and Task Load

This section looks at the differences between perceptual demands and working memory demands.

Rees, Frith and Lavie (1997)

• They assessed brain activity in motion related areas (V5) during changes in demands of a linguistic task
• Participants were asked to focus on single words that were successively, presented on screen. They were also told to ignore the white dots in the periphery.
• The white dots were either static or moving
• in the low load condition, they had to press a key for uppercase
• In the high load task they had to press a key for bisyllabic words
• Results: The mean activity in the V5 (motion detection area) was measured under different perceptual loads.
• In the low load example, irrelevant motion was detected. This did not occur in the high load task however. This is because selective attention only appears to be possible under high loads, as there is a higher allocation of cognitive resources to the task.

Yi et al. (2004)

• 'Neural fate of ignored stimuli: perceptual vs working memory demands'
• Participants were presented with a series of images, including a picture of a person, and had to identify whether the current face is the same as the one before or the same as two before (2 before=high working memory load)
• The degraded stimuli condition (high perceptual load) should reduce the amount of perceptual attention that is available for processing the background (house)
• The study also looked at how much the scenes were processed when they were repeated, or not repeated.
• Results: These showed low perceptual demand and high working memory load. There was greater activation in the parahippocampal place area (PPA) for the unrepeated condition suggesting that there was more processing of the background.
• In the high perceptual demand task, where there was degraded stimuli, the task irrelevant stimuli were easier to ignore.

Perceptual Load vs. working memory load:

• When perceptual load is high, early selection takes place, and there is good selectivity, meaning that the background is not likely to be processed.
• When there is a high working memory load, late selection takes place and selectivity is much poorer, meaning that the background is processed more.
• Cognitive load refers to perceptual load and working memory load combined

Object based attention

Advanced attentional processing can take place when it is based upon an object rather in the environment rather than a particular location. There is evidence for both location and object based models, seen in patients with visual neglect anad fMRI studies...

Attentional Disorders: Unilateral neglect and extinction

• Individuals suffering from unilateral neglect tend to have a lack of awareness of stimuli that are presented to the contralesional side of space (the side opposite to the damage).
• There is usually damage to the right hemisphere, particularly in the inferior parietal lobe so there is little awareness of stimuli in the left visual field.
• Driver and Veilleumier, 2001 said 'neglect patients often act as if half of their world no longer exists. In daily life, they may be oblivious to objects and people on the neglected side of the room, they may eat from only one side of their plate, etc.'
• Extinction is when an individual can detect a single stimulus that is presented to the left of the visual field, but fail to detect a similar stimulus when it is presented to the right of the first one.

Halligan & Marshall, 1994

• Two flowers were presented to a neglect patient and they were asked to draw what they see. The patient recognizes both flowers but cannot see the left hand hide of both. This implies there is attention to the object rather than the region of space.

O'Craven, Downing and Kanwisher (1999)

• Participants are presented an image with a face superimposed onto a house.
• They are asked to attend to either the face, the house or the motion.
• An fMRI was used to detect the activity in the Fusiform Face Area and the Parahippocampal Place Area. It detects the % change in signal.
• The location based model would suggest that participants should attend equally to both stimuli.
• The result show that there is greater activation in the FFA (fusiform face area) when the face is moving and PPA (parahippocampal place area) when the house is moving.
• This indicates that whole objects are selected and provides evidence that objects are units of attention selection, as the whole object is selected when only one visual attribute is relevant.
• This is a demonstration of attentional modulation of neural responses
• However... in 2000
• They focussed on a central fixation point
• They presented 2 ovals, one to the left and one to the right of the fixation point. Each oval was superimposed on a task irrelevant face or house
• The task was to indicate the orientation (left or right) of the one in a certain colour.
• fMRI showed that, based on activation findings, from 1999 study, there was greater processing of the stimulus superimposed on the attended oval than the unattended one
• This provides evidence that attention can be location based.

Models of Visual Attention

Humans have an ability to not attend to all the features of the environment. This offers a functional advantage. There is a focus as to how we direct our attention to specific details.

• An example of a location based model is the Spotlight & Zoom-Lens model
• Alternately there is an Object Based model

Spotlight of Visual attention

• This says that everything within a small region of visual field can be seen clearly. It is more difficult to see anything that doesn't fall within that beam.
• The information that is within the spotlight is processed more clearly than anything outside.
• Precueing Procedure - Posner et al. (1980). In this experiment, participants had to identify when a light appears. In the centre of the row, a precue was given to direct attention to the right or left. When a valid cue was given, there were faster reaction times than when an invalid cue was given. This supports the model of location based attention as the individuals spotlight of visual attention is diverted by the precue, making the light more easy to identify when it is within that visual field, or, more difficult to identify if it is outside the spotlight.

Zoom Lens Model

• This is an adaptation of the spotlight model.
• It says that attention is directed to a particular region of visual field.
• The area however ca be increased or decreased depending on the requirements.
• LaBerge (1983): In this experiment, participants were presented with 5 letter words. There were 2 conditions. In one condition, a probe would appear in place of a letter, in the other condition however, the probe would appear in place of a word. The results showed that the reaction time was faster when the participants had a narrower attentional beam, ie. in the first condition.
• There is less evidence for the zoom-lens than for the spotlight model, as we can still process unattended visual stimuli.

Blindness

The ability to spot changes in scenes provides an evolutionary advantage. It allows predators to be spotted ad prevent being eaten for example. There is evidence that we overestimate our ability to do this however. There are two main types of blindness:

• Change blindness and Inattentional blindness

Change Blindness

• This is the inability to detect changes in attended scenes
• Simons and Levin (1998) They carried out an experiment whereby there was an attentional disruption during a conversation where a board was carried between people. When this happened the conversational partner was changed. Generally this went unnoticed. This experiment suggests the key role in distraction, for example an eye blink, a flashed blank screen or a cut in motion picture.
• Flicker Teschnique (1997) - Rensink, O'Regan & Clark. In this experiment, 2 pictures were presented in rapid succession. The second had an object missing from it. The missing object is very difficult to detect.

Inattentional Blindness

• This type of blindness allows illusionists and 'hustlers' to direct attention towards a distractor.
• We are very overoptimistic about our ability to perceive important events when we are focussing on current goals
• Attention has an important role in the link between perception and the visual field

Automatic Processing and Working Memory

Jansma, Ramsey, Slagter and Kahn (2001)

• Looked at fMRI and development of automatic processing in constistent mapping.
• Practice was associated with reduces usage of capacity-limited working memory. (central executive)
• Automatic processing was evidenced by decreased activation of the left dorsolateral prefrontal cortex and the right superior frontal cortex
• Automatic and controlled processing have similar functional anatomical representation but differ in efficiency of working memory processing.

Schneider and Shriffin (1977)

• They Proposed clear theoretical distinctions between controlled and automatic processing
• Controlled: limited capacity, requires attention, flexible (can be modified)
• Automatic: Unlimited capacity, no attention required, inflexible (cannot be modified)

Norman and Shallice (1986)

• Fully and partially automatic processes
• controlled by supervisory attentional system (similar to the central executive see working memory lectures)

Cognitive Bottleneck

• Pashler et al. (2001)
• Experiment requires rapid response to 2 stimuli
• the second is presented close in time to the first which results in a slowed response to the second.
• Physiological Refractory period: processing bottleneck: cannot select response to 2 stimuli at the same time, can only respond serially
• This suggests that fully automatic processing rarely occurs.

Effect of Practice

• Practice had been seen to improve dual task performance.
• Controlled Processing: When a task requires conscious control and is high in cognitive demand
• Automatic Processing: This does not require conscious control and is also difficult to control consciously. It also uses little processing capacity. E.g. Skilled driver or musician

Stroop Task & Automatic Processing

• The Stroop Task required participants to say the colour a word is written in. The words are presented as other colour names.
• Participants tend to find difficulty in this task as they say the colour written in the word rather than the colour of the text.
• this indicates and provides evidence for the automatic processing of language.

Consistent Mapping Task

• Schneider and Shriffin (1977)
• The participant is given a target, and is presented with serial frames. They must identify when the target is present in a frame.
• Initially, participants had 55% correct performance, however after 900 trials, they reached 90% correct performance. This occurs without any intervention, and leads to the used of only a few cognitive resources.
• An increase in the number of characters in either memory set or distractor had no effect on performance.

Varied Mapping Task

• Schneider and Shriffin (1977)
• The memory and distractor sets are always letters. a letter can be in the memory set in one trial then become a distractor later. The distractor in one trial can also become the target on another
• Results: This is found to be so difficult that the participants don't achieve automatic processing, even with practice.
• In contrast with the consistent mapping task, increasing the number of characters caused a decrease in performance.
• Performance was only successful if distractors were shown for 400msec rather than 120 msec. Performance was still only 50% correct however in contrast to 90% in the consistent task which had faster presentations.

Cell Phone Use and Driving

Strayer and Johnston (2001)

• They used a driving simulator to investigate dual-task interference
• Participants were instructed to follow a target car and press 'brake' button when a red light flashed
• Reaction time and the number of misses were measured
• The results showed that driving was not disrupted by listening to the radio, but there were severe and equal impairments when talking on the phone either handsfree or handheld.
• There were twice as many signal misses and greater reaction times in both phone conditions than in the radio condition
• The difference was more pronounced when talking than when listening.

Strayer, Drews and Johnston (2003)

• This follow up study looked at how attention is affected.
• The phone conversation draws attention away from the scene, eg eye movements are not drawn to information along the route even when items are located in the centre of the visual field.
• There was failure to process and select relevant information, similarly to other dual task experiments.
• Participants had delayed reactions and more accidents when using the phone.
• They also found that there was no improvement to safety of performance when using a handsfree phone.

Strayer & Drews (2004)

• This study looked at the effect of age and found that there was no difference in performance in different age groups

Strayer, Drews & Crouch (2006)

• This study looked as the effect of alcohol by administering ethanol to the participant.
• They found there to be more aggressive driving with ethanol consumption.
• They found similar impairments in both phone and alcohol use.

However...

Drews, Pasupathi & Strayer (2008)

• They compared the effects of a cell phone, a passenger, or no distraction.
• There was a difference between the passenger and cell phone condition.

Divided Attention

This is the process of focussing on more than one thing at a time.

Limitations:

• Perceptual: how many things can we attend to at the same time?
• Central processing/executive: dual task performance and capacity limitations.

Theories:

• Multiple Resource: The success of dual task performance depends on whether the tasks require the same processing resources.
• Central Capacity: this depends on the demands of each task on the limited capacity central processor

Factors influencing the success of dual task performance:

• Task similarity: the participant is more likely to be successful if the task involves different stimulus or response modalities.
• Task difference: this does not necessarily mean the sum of the difficulties, but it also concerns coordination and interference difficulties.
• Practice: The demands placed on attentional resources may be reduced if the task or action is practiced. A development takes place from controlled to automatic processing.

Task Similarity

• Stimulus modality: Stimuli that are presented in the same sense modality produced poorer monitoring performance than when they were presented in different modalities (Treisman & Davies 1973)
• Response Modality: An experimental example of this comes from McLeod, (1977) where a tracking task and a tone-identification task were used, and a manual or vocal response was given. The performance on the tracking task was worse when the mode of response was the same as the task, ie manual, than when it was different ie vocal.

Task Difficulty

• The effectiveness of a dual task performance decreased as a task becomes more difficult
• The difficulty refers not only to the demands of each task, but also of the demands of coordinating the two. This can require additional processing resources.
• D'Esposito et al. (1995): Semantic judgement task AND/OR spatial rotation. In the DUAL task condition, fMRI shows significant activity in the prefrontal cortex and anterior cingulate

Lavie (1995)

Lavie (1995) stated that perceptual load is a necessary condition for selective attention.

• Lavie (1995) found evidence for both early and late selection, and said that we have a limited attentional capacity, so attention must be split between tasks and distractions.
• High cognitive load tasks require all cognitive resources to be allocated to a difficult task and this results in early processing and selection (Filter Theory)
• Low cognitive load tasks. In these tasks, remaining cognitive resources are automatically allocated to irrelevant stimuli. This involves late processing and selection, and therefore distractors are attended more than in the high load tasks.

Visual search

• This is when something specific is sought out of a range of items.
• It can be lead by top-down processing eg shopping using a list (personal objectives) or by bottom-up processing eg being lead by visual salience, being distracted by an attractive object.
• Experimental studies relating to this, ask participants to identify specific targets within a visual display. Their success is dependent upon the distinguishing features of the target, and how many conflicting or distracting items there are.

The Flanker Task

• This is an example of an experiment testing visual search
• The participant is presented with a number of visual displays and must identify a target shape.
• Distractors are present to divert attention. These can be either compatible, (where the distractor is the same shape as the target), or competing (where the distractor is a different shape to the target)
• It takes people longer to identify the target when there are competing distractors compared to compatible distractors. This indicates that the distractor is processed even though the participants are told to ignore it.
• The Flanker Test can be carried out with either a high or low cognitive load. A low load has just 1 target and distractor, while a high load has many distractors.
• High and low cognitive loads have similar reaction times. This is because, though the high load is more complex, it has all of the attention focussed on it.

Focused visual attention

Important concepts:

Two attentional systems: Corbetta and Shulman, 2002

• Endogenous systems - goal directed/top down processing. The voluntary system selects sensory information according to personal goals, knowledge and expectations. This uses the frontoparietal network.

• Exogenous systems - stimulus-driven/bottom up processing. This is used when a salient, unexpected visual stimulus is presented. The involuntary system selects the unattended stimuli as 'circuit breaking' redirects attention. This process involves the right hemisphere in the ventral frontoparietal network

Theories of focused auditory attention

• Filter theory: this is when distracting information is filtered out at an early stage and only attended information is furtherly processed
• Attenuation theory: unattended information is not filtered out, it is just attenuated and the strength turned down
• Late selection theory: information is not filtered, instead it is processed at a late stage via the evaluation of current importance