Neuroscience and clinical evidence- attention Flashcards
1
Q
Neuroscience of attention
A
- Behavioural cognitive psychology is essential for the study of attention and has generated many testable hypotheses.
- Studies assessing RTs and accuracy cannot fully describe the neural mechanisms of attention, as they depend on relatively independent measures of cognitive phenomena
- With the development of neuroscientific methods, we can understand what happens in the brain (i.e. at what time, at what intensity and at which level) when we direct the focus of our attention on certain stimuli
- The cueing paradigm is used a lot in neuroscientific research- important in helping us understanding how attention works and forms testable hypotheses
- Just measuring reaction times and accuracies is not enough- it does not tell us the mechanisms of how things work
- In order to knows what happens in the brain we need other scientific measures
- Attention is a complex process- to truly understand we need to look at brain activity to show us the brain mechanisms in focusing and ignoring distracting
- Key question to answer- how does attention influence sensory processing in the brain
- We know that when we focus and have a target in front of us the activity in the brain is different to when we ignore distractions
Balancing act between targets and distractors is what makes attention powerful
2
Q
neural representation hypothesis
A
- Representations are not created equally
- Neural representations of relevant sensory information are enhanced relative to representations of irrelevant sensory information
- Neural measures:
- Spike rate, local field potential
- Event-related potentials, spectral power
- BOLD signal
- These all reflect neural representations of sensory information and thus can be used to assess attentional modulation
- When we interact with the world a lot of the sensory information. Reaches our brain
- Not all of it gets processed in the same way
- sensory information can be presented in 3 ways: targets (reaches conscious awareness), irrelevant information (present but needs to be supressed) and ignored information (does not get processed at all so we remain blind or deaf to it)
- Use different neural measures to see how stimuli are represented
- EEG- allows us to measure brain activity in real time
- Event related potentials- how the brain responds to specific stimuli
- Spectral power- looks at the different brain waves
- fMRI- measures blood flow to different brain regions and gives us an idea of which regions are active when processing different information
- Each of these methods gives us a unique perspective in understanding how the brain processes sensory information and how attention shapes what we perceive
Important to pick the right method to match the hypotheses and what you want to investigate
3
Q
target enhancement vs distractor suppression
A
- Dual mechanism model
- Selective attention this is accomplished through the interplay of two mechanisms:
- Target Enhancement: enhancing neural activity associated with relevant information
- Distractor Suppression: suppressing neural activity associated with irrelevant information
- Suppression may function as a compensatory mechanism to target enhancement
Selective attention helps visual processing by enhancing the cortical representations of behaviourally relevant stimuli (targets) while suppressing the representations of irrelevant stimuli (distractors).
4
Q
how does the brain control the modulation of brain activity to allow selective attention
A
- Specific sets of (higher level control) regions control and coordinate attention modulation
- Involvement and interaction of such regions can be measured with neuroscientific techniques (fMRI, EEG, TMS..) and clinical observations (e.g. brain damaged individuals)
- Higher level brain regions coordinate and regulate attention
- Important in helping us focus on targets we choose to pay attention to and monitor distractors, deciding if they need attention or can be ignores
- Attention is not just about paying attention to something it is also about being flexible and reacting to something unexpected e.g. danger for survival
2 key neural pathways that control how the brain manages attention
5
Q
enhanced activity in early visual areas (Eason et al., 1969)
A
- 1 of the first EEG studies to show how attention affects brain activity very early in sensory processing
- EEG measures electrical activity in the brain
- ERPs allow us to see how the brain responds to specific stimuli
- In visual perception we can measure something called visual evoked potentials- these are thew typical peaks we see whenever a visual stimulus is presented
- If we are paying attention to a stimulus the ERP for the peaks are larger- higher amplitude
- If we ignore a stimulus the peaks is much smaller- the brain still processes this stimulus but it is not as strong as the stimulus we are paying attention to
- This was demonstrated first through Posner’s cueing paradigm: they found that if the target appears in the attended location then the ERP peaks are very large. If the target appears in the unattended location the peaks are much smaller.
- One of the first pieces of evidence to show that attention enhances brain processing
Even though that the stimulus is the same the brains response depends on whether we are paying attention to it or not
6
Q
target related enhanced activity- Hopfinger et al., 2000
A
- fMRI evidence
- Spatial attention enhances activity in visual cortex contralateral to the attended target
Attention effects on target processing result from a gain-control mechanism that enhances the excitability of extrastriate neurons coding attended regions of visual space
7
Q
target related enhanced activity is retinoptic- Heinze et al., 1994
A
- with bilateral stimuli in the upper visual field…
- Retinotopically enhanced activation not only contralateral to the target but also in the ventral part of the occipital cortex
- PET evidence
Confirmed EEG – enhanced P1 amplitude contralateral to target
8
Q
evidence for multiple spotlights of attentional selection- McMains et al., 2004
A
- Spotlight model does no account for it we need to pay attention to two more things at the same time
- Multiple spotlight model allows us to split our attention across multiple stimuli
- In this study participants had to attend to either 1 target or 2 targets
- In the single target condition there was increased activation in the retinotopically corresponding brain area
- In the attended 2 condition, if the zoom lens model is correct we should expect there to be activation spreading across the broader area including distractors. If the multiple spotlights model is correct only the 2 relevant targets would be lit up. Data supports the multiple spotlights model- enhanced activation only in the areas corresponding to the intended targets, no widespread activation which rules out the zoom lens model
- Brain can split focus across multiple things
- Important as it helps us to efficiently process complex visual scenes without wasting resources on distractors
Explains how we can drive
9
Q
attention activity in the lateral geniculate nucleus- O’Connor et al., 2002
A
- Looks at how attention modulates early visual processing (before V1)
- LGN is the structure that everything you look at comes to and distributes to higher order areas in the brain
- Located in the thalamus
- This study shows that the LGN plays an active role in visual processing and attention
- Provides evidence that attention influences processing at the LGN level
- These findings challenge the traditional idea that attention only acts at the level of the cortex
- Instead, attention is already shaping what we see at a very early stage
- This means the LGN is not a passive gateway but an active gatekeeper- deciding what gets ignored and sent to visual cortex
- Before we become aware of a visual stimulus our brain is already filtering information- huge implications for how we understand perception and attention in the brain
- Spatial attention modulates activity as early as the Lateral Geniculate Nucleus.
The LGN, traditionally viewed as the gateway to visual cortex, may also serve as a ‘gatekeeper’ in controlling attentional response gain.
10
Q
attention activity in the lateral geniculate nucleus- O’Connor et al., 2002 attentional enhancement
A
- Attentional enhancement (A)
- When participants directed their attention to a stimulus, activity in the contralateral LGN increases
- Stimuli produced a stronger neural response when it was attended to, suggesting that attention enhances relevant information before it even reaches the visual cortex
11
Q
attention activity in the lateral geniculate nucleus- O’Connor et al., 2002 attentional suppression
A
- Attentional suppression (B)
- When attention is focused elsewhere responses in the LGN were reduced
- This means that LGN is not just boosting relevant information it is also suppressing irrelevant stimuli
- This suppression helps filter out distractions by preventing unnecessary information from reaching the higher visual areas
12
Q
attention modulation for nonspatial features- Anllo-Vento et al., 1998
A
- Attention can also modulate processing based on what something is
- In this experiment the stimulus always appeared in the same location- no need to shift attention in space. Instead participants had to selectively attend to a specific colour- allowed the researchers to isolate how attention modulated processing of non spatial features such as colour
- To investigate this they recorded EEG activity- specifically ERPs
- Found that attended to a colour produced a distinct sustained negative ERP wave- selection negativity over the parietal occipital scalp
- Key findings tell us that attention can modulate visual processing based on non spatial features even thought he stimulus location did not change, the brain responded differently depending on which colour was attended
- This means attention is not just about where we look but what we focus on
- Important as it highlights the flexibility of the attention system
Implications for real world perception e.g. focusing on a red traffic light
13
Q
attention modulation for non spatial features- Craven et al., 1997
A
- Example of how attention modulates visual processing not based on spatial location but on motion (moving features)
- The motion-processing area MT–MST (V5) is more active during attention to moving dots
- Participants were presented with a particular display of 2 different types of dots: stationary dots and the moving dots (these were moving towards the fixation cross)
- Both types of dots were always present- the visual stimulus did not change, the difference was where the participant directed their attention
- In different blocks participants had to focus on either the moving or stationary dots
- When participants attended to moving dots there was a clear increase in activity in area V5
- When they attended to stationary dots, activity in V5 (MST) was suppressed- even though the stimulus remained identical, attention alone was responsible for changes in activity
- Study highlights 2 key points about attention
- Feature based attention- it shows that we selectively enhance processing for specific visual features, in this case motion
- Attentional suppression- just as attention can enhance relevant information it can also suppress the irrelevant information
Means that perception is not a passive process- our attentional focus shapes what we process and perceive
14
Q
attention modulation on object reasoning- Wojcuilik et al., 1998
A
- Fusiform face is typically tuned to processing faces- only active when we look at faces
- Participants viewed images containing faces, houses and also a fixation cross
- Red and green fixation cross was a control condition
- Attention was selectively manipulated In different conditions: if they saw a face they attend to that and if they saw the house they attend to that
- Found that when participants attend to faces we see activity in the fusiform face area- increased strong activation
- Less activity in houses or any other objects
- When they attended to houses or bars the activity in the fusiform face area dropped significantly
Shows that even though faces were always present the attention determined whether the fusiform face area was activated or suppressed
15
Q
evidence for target enhancement and distractor suppression in the FFA- O’Craven et al., 1999
A
- Researchers presented superimposed images- face overlayed on a house
- Both stimuli always present and visible
- Participants had to either attend to the face or house or a moving stimulus (one rotated slightly)
- Found that the fusiform face area most active when they looked at the face
- The parahippocampal place area was most active when the house was attended to
- When attention was directed to the rotating stimulus, activity levels of both areas depended on which one was moving
- Study highlights that perception is not just about what is physically present, it is shaped by attention- brain activity only in increased for the attended stimulus.
- Provides evidence for feature based attention- we selectively enhance the processing of the stimulus we attend to
- Also provides evidence for target enhancement vs distractor suppression- attended stimuli triggers strong neural responses while unattended ones are suppressed
Attention has a fundamental role in shaping visual perception, directing neural responses towards the most relevant stimuli
16
Q
dorsal attention system
A
- DORSAL ATTENTION SYSTEM
- All to do with staying focused
- Brains focused mode- helps you to pay attention to something on purpose (chosen to focus on something)
- Starts in the frontal lobes of the brain and connects to parietal lobes
- Lets you choose what to focus on based on goals e.g. looking for a friend in a crowd
- FRONTO-PARIETAL NETWORK (including Dorsal – Medial Prefrontal Cortex and intra-Parietal Sulcus)
- TOP-DOWN CONTROL
- Attention is controlled by the individual’s expectations, knowledge and goals.
ENDOGENOUS ATTENTION
17
Q
ventral attention system
A
- Works side by side with the dorsal attention system
- Both crucial for navigating the world- brain keeps the systems balanced to remain focused but react whenever we need to
- TEMPORO-PARIETO-FRONTAL NETWORK
- (including Temporo-Parietal Junction and Inferior Frontal Cortex, IFG IFJ)
- BOTTOM-UP CONTROL
- Essentially works like an alarm- takes over when something in the environment grabs your attention unexpectedly e.g. a loud bang
- Starts in the sensory areas e.g. eyes and moves up through the brain to process that information
- Automatically shifts focus when something happens
- Attention is driven by an unexpected, and potentially important, stimulus EXOGENOUS ATTENTION
18
Q
two attention systems model of attention control
A
- Attention is not just simple one directional process]involved 2 interconnected systems that work together to help us focus whilst staying aware of our surroundings- important for survival
- These 2 systems are not separate- they are constantly interacting with each other
- E.e. driving a car: top down system would keep us focus on the road but if a pedestrian steps into the road the bottom up would shift our attention making us break
- Important because if we only had one system our attention would not work properly e.g. too rigid missing important changes like danger or we would be too distracted, constantly shifting our focus to every little thing
Balance between focus and flexibility allows us to focus in every day life
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Q
two attention systems model- Maurizio Corbetta & Schulman, 2002; Vossel et al., 2014)
A
- Demonstrated bilateral organization of the dorsal system,
- Potential right lateralization of the ventral system (possibly evolutionary explanations)
- VFC (inc. inferior and middle frontal gyrus) play a key role in the flexible interplay between the two
- Dorsal and ventral networks are anatomically segregated cortical systems (no overlap) with functionally specialized nodes promoting specific processes for attentional control.
- BUT they don’t control attention in isolation
- Flexible interaction between both systems enables the dynamic control of attention in relation to top-down goals and bottom-up sensory stimulation.
- Preparatory activation (in response to a spatial attention-directing endogenous cue) of sensory cortices during attention control (Hopfinger)
- Participants instructed to direct their attention to a target either left or right of fixation
- Even though the visual stimulation was same on both side, the attended side showed increased activity, highlighting the importance of attention modulation
- Researchers also examined brain activity before target appeared, specifically when a cue directed attention endogenously to one side
- Since there was a slight delay between the cue and target they had enough time to shift their attention accordingly
20
Q
two attention systems model- Maurizio Corbetta & Schulman, 2002; Vossel et al., 2014) results
A
- The cue triggered activation in key attentional control areas in the brain including the intro-parietal sulcus (IPS). That was activated on both sides regardless of whether attention was directed left or right. This shows that the dorsal attention network is bilaterally engaged in controlling attention
- Also found that when activity was observed in the superior frontal lobe this confirmed the goal directed attention and the frontal eye field is related to goal directed attention- activated before the target appeared and even higher increase in activity when they did
Study highlights how top down attention control actually prepares the brain for incoming information and is enhancing processing efficiency before a stimulus even appears.
- Also found that when activity was observed in the superior frontal lobe this confirmed the goal directed attention and the frontal eye field is related to goal directed attention- activated before the target appeared and even higher increase in activity when they did
21
Q
Maurizio Corbetta, 2002
A
- Used a cueing paradigm
- Provides evidence for the brain regions that are involved in orienting attention in response to an unexpected stimuli- exogenous orienting
- The key was highly predictive meaning it usually indicated the correct location of the upcoming target
- Because of this participants developed very strong expectations about where the target would appear.
- So they knew that it was going to appear in a particular location because every trial it was going to pair where the cue directed them
- When the target appeared in the unexpected location there was very strong activation in the temporal parietal junction (TPJ) and the inferior frontal gyrus (ventral attention network)
- This shows the ventral network plays a key role in detecting and responding to unexpected stimuli
- Good study for highlighting how our brain dynamically shifts attention
- A Ventral Parieto- Frontal system is activated in response to sudden stimulus onset.
- Evidence from attention reorienting after rare invalid targets vs. frequent valid targets.
- Right Temporo- Parietal Junction is more strongly activated by invalidly than validly oriented cues – Indicates
22
Q
terminology- visual impairments
A
- Unilateral neglect is also called:
- Hemi-inattention
- Visual neglect
- Visual spatial neglect
- Unilateral spatial neglect
- Contralesional: opposite side to brain damage
Ipilesional: same side as brain damagen
23
Q
neglect
A
- “Following right hemisphere brain damage a patient without impairment of intellectual functioning appears to ignore, forget or turn away from the left side of space- as if that half of the world has ceased to exist…” - Mesulam, (1985, as cited in Robertson and Marshall, 1993)
- Brain fails to process anything on one side of space
- What happens with unilateral neglect following the right hemisphere damage
Neglect is not blindness- eyes are functioning normally and there is nothing wrong with a persons vision but there is an attentional deficit- patients fail to acknowledge objects, people or their own body parts on the left hand side of space
24
Q
Brain 1943- Case 5: patients with right parieto-occipital damage
A
- One of the first patient cases to be reported
- Case 5
- “When asked to describe how she would find her way from the tube station to her flat she described this in detail correctly and apparently visualising the landmarks, but she consistently said right instead of left for the turnings except on one occasion.”
- This particular study highlights how neglect can manifest in spatial navigation
Patients may systematically ignore the left hand side even when they are on a familiar route they do every day e.g. always turning right not left
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cases with missile wound right parieto-occipital region (including angular gyrus)- Paterson & Zangwill, 1944
- Case 1: “The patient often collided with objects located on his left which he had clearly perceived a few moments before. He was liable to knock over dishes on his left-hand side and occasionally missed food on the left-side of his plate.”
* Common symptoms of neglect- even if they have perceived a particular thing on the left hand side (acknowledge it is there but then it isn't a few seconds later)
- Case 2 (right parietal damage): “It was noticed that the patient totally neglected his left upper extremity (of his own body) despite good preservation of motor power”
* This patient completely ignored anything on the left side of his body e.g. not shaving one side of his face.
* Shows that in neglect you also ignore the left side of yourself
Nothing to do with anything intellectual or motor
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nature of brain damage associated with neglect
- Neglect is most commonly observed in humans following damage to the right hemisphere (left neglect)
* As a result of this we will see deficits in attention to the left side of space because the right hemisphere is dominant for spatial attention and it processes both the left and right visual fields.
- Posterior parietal cortex (Specifically Inferior parietal lobe): plays a crucial role in neglect
* Damage to this strongly links to deficits in spatial awareness and attention
* Brodman’s areas 39 and 40 (dorsal ‘where’ visual pathway): processes spatial location so explains why neglect patients often bump into objects or they fail to respond to stimuli on the left hand side
* Left parietal damage rarely produces right sided neglect (and quickly recovers)
- Also some cases following sub-cortical damage
* Thalamus, basal ganglia, white matter
* Not all of the subcortical damage is equal e.g. damage the thalamus you are the most likely to see neglect compared to the basal ganglia and white matter
- The right parietal cortex appears to play a dominant role in spatial cognition in humans
* Region is important for how we process space and how we direct our attention to that space
- Most commonly the right inferior parietal lobe
This is an attentional deficit, not a sensory deficit e.g., caused by lesions in the visual cortex - blindness
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right hemipshere regions associated with neglect- Corbetta & Schulman, 2011
- Heterogeneous condition in which the brain areas involved vary considerably across patients.
- The main areas damaged are typically in the right hemisphere
- the attentional problems of neglect patients depend on brain networks (i.e. connected brain areas)
The region most commonly affected is in the right inferior parietal lobe – superior temporal gyrus, the inferior frontal gyrus, the insula, the supramarginal gyrus and the angular gyrus (Corbetta & Shulman, 2011).
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Vallar & Perani, 1986
- Wanted to understand where the actual damage of neglect occur in the brain
- 8 neglect patients and looked at where the damage occurred in each person
* Then superimposed everyone's brain onto each other, overlapping everyone's brain
- Most of the damage occurred in the in the inferior posterior parietal region
Contour map of lesion location of 8 patients with neglect. Right inferior parietal lobe (IPL)
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functions of the posterior parietal cortex
- Visuo-motor control of behaviour- how vision guides our actions
- Single cell recording shows these neurons involved in:
* Visually-guided reaching, Eye movements, Head (gaze) shifts
- Effects of lesions to PPC in humans
* Mis-reaching (optic ataxia)
* Eye movement problems (fixed gaze)
* Constructional apraxia (difficulty putting things together)
* Simultanagnosia (inability to perceive more than one object at a time)
Neglect (ignoring the left side of space)
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spatial neglect- Kamath, 1994
- Patients had to look at line drawings and scenery
- Patients failed to scan the left hand side
- Even with eye movements they failed to look at the left hand side
- Shows that in negkect eye movements are not even made to the left hand side
- Dissociation in eye movement behaviour
- Scenes chosen to guide (top-down) active search of left side
- Eye movement scan path
Failure to scan left side of scene (spatial neglect)
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subject centred (egocentric) neglect
- Egocentric: referring to the patients own left side
- Line dissection tasks: give out a piece of paper with different lengths of line
* Participants have to dissect (find the middle) of the line
* Participants with neglect cannot do this as they cannot acknowledge the left hand side of the line
- When patients try to put a mark through a horizontal line at its centre (line bisection task), they typically put it to the right of the centre.
- Patients can see stimuli in left visual field – they simply tend to ignore them, not to notice them
Patients can name objects in the contralateral visual field, if they are specifically pointed out.
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object centered (allocentric) neglect
- Not clear whether object- and subject- centred neglect reflect similar or different underlying disturbance to the attentional system
- This involves a lack of awareness of the left side of objects rather than simply the left side of the visual field
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extinction
- Milder form of neglect
- The phenomenon involves a failure to detect a stimulus presented to the side opposite the brain damage (contro-lesional field) when a second stimulus is presented to the same side as the brain damage (ipsi-lesional field) simultaneously
The competition elicited by the two stimulus inputs on both sides, is dominated by the right visual field, which “extinguishes” the input from the left
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Ballints syndrome
- Bilateral damage to the dorsal posterior parietal and lateral occipital cortex leads to an attentional deficit called Balint’s Syndrome.
- Three key symptoms:
* Simultagnosia: inability to attend and/or perceive more than one object at the time
* Optic Ataxia: impaired ability to reach for or point to an object in space under visual guidance
Oculomotor Apraxia: difficulty to voluntarily direct eye gaze towards
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Simultagnosia in Ballints syndrome- Cooper & Humphreys, 2000)
- Deficit lies in the inability to detect multiple objects rather than an inability to attend multiple qualities
Similarly participants are better than chance at comparing the length of two bars if these are connected as part of the same object
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why are faces important?
- Identity Recognition: Critical for social interactions.
- Emotion Communication: Convey feelings and intentions.
- Social Bonds: Essential for building relationships.
- Survival Mechanism: Detecting threats based on facial cues.
- Developmental Aspects: Innate preference for faces
It takes around 100 ms to detect a face
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what makes face perception special?
- Holistic Processing: Recognition of faces as whole units.
- Feature Relationships: Understanding spatial arrangements.
- Expertise Effect: Enhanced processing for familiar faces.
- Emotional Sensitivity: Quick recognition of emotional cues.
Developmental Evidence: Early recognition abilities.
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face processing
- Configural Processing: Emphasis on facial feature relationships.
- Feature-Based Processing: Focus on individual facial features.
- Dual-Process Theory: Interaction of configural and feature-based processing.
- Holistic vs. Analytic Processing: Differences in expert vs. novice recognition.
Cognitive Load Theory: Impact of cognitive load on face recognition.
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configural processing
- Definition: Recognizing faces based on the spatial relationships between features.
- Importance: Critical for identifying familiar faces.
- Example: Recognizing a friend by the arrangement of their features.
- Key Studies:
* Valentine (1991) discusses how configural processing contributes to the distinctiveness of faces.
* Yin (1969) demonstrated that recognition of faces is impaired when they are inverted.
- NOTE! Key concepts in configural processing include: Holistic processing, second-order relations and face-space theory
Effective for familiar faces.
- Explains the impact of feature arrangement on recognition
- Less effective for unfamiliar or distorted faces.
- Requires prior exposure to be effective
- Social interactions.
- Facial recognition in social contexts.
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feature based processing
- Definition: Focusing on individual facial features for recognition.
- Focuses on recognizing individual facial features, such as the shape of the nose, the colour of the eyes, or even a distinct hairstyle.
- Characteristics: Unique attributes (nose shape, eye colour, hairstyle). Utilized in various contexts (distinguishing similar faces)
- Research shows that people remember faces better when they can focus on specific features like a smile or distinctive glasses. – Schmidt 2016
- Key Studies: Santos & Young (2008) discuss the importance of feature recognition and how it can be advantageous under certain circumstances.
Useful for recognizing unfamiliar faces.
- Can highlight unique characteristics of individuals.
May lead to errors if features are similar (e.g., distinguishing between people with similar traits).
Law enforcement (e.g., eyewitness identification).
- Medical applications (e.g., diagnosing conditions).
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dual process theory
- Definition: Combines configural and feature-based processing based on familiarity with faces.
- Processing Styles:
* Familiar Faces: Primarily use configural processing for quick recognition.
* Unfamiliar Faces: Rely on feature-based processing to identify unique attributes.
- Real-Life Applications:
* Recognition in social interactions and law enforcement.
* Adjusting recognition strategies based on context.
- Studies show we can recognize faces more accurately when we see them in their natural settings (Brady & Alvarez, 2011)
- Research indicates that experts in specific fields, like forensic artists, use this dual-process approach effectively (Graham & McCulloch, 2008)
Accounts for different recognition strategies.
- Explains variability in face recognition success.
- Complexity in understanding which process dominates in different situations.
- Requires further research to clarify interactions.
Forensic psychology.
- Development of AI systems for face recognition.
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holistic vs analytic processing
- Definitions:
* Holistic Processing: Recognizing faces as a whole, emphasizing the arrangement of features.
* Analytic Processing: Focusing on individual features, assessing attributes separately.
- Processing Styles:
* Holistic is often more efficient for familiar faces.
* Analytic is used for unfamiliar faces or distinguishing similar individuals.
- Real-Life Applications: Critical in social interactions and identity recognition. Impacts in areas like marketing (brand recognition) and security (facial recognition technology).
- Research indicates that people are faster and more accurate in recognizing familiar faces holistically compared to unfamiliar ones (Tanaka & Farah, 1993)
- The famous “Thatcher Effect” demonstrates how our perception can be distorted when faces are inverted, emphasizing holistic processing (Thompson, 1980)
- More efficient for recognizing familiar faces.
- Supports quick social interactions.
Holistic processing may falter for unfamiliar faces or when identifying similar individuals
Marketing strategies (e.g., brand recognition).
- Social networking applications.
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cognitive load theory
- Definition: Cognitive Load Theory, posits that our working memory has limited capacity for processing information.
- Types of Cognitive Load:
* Intrinsic Load: The inherent difficulty of the material being learned.
* Extraneous Load: The way information is presented, which can hinder learning if poorly designed.
* Germane Load: The effort associated with processing information, organizing it, and integrating it into existing knowledge.
- Implications for Face Recognition: Understanding cognitive load can help optimize learning environments, particularly in tasks involving facial recognition.
- Real-Life Applications: Designing effective educational materials.
- Enhancing user experience in facial recognition technologies.
- Highlights the importance of minimizing extraneous cognitive load for better recognition outcomes.
- Applicable across learning contexts.
- Primarily focuses on memory processing rather than the mechanisms of face recognition.
- Educational design for improving learning.
- User experience optimization in facial recognition software.
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Prosopagnosia
- Prosopos (gr.): ‘face’ or ‘person’ Agnosia (gr.): ‘not knowing’
- = FACE BLINDNESS
= Inability to recognise familiar faces
* Symptoms
* Difficulty recognising faces
* Relying on other cues
* Confusion in social situation
* Impaired memory for faces
- Often correlated with other visual deficits; but face recognition problems are disproportionate to their deficits in recognising other objects (visual agnosia)
- this suggests that prosopagnosia is not related in a simple way to the recognition performance of non-facial stimuli
- Double dissociation of face and object processing (one can be affected without the other one being affected)
- Strategies for life improvements
* Compensatory strategies
* Face recognition training
* Cognitive rehabilitation
* Assistive technology
Psychological support
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prosopagnosia causes
Causes
* Congenital (developmental): Some people are born with prosopagnosia due to differences in brain development. It’s often hereditary.
* Acquired: It can also occur after brain damage from a stroke, head injury, or certain neurological conditions. The damage typically affects the fusiform gyrus, which is crucial for facial recognition.
- Damage to infero-temporal area (IT) is often associated with prosopagnosia
