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Perception and Cognition - Coggle Diagram

- - - - It is thought that this is why eye movements evolved.
      - To build up a visual representation the image on the back of the eye needs to be kept still.
      - Stabilisation occurs through optokinetic and vestibulo-ocular reflex.
    - - If an image is kept fixed on the retina it starts to fade away in the periphery after a while.
      - This is called Troxler’s fading (1804!)
      - It is caused by adaptation of the neurons in the retina, they do not fire after a while to the same stimulus.
    - - The retina is not uniformly sensitive.
      - A central part called the fovea has a high density of photoreceptors.
      - Most of the processing power is given to this area.
      - In order to have a detailed representation of a part of the image the light from that part needs to land in the fovea.
  - - - Smooth pursuit: We use this to track a moving object, It ensures that the light from the object stays focussed on the back of the eye. Requires a
        continuous feedback loop – the eye needs to adjust to the perceived position of the object.
      - Saccades: Fast, ballistic movements.
        
        Fast, ballistic movements
        
        Speeds of up to 700°/s
        
        We usually makes saccades 3-4 times a second.
        
        They show characteristic patterns of acceleration.
        
        Both eyes move together in an almost identical fashion.
      - Vergence: We move our eyes to focus on objects at different distances away from us.
    - - Optokinetic reflex - eye stabilization on the visual scene: These stabilising movements are made in reaction to the whole visual field moving
        They can be studied by using rotating drums or tumbling rooms.
  - - - Using this kind of technology we can build a picture over time of where a participant was looking.
      - We can measure: dwell time (each fixation), frequency of fixation, total duration of fixations (total looking time), order of fixation positions.
- - - - Colour : small number linguistic categories: different number of colour names in different cultures (Berlin & May 1969)
      - perceptual colour space: arrange colours
      - objective ‘
      - brightness’
      - according to similarity: Colour circles
      - measure discrimination thresholds
      - 3 M different colours
      - (24 bit computer display ~ 16 M)
  - - - The grey spots in the Hermann grid are believed to be the result of opponency filtering (contrast enhancement: excitation - inhibition)
      - Inside black squares: no stimulation of excitatory centre and inhibitory surround : no overall excitation >> perceived as dark
      - white bars: only small parts of the inhibitory surround are stimulated: excitation dominates inhibition >> bright
      - white intersections: larger parts of the inhibitory surround are stimulated: small overall excitation >> apparent reduction of brightness
      - Contrast illusion: enhancement of colour differences in space when presented next to each other
      - Colour assimilation: Bunker-white illusion- where object boundaries override simple colour contrast effects.
    - - Adaptation :
        
        • green-red stimulus > response jumps up and then gradually returns to resting levels.
        
        • NOTE: this encodes only changes (in time)
      - Opponency :
        
        • red-green are subtracted from each other
        
        • NOTE: this is contrast enhancement
      - Perceived aftereffect:
        
        Opposite in time = successive colour contrast
        
        • red-adapted regions turn green
        
        • green-adapted regions turn red
        
        • NOTE: contrast enhanced in the time domain
  - - - Size, perspective, occlusion
      - Motion parallax
      - Using two eyes
      - Texture, contrast, shading
    - - Stereopsis:Retinal projection of object on opposite sides of the fovea (disparity δ) indicates its depth relative to the plane of fixation. stereopsis is exploited to produce depth impressions in projected/printed pictures (Wheatstone stereoscope, red-green anaglyphs, lenticular cards, magic eye
- - - - sensory substitution: replacing a (lost/missing) sense with some other sense!
        
        (one in every 25,000 people !)
        
        synaesthesia: a mixing of senses causing a person to experience such things as colored hearing, gustatory sights, and auditory smells...
        
        ventriloquism: speaking or uttering sounds so that they seem to come from the speaker’s dummy or some other source than the speaker
    - - OTHER : magnetoreception? electroception? ultrasound?
      - PLUS : temperature ? pain ? balance ?
      - FIVE SENSES : sight, hearing, touch, smell, taste
  - - - praegnanz: good shape • similarity, symmetry
      - • proximity
      - • smooth continuation
      - • closure
      - • common fate
    - - comprehensive capture of information in optic array
        
        • unambiguous information about spatial layout (flowfield)
        
        • object affordances: meaning/usabilit in behavioural context
        
        • resonance: process to extract information (~ filter tuning
    - - active ‘construction’ of percepts
        
        • iterative comparison of sensory input with internal (stored) knowledge
        
        • hypotheses & expectations generate specific errors (illusions)
        
        • physiological basis ?
        
        • revival: Bayesian estimation
    - - receptor: transform stimuli to neural signals
        
        • receptive field: localisation and tuning
        
        • filter: encoding of information efficiently
        
        • representation: cortical processing and mapping • illusions: inherent misrepresent of physical world • active sensing: intelligent search system strategies
- - - - Discrimination
      - Generalization:
      - lighting conditions
      - varying context
      - rigid and non-rigid
      - transformation
- - - - The Secrets of Magic:
        
        The Secrets of Magic
        
        • sleight of hand : palming a card
        
        • misdirection : diverting peoples’ attention away from an important event
        
        • memory distortions: false memory altering spectators’ recollection of an event • perceptual distortions e.g. visual illusions
- - - - Harmonic intervals are determined by characteristic frequency ratio.
  - - - Physical intensity (SPL = sound pressure level) is recorded as ‘perceived loudness.
        
        Equal loudness contours are determined by matching the perceived intensity of tone pairs at various base intensities
  - - - Noise exposure can lead to temporary threshold shifts (auditory fatigue) and permanent (partial) deafness.
      - Tinnitus: continuous humming or ringing >> leads to suppression.
      - Presbycusis: selective high- frequency hearing loss with age (ongoing).
    - - Inter-aural processing to find azimuth (left-right) of sound source :
      - intensity differences (I I D) : acoustic ‘shadow’ of the head.
      - Pinnae : crucial for sensation of space (earphones); locate elevation (up-down).
      - Temporal or phase differences (I T D): inter-aural delays of 10 - 650 μsec
      - Cocktail party affect: The cocktail party effect is the phenomenon of the brain's ability to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli.
        
        Binaural unmasking : spatial distance and difference in frequency support separation < difference between ears.
        
        High-level effects (attention, familiarity of voice, language) & sensory fusion.
        
        Masking: the detection of a tone is impaired if another tone or noise is presented at the same time
        masking depends on proximity in space and similarity in frequency composition.
- - - - Presented a list of words, Each word could be associated with one of three types of encoding. Imagine one of the words was MEAL...
      - Three encoding conditions:
      - Structural (Orthographic): Is the word in upper case? (Yes)
      - Phonological: Does the word rhyme with “mat”? (No)
      - Semantic: Does the word fit in this sentence: “the man ate his _” ? (Yes)
  - - - Poor
      - Good
    - - Deep
      - Shallow.
    - - Phonological.
      - Semantic.
      - Structural.
  - - - Which of the following cues will be more effective for recalling the word PIANO? – 1)somethingmelodious?,or
      - – 2)somethingheavy?
      - • Depends on the learning context (Barclay et al., 1974)
      - • Participants who learn in this context: The man tuned
      - the PIANO showed better recall with cue (1) than cue (2)
      - • Participants who learn in this context: The man lifted
      - the PIANO showed better recall with cue (2) than cue (1)
      - • Conclusion: Participants encoded words with their
      - context
  - - - Asked divers to learn lists of words on land or underwater.
      - Recall was then tested either on land or underwater.
  - - - Alcohol (Goodwin et al., 1969; Overton, 1972),
      - Caffeine (Kelemen & Creeley, 2001),
      - Nicotine (Kunsendorf & Wigner, 1985)
      - Marijuana (Eich et al., 1975)
  - - - Decay?Perhaps long-term memories gradually fade over time.
      - Decay theory suggests that rate of forgetting should be fixed over a given period of time, whatever the individual does in that time...
        
        Retention interval is typically confounded with the number of additional experiences.
        
        If forgetting is due to decay, then recall should simply depend on length of retention interval.
        
        If forgetting is due to interference, then recall should depend on amount of similar learning within the retention interval (independently of its length).
        
        According to decay theory, there should be more forgetting after longer retention intervals even though the amount of new information remains constant.
        
        According to interference theory, there should be more forgetting after more new learning even when length of retention interval remains constant.
        
        Proactive Interference: Previous learning disrupts later learning.
        
        Retroactive Interference: Later learning disrupts earlier learning
  - - - Short capacity- 20 seconds
      - Limited storage: 4-7 items.
      - Primacy and recency effect:
        
        Primacy: Primacy gradient – First few items can be rehearsed a lot and so more likely to move into long-term memory.
        
        Recency gradient: Last few items of the list are still in STM when you start to write the list down.
    - - Unlimited capacity.
      - Unlimited storage.
      - Explict/ Implicit memory:
        
        Explicit memory: when retrieval of a memory is deliberate/requires conscious recollection. Also called declarative memory
        
        Implicit memory:Implicitmemory–whenbehaviour/performance indicates that memories are being retrieved in the absence of a deliberate, conscious, attempt to retrieve them, e.g.,
    - - Literal record of perceptual
        experience.
      - But lost quickly (transient)
      - Large capacity.
      - Visual and auditory:
        
        Iconic memory: Holds visual input for 250 msec.
        Representation is pre-categorical (literal record of percept)
        
        Echoic memory: Holds auditory input for 2-3 seconds.
    - - Episodic memories (memories for
        experiences/events)
      - Semantic memories (general knowledge about the world).
  - - - Causes:
        
        Organic: Acute damage, Degenerative to the brain disease.
        
        Psychogenic (purely psychological)
      - Retrograde: a loss of memory-access to events that occurred or information that was learned in the past.
      - Anterograde amnesia: A loss of the ability to create new memories after the event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact.
      - Amnesia and dissociations between different types of memory:
        
        Amnesia provides evidence for a dissociation between STM and LTM.
        
        Amnesics have poor episodic memory, and often (though not always) have poor semantic memory, but: Still have motor memory (skills), such as making a telephone. call or making coffee (procedural memory).
        
        Show normal sized priming effects.
        
        Still have motor memory (skills), such as making a telephone.
        
        Can learn new procedural skills such as tracking a moving target in the pursuit rotor task.
      - Several theories have been considered, including:
        
        Accelerated forgetting.
        
        Faulty retrieval.
        
        Faulty encoding.
        
        Faulty encoding/storage of contextual information.
      - Temporal gradient in retrograde amnesia: Temporal gradient may be due to slow-scale consolidation processes => earlier memories have had longer to be consolidated.
      - Consolidation theory of retrograde amnesia:
        
        Episodic memories are initially encoded and stored in hippocampus, and retrieving these memories requires reactivating the hippocampus. Over time, the hippocampal memory trace becomes less important, and the cortex can retrieve the memory without the hippocampus.
        Consequently, older memories are spared in retrograde amnesia.
      - Psychogenic amnesia:
        
        Dissociative type:
        
        Refers to loss of memory for specific events due to trauma (no anterograde amnesia).
        
        25-45% of homicide suspects claim amnesia for the crime!
        
        No cases reported before 1800: “dissociative amnesia is not a natural neuropsychological phenomenon, but instead a culture-bound syndrome, dating from the 19th century” (Pope et al., 2007).
        
        These types of psychogenic amnesia are extraordinarily rare (though much more common in fiction!).
        
        Very difficult to rule out malingering as a possible cause.
        
        Fugue states:
        
        Sufferer typically found wandering, often a long way from home.
        
        Triggers include severe stress, depressed mood ,history of transient organic amnesia (Kihlstrom & Schacter, 1995).
        
        Lasts a few hours or days (can be longer).
        
        After recovery, memories from the fugue state are lost.
        
        Very rare.
    - - Amygdala: (Emotional content of episodic memories).
      - Basal ganglia: (Important for learning motor skills).
      - Cerebellum: (Memory for automatised skills).
      - Frontal lobes [working memory (central executive); source monitoring; prospective memory].
      - Occipital lobes: (Visual Perceptual representation memory).
      - Hippocampus: Main section for creating and storing memories in the brain.
        
        Case of HM:
        
        HM: operated on in the 1950s to bilaterally remove the medial temporal lobes (about 2/3 of the hippocampus). Following surgery, his epilepsy was greatly improved. Personality was unchanged. IQ went up. However.... Unable to encode/retrieve new episodic memories. HM had developed severe anterograde amnesia.
    - - Temporal gradient of retrograde amnesia: Recall for events in the time immediately leading up to its onset very poor, but earlier memories relatively intact.
      - Encoding/retrieval of new episodic long-term memories impaired
        (i.e., anterograde amnesia).
    - - Pattern of impairments involves 'information-processing' deficits superimposed upon an amnesic syndrome (Morris & Kopelman, 1986)