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42 Cards in this Set
- Front
- Back
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What important differentiation do we need to make to study conscious awareness |
Our awareness of events and the phenomenological experience associated with this - phenomenal consciousness
Out awareness of having mental states, agency, etc. - meta-consciousness |
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When looking for the neural correlate of consciousness (the NCC), what is usually implied by 'consciousness' |
(visual) awareness |
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Defien the NCC |
the minimal set of neuronal events jointly sufficient for any one specific aspect of a conscious percept |
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What three methods/areas of study are used to identify the NCC/NCA? |
Lesion patients
Correlational methods using subtraction imaging analysis
Inference methods using drugs, TMS, etc. |
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What are zombies? |
People with no awareness or phenomenological experience |
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What behaviours characterise blindsight? |
The ability of patients with lesions to the primary visual cortex, V1, to make better-than-chance visual discriminations in the absence of visual awareness. |
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What do V1 lesion studies demonstrate? |
V1 is necessary for most visual awareness
Visually-guided behaviour can occur in the absence of conscious awareness
Parallel routes for processing visual information unconsciously are available |
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What evidence is there for visual phenomenological awareness in monkeys? |
Cowey and Stoerig (1997) showed that even with unilateral V1 lesions and preserved visual behaviours, monkeys reported not having seen cues to which they make accurate responses. |
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Give four examples of stimuli-specific awareness deficits |
achromatopsia akinetopsia prosopagnosia alexia |
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What do lesions to functionally specialised nodes within the visual system do, if not wholly abolishing visual awareness? |
They block awareness of the features/attributes coded by that particular area. |
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What type of visual agnosia does patient DF have? |
Form agnosia - cannot recognise or perceive shapes but can use visual information to guide action. |
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What area in monkey brains is recruited in object/shape recognition? |
IT (LOC in the occipital cortex in humans) |
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What do imaging studies of patient DF tell us about her dorsal processing stream? |
It is activated as normal in visually guided tasks James et al., 2003 |
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Describe an example of a general task used to identify neglect. |
Show two stimuli at once - one in the ipsi- one in the contralesional side of space. Ask what they see and press for two answers. Ipsilesional stimuli = correct Contralesional stimulus - reported correctly more often than chance despite reports of nothing being there. |
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What types of residual processing have been demonstrated in neglect patients? (4) |
1. motor preparation 2. implicit memory 3. semantic processing 4. perceptual Gestalt grouping |
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Patient HM had damage to what area causing amnesia: |
temporal lobe |
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Give an example of a learning phenomenon that proves that some unconscious residual memory abilities remain in amnesic patients |
mirror drawing skills |
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What is semantic priming through subliminally presented words? |
Words that you cannot have been consciously aware of (as they are presented briefly and then masked by other words) make you faster at lexical decision tasks on semantically related words. |
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What did Kahneman propose about unconscious and conscious processing of our environment? |
We have an autonomous set of processes running on cruise control all the time. Only in novel or challenging situations so we turn on the slow, conscious, effortful processes needed for deeper analysis. |
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Invisible, masked stimuli activate which areas? |
Early retinotopic areas and areas specialised for object an face processing. |
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What area is activated by emotional (fearful) faces even when suppressed in binocular rivalry or masking? |
The amygdala |
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What is binocular rivalry? Why is this such an interesting concept to investigate? |
When each eye is presented with a different stimulus, these images will compete to occupy visual awareness. The subjective percept alternates between the two images. This is a useful paradigm for investigating awareness, since the input remains constant , but the contents of awareness changes |
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Activity in which brain areas is most modulated by subjective percepts? |
Higher level visual processing areas like IT/V5, FFA and PPA |
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Give four other visual stimuli that show patterns of percept modulation in prefrontal and parietal activation |
Face/vase optical illusion Spontaneous perception in stereo pop-out displays Perception of fragmented figures Detection of changes in in attentional blindness displays |
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How are threshold stimuli defined? Why are they used? |
Those that elicit awareness on 50% of trials. Contrasts in V1 activity between perceived and non-perceived trials reveal activation in the relevant functionally specialised visual areas for awareness on top of sensory stimulation. |
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What patterns of activation are seen for illusory percepts like motion illusions and afterimages? |
Activations in functionally specialised areas like V4 and MT |
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What are hallucinations? |
false sensory perceptions in the absence of external stimulation, induced by sleep deprivation, drugs or neurological and psychiatric disorders. |
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What neural activity is seen during visual and auditory hallucinations respectively? |
visual: object-selective brain regions in the ventral stream
auditory: primary auditory cortex + subcortical and limbic areas |
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Which hemisphere(s) of the brain are capable of visually guided action initiation and which are responsible for comments on and interpretations of perceptual events? |
Both can initiate visually guided actions
Only the left-hemisphere comments on and interprets perceptual events. |
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Why might people undergo surgery to split the corpus callosum? |
Severe treatment-resistant epilepsy |
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What behavioural observations can be made of callosal split patients? |
Left hemisphere is florid and tells you about conscious experience (because it is linked to speech production?) but right hemisphere does not. |
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What common methodological oversight is made in tasks contrasting awareness and unawareness conditions? |
The task difficulty (or other nuisance variables) are not equated. |
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Along with behavioural reports, what two forms of subjective report should be used to determine awareness? |
1. commentary keys 2. confidence ratings |
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When Lau and Passighman (2006) compared brain activations under different levels of subjective experience but the same forced-choice discrimination, what did they observe? |
Not the usual pattern of activation in the frontoparietal network plus specialised visual areas - but rather they only saw activation in the prefrontal cortex. |
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What did Descartes propose was the interface between the distinct mind and body? |
The pineal gland |
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What did David Milner propose about the neurological underpinnings of visual awareness? |
The phenomenological contents of visual awareness is maintained in the ventral visual stream, although the dorsal stream may play a role in guiding what becomes maintained using top-down biases. |
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Dorsal stream guides...? Ventral stream guides...? |
Dorsal stream guides immediate action and its calibration
Ventral stream guides action indirectly and mediated through memory |
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Outline the Biased-Competition Account of attentional control of representations proposed by Frith and Rees. |
1. object representations compete for dominance in ventral pathway 2. frontoparietal system biases this competition 3. evidence points to an important role being played by parietal and frontal areas in determining awareness as long-range coupling with appropriate sensory areas. |
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What did Shallice (1972) equate awareness with? |
The focus of attention and working memory |
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Outline Koch and Crick's idea of mutually reinforcing coalitions of neurons. |
Coalitions of neurons in sensory (posterior) areas and coalitions of neurons in executive (anterior) areas are separate but interact.
Posterior coalitions include essential nodes of functional specialisation.
Frontal coalitions relate to feelings of ownership and agency.
Oscillations are important in establishing coalitions, as are projections to other regions and re-entrant circuits. |
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Give 3 examples of theories linked to the mutually reinforcing coalitions of neurons theory. |
Global neuronal workspace Information integration theory Recurrent processing theory |
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What are high-frequency oscillations proposed to do? |
They serve as a mechanism to unify perception by temporally binding activity across populations of neurons linked to a given percept.
High-frequency synchronisation boosts downstream processing of selected attributes thus facilitating integration of percepts and helping overcome the binding problem. |
