First-Person Data
Our subjective experiences
–> the feeling that there is something it is like to be us
–> can be different at different times
Third-Person Data
objective experiences
Data about:
- brain processes
- behavior
- environmental interactions
Science of Consciousness
connects the first-person data to the third-person data
–> explains the1st terms of the 3rd
!! 1 cannot be expressed wholly in terms of 3 data
Methodologies for Third-Person Data
assessing what is going on in the brain:
- EEG,
- brain imaging,
- single-cell studies,
Formalisms for Third-Person Data
-language,
- images and diagrams,
- computational models
Methodologies for First-Person Data
- not a lot of options
- untutored introspection and verbal report
Obstacles:
- lack of access to experience
- impossibility to access all at once
- illusions
- changing experiences while introspecting
Formalisms for First-Person Data
- simple language
- relies on subjective experience
Obstacles:
- imprecision
- non-structural aspects of experience
- different individuals have different experiences
Neural Correlate of Consciousness (NCC)
The neural system of systems primarily associated with conscious experience
Interpretation
we interpret physical systems to judge the presence of consciousness
Bridging Principles
Principles that bridge the gap between physical and phenomenal aspects of consciousness
–> connect the brain activity and subjective experience
–> bridge the gap between first-person and third-person data
Principle of Verbal Report
when information is directly available for verbal report or verbally reported, it is conscious
Principle of Availability for Global Control
when information is directly available for global control in a cognitive system, then it is conscious
–> global control allows for flexible, adaptive behavior
consciousness selects and prioritizes certain mental processes based on the information that is currently available to it
= this selection process determines the content of conscious experience
Directness Criterion
A perceptual experience is considered direct, if the experience
+ is a direct result of sensory input
+ does not involve any
- interpretation,
- inference
- cognitive processing
Rational Reconstruction
(1) Consciousness <-> global availability (bridging principles)
(2) Global availability <-> neural process N (empirical work)
(3) Consciousness <-> neural process N (conclusion)
Consequences of NCC
- the NCC will be a mechanism of global availability
- NCC cannot be established in an independent test for consciousness -> there are limitations to NCCs
- it is likely that there will be many NCCs
- global workspace: a functional area responsible for integrating information in the brain and disseminating it to multiple nonconscious specialized processes
- processes of access consciousness might be the same for phenomenal consciousness
Vegetative State
patients who emerge from coma appear to be awake but show no signs of awareness
–> no reproducible evidence of purposeful behavior in response to external stimulation
–> “islands” of preserved brain function may exist
Consciousness in Vegetative State Patients
- conscious processing is abolished
- no mental states, interactions with their environment, intentional actions
–> in a minority of cases, patients have residual cognitive function and even conscious awareness
When is someone conscious?
- the ability to report one’s own mental state = fundamental property
- active maintenance of mental representations
- strategical processing
- spontaneous intentional behavior
Functional Neuroimaging Techniques and Consciousness
- detect conscious awareness in patients who are assumed to be vegetative
- fMRI can evaluate vegetative patients’ performance on motor and spatial imagery tasks
- fMRI can show precursors of perception –> it cannot tell whether a person is aware of this perception
Mental Tasks
non-communicative patients can communicate their thoughts by modulating their own neural activity
Owen study:
- playing tennis
- imagining the rooms of their house
Minimally Conscious State
Patients show inconsistent but reproducible signs of awareness
-> including the ability to follow commands,
-> but they remain to communicate interactively
