Consciousness 2025

1st Person Data

Subjective experience or qualia; measured via questionnaires, interviews, or journals. Reflects personal consciousness.

3rd Person Data

Observable behaviors or brain activity; measured using observations, psychological tools, or neuroimaging. Focuses on external correlates.

How do you infer consciousness?

Voluntary actions, communication, arousal, attention, awareness and brain activity

Consciousness

the subjective experience of being aware of oneself and the environment

NCCs (Neural Correlates of Consciousness)

Patterns of neural activity associated with conscious experiences

How is consciousness created?

arises from mental representations of experiences

Phenomenal

Subjective experiences or "what it feels like."

Psychological

Introspection and reporting

Philosophical Zombie

A being physically identical to a human but without subjective experience (qualia)

Introspection

The act of observing one’s own thoughts and conscious experiences

IVR

Reporting conscious experiences verbally.

PAS (Perceptual Awareness Scale)

Rating clarity of perceived stimuli

Limitations of Measuring Introspection

Issues with verbal reports, censorship, memory influences, and verification

Attention

Selective information processing

Involuntary (exogenous)

Stimulus-driven

Voluntary (endogenous)

Goal-driven

Binocular rivalry

two different images are presented to each eye, leading to a perceptual struggle between the two

How could we measure binocular rivalry?

Subjective Measures (Report-Based): Individuals can provide verbal reports describing their conscious experience

The Perceptual Awareness Scale (PAS)

a tool used to measure a person's level of awareness or consciousness of a stimulus

Neural Correlates of Attention (NCA)

the brain areas or activity patterns that are associated with the allocation of attention

Lamme’s Theory

suggests that attention does not always lead to awareness, and some stimuli are excluded from our conscious experience

Feedforward processing

a rapid, initial sweep of information through the visual hierarchy, extracting basic and complex features

Feedbackward (recurrent) processing

refers to how higher brain areas send information back to lower brain areas to refine perception and decision-making.

The split-brain phenomenon

Refers to the set of effects observed in individuals who have undergone a commissurotomy, a surgical procedure where the corpus callosum, the main connection between the two cerebral hemispheres, is severed

Tactile Stimulation

Subjects are asked to identify objects hidden in a box just by touch, using only one hand at a time

Lateralized Visual Presentation

A tachistoscope (T-scope) is used to present visual stimuli (pictures or words) briefly to either the left visual field (LVF) or the right visual field (RVF)

Corpus callosum

the major pathway connecting mostly homotopic (corresponding) points between the two cerebral lobes

Anterior commissure

A smaller pathway that connects portions of the anterior temporal lobes and the amygdala

What is the left hemisphere better at?

Verbal Tasks, Language Production, Math Problem Solving, Local Detail Recognition, Self-Recognition, Spontaneous Writing, Interpretation

What is the right hemisphere better at?

Nonverbal Tasks, Visuospatial Tasks, Drawing, Tactile Recognition, Face Recognition, Temporal Discrimination, Object Recognition, Visual Scene Regularities, Emotional Reactions

The doctrine of concordance

states that there is a close agreement between what people know, how they behave and what they experience

Amnesia

a condition characterized by a partial or complete loss of memory. It can affect the ability to recall past experiences or form new memories

Anosognosia

a condition in which a person is unaware of or unable to recognize their own illness or disability. This lack of insight is not due to denial but is instead caused by damage to specific brain areas, such as the parietal or frontal lobes

Anton’s Syndrome

a rare neurological condition where a person is cortically blind but is unaware of their blindness and denies it

Asomatognosia

a neurological condition characterized by a lack of awareness or recognition of a part of one’s own body. Individuals may deny ownership of a specific body part, most commonly a limb.

Somatoparaphrenia

a rare subtype of asomatognosia in which an individual not only denies ownership of a part of their body but may also attribute it to someone else.

Neglect

A neurological condition where a patient exhibits a lack of awareness of a part of their world or their own body, despite the sensory input being available

Free will

The capacity for self-initiated action, accompanied by the subjective feeling of control and the freedom to choose whether or not to ac

Global Workspace Theories (GWTs)

suggests that consciousness arises when information is broadcast across the brain, allowing different brain areas to share and process it.

Higher-Order Theories (HOTs)

suggest that a mental state becomes conscious when there is a thought or perception about it. Example: You feel pain, but it only becomes conscious when you realize you are feeling pain

Integrated Information Theory (IIT)

proposes that consciousness comes from the ability of a system to integrate and process information in a unified way

Predictive Processing Theories

broader accounts suggesting that the brain functions to minimise prediction error by reciprocally exchanging top-down perceptual predictions and bottom-up prediction errors

highlighted the differences between 1st and 3rd person data

Chalmers (1999)

used fMRI to detect awareness in vegetative patient by observing task specific neural activation

Owen (2006)

Showed that minimally conscious and vegetative patients can modulate brain activity to answer yes/no questions

Monti (2010)

Use various methods (e.g., backward masking, crowding) to find neural correlates of visual awareness.

Kim and Blake (2005)

investigated attention and its affects on perceptions using the spotlight metaphor

Blackmore

measured readiness potentials preceding voluntary actions suggesting unconscious initiation of action. Found that readiness potential (RP) precedes conscious decision-making by ~350-400ms.

Libet

used fMRI to predict participant decisions several seconds before they reported being aware of their choice, showing that frontopolar and parietal cortex activity precedes awareness by up to 10 seconds.

Soon et al (2008)

found that split-brain hemispheres can partially communicate through alternative pathways despite the severed corpus callosum

Pinto et al (2017)

criticized fMRI use saying that preserved neural responses don’t necessarily indicate conscious experience

Burton (2007)

Differentiates between Phenomenal (P-consciousness) and Access (A-consciousness). Argues that blindsight patients lack both, contrary to common claims that they have A-consciousness without P-consciousness.

Block

Defines the "easy" and "hard" problems of consciousness. Psychological (easy) vs. Phenomenal (hard) aspects.

Chalmers (1995)

Proposes a partial consciousness model, where the left hemisphere is responsible for linguistic thoughts

Eccles

Gazzaniga (early findings)

Proposes a partial consciousness model, where the left hemisphere is responsible for linguistic thoughts

Gazzaniga (later findings)

Proposes a Partial Consciousness Model with the left hemisphere as an interpreter system.

Covers split-brain experiments and introspection

Farthing

Warns against overgeneralizing from a single case. Emphasizes the need for direct subjective reports.

Naccache

Backward Masking

A brief target stimulus is quickly followed by a masking stimulus, preventing conscious awareness of the target while still allowing the brain to process it

Studied binocular rivalry in monkeys. Found that neurons reflecting perception are distributed across the visual pathway, with higher areas being more specialized.

Logothetis

Investigated binocular suppression in V1. Found that attention (not awareness) modulates BOLD signals

Watanabe

Developed a task to study endogenous/exogenous attention

Posner

created the AIM model of consciousness (Activation, Input, Mode). Studies lucid dreaming and brain areas involved.

Hobson

Found that monks practicing one-point meditation could alter their perceptual experience, leading to greater perceptual stability.

Carter

Maps states of consciousness using two dimensions: Wakefulness (Level of Consciousness) vs. Awareness (Content of Consciousness).

Laureys

Argues that no one is truly morally responsible for their actions, discussing determinism.

Strawson

Re-entry theory

suggests that consciousness arises from continuous two-way communication between different brain areas

Predictive Processing Theory

suggests that the brain is constantly making predictions about the world and updating them based on new sensory input