Chapter 8: Consciousness – Study Notes
8.1 The nature of consciousness
Learning outcomes for this chapter:
8.1 Describe the two main functions of consciousness
8.2 Distinguish among the different theoretical perspectives on consciousness
8.3 Describe the functions of sleep and distinguish among the psychological views of dreaming
8.4 Explain how people might experience altered states of consciousness
Key definitions and overview
Consciousness: the subjective awareness of mental events (thoughts, feelings, perceptions, etc.).
Two core functions of consciousness:
Monitor: of the self and the environment (surveying perceptions, thoughts, emotions, goals, problem-solving strategies).
Control: initiating and terminating thoughts and behaviours to attain goals.
Attention: the process of focusing conscious awareness on a limited range of stimuli or thoughts, requiring deeper information processing.
Measurement of consciousness: self-report questionnaires, brain imaging (EEG, fMRI, PET), behavioural observation; experience-sampling techniques (e.g., beeper studies).
Normal flow includes daydreaming: attention turns inward to internal thoughts and imagined scenarios.
Flow: a mental state of complete absorption, energised focus, and intrinsic enjoyment in an activity.
Experience-sampling techniques and beeper studies provide insights into everyday conscious experience.
The Stroop task demonstrates conscious control and engages brain regions; see neural correlates below.
Attention and its components
Attention is the selection of a location, object, or thought to focus on; it is guided by external stimuli and activated goals.
Components of attention (three core functions):
Orienting to sensory stimuli (visual/tacial focus) – involves midbrain (e.g., superior colliculi), thalamus, and parietal lobes; reflexive and voluntary components.
Controlling the contents of consciousness (selective attention) – frontal lobes and basal ganglia involvement.
Maintaining alertness (arousal) – reticular formation and broader networks.
Neural evidence: dorsolateral prefrontal cortex (DLPFC) is activated when exercising conscious control (e.g., Stroop task). Anterior cingulate cortex (ACC) activates when conflict between ink colour and word arises, signaling conscious regulation of competing cues.
The Stroop task (classic example): name the colour of the ink, ignore the word itself; robust interference demonstrates conscious control and selective attention.
Lesion/activation data: DLPFC for preparatory control; ACC for conflict monitoring; together support a fronto-cingulo-thalamo-cortical network for conscious control and monitoring of processing.
Everyday implications: attention can be filtered (Cocktail party effect), mind wandering, and divided attention (e.g., dichotic listening, shadowing).
The normal flow of consciousness and daydreaming
Daydreaming: shifting attention from external stimuli to internal thoughts; common across people; linked to memory consolidation, problem solving, and social processing.
Types of daydreaming (Singer, 1975):
Positive constructive daydreaming
Guilty-dysphoric daydreaming
Poor attentional control
Large-scale findings: people daydream daily; university students spend roughly half their conscious time daydreaming; daydreaming frequency tends to decline with age; higher task-unrelated thoughts predict poorer exam performance in some studies.
Functions of daydreaming: proposed adaptive roles in memory consolidation, social skills, creativity; positive constructive daydreaming can aid problem solving and memory.
Flow state: mutually exclusive with boredom or overload; neural correlates include increased activation in inferior frontal gyrus and putamen, decreased amygdala and medial prefrontal cortex activation, implicating reward and emotion regulation networks.
Perspectives on consciousness (intro to section 8.2)
Four major theoretical traditions:
Psychodynamic perspective (Freud): conscious, preconscious, unconscious; repression as a dynamic mechanism to keep threatening material out of awareness.
Cognitive perspective: cognitive unconscious – information-processing mechanisms outside awareness (procedural knowledge, implicit memory).
Behavioural perspective: consciousness as monitor and control of experience; in practice, many behaviours occur automatically without conscious awareness.
Evolutionary perspective: consciousness evolved to direct adaptive behaviour, overlaying more primitive conditioning processes.
Integrative aim: synthesise these perspectives to understand how conscious and unconscious processes contribute to adaptive behaviour.
The psychodynamic unconscious (Freud)
Freud’s three regions (conscious, preconscious, unconscious) form a dynamic system:
Conscious: current subjective awareness.
Preconscious: not currently conscious but can be readily brought to consciousness.
Unconscious: dynamic processes kept out of consciousness because they are threatening; repression acts as a censor.
Repression as dynamic unconscious energy: ongoing psychological effort to keep distressing content out of awareness.
Subliminal perception: perception below conscious threshold can influence conscious thought and behaviour; tachistoscope studies show stimuli presented too briefly for conscious recognition can affect mood, preferences, and subsequent responses.
Unconscious emotion and motivation: implicit motives and priming can shape behavior outside conscious awareness; cognitive unconscious refers to non-conscious information processing (implicit memory, procedural knowledge).
Making connections: unconscious processes can drive behaviour; conscious goals reallocate activation to goal-relevant networks; the distinction between descriptive unconscious (not conscious) and dynamic unconscious (threatening material) is central to Freudian theory.
The cognitive unconscious
Information-processing mechanisms outside awareness (procedural knowledge, implicit memory).
Information-processing models often distinguish explicit (conscious) vs implicit (unconscious) memory and cognition.
Connectionist views: parallel processing across many unconscious networks; conscious experience arises from a distributed, integrated pattern that highlights networks best fitting data.
Strengths and trade-offs: unconscious processes are fast, efficient, and parallel; conscious processes are slower but more flexible and capable of solving problems requiring big-picture integration.
Role of the conscious spotlight: redistributes activation among networks; when conscious goals are active, they bias attention and processing toward goal-relevant information.
The behavioural perspective and neural basis of attention and consciousness
Consciousness has a biological basis: observable neural correlates of conscious control and awareness.
Key neural pathways: reticular formation (wakefulness/arousal) → thalamus (sensory relay and gating) → cortex (especially prefrontal for working memory and conscious access) and back to thalamus/reticular formation.
The prefrontal cortex and thalamic loops create the conscious spotlight that selects relevant information and suppresses irrelevant detail.
Blindsight as evidence for distributed networks: patients with V1 damage can respond to visual information without conscious awareness, suggesting consciousness is not localized to a single “centre” but emerges from distributed networks.
Sleep and the brain: integrated view of consciousness
The sleep-wake cycle is a circadian rhythm: driven by light-dark cycles, with melatonin from the pineal gland increasing at night, regulated by hypothalamic circuits.
Sleep stages monitored by EEG; major distinction is REM vs NREM sleep.
REM sleep: rapid eye movements, autonomic arousal, vivid dreaming; brain activity resembles waking, but motor systems are inhibited to prevent acting out dreams; prefrontal cortex tends to be less active during REM dreams.
NREM sleep: slower brain activity; delta sleep (Stages 3-4) features large slow waves (delta waves) and muscle relaxation; dreams can occur but are less frequent than in REM.
Dream theories (overview): psychodynamic, cognitive, and biological explanations; these are not mutually exclusive and can be integrated with sleep's role in memory processing.
Dream content, sleep biology, and synaesthesia as a related phenomenon
Dreaming occurs most often in REM sleep; approximately 80% of awakenings from REM report dream activity; dreaming also occurs in NREM sleep though less frequently.
Dream neural substrates: REM involves a network including pons, thalamus, amygdala, and visual association areas; primary visual cortex is less active; prefrontal areas involved in attention and conscious evaluation are reduced, which may explain the bizarre and emotionally intense quality of dreams.
Synaesthesia (case studies and neural basis): a condition where cross-sensory experiences occur (e.g., letters/numbers evoking colours or textures). Prevalence estimates up to ~4% of the population; grapheme-colour synaesthesia is common.
Real-world examples: Helen Besgrove experiences colours/textures with words; Josie Moon experiences music as colours and textures; both report benefits (e.g., memory aids, language learning) and challenges (e.g., navigating directions when ‘left’/‘right’ map to colours).
Neuroscientific findings: magnetoencephalography (MEG) shows overlapping neural patterns when processing real colours and colour-evoked by letters/numbers, suggesting shared colour knowledge systems; two main hypotheses for synaesthesia: extra connections or stronger/inhibition-difference in existing connections. Research indicates an objective neural signature for synaesthetic colour experiences, supporting the authenticity of these perceptual experiences.
New connections and clinical relevance
The chapter argues for integration: the neural basis of consciousness involves distributed networks; unconscious processes can contribute to conscious experience; experience-sampling methods illuminate the everyday flow of consciousness; neuroimaging links consciousness to fronto-thalamo-cortical circuits.
Practical applications include understanding recovery in vegetative states (e.g., fMRI-detected task-based activations), addressing the effects of psychoactive substances on states of consciousness, and recognizing the ethical implications of altered states of consciousness.
8.2 Perspectives on consciousness
Freud’s model of consciousness (conscious, preconscious, unconscious)
Conscious: current subjective awareness (e.g., what you read right now).
Preconscious: not currently in awareness but can be retrieved (e.g., a memory you can bring to mind if asked).
Unconscious (dynamically unconscious): inaccessible because it is threatening and kept out by repression; requires ongoing mental energy to maintain censorship.
Subliminal perception: stimulus exposure below conscious threshold can influence thoughts/emotions/behaviours; tachistoscope studies and later priming research show robust effects despite lack of conscious awareness.
Unconscious emotion and motivation: motivation can operate outside awareness; priming with motive-related words can alter behaviour even without awareness of the prime.
Making connections with cognitive theory: the cognitive unconscious includes non-conscious information-processing mechanisms (implicit memory, procedural knowledge) that interact with conscious processing to solve problems; conscious awareness is a spotlight that can reallocate processing across networks.
The cognitive unconscious
Information-processing mechanisms outside awareness include procedural knowledge and implicit memory; cognitive scientists view consciousness as a coordinating system for multiple parallel processes rather than a single central controller.
The “team of experts” analogy: many unconscious networks provide potential solutions; conscious goals bias which networks gain access to awareness.
Distinguishing explicit vs implicit memory and cognition; connectionist models emphasize simultaneous, parallel processing across many networks.
The neural basis of consciousness (overview)
The hindbrain and midbrain (reticular formation, pons, medulla) regulate wakefulness/arousal; the thalamus and prefrontal cortex negotiate the conscious spotlight; feedback loops between thalamus, cortex, and reticular formation help maintain conscious access to relevant information.
Not all sensory areas have direct access to consciousness (e.g., early visual cortex V1 may process information without entering conscious awareness; attention can modulate activity in V1 without changing external stimulus).
An integrated view: consciousness is a specialized processing function that monitors and controls current states to maximise adaptation; consciousness emerges from a distributed neural network.
8.3 Sleep and dreaming
Sleep-wake cycle and circadian rhythms
Circadian rhythms are biological clocks aligned with day-night cycles; sleep is a cycle of alternating states roughly across the 24-hour day.
Melatonin, produced by the pineal gland at night, helps regulate sleep; hypothalamic circuits control circadian timing; light exposure via retinal pathways influences this system.
Jet lag and shift work: crossing time zones disrupts rhythm; melatonin supplementation can help recalibrate; wakefulness and sleep patterns adapt over several days.
The duration of sleep varies; most people benefit from about [6.5, 8.5] hours per night; optimal sleep is often around 7 hours, with deviations associated with higher health risks.
Sleep deprivation has broad consequences: immune function, cognitive performance, mood, and mortality risk increase; chronic sleep loss is linked to psychological distress; excessive sleep also linked with health risks.
Infants sleep a lot (around 70% of their time) and can require behavioural sleep interventions (e.g., controlled crying) to establish regular patterns; such methods are debated in the literature due to potential effects on emotional development.
Sleep: stages and EEG signatures
EEG tracks stages of sleep: waking state shows beta activity; relaxation with eyes closed yields alpha waves; progression through sleep stages involves slower, more rhythmic activity as sleep deepens.
REM sleep characteristics:
Stage characterized by rapid eye movements, autonomic arousal, irregular respiration, penile/vaginal arousal, and muscle atonia; EEG resembles waking, suggesting high brain activity with motor inhibition.
REM dream reports are common (~80% of awakenings from REM report dreaming). Dreams also occur in non-REM, but are typically less elaborate.
Non-REM (NREM) sleep stages:
Stage 1: light sleep, theta waves roughly 3-7 ext{ Hz}; transition from wakefulness.
Stage 2: sleep spindles and K-complexes (bursting, high-amplitude activity; no explicit frequencies given in the text).
Stage 3-4: delta sleep; delta waves with frequencies typically below 1 ext{ Hz}; more than 50% delta activity indicates deep sleep (Stage 4).
Dream content and neurobiology:
Dreaming involves a neural network including the pons, thalamus, amygdala, and visual association areas; primary visual cortex is less active during REM dreaming.
Prefrontal cortex activity is reduced in REM dream states, which may explain the lack of critical thinking and illogical dream content.
Dream content in blindness:
Congenital or early-onset blindness often results in auditory or other-sensory dreams rather than visual imagery; nevertheless, dream content still includes the dreamer and topographical environment.
Dream theories (three contemporary views):
Psychodynamic view (Freud): dreams as ‘language of the unconscious’ with manifest content (storyline) and latent content (underlying meaning); dreaming expresses unconscious wishes or emotional concerns; interpretation seeks to uncover latent content; day residue can prime dream content.
Cognitive view: dreams reflect current concerns and metaphorical thinking from waking cognition; dreaming may contribute to problem-solving and cognitive development; dreams use the same metaphors as waking thought; monitoring of conscious content is reduced.
Biological view: dreams are cortical interpretations of random midbrain activity during REM sleep; some variants propose dreams serve memory consolidation (hippocampus↔cortex interactions) or erasure of old memories while consolidating new ones.
Integrative perspective: these views are not mutually exclusive; content can reflect waking concerns and be shaped by memory processing, while still arising from biological processes; memory consolidation theories align with the cognitive and psychodynamic emphasis on emotionally salient material.
The memory consolidation hypothesis and dreaming
Sleep supports memory consolidation: hippocampus replay during NREM strengthens cortical representations; during REM, cortical-to-hippocampal activity may help reorganise or erase older memories as consolidation proceeds.
This view integrates with the idea that dreams may reflect or deploy recently activated cognitive/emotional networks involved in learning.
Synaesthesia as a related consciousness phenomenon (case-coupled example in 8.1)
Prevalence up to about 4 ext{ %} of the population; grapheme-colour synaesthesia is common.
Two hypotheses for neural basis:
Additional cross-connecting links between sensory regions.
Normal connections that are stronger or less inhibited.
Objective evidence: magnetoencephalography (MEG) shows overlapping neural patterns for real color and color evoked even when colour is not present; indicates same color-knowledge systems may be engaged.
Implications: provides an objective validation of subjective synaesthetic experience and supports a distributed neural basis of conscious perception that spans cross-modal processing.
8.4 Altered states of consciousness
What constitutes altered states of consciousness (ASC)?
ASC are states in which normal waking consciousness is modified or disrupted; these can be induced by meditation, hypnosis, psychoactive drugs, and religious experiences.
Common examples: meditation and mindfulness, hypnosis, and drug-induced states (psychoactive substances).
Meditation
Definition: a practice to achieve a deep state of tranquillity by altering the normal flow of conscious thoughts; focus on a single stimulus or on background stimuli (e.g., breathing).
Physiological correlates: can increase alpha activity (relaxed wakefulness) or beta activity; some forms can even produce theta waves (deep internal focus) in some practitioners.
Mindfulness: a focused, nonjudgemental awareness of present moment experience (thoughts, feelings, sensations) with acceptance; used widely in schools and clinical settings; benefits include reduced anxiety and improved well-being; mindfulness programs show improvements that can persist for months after training.
Practical notes: mindfulness training emphasizes attention focusing, tolerance of emotional discomfort, and compassionate responses. It has evidence-based benefits in chronic pain and overall health.
Critical questions: to what extent is mindfulness a true ASC versus a trained cognitive skill that modulates brain function? What are the physiological/psychological benefits?
Hypnosis
Definition and characteristics: an ASC characterized by deep relaxation and high susceptibility to suggestion; can alter sense of time, agency, and perception; arm-raising example demonstrates altered volition under hypnotic suggestion.
Clinical uses: pain management (hypnotic analgesia), smoking cessation, weight loss, pain relief during labour, and various mental health applications.
The hidden observer (Hilgard): a dissociated aspect of consciousness that can perceive information even when the person reports amnesia; classic hypnotic experiments demonstrated the hidden observer rate the pain while the primary experience reported little pain.
Hypnosis and memory: controversial as a memory tool; posthypnotic suggestions can influence behaviour after hypnosis; concerns about memory accuracy and the risk of false memories due to suggestibility.
Debates on reality and mechanism: hypnosis shows distinct EEG/neural patterns and can produce perceptual changes (e.g., color perception under hypnotic suggestion) not found when not hypnotized; some effects can be produced by non-hypnotic techniques (imagery, social pressure).
Professional use and ethics: clinicians trained in hypnosis follow guidelines; stage hypnosis is entertainment and not representative of clinical practice.
Psychoactive substances (drugs) and ASC
Core idea: drugs alter consciousness by acting on the nervous system to modify mental activity; effects depend on pharmacology and psychosocial context (expectations, culture).
Major drug classes overview:
Depressants (e.g., alcohol, heroin, benzodiazepines, barbiturates) — slow CNS activity, can produce dependence, cognitive impairment, and various health risks; alcohol increases GABAergic inhibition and dopamine/endorphin reward pathways; cross-cultural use with associated social/health costs.
Alcohol statistics: high lifetime use and ongoing prevalence; risk factors include harmful levels of intake and associated health issues. Alcohol abuse linked to violence and crime in various contexts.
Stimulants (e.g., nicotine, caffeine, amphetamines, cocaine) — increase alertness and arousal; nicotine affects both sympathetic and parasympathetic systems; long-term use linked to health problems; prevalence data show varying use across age groups. Amphetamines and methamphetamines pose significant health risks, including psychosis and cardiovascular problems; long-term use causes neurotransmitter depletion and cognitive deficits; new patterns of use (e.g., “ice”/crystal meth) are tracked.
Hallucinogens (e.g., LSD, psilocybin/magic mushrooms, PCP) — induce perceptual distortions and altered realities; long-term use can be associated with lasting psychological disturbances; risk profiles vary by substance and user history.
Cannabis — common recreational drug; mixed evidence on long-term cognitive effects; some evidence of health risks with heavy use; its legal/policy status and medical potential remain debated; cannabis acts on dopaminergic systems and can alter attention, memory, and motor function.
Ecstasy (MDMA) — entactogenic/hallucinogenic properties; effects include mood elevation, empathy, but also risk of cognitive and mood disturbances; long-term data suggest potential neurochemical changes with repeated use; use often occurs with club/drug culture contexts.
Pharmacology and psychology interaction: drug effects are not purely physiological; expectations and social context shape experiences and outcomes (placebo/nocebo effects, cultural norms).
Lifestyle and health implications: tobacco use (nicotine) shows shifts in population-level patterns; vaping trends have emerged with evolving health debates; alcohol/cannabis/drug use during pregnancy can affect fetal development; cross-cultural patterns influence risk exposure and outcomes.
Driving impairment and safety: stimulant use can impair judgment and coordination; fatigue and extended driving hours plus stimulant use create safety concerns in transport settings.
Disorders of consciousness and ethical considerations
Disorders of consciousness (e.g., unresponsive wakefulness syndrome, minimally conscious state): advances in functional imaging reveal residual awareness in some patients; ethical considerations arise for care, decision-making, and quality of life.
The central theme across ASC research: biological substrates interact with cultural meanings and expectations to shape altered states; ethical implications arise in clinical practice and research settings.
Central questions revisited
The chapter emphasizes synthesis across perspectives: consciousness involves monitoring and controlling the self and environment; unconscious processing is widespread; attentional networks coordinate to highlight relevant information; experiences of consciousness arise from distributed neural systems rather than a single centre.
The convergences across psychodynamic, cognitive, and neurobiological accounts suggest a unitary rather than dualistic view of consciousness, where unconscious processes and conscious processes interact to support adaptive behaviour.
Summary points
Consciousness is a dynamic, multifaceted construct involving subjective experience, attention, memory, and action regulation.
The major theories (psychodynamic, cognitive unconscious, behavioural, and evolutionary) provide complementary views on how consciousness arises and functions.
Sleep and dreaming involve structured cycles (REM and NREM) with specific neural correlates; dreaming can be interpreted through multiple theoretical lenses, with a growing consensus that memory consolidation and cognitive processing are central to dreaming.
Altered states of consciousness include meditation, hypnosis, and psychoactive substances; each ASC has characteristic cognitive/neuronal signatures and practical applications/risks.
Real-world exemplars (synesthesia, Stroop task, mind wandering, daydream types, flow) illustrate how consciousness and attention operate in everyday life.
Key terms (selected)
altered states of consciousness – Deviations in subjective experience from a normal waking state.
attention – The process of focusing consciousness on a limited range of experience.
beeper studies – Experience-sampling technique providing a natural window to flow of consciousness in daily life.
circadian rhythm – Biological rhythm aligned with the 24-hour day; regulated by light exposure and melatonin.
cognitive unconscious – Information-processing outside awareness (implicit memory, procedural knowledge).
conscious vs unconscious – Distinct levels of processing and awareness; subliminal perception can influence conscious thoughts.
daydreaming – Volitional or spontaneous shifts of attention from external stimuli to internal thoughts.
flow – A state of complete immersion and intrinsic enjoyment in a task; balanced challenge and skill.
mindfulness – Focused, nonjudgemental awareness of present moment experience.
memory consolidation – Sleep-related processes that stabilise and reorganise memories; hippocampus–cortex interactions differ between NREM and REM.
pondering: The neural pathways for conscious processing involve a loop from reticular formation through thalamus to prefrontal cortex and back, shaping conscious access.
synaesthesia – Cross-modal experiences; prevalence around ext{up to } 4 ext{%}; grapheme-colour synaesthesia common; neural evidence for cross-activation and color-knowledge representations.
Stroop task – Classic measure of cognitive control and attention involving DLPFC and ACC.
Formulas and numerical references
Sleep stages and cycles:
A complete sleep cycle repeats about 90 ext{ minutes}.
REM sleep accounts for about 25 ext{%} of total sleep time.
Delta sleep (Stages 3-4) features delta waves with frequencies f<1 ext{ Hz}.
DREAMING hours: lifetime dream time estimated at about 50{,}000 ext{ hours} \, ext{(≈2{,}000 days ≈ 6 years)}.
Optimal sleep duration: most people require [6.5, 8.5] ext{ hours} per night; target often around 7 ext{ hours}; deviations linked to health risks.
SIDS/SUDI: Aboriginal and Torres Strait Islander infants accounted for about 5 ext{%} of deaths in 2011–2015.
Synaesthesia prevalence: up to 4 ext{%} of population (phenomenon: grapheme-colour synaesthesia most common).
Brain regions (examples): DLPFC, ACC in cognitive control; pons, thalamus, amygdala in REM/dreaming; prefrontal cortex involvement in conscious access.
Connections to broader themes
The chapter emphasises that consciousness is not a single module but a distributed system interacting with learning, memory, emotion, and perception.
It highlights the interplay between emotion and cognition: unconscious motivational states influence behaviour; conscious strategies can regulate performance and solve problems.
Ethical and clinical implications arise in disorders of consciousness, hypnosis, sleep disorders, and the use of psychoactive substances.
Examples and case illustrations
Synaesthesia cases: Helen Besgrove and Josie Moon illustrate cross-sensory experiences; research shows objective neural signatures for synaesthetic colour experience.
Flow in real-world activities: athletes and musicians in flow states show distinct neural activation patterns, linking performance, reward systems, and emotion.
Stroop task: demonstrates the involvement of DLPFC for deliberate control and ACC for conflict monitoring; practical demonstration via interactive Stroop exercises.
Mind wandering and goal setting: experience-sampling data showing how mind wandering correlates with task demands and cognitive load; strategies for focusing attention in studying.
Dream theories and memory: cognitive and psychodynamic links between waking concerns and dream content; biological memory consolidation during sleep.
Overall takeaway
Consciousness integrates subjective experience with neural processes across multiple brain systems; both conscious and unconscious mechanisms contribute to adaptive behavior, decision making, and learning. The study of ASC, dreaming, attention, and memory reveals a nuanced, integrated picture rather than a single causal center.