Consciousness: Attention and Sleep - Lecture Notes

Consciousness: Attention and Sleep  Attention Attention – focusing consciousness on specific stimuli or aspect of stimuli – Selective attention – focusing on specific information while ignoring other information  Selective Attention Inattentional...

Consciousness: Attention and Sleep  Attention Attention – focusing consciousness on specific stimuli or aspect of stimuli – Selective attention – focusing on specific information while ignoring other information  Selective Attention Inattentional blindness – failing to detect available stimuli due to selective attention Change blindness – failing to detect changes in stimuli due to selective attention Sleep and Dreams What controls our sleep-wake cycle? What are our brains and bodies doing during different sleep stages? Why do we sleep? Why do we dream? Circadian Rhythms Circadian rhythm – biological clock (controlled by hypothalamus) – Provides approximate schedule for physical processes – Suprachiasmatic nucleus (SCN) – in hypothalamus – sensitive to changes in light Controls pineal gland – Pineal gland – secretes melatonin Melatonin – hormone that causes sleepiness Circadian Rhythms Darkness SCN directs pineal gland to secrete melatonin Light SCN directs pineal gland to stop secreting melatonin Implications of Circadian Rhythms and Light Artificial lighting – interferes with circadian rhythm Sleep Stages ~90-minute cycles of sleep stages Types of sleep: 1. Non-rapid eye movement (N-REM) – 3 stages N1 – light sleep – Hypnic or hypnagogic jerk – Hypnagogic hallucinations  Sleep Stages (N-REM cont’d.) – N2 – true sleep Brain activity slows Reductions in heart rate and muscle tension – N3 – deep sleep Further slowing of brain activity Hard to awaken, disoriented when awakened Growth hormones released from pituitary Sleep Stages 2. Rapid eye movement (REM) – brain waves resemble wakefulness – Eyes move back and forth – Heart rate, blood pressure, breathing – rapid or irregular – Sleep paralysis – “Paradoxical sleep” – Dreams Sleep Cycle Theories of Sleep Evolutionary/adaptive theory – protection – not out and vulnerable to predators in the dark Restorative theory – sleep supports growth and healing – Production of growth hormone – Supports immune functioning Sleep deprivation slower healing, reduced immune system activity Theories of Sleep Information processing theory – sleep supports cognitive processes – Supports learning – Restores and rebuilds memories Sleep deprivation impairment of memory formation – Supports creative thinking Effects of Sleep Deprivation Irritability, mood disruption Increased risk of depression Increased risk of obesity Dreaming Why do we dream? – Freud – dreams stem from unconscious thoughts Manifest content – the actual images in the dream Latent content – the unconscious thoughts, feelings, and wishes behind the manifest content – Activation synthesis – brain’s internally generated signals form dreams – Information processing – memories of events form dreams – Preserving neural pathways – purpose of dreaming is to provide brain stimulation