The Reticular Activating System: Arousal, Alertness, and Sleep Stages - Prof. Douglas N. I, Study notes of Biology

Download The Reticular Activating System: Arousal, Alertness, and Sleep Stages - Prof. Douglas N. I and more Study notes Biology in PDF only on Docsity! 10 February Reticular activating system Percolates upwards Alters arousal/alertness Influenced by circadian rhythms Brain 2% total body mass, 20 – 25% total O2 supply Conscious (Aware) Awake state External sensory experiences Objects Events Internal states Moods – happy, sad Dreams Drives – sex, thirst, hunger Memories, thoughts Self awareness Selective attention Coma Unconscious External stimuli cannot arouse Cannot be awakened No response to stimuli No voluntary activities No sleep-wake cycles EEG – electroencephalogram Electrodes on skull surface Neurons activated – alterations in extracellular ion concentration Measures electrical potentials being generated Alpha and beta rhythms Alpha – relaxed Beta – alert Sleep stages 4 stages Relaxed → stage 1 → 2 → 3 → 4 → 4 → 3 → 2 → 1 → REM Stages 1-4 are NREM REM Consolidating memory Dreaming Paradoxical sleep – EEG is similar to aroused state, but sleep is deep 4-5 full cycles/night Apnea Anesthesia Anoxia Reduced brain temperature Reduced brain blood flow Blocked independently of long-term memory All block action potentials Long-term memory Rehearsal or associations can consolidate short- to long-term memory Sleep may be required – REM Requires protein synthesis May require LTP (long-term potentiation), dendritic spines Persist for days to decades Recall may be required to prevent forgetting Recall may modify memories Rats in enriched environment have more dendritic spines Hippocampal lesions Loss of memory consolidation Loss of long-term declarative memory Memory types Declarative memory – can be described Episodic Events of specific time and place Autobiographical Semantic General knowledge, facts Independent of where and when fact was learned Procedural memory Non-declarative Motor skills Learned reflex – Pavlovian Emotional memory Emotions strongly enhance memory Elicit physiological response Fears Amygdala