Central theme in philosophy of mind.
Different views on the relation between consciousness and matter:
Monism: Mind is a product of matter (brain).
Dualism: Mind and matter are distinct.
Solipsism: Only one's own mind is sure to exist.
Modern neuroscience supports the monistic view.
Describes the gap between neural activity and subjective experience.
Neural interactions can explain behaviors but not the experience itself.
Researchers focus on the phenomenology (experiential quality) versus brain function.
Understanding this relationship may eventually solve the hard problem.
Focuses on conditions under which stimuli reach conscious perception.
Identifies contrasts in states of consciousness (conscious vs. non-conscious).
Categorized based on patient responses to stimuli and sleep-wake cycles.
General Correlates: Found in upper brainstem, base of brain, frontal and parietal cortices; backbone of conscious experience.
Specific Correlates: Found predominantly in sensory areas of the cortex; associated with distinct experiences.
Wakefulness: Active interaction with environment, contrasts with sleep.
Alertness: Variable measure of responsiveness; linked to physiological markers (oxygen, glucose levels).
Influence neuronal activity beyond synaptic transmission.
Neurotransmitters involved: serotonin, noradrenaline, dopamine, acetylcholine, histamine.
These are released from brainstem and diencephalon nuclei.
Sleep deprivation leads to decreased alertness and can cause microsleeps.
Observed by Constantin von Economo: damage to anterior hypothalamus leads to insomnia.
This area inhibits activity of neuromodulatory nuclei.
Neuromodulatory systems activity decreases during sleep; varies across sleep stages.
REM Sleep: Characterized by increased activity in specific acetylcholinergic nuclei.
Different conscious states (wakefulness, NREM sleep, REM sleep) coincide with varied brain states.
Difficult to define, considered a separate cognitive function.
Divided into three aspects:
Alertness
Orientation
Executive function
Helmholtz's findings: Covertly attending to stimuli enhances memory recall.
A phenomenon where one selectively processes one stream of information among many, first studied in air traffic controllers.
Attention acts as a filter, enabling selective information processing.
Selection theories explore where filtering occurs in the processing hierarchy.
ERP Studies: Show greater processing of attended stimuli.
fMRI Studies: Attention modulates neural activity; stronger BOLD response for attended stimuli.
Explored in visual search paradigms; identification slows with distractors sharing attributes.
Condition where patients fail to orient to stimuli in one side of their visual field.
Potential recovery as observed in a stroke survivor painter.
Divided into:
Ventral Attention Network (VAN): Reflexively directs attention.
Dorsal Attention Network (DAN): Voluntarily directs attention.
Also known as frontoparietal networks, comprise frontal and parietal cortex areas.
Modulates sensory activity; right hemisphere dominance explains left visual field neglect.
Frontoparietal networks focus on external stimuli, while DMN focuses on internal mental processes.
Activity in these networks is often negatively correlated.
Understanding consciousness, attention, and their neural correlates is essential for delving deeper into cognitive psychology. Further investigations will continue in the next lecture on short-term and working memory.