Attention And Unconsciousness Flashcards
Define attention
The ability to focus on one aspect of sensory input
Define consciousness
Awareness of something
What is the resting state activity
Activity in the brain during quiet restful wakefulness
What are some observations of the brain at rest?
- During tasks, there are decreases and increases in the resting state
- Areas that show Decreased activity compared to the resting state are consistent when the nature of the task is changed. Areas showing decreased during activity are always active at rest
- Patterns in the brain activities change consistently across human subjects
What brain areas show more activity in the resting state than during behavioural tasks?
Medial prefrontal cortex
Posterior cingulate cortex
Posterior parietal cortex
Hippocampus
Lateral temporal cortex
Define default mode network
An interconnected group of brain areas that are consistently more active when the brain is at rest than during active behavioural tasks.
What is the sentinel hypothesis?
Even when we rest, we must broadly monitor (pay attention to) our environment.
When we are active, we focus our attention on the matter at hand,
What is simultagnosia
People have normal visual fields and are able to perceive individual object, but are unable to integrate simultaneous information to understand a complex scene
What is the internal mentation hypothesis?
The default network mode up supports thinking and remembering, the sort of daydreaming we do while sitting quietly.
What is exogenous attention of bottom up attention?
Attention reflexively directed to an external stimulus because of its salience
What is endogenous attention or top down attention?
Attention voluntarily directed by the brain to serve a behavioural goal
What is covert attention
Shifting attention to objects imaged on part of the retina outside of the fovea
What were the results on an experiment studying that effects of direct visual attention to different locations?
Plus sign cue = 60% correct
Right arrow cue = 80% correct
However, when the cue pointed to the right, the observers detected the target stimulus to the left only 50% of the time
What are the behavioural consequences of attention?
- Increases our visual sensitivity, making things easier to detect
- Increases speed of our reactions to sensory events
What were the results of the experimenting demonstrating attention increases speed of reaction?
Plus sign cue = 250-300msec to push button
Arrow cue = 20-30 maces faster
Incorrect arrow cue = 20-30msec slower
What is the spotlight of attention?
Moves into illuminate objects of particular interest or significance
What are selective attention experiments?
Pay attention to just one feature
What are divided attention experiments?
Simultaneous monitoring of all features
What did the ventromedial occipital cortex pay attention to?
Colour
Shape
What did the parietal cortex pay attention to?
Motion tasks
What specific areas of the brain may pay attention to colour and shape?
V4 and IT and other visual cortex of the temporal lobe
What specific areas of the brain is most active during a motion task?
Area MT
What structure has been studied for its possible role in guiding attention?
Pulvinar nucleus of the thalamus
Why is the pulvinar nucleus of the thalamus studied in guiding attention?
- Respond strongly to stimulus in receptive field
2 reciprocal connections with most visual cortical areas of the occipital, parietal and temporal lobes. - Increased synchronisation between neural activity in the pulvinar, area V4 and area IT,
What happens to humans when there is a lesion on the pulvinar?
Responds Abnormally slowly to stimuli on the contra lateral side, particularly when there are competing stimuli on the ipsilateral side,
What does muscimol affect in attention?
An agonist to GABA - suppresses neurons.
Injection produces difficulty in shifting attention to contralateral stimuli
Define frontal eye fields
A cortical area in the frontal lobe involved in generation of saccadic eye movements
What are the direct connections to the FEF?
V2, V3, V4, MT, and the parietal cortex
What happens when the FEF is electrically stimulated?
Visual response is faster only inside the motor field
The visual response of the V4 neuron was increased compared to no stimulation
What is a salience map?
A map of visual space that highlights the locations of conspicuous objects
What is a priority map?
A map showing locations where attention should be directed based on stimulus salience and cognitive input
What role does lateral intraparietal cortex play?
Directing eye movement
What is neglect syndrome ?
An inability to attend to half of the environment
What is the frontoparietal attention network?
A group of interconnected brain areas involved in guiding visual attention
What is the temporal sequence in attention?
Frontal lobe (prefrontal cortex and FEF) and followed progressively by areas LIP, V4 and MT, V2, and then V1.
What are materialists and dualism?
Materialists - consciousness arises from physical processes
Dualism - mind and body are different things and one cannot be fully explained by the other
What are easy problems of the consciousness?
Phenomena that seems answerable by standard scientific methodology
What are the hard problems of consciousness?
The experience itself (emotions, sensory information)
Define neural correlates of consciousness
Minimal neuronal events sufficient for a specific conscious percept
Define binocular rivalry
Perception that alternates in time between the image seen by one eye and dissimilar image seen by the other eye
