c.n. e2: attention & consciousness

describe the basic principle of attention

if you do not attend to information, you are at a severe disadvantage to do anything useful with it

describe change blindness

unable to detect change unless we are fully attended on the thing that is going to change

describe inattentional blindness

when our attention is focused on one object or task, we are unable to detect other changes not related to what we are focused on

describe how attention is a spotlight

• like a spotlight, attention may move from one location to another

• it may zoom in or out (coarse vs fine grained)

• can’t highlight everything

describe one aspect of attention that does not fit our comparison to a spotlight

our focus of attention is not always match our eye fixation (where we are looking)

what is the Posner Cueing Task and what does it tell us about attention?

Task

• there are three boxes, and were instructed to always look at the center box

• then you must detect the target that might appear on the left or the right

• before you must detect the target, there is a cue that will appear but it may be correctly or incorrectly cueing you to the location that the target may appear

  • cue is salient: captures attention but not informative

• results:

  • initially, there is a faster reaction time when you are cued to the correct location versus no cue/incorrect cue

  • but once there is a delay between the cue and the appearance of the target, we see a longer reaction time to those that were cued versus those that were uncued

    • can’t attend to everything at once

    • there is a capacity limit

    • !!bored easily: if there was a cue, but nothing happened directly as a result of the cue then our attention is brought to somewhere else

describe the two types of orienting

• covert: moving attention but not the eyes/head

• overt: moving attention as well as the eyes/head

endogenous orienting

internally-guided attention

• drive by goals and motivation

• more top-down

exogenous orienting

externally-guided attention

• driven by sudden change in sensory input

• more bottom-up

describe the attentional blink

looks at the attentional resources over a window of time

what does attentional blink tell us about attention

• if the target are really close or far apart we are likely to correctly detect the two targets

• however, there is a small window in which if they are 2-3 frames apart, we will most likely

• this shows how our attention resources are finite: when we ‘get’ the thing we are attending to, our brain shuts off for a brief period of time

how does brain activity differ between attended vs unattended stimuli?

• firing of neurons is smaller when we are unattended versus when we are attended

• attention allows for more firing

describe what areas of the brain are more externally-guided attention versus internally-guided attention

• external: lateral

  • object, location, etc external to self

• internal: medial

  • person i missed, place i want to go, etc

describe difference in brain active regions between conscious and unconscious awareness

• when we consciously perceive something, parietal and PFC are involved

describe how conscious awareness is a hierarchical process

it is dependent on the strength of the stimulus and whether you are attending to it or not

• weak and absent: activation in sensory cortex but activation is weak and information is not sent to other areas of the brain

• strong and absent: pushes further out of cortex but doesn’t reach PFC or get far into parietal lobe (aware but not thinking about it — being in busy city but filter out noise)

• weak and present: pushed further out of cortex but not processed fully (someone whispers but can’t make out what they say)

• strong and present: all areas are active and spreading information

describe hemineglect

inability to perceive one side of the visual work

• typically right-hemisphere damage (leads to neglect of left side)

sensory cortex still responds to information but cannot consciously attend or use information

describe neglect

disorder of attention

can neglect patients attend to the ignored hemifield when instructed to?

yes, but it is very difficult and can only do for brief period of time

what happens to neglected info in those with neglect?

ventral stream may continue to process neglected objects up to the stage of object recognition and possibly semantics

• however, there is some awareness guiding their behavior but are unable to attend or report how it guides their behavior

describe or give an example that shows how neglect isn’t just about absolute space but also spatial reference frames

in a study they presented two sets of images where the patient must detect if the images were the same or not: one where the object were upright and difference is on left side and one where the object was tilted and difference is on right side

• the patient with object neglect cannot detect differences on left side of an object even when the object may fall into the right side of visual space

describe the biased competition model

• there are similar, competing neurons that respond to different things

• however, we can use attention to bias response towards one representation over the other

describe the study that provided evident for the Biased Competition Model in attention

• participants are either looking at scenes or at faces and are instructed to either ignore or pay attention to a particular thing

  • FFA: responds to faces

  • PPA: responds to scenes

• FFA

  • more response when told to remember faces

  • less response when told to ignore faces

• PPA:

  • more response when told to remember scenes

  • less response when told to ignore scenes

these areas still respond but at a much higher rate when told to attend to it

describe the study of selecting and de-selecting stimuli

• they measure the activity for a V4 neuron that had a face-preference

• at first they showed just a house or a face, with the face having a higher activation than house

• then they showed a face and house and were instructed to either attend to the face or to the house

  • attend to face:

    • large initial peak (but still smaller than the condition with just the face) and then levels off

  • when they were asked to attend to the house:

    • large initial peak (higher than that of the condition with just the house) and it then levels off

but the large initial peak was a result of there being a face present

• activity then starts to level off since top-down processing allows you to attend to the goal (paying attention to the house)

describe the dorsal route of frontal-parietal attention mechanism

• involves lateral infraparietal cortex and frontal eye fields

• goal-related attention of the world

  • orienting in a salience map (weighted by importance)

    • ex: paying attention to court than attendees at basketball game

• more endogenous

describe the ventral route of frontal-parietal attention mechanism

• involves tempoparietal junction and ventral frontal cortex

• “circuit breaker” that interrupts ongoing activity to redirect attention to some important feature

• more exogenous

does subliminal messaging work? For what kinds of information does it work, and for what kinds of information does it not work?

• it is possible

• you can unconsciously perceive a scary image

• you can’t make someone commit murder unwillingly

• context matters a lot

  • ex: popcorn and coke imagery at theatres

what are conditions of consciousness

• sentience: ability to feel/perceive

• awareness of external reality

• awareness of internal sensation/experience

• awareness to the “self”

describe how consciousness is constructive

our experience of reality is shaped by our own lived experiences, biases which impact how we interpret sensory inputs

what brain areas are involved in consciousness?

precuneus in medial parietal lobe, thalamus (sensory highway), reticular formation in midbrain (gate to thalamus)

what is thought to underlie consciousness?

synchronization: the idea that one neuron communicates with many others and so on

describe sleep

state of unconsciousness

nested int he body’s innate circadian rhythm through light cues

stage 1: similar to activity while awake

stage 2: start to get deeper waves and some big spikes

stage 3: characterized by big slow waves

REM

describe stage 3

muscle atonia: paralyzing of muscles

difficult to wake people up

describe stage 2

where sleep walking happens

body is not paralyzed yet but you are also not conscious

describe REM

dreams

describe the communication between brain areas when you are awake

base level of communication between precuneus, medial frontal cortex, inferior parietal cortex

describe the communication between brain areas when you are in light sleep

more communication between precuneus, medial frontal cortex, inferior parietal cortex

describe the communication between brain areas when you are in deep sleep

communication between precuneus and inferior parietal cortex, no medial frontal cortex

describe the different definitions of dreams

• could be epiphenomenal (accidental feature)

• spontaneous neural activity

  • random firing

  • or replay of prior patterns, tied to experiences

• brain likes making sense of patterns, so it tries to create a story

• nightmares are better remembered because they cause big reactions

• ideas about unconscious thoughts/feelings

describe sleep paralysis

• condition affecting REM sleep

• body immobilized, but person is partially conscious

• “waking nightmare” with hallucinations (between deep sleep and REM)

describe sleep walking

• occurs in stage 2

• stimulate habitual movements from when awake

describe lucid dreaming

• becoming ‘aware’ in the dream & taking control

• often fantastical/se_ual choices

• most people experience this at some point, but can be practiced

describe what hypnosis can/cannot do

can:

• help with relaxation

• help with pain reduction

• help with therapy progress

• take advantage of suggestibility (ex: quit smoking)

• retrieve “long lost” memories but oftentimes these are false

cannot

• most of what hollywood depicts

describe anesthesia

reversibly alters consciousness without long-term damage

what is the general mechanism driven by anesthesia

• reduce excitatory signals

or

• enhance inhibitory signals

describe the different anesthetics and their effects

• nitrous oxide (laughing gas): not unconscious, but disconnected

• propofol or ketamine: cause full-on lack of conscious awareness

how does anesthesia affect the brain (physiologically)

• lowers blood flow and glucose metabolism

• large decrease in precuneus activity

describe drugs that affect dopamine

• cocaine (stimulant): blocks reuptake of dopamine

• heroin/other opiates (depressent): can bind opioid receptors, which stimulates transmission of dopamine

describe drugs that affect serotonin

• marijuana, LSD< DMT (hallucinogens): dysregulate serotonin (usually increase)

  • can cause serotonin syndrome: depletion of serotonin

describe ‘downers’ affect on brain

• alcohol(depressent)

• binds GABA to allow Cl- ions into brain (inhibitory)

describe the general principle of addiction

• a drug alters the presence of a neurotransmitter

• overtime synapse adjust to change (tolerance)

• eventually, this becomes so “normal” that a change (withholding drug) is now abnormal (withdrawal)

  • can be deadly

• this is paired with a general disruption of the brain’s reward circuitry, as well as dysregulated executive function

describe coma

• deep, prolonged state of unconsciousness

  • no response to pain/light/sound, no sleep cycle, breathing abnormality

• usually caused by any damage to brainstem (regulating neurotransmission & basic bodily function) or major damage to cortex

• usually come out of it within a month

describe vegetative state

• brainstem intact/healed (breathing, eyes, sleep-wake, thrashing, etc) but no perception, communication, awareness

  • though there are debates about consciousness

• comatose patients can ‘awaken’ to vegetative state

• can remain in state indefinitely if medically supported

• in general, brain metabolism is permanently decreased

describe the different theories of consciousness

1. dualism: mind and body are totally separate

2. functionalism: brain’s specialized processing units underlie different aspect of conscious experience

   1. ex: FFA allows us to consciously perceive a face, etc

3. integrated information theory: informative and combined info across the brain

   1. informative: experience of ‘red’ is unique from green or blue

   2. integrated: you perceive a face not a separate experience of shapes and colors and textures

describe the view on whether non-human animals are conscious

• historically: the answer would have been no

• modern view:

  • many are conscious to some degree

  • they possess much of the same neural machinery

  • growing evidence for heightened sense of awareness & knowledge of ‘self’ in animals

examples of non-himan consciousness

• self-recognition via mirror, smell

• association of human words/symbols with semantic meaning

• neuronal responses in crow endbrain (analogous to human PFC) found to correlate with their subjective preferences for stimuli

• evidence for complex learning & self-awareness in octopuses, corvids, and maybe other animals as well