PS Cards Flashcards
(88 cards)
convergence
– things far away, eyes are relaxed. Things close to us, eyes contract.
the vestibular system
-semicircular canals filled with endopymph and sense rotation
- Otolithic organs (utricle and saccule) help us to detect linear acceleration and head positioning. In these are Ca crystals attached to hair cells in viscous gel. If we go from lying down to standing up, they move, and pull on hair cells which triggers AP.
Also contribute to dizziness and vertigo
bottom up processing
stimulus influences our perception.
• Processing sensory information as it is coming in (built from smallest piece of sensory information)
• Inductive reasoning
-feature detection: serial processing, happens after parallel processing: multiple paths for the same stim
top down
background knowledge influences perception. Ex. Where’s waldo
• Driven by cognition (brain applies what it knows and what it expects to perceive and fill in blanks)
• Deductive Reasoning
-gestalt, depth, motion, constancy
distal stim
what cause the stim(a tree)
proximal stim
what is actually perceived (photons from the tree interacting with retina)
anterior chamber
space filled with aqueous humour, which provides pressure to maintain shape of eyeball
vitreous chamber
filled with vitreous humour, jelly-like substance to provide pressure to eyeball.
sclera
whites of the eye, thick fibrous tissue that covers posterior 5/6th of eyeball. Attachment point for muscles.
choroid
pigmented black in humans, a network of blood vessels. Bc black all light is absorbed.
Phototransduction Cascade – when light hits rods and cones
normally on, but when light hits it turns off, receptors go off but other cells turn on
• As less Na+ enters the cell, rods hyperpolarize and turn off. Glutamate is no longer released, and no longer inhibits ON bipolar cells (it’s excitatory to OFF bipolar cells).
• So bipolar cells turn on. This activates retinal ganglion cell which sends signal to optic nerve to brain.
organ of corti
- splits cochlea into 2
- Reason doesn’t go back to oval window, is because in middle of cochlea is a membrane – the organ of Corti (includes the basilar membrane and the tectorial membrane
- has hair cells
- hairs attached to K channels, when K influxes it depolaraizes
Freq in cochlea
20-20000dB, high freq at base, low at apex
tonotopical mapping
- Primary auditory cortex is also sensitive to various frequencies in diff locations.
- So with basilar tuning, brain can distinguish diff frequencies – tonotypical mapping.
- Mapped along the cochlea
proprioreception
- balance/position
- Proprioception was cognitive awareness of body in space.
- always know how contracted/relaxed muscles are
Kinaesthesia
is talking about movement of the body
3 types of fibres – fast, medium, slow.
- A-beta fibres - Fast ones are thick and covered in myelin (less resistance, high conductance)
- A-delta fibres -– smaller diameter, less myelin.
- C fibres - small diameter, unmyelinated (lingering sense of pain).
taste receptors
GPCR: sweet, umami, bitter
Ion: salty, sour
EEG
- Beta (13-30Hz) – associated with awake/concentration. Increased stress, anxiety, restlessness. Constant alertness.
- Alpha waves (8-13 Hz) – in daydreaming. Disappear in drowsiness but reappear in deep sleep. During relaxation.
- Theta waves (7 Hz) – Drowsiness, right after you fall asleep.
- Delta waves (0.5-3 Hz) - Deep sleep or coma.
- EEGs can measure brainwaves
REM
- prefrontal cortex activity decreased
- rythm controlled by melatonin from pineal gland
- desynchronous waves
- memory consolidation
activaiton synthesis
Do our dreams have a meaning? Sigmund Freud’s theory of dreams says dreams represent our unconscious feelings/thoughts. Like an iceberg.
1. What happens? Manifest content (Ex. Monster chasing you)
2. What is hidden meaning? Latent content (Ex. Job pushing you out)
• Can help us resolve and identify hidden conflict.
Activation Synthesis Hypothesis
Brain gets a lot of neural impulses in brainstem, which is sometimes interpreted by the frontal cortex.
Brainstem = activation, and cortex = synthesis.
Our brain is simply trying to find meaning from random brain activity. Therefore might not have meaning.
sleep deprivaiton
makes more cortisol
hypnotism
more alpha
2 theories for how it works:
• Dissociation Theory - hypnotism is an extreme form of divided consciousness
• Social Influence Theory - people do and report what’s expected of them, like actors caught up in their roles
barbiturates
sed to induce sleep or reduce anxiety. Depress your CNS.