how do we intake reality into our knowledge?
physical stimuli is transduced into nerve impulses by our sense organs
what is the phenomenological world?
- each individual experiences the physical stimuli by reconstruction or representation of experiences of sounds, shapes, colours, smells, heat etc.
what are the 5 main senses & are there any more senses?
Visual - eyes
Auditory - ears
Olfactory - nose
Gustatory - nose
Tactile/ Haptic - skin
there are more than the 5 senses:
balance (equilibrioception)
body awareness - (proprioception, joints)
heat (thermoception, skin/ internal)
what is the most dominant sense? and why?
VISION
- amazing range, spatial resolution
- when senses conflict, we tend to believe the visual input
- 50% of the cortex is involved in visual processing
- best understood system in the brain - multidisciplinary
what big 3 areas/ fields of psychology are affected by PERCEPTION? & what specific studies?
- Neuropsychology
- the study of brains
- rubber hand illusion - Clinical Psychology
- eating disorders - Forensic psychology
- eyewitness testimony
what are the problems of perception:
- our perception is not always right, our senses can get it wrong (illusions & aftereffects)
- we have illusions in colour, depth & perspective, faces and motion.
what are the main types of illusions?
- illusions of colour: colour aftereffects, e.g. the dress
- illusions of depth & perspective - e.g. pavement arts
- illusions of faces: thatcher illusion
- illusions of motion: rotating snakes
what is the study of psychophysics?
- it refers to the scientific study of the subjective experience of perception
- relationship between physical stimuli and psychology we experience
what are the sensory systems?
the perceptual modalities:
- chemical senses (Taste and smell)
- body senses (touch, balance, etc)
- hearing
- vision
how is Touch (somatosensation) felt in the body
- the various layers of skin containing a bewildering array of receptors with an astonishing range of sizes and shapes.
- skin sensors for pain - receptors in skin convert pressure into neural signals
- convert heat energy into neural signals therefore signal temperature:
which part of the cortex is responsible for the touch? and where in the brain is it located?
the somatosensory cortex: which is at the top of the brain, sits behind the motor cortex - so the somatosensory cortex can order motor activities
how is taste (Gustation) felt in the body?
taste receptors are collected together in clumps called taste buds located on small projections on the tongue:
- different sorts of taste receptors:
- salt
- sweet
- sour
- bitter
- umami - savoury
how is smell (olfaction) felt in the body?
- As in taste, only dissolved chemicals (in the mucus in the nose) can activate the smell receptors.
- Also in taste, it seems as if certain smell receptors respond to particular chemicals
All the smells we experience are some combination of these primary smells. (at least 7)
how does smell work in the brain?
- The gas molecules go through the nasal cavity
- These receptors synapse directly onto the olfactory bulb (a specialised part of the brain for processing smells)
- Smell bypasses the usual route from sense organ to the brain via the thalamus.
This might justify the emotional significance as it BYPASSES usual route from sense organ right to the cortex.
how is balance acquired in the body:
the vestibular system provides us with information about accelerations we are undergoing and about our orientation relative to vertically (Gravitationally) downwards.
what are the semicircular canals:
provide information about angular (rotational) accelerations of our head in all three dimensions: and allows us to maintain balance:
- provides the signals to drive reflexive eye movements which keep the visual word stable
what are the semicircular canals:
provide information about angular (rotational) accelerations of our head in all three dimensions: and allows us to maintain balance:
- provides the signals to drive reflexive eye movements which keep the visual word stable
e.g. when we’re walking our head is moving around but the world seems stable because our eyes are compensating movements to fixate to freeze things effectively on the retina.
what are the 3 dimensions of semicircular canals:
the main 3 points: -
Y - pitch
Z - rotation
X - rotation
what is the purpose of the body sense (proprioception)?
- to produce smooth, coordinated movements, and to make all the fine adjustments required to keep us upright, recepts in our brain which provide the brain with information about the angles and tensions in our limbs, digits, etc.
what is hearing (audition)
a pressure wave in air, that has sound waves that vary in amplitude and frequency
what is the main structure of the ear:
the outer flesh: pinna/ pinnae
the thing that does the hearing: the cochlear
what is the basic hearing process:
- sound eaves come into ear canal
- travel up hitting tympanic membrane
- causes ossicles to hinge and transfer the vibration into the cochlea allowing to be specifically processed (the basilar membrane)
- the auditory signal gets sent upwards towards the brain
how does sound processing work?
the processing of a sound is a consequence of the mechanical properties of the basilar membrane (in the cochlea)
- the activation of hair cells along it’s surface
- amount of basilar membrane movement/ hair cell activity “codes” amplitude perceived as loudness
- place of maximum movement ‘codes’ frequency (perceived as pitch)
what do low-frequency sounds look like in the cochlea?
the maximum basilar membrane displacement at the end furthest from the stapes
