Lecture Five Reading Flashcards
What is perception?
The processes that organise and interpret information
What is sensation?
The process by which stimulation of a sensory receptors receptor gives rise to neutral impulses that result in an experience or awareness of conditions inside or outside the body
What is accommodation in terms of eyesight?
The process by which ciliary muscles change the thickness of the lens of the eye to permit variable focusing
What is the retina?
The layer at the back of the eye which contains photoreceptors which convert light energy to neural responses
What is a rod?
A photoreceptor on the periphery of the receptor which is most active in dim light and does not produce colour
What is a cone?
A photoreceptor concentrated in the centre of the retina which works best under normal viewing conditions and sees in colour
Which section of the retina contains densely packed cones responsible for the sharpest vision?
Fovea
What is the reason for the blind spot?
It is the part of the retina where the optic nerves leave the back of the eye and contains no light receptors
What is the function of an amacrine cell?
Integrates information across the retina by linking bipolar cells to other bipolar cells and ganglion cells to other ganglion cells
What is the function of a ganglion cell?
A cell in the visual system that integrates impulses from many bipolar cells in a single firing rate
What is the function of a bipolar cell?
A cell in in the visual system which that combines impulses from many receptors and transmits the result to ganglion cells
What is the function of a horizontal cell?
A cell which integrates information across the retina
What is a receptive field?
The area of the visual field to which a neuron in the visual system responds
What is hue?
The dimension of colour space which captures the qualitative experience of the colour of light-largely determined by the wavelength
What is saturation?
The dimension of colour space which captures the purity and vividness of colour sensation
Which colour has zero saturation?
Grey
What is brightness?
The dimension of colour space which captures the intensity of light
Which colour has the least brightness?
Black
What are complimentary colours?
Colours opposite each other on the colour circle which add to produce white light
What is the Young-Helmholtz trichromatic theory?
The theory that there are the three types of colour receptor that produce red, green and blue
What is Hering’s opponent-process theory?
All colour experiences arise from three underlying systems, each of which includes to opponent elements
How does Hering’s theory explain negative after imaging?
One element becomes fatigued from overstimulation and therefore increases the relative contribution of the opposing colour
What is pitch?
The highness or lowness of a sound, depending on the frequency of the soundwave
What is loudness?
A perceptual dimension of sound determined by the amplitude of the sound wave
What is timbre?
The dimension of auditory sensation that reflects the complexity of a soundwave
What is the primary organ of human hearing?
Cochlea
What is the basilar membrane?
A membrane in the cochlea that stimulates hair cells when it moves to induce the neural effects of auditory stimulation
What is place theory?
The theory that different frequencies produce maximum activation at different places on the basilar membrane, resulting in different pitches depending on the different places
What is frequency theory?
Pitch is equal to the frequency that occurs as a result of the specific rate of vibration in the basilar membrane
What is the volley principle?
Several neurons fire at once when the peaks in a sound wave come too close together- ie. at really high frequencies
What is a pheromone?
A chemical signal released by organisms to communicate with other members of the same species
What is anosmia?
Inability to smell
What is the difference between a cutaneous sense and a vestibular sense?
Cutaneous is the skin sense (temperature and sensation) whilst vestibular sense is the sense that tells you how your body is orientated with respect to gravity
What is kinaesthetic sense?
The sense concerned with movement of the body parts relative to one another
What is the gate-control theory?
The theory that certain cells in the spinal chord act to block some pain signals when other signals are trying to get through
Ascending messages are biological in nature and carry pain messages
Descending message are psychological in nature and can open or close the gate
When do babies begin to fear the visual cliff?
Once they begin crawling
