Week 8 Flashcards
Sensation
Physiological process that underlies transformation of the chemical, mechanical, light and sound energy in the world into electrical activity in the brain
Perception
Psychological process involved in the organization and interpretation of sensations
Transduction
Conversion of physical energy into electrical potentials - happens in sensory receptor cells, which are specialized neurons
Quantitatively
Referring to amounts or quantities that can be measured objectively
Qualitatively
Pertaining to some quality or characteristic other than magnitude (wavelength/sound/light)
Gustation
Sensing with taste
Olfactory
Sense of smell
Somatosenses
Bodily senses.
Proprioception
Vestibular senses
Proprioception
A sense of relative position of lims and other parts of the body, due to receptors in muscles and joints, sometimes called kinesthesis
Vestibular senses
Senses involved with balance
Receptor cells
Specialized neurons that transduce physical energy (light etc) into electrical signals
Adequate stimulus
Type of physical energy to which a sensory receptor is especially tuned
Sensory adaptation
A change, usually decreased, in sensitivity that occurs when a sensory system is repeatedly stimulated in exactly the same way
Fatigue
Neurons that are subjected to steady, continuous stimulation become unable to send signals across synapses
Pattern (or population) code
Instead of information being conveyed by single cell nerves or a small group of cells, it is conveyed in the activity across a whole population (a lot) of cells
Temporal code
uses the rate at which the neurons are firing to determine perception
Place coding
Depends on the location of the neurons firing to determine perception
Spontaneous rate
Rate of neural firing when no stimulus is present
Rate of firing
Codes the intensity of the stimulus
Multisensory
Relating to or involving more than one physiological sense
Cranial nerves
12 pairs of nerve fibres that travel onto and out of the skull and carry all sensory information (except somatosenses) from parts of the body below the neck
Psycophysics
The study of how sensation relates to perception
Sensory thresholds
The point at which a stimulus triggers the start of an afferent nerve impluse
Difference threshold
The just noticeable difference between 2 stimuli
Webers Law
The size of the just noticeable difference of a stimulus divided by its initial intensity is a constant
Fechner’s Law
In every sensory domain, each just noticeable difference represents an equal step in the psychological magnitude of a sensation. This means that changes in stimulus can be compared across sensory domains, for example, between vision and touch
Steven’s Power Law
Proposed relationship between the magnitude of a stimulus and its perceived intensity and strength
Absolute thresholds
Minimum value of a stimulus that can be detected
Cognitive factors
Factors that involve thought processes, including changes in attention, expectation and altertness
Signal detection theory
Mathematical theory of the detection of stimulation in which every stimulus event requires discrimination between the signal (stimulus) and noise (consisting of both background stimuli and random activity in the neurons system)
Receiver operating characteristics
Graph of hits and false alarms of participants under different motivational conditions; indicated people’s ability to detect a particular stimulus
3 perpetual decisions
- Assuming what you’re looking at
- Based on previous knowledge of what that thing is, decide how far away it is
- If the spots are getting bigger, it must mean it’s getting closer
Unconscious inferences
Perception us built up from elemental sensations - but this doesn’t explain illusionary contours
Gesalt Grouping Rules
A set of rules that describe when elements in an image will appear to group together
Constructivist approach
Perceptions are constructed from degraded, bare bones sensory input, plus guesswork based on knowledge and experience
