Flashcards in Psychology Chapter 4 - Basic terms and concepts and sensation and perception Deck (44)
What is an illusion?
Alters perception of a stimulus so it doesn't match physical reality.
What is sensation?
Refers to the detection of physical energy by our sense organs, including your eyes, ears, skin, nose and tongue, which then relay the information to the brain.
What is perception?
The brain's interpretation of raw sensory inputs.
What is transduction?
Process by which the nervous system converts an external stimulus into electrical signals within neurons.
What is a sense receptor?
Specialized cell that transduces a specific stimulus.
The greatest activation of our senses occurs when we _________ detect a stimulus.
What is sensory adaptation?
Neural or sensory receptors change/reduce their sensitivity to a continuous, unchanging stimuli.
Where does adaptation take place?
At the level of the sense receptor.
What does sensory adaptation allow us to do?
Conserve energy for more important stimuli
What is psychophysics?
The study of how we perceive stimuli based on their physical characteristics.
What is the absolute threshold of a stimulus?
The lowest level of a stimulus we can detect on 50% of the trials when no other stimuli is present.
What is the Just noticeable difference?
The smallest change in the intensity of a stimulus that we can detect. This is relevant in our ability to distinguish a stronger stimulus from a weaker one.
What is Weber's Law?
States that there's a constant proportional relationship between the just noticeable difference and the original stimulus intensity. (The stronger the stimulus, the bigger the change needed for a change in stimulus intensity to be noticeable.
What is signal detection theory?
Used to describe how we detect stimuli under certain conditions.
ex: talking to friend over phone with a lot of background noise, we need to speak louder for our friend to understand.
What is the signal-to-noise ratio?
Compares the level of desired signal to the level of background noise.
What are response biases?
Tendency to make one type of guess over another when we're in doubt about whether a weak signal is present of absent under noisy conditions. False positives or negatives implications often plays a role. (ex: if defusing a bomb, would be more likely to say its real then not if unsure)
What are specific nerve energies?
States that even though there are many distinct stimulus energies, the sensation we experience is determined by the nature of the sense receptor, not the stimulus.
What are phosphenes?
Vivid sensations of light caused by pressure on your eye's receptor cells?
What do phosphenes validate?
Specific nerve energies.
What is synesthesia?
A condition in which people experience cross-modal sensations, like hearing sounds when they see colours.
What is grapheme colour synesthesia?
in which numbers are associated with certain colours.
What is lexical state synesthesia?
Words have associated tastes.
What is peculiar of synethesia?
Even if children aren't synesthetes, they tend to associate letters with colours but, as we age, we lose this.
What is parallel processing?
Ability to attend to many sense modalities simultaneously.
What is bottom-up processing?
We construct a whole from parts. This kind of processing begins with activity in the primary visual cortex, followed by processing in the association cortex.
What is top-down processing?
We start with our beliefs and expectations, which we then impose on the raw stimuli we perceive.
Top down processing starts with processing in the association cortex, followed by processing in the primary visual cortex.
What are perceptual sets?
When our expectations influence our perceptions. (Think of the mishapen letter example in the book where the surrounding letters made them look like A's)
What is perceptual constancy?
Process by which we perceive stimuli consistently across varied conditions.
What is an example of shape constancy?
We still see a door as a door whether its completely shut, open or barely open.
What is size constancy?
Our ability perceive objects as the same size no matter how far away they are from us.
What is colour constancy?
Our ability to perceive colour consistently across different levels of lighting.
What is selective attention?
Allow us to select one channel and turn off the others (tv example), or at least turn down their volume.
What are the major brain regions associated with selective attention?
The RAS and forebrain. These areas activate regions of the cerebral cortex, such as the frontal cortex, during selective attention.
What is the filter theory of attention?
Views attention as a bottleneck through which information passes. This mental filter allows us to pay attention to important stimuli and ignore others.
What is dichotic listening?
Subjects hear two different messages, one delivered to the left ear and one to the right ear. They were asked to ignore certain messages (i.e. left ear messages). When asked about the ignored messages, they seemed to know little or nothing of them.
What is shadowing?
Dichotic listening where participants had to repeat the messages they heard. Sometimes they would mix in some of the information they were supposed to ignore, especially if it made sense to add it.
What is the cocktail party effect?
Refers to our ability to pick out an important message, like our name, in a conversation that doesn't involve us.
What is inattentional blindness?
Failure to detect stimuli that is in plain sight when our attention is focused elsewhere.
What is change blindness?
Failure to detect obvious changes in one's environment.
What is the binding problem?
When we perceive a stimuli, different regions of our brains process different aspects of it. Our brains then manage to bind these diverse pieces of information together into a unified whole.
What is subliminal perception?
The processing of sensory information that occurs below the limen; that is, the level of conscious awareness. The effects of subliminal information often vanish when subjects become aware of or even suspect attempts to influence them subliminally.
What is subliminal persuasion?
Subthreshold, influences over our votes in elections, product choices, and life decisions.
What it the illusory placebo effect?
Subjects didn't improve at all, but thought they had. Ex: people getting self help tapes think they improve, even if they don't