9. Attention and perception Flashcards
Define sensation
the stimulus detection system by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain
define perception
the active process of organising the stimulus output and giving it meaning (the way in which we make sense of the information around us)
Perception is an active, creative process in which raw sensory data are organized and given meaning
what is top-down processing and bottom-up processing?
top-down: processing in light of existing knowledge - influenced by many psychological influences such as our motives, expectations, previous experiences, and cultural expectations
Bottom -up : individual elements are combined to make a unified perception - the nerve impulses we receive from senses activate higher cortical areas in order for us to perceive them
Bottom-up Processing: the system takes in individual elements of the stimulus and then combines them into a unified perception
Top-down Processing: sensory information is interpreted in light of existing knowledge, concepts, ideas, and expectations
Bottom-Up Processing – Individual elements are combined to make a unified perception
- Refers to the idea that the nerve impulses we receive from senses activate higher cortical areas in order for us to perceive them
- (Laz) the stimulus-detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain
Top-Down Processing - Processing in light of existing knowledge.
•(Laz) Prior knowledge, expectations or thoughts act on this information to influence our final perceptual state
Bottom-up processing refers to processing sensory information as it is coming in. In other words, if I flash a random picture on the screen, your eyes detect the features, your brain pieces it together, and you perceive a picture of an eagle. What you see is based only on the sensory information coming in. Bottom-up refers to the way it is built up from the smallest pieces of sensory information.
Top-down processing (when you are given context and you fill in the blanks), refers to perception that is driven by cognition. Your brain applies what it knows and what it expects to perceive and fills in the blanks, so to speak.
what factors affect perception?
- attention - past experiences - current drive state (e.g. arousal state) - emotions - individual values and expectations - environment - cultural background
what are the 6 principles in Gestalt’s laws?
- similarity - proximity - good form - closure - common fate - continuation
what is visual agnosia?
impairment in visual recognition
what are the key features of visual agnosia?
- basic vision spared - primary visual cortex mostly intact - knowledge about info from other senses - associated with bilateral lesions to the occipital, occiptotemporal or occipitoparietal lobes
what is apperceptive agnosia?
a failure to integrate the perceptual elements of the stimulus
what is associative agnosia?
a failure to retrieve semantic information
define attention
the process of focusing conscious awareness, providing heightened sensitivity to a limited range of experience requiring more intensive processing
Attention involves two processes:
Focusing on certain stimuli
Filtering out other incoming information
Stimulus characteristics that affect attention:
Intensity
Novelty
Movement
Contrast
Repetition
Personal factors that affect attention:
Motives
Interests
Mood
Arousal
Physiological state
Threats to well-being e.g. participants are faster at finding a single angry face in a happy crowd than a single happy face in an angry crowd
what are the 2 types of attention?
- Focused Attention (the spotlight) - the ability to respond discretely to specific visual, auditory or tactile stimuli
- Divided Attention (paying attention to more than one thing at once) -the highest level of attention and it refers to the ability to respond simultaneously to multiple tasks or multiple task demands
outline the stimulus factors affecting attention and the personal factors?
Stimulus factors:
- Contrast
- Repetition
- Intensity
- Movement
- Novelty
Personal factors:
•Motives
- Interests
- Mood
- Arousal
- Threats
outline the personal factors affecting attention
- motives - interests - threats - mood - arousal
what is the digit span test?
you read a number of digits in a row and ask the patient to repeat it back
what are the stages of attention and clinical skill development?
- cognitive stage: development of mental resources, learning requires explicit instruction through teaching, demonstration and observation 2. associative stage: effective motor programme has been developed to carry out the broader skill but lacks ability to perform finer tasks with fluency 3. autonomous stage: skill is largely automatic and relies on implicit knowledge and motor co-ordination
how do many medical mistakes happen?
from the autonomous stage as the more automatic a task, the less conscious control available
how does perception of bodily symptoms change?
focus of attention contributes to the perception of our bodily symptoms
give examples of how perception of bodily symptoms can change
- 56 participants walked on a treadmill twice for 11 minutes, the first time they wore headphones but heard nothing and the second time half the participants heard amplified sounds of their own breathing while the other half heard street sounds. the first time round reporting of sensations was similar in everyone, the second time round the group hearing street sounds perceived physical symptoms less because they were less focused - students were asked to touch a vibrating piece of sandpaper and were either told nothing, told it would be painful or it would be pleasant. the group that were told it would be painful found it much more painful than the other two groups
what is the effect of chronic pain on pain perception?
experiencing pain over several years may make people avoid things for fear of pain increased pain sensation correlates with low activity and means patients are more likely to feel low stressed and anxious
what is perpetual schema?
Perceptual Schema: a mental representation or image containing the critical and distinctive features of a person, object, event, or other perceptual phenomenon
Schemas provide mental templates that allow us to identify and classify sensory input
Each of our perceptions is essentially a hypothesis about the meaning of the sensory information
Illusions: compelling but incorrect perceptions. Most can be attributed to perceptual constancies that ordinarily help us perceive more accurately e.g. Muller-Lyer Illusion
Perception and attribution of physical symptoms
“A physical symptom or sensation is a perception, feeling, or belief about the state of our body. (It)….is often-but not always – based on physiological activity. Above all, a physical symptom represents information about our internal state.”
Pennebaker (1983)
“Given an undefined state of bodily arousal, individuals will seek out labels, and given a label individuals will seek and find symptoms”
Meyer et al (1985)
Acute pain is an important sign that the body has been damaged or something is wrong. At what point since time of damage does acute pain become normally considered chronic or persistent pain?
3 months
