stimulus

Examples of stimulus in the following topics:

• Basic Principles of Classical Conditioning

  • Classical conditioning is a form of learning whereby a conditioned stimulus (CS) becomes associated with an unrelated unconditioned stimulus (US), in order to produce a behavioral response known as a conditioned response (CR).
  • The conditioned response is the learned response to the previously neutral stimulus.
  • The unconditioned stimulus is usually a biologically significant stimulus such as food or pain that elicits an unconditioned response (UR) from the start.
  • The unconditioned stimulus was the sight or smell of the food itself.
  • The conditioned stimulus was the ringing of the bell.

• Sensory Absolute Thresholds

  • The absolute threshold is the lowest intensity at which a stimulus can be detected.
  • The recognition threshold is the level at which a stimulus can not only be detected but also recognized; the differential threshold is the level at which a difference in a detected stimulus can be perceived; the terminal threshold is the level beyond which a stimulus is no longer detected.
  • However, perhaps the most important sensory threshold is the absolute threshold, which is the smallest detectable level of a stimulus.
  • The absolute threshold is defined as the lowest intensity at which a stimulus can be detected.
  • Because you are focused on one stimulus, the absolute threshold (in this case, the minimum volume at which you can hear) is lower for that stimulus than it would have been otherwise.

• Sensory Adaptation

  • Sensory adaptation is the decrease in the responsiveness of a sensory system that is confronted with a constant stimulus.
  • This change can be positive or negative, and does not necessarily lead to completely ignoring a stimulus.
  • These corpuscles rapidly change and adapt when a stimulus is added.
  • Then they quickly decrease activity, and eventually cease to react to the stimulus.
  • When the stimulus is removed, the corpuscles regain their sensitivity.

• Basic Principles of Classical Conditioning: Pavlov

  • The unconditioned stimulus is usually a biologically significant stimulus such as food or pain that elicits an unconditioned response (UR) from the start.
  • Extinction is the decrease in the conditioned response when the unconditioned stimulus is no longer presented with the conditioned stimulus.
  • Before conditioning, an unconditioned stimulus (food) produces an unconditioned response (salivation), and a neutral stimulus (bell) does not have an effect.
  • During conditioning, the unconditioned stimulus (food) is presented repeatedly just after the presentation of the neutral stimulus (bell).
  • After conditioning, the neutral stimulus alone produces a conditioned response (salivation), thus becoming a conditioned stimulus.

• Unconscious Perception

  • Priming occurs when an unconscious response to an initial stimulus affects responses to future stimuli.
  • When information from an initial stimulus enters the brain, neural pathways associated with that stimulus are activated, and a second stimulus is interpreted through that specific context.
  • The presentation of an unattended stimulus can prime our brains for a future response to that stimulus.
  • When information from an initial stimulus enters the brain, neural pathways associated with that stimulus are activated, and the stimulus is interpreted in a specific manner.

• Interpretation

  • Each stimulus or group of stimuli can be interpreted in many different ways.
  • That is their interpretation of the stimulus (a raised hand).
  • Someone who has not experienced abuse but has played sports, however, might see this stimulus as a signal for a high five.
  • An individual's hopes and expectations about a stimulus can affect their interpretation of it.
  • The individuals' desire to avoid the unpleasant drink led them to interpret a stimulus in a particular way.

• The Role of Attention in Memory

  • Explicit attentional capture is when a stimulus that a person has not been attending to becomes salient enough that the person begins to attend to it and becomes cognizant of its existence.
  • Very simply, it's when something new catches your focus and you become aware of and focused on that new stimulus.
  • Implicit attentional capture is when a stimulus that a person has not been attending to has an impact on the person's behavior, whether or not they're cognizant of that impact or the stimulus.
  • A person pays attention to a given stimulus, either consciously (explicitly, with awareness) or unconsciously.
  • This stimulus is then encoded into working memory, at which point the memory is manipulated either to associate it with another familiar concept or with another stimulus within the current situation.

• Reinforcement and Punishment

  • Positive reinforcers add a wanted or pleasant stimulus to increase or maintain the frequency of a behavior.
  • Positive punishments add an aversive stimulus to decrease a behavior or response.
  • Negative punishments remove a pleasant stimulus to decrease a behavior or response.
  • The stimulus used to reinforce a certain behavior can be either primary or secondary.
  • In the context of operant conditioning, whether you are reinforcing or punishing a behavior, "positive" always means you are adding a stimulus (not necessarily a good one), and "negative" always means you are removing a stimulus (not necessarily a bad one.

• Habituation, Sensitization, and Potentiation

  • Recall that sensory adaptation involves the gradual decrease in neurological sensory response caused by the repeated application of a particular stimulus over time.
  • Habituation is the "behavioral version" of sensory adaptation, with decreased behavioral responses over time to a repeated stimulus.
  • In other words, habituation is when we learn not to respond to a stimulus that is presented repeatedly without change.
  • As the stimulus occurs over and over (and as long as it is not associated with any reward or punishment), we learn not to focus our attention on it.
  • Sensitization is the strengthening of a neurological response to a stimulus due to the response to a secondary stimulus.

• Sensory Difference Thresholds

  • The just-noticeable difference (JND), also known as the difference limen or differential threshold, is the smallest detectable difference between a starting and secondary level of sensory stimulus.
  • In other words, it is the difference in the level of the stimulus needed for a person to recognize that a change has occurred.
  • The difference threshold is the amount of stimulus change needed to recognize that a change has occurred.