Concepts in Psychophysiology Flashcards
Describe the law of initial values.
Emphasises the importance of a baseline. Physiological response to a stimulus is dependent on pre-stimulus level of the system. The higher the initial level of the system, the smaller the response or the larger the decrease produced by a stimulus.
Research has suggested that both heart rate and respiration rate are affected by pre-stimulus levels, however, SCL and temp are not.
What is autonomic balance?
Balance between sympathetic and parasympathetic nervous systems. Ideally the two systems are balanced, however, this is not always the case.
We measure which is dominant by taking multiple recordings and averaging them, in a resting state.
The score if referred to as Ā. A high score means that the parasympathetic nervous system is dominant. A low score means that the sympathetic system is dominant and that an individual is typically very activated.
Ā has been found to have a normal distribution. Therefore 68% of the population have a good balance, 16% are too low and 16% are too high
Trait index - could Ā be used to predict those prone to psychometric disorders? Studies have found that the Ā score was lower in patients with stomach ulcers, skin disorders and gastritis than controls
State index - is Ā sensitive to psychological stress? Measured students prior to taking an oral exam and in a relaxed condition and found that Ā decreases with anxiety
Treatment specificity based on understanding the Ā of an individual
What is the difference between activation and arousal?
Activation is the state of the physiological system in general or at baseline
Arousal is the state of the physiological system in response to stimulation
Activation and arousal are reflected in responsivity of measures such as HR, BP, EMG, SCL, EEG
What is the Yerkes-Dodson Law (inverted U hypothesis) and how does it relate to arousal in ADHD?
The Yerkes-Dodson Law states that there is an optimal level of arousal for performing. Performance increases with physiological arousal, but only to a point.
Low arousal = low performance, high arousal = high performance
In children with ADHD low arousal/low performance is referred to as hypoarousal. High arousal and low performance is referred to as hyperarousal.
What is stimulus response specificity?
Stimulus response specificity states that an individual’s pattern of physiological activity will be similar in a given situation. If this wasn’t true, we would have no consistent responses. The pattern may vary when the situation is difference
Explain fractionation.
Specific directional change in the systems
Lacey (1959) - directional fractionation of response, different physiological variables show different directions of response. Primary evidence for this notion was a study which looked at four different conditions and measured SCL and HR in all of these conditions
- Visual attention: decreased HR, increased SCL
- Listening (auditory attention): decreased HR, increased SCR
- Thinking: increased HR, increased SCL
- Withstanding pain: increased HR, increased SCL
What is habituation and why do we habituate?
Habituation is a decrease in physiological responsivity with repeated presentation of the same stimulus. We habituate less to intense, important, novel or complex stimuli
We habituate as a survival mechanism. It would be a waste of energy resources if similar magnitude responses occurred to repeated and non-threatening stimuli
Compare the orienting response and the defensive response.
The orienting response is a fundamental aspect of attention processing. It is a reflex which allows an animal to attend to novel stimuli. The OR occurs to novel stimuli, habituates rapidly, increased perceptibility and heart rate decreases. It is about bringing the stimulus in.
The defensive response occurs to dangerous/intense stimuli, habituates slowly, perceptibility is decreased, heart rate is increased
Hare (1973) - study looked at HR to slides of spiders for individuals with and without arachnophobia. Fearful participants showed a DR, non-fearful participants showed an OR .
Describe Lacey’s Intake-Rejection Hypothesis.
HR deceleration is associated with stimulus intake and OR
HR acceleration is related to stimulus rejection and the DR
