Applications of Psychophysiology Flashcards
How can N2 ERP component be applied to the real-world?
Pure:
- Present during inhibition tasks
- Larger to inhibited (NoGo/Stop) stimuli than ‘Go’
- Indexes a covert inhibition process
- Reduces with age through childhood, with improved inhibition success
Applied – Level 1
- Application to inhibitory processing in AD/HD
- Reduced in AD/HD compared to controls
Applied – Level 2
- Measure of training programs success at aiding inhibition in AD/HD
How is physiology used in detection of deception?
Measures of emotional reactions may aid in detecting innocent from guilt. Idea is the physiological system will reveal the truth/realty, even if you are a good liar. Partially scientific due to the use of control conditions and objective measures of deception.
Two main approaches:
- Control Question Test (CQT) - a deception test. Different physiological responses occur to certain questions when the person is deceptive. Relevant questions are asked along with irrelevant, or control questions and the response to relevant questions is compared to the response to irrelevant questions.
- Guilt Knowledge Test (GKT) - an information test. Information only someone related to the crime would know. Critical information can produce differential physiological responses to other less relevant items. Critical information is determined then multiple-response questions are created. Physiological responses compared between actual and contrived answers.
- CQT and GKT tests are 90% accurate when properly conducted and evaluated.
- Advantages of using P300 as a measure of deception is that it is not dependent on emotional responses.
What is brain fingerprinting?
Computer based technology designed to determine hidden information in an individual’s brain by measuring electrical brain wave responses.
Clear differentiation within each of the measures between people who were guilty, very little differentiation between critical and non-critical information for those who were innocent. Combining the ERP and autonomic measures did increase the discrimination performance of the autonomic-based CIT.
How are auditory system tests applied?
- Brainstem evoked potential - auditory system damage in infants.
- Also able to measure ERPs in those unable to respond such as disabled, children, cerebral palsy.
- Allows early diagnosis of conditions which may be lead to speech and language problems later
- BAEP test in newborn babies
How are visual system tests applied?
- Assess damage at levels of visual system. ERPs and electroretinogram used with stimulation of involved eye:
o Retinal disease = ERP and ERG effected
o Optic nerve disease = ERP suppressed
o Damage to prior optic nerve = Loss of ERP
o Damage between lateral geniculate bodies and cortex = Loss of early ERP components, later ones ok - Assess visual activity with ERP – N1/P2 amplitudes decrease with focus reduction. ERP amplitude larger with focussed than defocussed images
- Assess colour vision deficits – Colour-defective individuals do not produce ERPs to stimuli formed of colours they could not discriminate
How is EEG and ERPs used in the diagnosis of schizophrenia?
- Increased variability in ERP responses – suggests unstable and variable thought processes
- Increased CNV – suggests neural disinhibition, i.e. brain control. Therefore, schizophrenia is over preparing for oncoming stimulus
- Decreased P300 amplitude – suggests less effective memory updating
- EEG: high bet and low alpha
- Faster and prolonged alpha blocking. People with schizophrenia switch quicker and stay engaged for longer, don’t switch off
- Suggests resting SZ is in a constant state of cortical processing
- Deficient filtering of sensory input (overload)
How is EEG and ERPs used in the diagnosis of AD/HD?
- Inattention, impulsivity, hyperactivity
- Subjective behavioural indicators used for diagnosis
- Problems – reporting bias due to diagnosis seeking, lack of behavioural baseline
How is EEG and ERPs used in biofeedback?
- Information regarding physiological processes are provided to individual. E.g. muscle tensions, blood pressure, heart-rate, EEG activity
- Key is usual lack of awareness of this activity. Individual learns to self-regulate activity
- Implications
o Are BP, HR, skin temp (ANS) really automatic and involuntary?
o Offers promise for control of disorder such as hypertension, epilepsy, AD/Hd. Offers an avenue for training and change
How has biofeedback beed used to improve tension headaches?
- Frontalis and splenius (neck) EMG feedback reduced frequency of tension headaches
- Another study found 40-60% frequency reduction
- EMG feedback and relaxation found that participant showed improvements and also changed their beliefs that the headaches were beyond their control. They had higher confidence in their abilities.
Combined physiological/psychological effect
How has biofeedback been used to improve stuttering?
Stuttering is the blocking of speech, or repetition of initial sound of words
- Jaw muscle feedback reduced in major reductions in stuttering
- EMG of speech muscles higher during stuttered than non-stuttered words. EMG feedback resulted in 60-80% reduction in stuttering in home environment. 9-month follow up showed continued improvement. Problem with this study – no control group tested
How has biofeedback been used to treat ADHD?
- Aim: modify ‘atypical’ brain activity
- Excess theta (slow-wave), decreased beta (fast-wave)
- May reduce or replace treatment with stimulant medication
- AD/HD medication side effects: nervousness, insomnia, anorexia, dizziness, headaches, BP and pulse changes, cardiac arrhythmia, abdominal pain, weight loss
- UOW AD/HD training tool targets several core deficits of children with AD/HD. Cognitive Energetic Model of AD/HD suggests targeting deficits at different levels. Direct evidence and ongoing research.
o WM and inhibitory control via cognitive training with EEG-based attention monitoring
o Arousal-regulation via neurofeedback
What is the procedure involved in biofeedback?
- Objective: train subject to produce alpha with eye open (relaxation)
- Record EEG at site where alpha predominant
- Filter signal (8-13Hz activity)
- Provide feedback regarding desired response
- Ask subject to keep tone on as long as possible
- Train with both ‘alpha-on’ and ‘alpha-off’ (development of neural control. Goal not just to measure something and give feedback loop. Goal is to understand the reality of feedback and train it to go both ways because we don’t carry around the equipment all day. Know how it feels subjectively and what process to go through to achieve that. With repeated exposure, the association becomes stronger. Doing the physical thing to achieve a goal
How generalisable is biofeedback training?
- How is generalisation of training effects/benefits to the real world established? Training people to achieve their goal without feedback. Reduce feedback over sessions
- What is learned? Awareness of physiology or S-R relationship. If it was just a stimulus-response reaction then it wouldn’t be generalisable, you would always need the software/hardware. Know this isn’t true
- What variables influence learning? Effects of quality or quantity of reinforcement
- Which physiological responses respond best? EEG for anxiety, EMG for muscle
- Does transfer from lab to real-life occur? Self-regulation at home as well as in the clinic/lab
- How does motivation and/or expectancy influence BFT? If you as an individual are motivated because the training will get you away from drugs, think it’s going to be good for you, how does that influence the outcome?
- Placebo effect? Non-specific effect, due to equipment, etc.?
- How does BFT compare with relaxation, meditation, hypnosis?
Why is biofeedback beneficial?
- Provides objective indication of change
- Aids in convincing person that they can self-regulate physiological responses
- Relaxation - physiological change, reinforced by feedback from equipment
- Some are unable to detect tension (e.g. chronic pain sufferers)
