W8: Are we in control while we are intoxicated? Flashcards
1) Outline the cog psy methods used to examine the influence of intoxication on cognition
2) To examine how such evidence can be used to influence policy
purpose!
Can we be accounted for our actions when intoxicated?
Current law:
(S6,7)
lower max penalty for the crime committed
Extention to Psychotic symptoms:
Why?
symptoms may be part of an intoxication syndrome, and resolve rapidly with the excretion of the psychotogenic (that is, psychosis-causing) substance from the body.
substance induced psychosis is used in the diagnostic classification schemes employed in mental health to describe such transient disorders.
It is usually long term, especially psychotic illness, -> long going even in even in the absence of ongoing substance use. furthermore, a person with an established psychotic illness may engage in substance abuse, which appears to precipitate psychotic relapses.
Meth Use and Violent Behaviour:
Animal study
Acute doses in animals have inconsistently produced violent behaviour,
low to moderate doses appear to augment aggressive responses,
but the effects are not consistent across species or paradigms
Chronic methamphetamine exposure in animal studies (Sokolov and colleagues) has consistently demonstrated increased aggression and fighting behaviour
Meth Use and Violent Behaviour:
Animal study
confound
confounded by the acute effects of meth on increased vigilance and psychomotor behaviour
Acute doses of dextro-amphetamine, which is an oral medication used to treat narcolepsy and other conditions, show no increases in aggression
Increased talking, motor activity, anorexia, ‘friendliness’ but no acute or chronic increases in aggression
Chronic use has been prescribed to successfully treat aggressive behaviour in children with ADHD
opioid withdrawal
Consistently associated in animal experiments and human observational studies with increased aggression
60+% of heavy chronic Meth users report problems with aggression and problems controlling violent behaviour
Australian data indicates that prevalence of violent crime amongst regular Meth users is comparable to other illicit drug using groups (McKetin et al, 2005)
Intoxication and Crime:
NSW Sentencing Council 2009 – Sentencing for Alcohol-related violence
Almost half of assault offences and three quarters of offensive behaviour incidents involve intoxication
A review of crime statistics from 11 countries, 62% of offenders convicted of a violent crime had been consuming alcohol shortly before committing the crime – Murdoch et al. 1990
Alcohol was more than twice as likely to be a contributing factor to violent crimes, compared to non-violent crimes
The magnitude of violence was related to the magnitude of consumption
Does Intoxication increase aggression?
Links: (4)
1) Psychomotor stimulant effects
2) Interrupted threat detection
3) Alterations of the pain system
4) Alterations of cognition
Psychomotor stimulant effects
Euphoria accompanying intoxication is rewarding, which is accompanied by increases in nervous system stimulation
1) increased BP, HR, respiration
2) Also increase sensation seeking, approach behaviours
3) Confrontational and provocative behaviours
Interrupted threat detection
Alcohol alleviate subjective feelings of stress, (upregulation of GABA in the brain)
Intoxication can result in diminishing appropriate levels of stress and or fear
Other drugs that have an anxiolytic effect (e.g., cannabis) but are not linked to violence, also have a CNS depressant effect
(combi effect)
Measures of aggression
S17-19
Influence of sub. Intixication,
…..
Taylor Aggression paradigm
Subjects are placed in a situation where electric shocks are received from and administered to a fictitious opponent during a competitive reaction-time task
Physical aggression is indexed as the intensity of shocks administered to the opponent
Given that aggression is highly related to provocation, the TAP has low and high provocation conditions
Opponents are introduced at the beginning of the experiment and sit opposite throughout, they are same gender and race
Pain thresholds are individually assessed and factored into shock intensity
Results from study (card 15)
Alcohol significantly increased aggressive behaviour in comparison to the placebo, for men but not women
The effect of alcohol expectancies on aggression in men was rendered nonsignificant when statistically controlling for dispositional aggressivity
alcohol may amplify aggression
Four pharmacological links between intoxication and aggression
Alterations of the pain system
In the descending limb of alcohol intoxication pain sensitivity is decreased
Four pharmacological links between intoxication and aggression
Alterations of the pain system
In the descending limb of alcohol intoxication pain sensitivity is decreased
Four pharmacological links between intoxication and aggression
Alterations of the pain system:
The paradox
In the ascending limb of intoxication humans sensitivity to pain increases (Gustafson, 1985, Gray, 1982)
The effect of alcohol is therefore thought to be paradoxical
Four pharmacological links between intoxication and aggression
Alterations of the pain system:
The paradox
In the ascending limb of intoxication humans sensitivity to pain increases (Gustafson, 1985, Gray, 1982)
The effect of alcohol is therefore thought to be paradoxical
Four pharmacological links between intoxication and aggression
Alterations of cognition
Alcohol is known to interfere with many aspects of cognition, but the studies to understand the nature of this relationship have only been conducted in the last 20 years
Early research examined a broad range of tests such as reaction time, visual and auditory acuity, hand-eye co-ordination, gross body movement, short term memory
Threshold or effective blood alcohol concentration (BAC) -> majority of subjects displayed a reliable impairment for a given task
(as change is usually relative showing this is important)
Four pharmacological links between intoxication and aggression
Alterations of cognition
Study 1:
REview: results
Holloway (1995), Kruger (1992), Mitchell (1985)
Reviews indicate that most behaviours experimentally tested have a threshold BAC of 0.08% -> simple reaction time
Higher-order cognitive functions, (decision-making, judgement, memory) -> BAC threshold of 0.06%
More complex divided attention tasks that (dual task), BAC threshold of 0.05%
Processing speed
Simple reaction time tasks showed intoxication slowed behavioural responses to stimuli
1) Motor issue
2) Flicker fusion task
3) Subtraction task (count down from 100 each time - 7)
2) Flicker fusion task
Strobe-like flashing light that increases the ‘flicker’ frequency until it gives the impression of a continuous stream of light, from a flicker to a fusion
With alcohol consumption the point at which subjects report the flicker to fusion transition is earlier -> Attributed to a slowing of neural processing somewhere in the visual processing system between the retina and visual cortex
