Cognitive and neural effects of drugs of abuse

Concept of Drug dependence

Concept of Drug Dependence PFC (prefrontal cortex) is the “executive centre” for planning and decision making.

PFC integrates glutamate and dopamine inputs

It involves attention *salient information and *working memory; PFC integrates glutamate and dopamine inputs

Association between cognitive domain and brain region

5-CSRTT

The Five-choice serial-reaction time task is a laboratory behavioural task used in psychological research to assess visuospatial attention and motor impulsivity in animals

5-CSRTT

The 5CSRTT requires the animal to correctly identify which of the five apertures has been briefly illuminated, via a nose poke, in order to receive a sugar reward

Assesses sustained attention, divided attention and selective attention.

Animal models of Impulsive behaviour (ADHD)

Stop-Signal Reaction Time Task
Five-Choice Serial Reaction Time Task
Delay-Discounting Paradigm: Delay discounting refers to the tendency for individuals to prefer immediate rewards over rewards received after a delay, even if the magnitude of the delayed reward is larger (Kirby et al., 1999; Berns et al., 2007) 延迟满足

There are similarities between patients with ventromedial prefrontal/orbitofrontal cortex (VMPC) damage and drug addicts.

Tools to assess decision

Iowa gambling task

Summary

Acute administration of stimulants can enhance performance - may be one of the reasons for self-administering the drug – ‘functional reinforcement’.
The acute withdrawal from these abused substances can transiently disrupt cognitive control functions such as attentional selection.
These observations of impaired performance have been observed in subjects dependent on nicotine, cocaine and heroin.