Introduction
Cognition is a complex of biological discoveries, behavioral theories, and experimental discoveries. As such all its components have various models and hypotheses explaining the processes. Some components of cognition include memory, attention, and implicit and explicit functions. The effect of drugs to impair cognition has been researched extensively and all major substances of abuse have been found to affect cognition. Most accomplish this through their toxicity to the brain cells while others cause adaptability and hyperfunctioning of certain areas of the brain involved in decision making, reward, and impulsiveness. These findings were initially theories based on experimental models and biochemical reactions. However, newer techniques of imaging and measuring brain activity, as well as the development of sensitive tests that measure and evaluate aspects of cognition have provided proof. Detailed knowledge about addiction and the mechanism of dependence, abuse, craving, and loss of control allows the development of interventions that target the different processes of cognition, thereby preventing further damage and helping with the addiction. The detail also enables tailoring of these interventions according to the individual’s level of impairment thereby maximizing success and reducing relapse. A combination of pharmacological and behavioral therapy ensures maximal success in treating addiction.
Cognition in addiction
Social cognition is a field of cognitive neuroscience, which is a combination of neuroscience and cognitive psychology. It attempts to explain people’s attitudes, interactions, emotions, and self-control by looking at key components such as memory, attention, and implicit and explicit cognition. The theories behind these themes have roots in biological and psychological discoveries that have been based on experiments on human and non-human subjects. These discoveries have shaped what we know and understand about complex behaviors in normal as well as impaired individuals such as autistics. Whereas the biological theories stem from the delineation of brain pathways, neurotransmitters, and imaging analyses, the psychological ones also look at the influence of aspects of the environment such as education and culture on the development of cognition.
The highest level of cognition involves monitoring one’s behavior and adjusting it according to feedback relating to the outcome of the behavior. It involves problem-solving and making complex decisions. This process has multiple levels, from processing environmental cues and judging the extent of motivation to alter behavior. This self-regulation is directly affected by certain drugs, so pointing the finger at the reward and reinforcement center in the brain is not sufficient to explain this dysregulation in cognition. Drug addiction might be associated with psychiatric conditions like depression, anxiety, and post-traumatic stress disorder because for drug addicts just thinking about using drugs provides relief from unpleasant moods and sensations.
Memory and its changes
Memory is simply the ability of an individual to register, store and recall information when needed. As a component of cognitive neuroscience, it is based on several models. The Atkinson-Shiffrin model is relatively simple and proposes that long-term memory is made up of procedural and episodic memory, among other components, and that events only reach long-term memory stores after having been recalled several times. However, it was shown later that no such practice was needed for all events. Later in 1974, a working-memory model was proposed. According to this, memory was composed of three units, the central-executive, also known as attention, which sends all information to the other components. The phonological loop stores auditory information, and the visuospatial sketchpad stores visual and spatial data. Another component, the episodic buffer, works to link all these pieces of data so that they are stored as integrated pieces and with chronological meaning. Around this time, another model explained memory through levels of processing, such as organization, distinctiveness, effort, and elaboration.
Certain factors can result in a change in memory function. However, if left undiagnosed and untreated they can result in irreversible memory impairment. Addiction to certain substances can result in such changes. Most importantly, alcohol has been known to result in short-term memory loss which progresses on to amnesia and then a disorder known as Korsakoff’s syndrome, characterized by confabulation which makes up for the gaps in memory. Drinking can deprive the body of thiamine, or Vitamin B12, which can cause permanent damage to neurons. The chances of an addict developing this deficiency increase with age, as the rate of absorption of this vitamin and other nutrients go down. A recent study cited in the database of the National Institutes of Health found that people infected with HIV are often heavy drinkers, and this deals a double blow to their short-term episodic memory. (Fama et al) Drugs have neuro-toxic and neuro-adaptive effects that lead to cognitive impairment in which memory loss is prominent. Moreover, areas in the brain such as the anterior cingulated and pre-frontal cortex are concerned with drug-related memories that lead to drug craving. (Robbins et al)
Craving
This leads us to another important aspect of cognition impairment in addiction; craving. It was thought previously drug abuse and addiction can best be explained by the ‘high’ produced by drugs. However, this simplistic view was challenged once it was discovered that disruptions in the frontal part of the brain due to repeated drug use were responsible for impairment in decision making, response inhibition, and planning. Side-effects that were thought to be incidental findings in drug addicts have now been attributed to the effects of the drugs themselves. One model of craving is the know/go system. This explains the interaction of cognition and emotion. A ‘cool’ know system and a hot emotional ‘go’ system are involved in craving and abstinence. The cool system can self-regulate and control whereas the hot system is impulsive and reflexive and the basis of classical conditioning. The balance between the emotional and composing systems is determined by stress, developmental maturity, and the individual’s self-regulatory dynamics.
The hallmark of addiction, which is craving or compulsive drug-seeking, can be explained by changes in the frontal cortex. PET scanning and MRI have been used to measure drug abusers’ brain activity during episodes of craving, and it was found that activity in the decision making and motivation centers in the brain’s frontal cortex had heightened activity. These findings were reproducible in other labs, and they suggested that this impairment resulted in the inability of addicts to look beyond the immediate gratification that drugs afforded or the long-term negative impact of drug use. (Carpenter) The biological explanation involves dopamine (plays a role in reward center) and serotonin pathways in the brain and depletion of other neurotransmitters such as tryptophan and phenylalanine.
Attention
Another aspect of cognition, which also plays a part in memory, is attention. It is the process of focusing and concentrating on one source. It can be classified into five different types, and this classification has been valuable in evaluating attention in people with different brain pathologies. The types include focused, sustained, selective, alternating, and divided attention. The ‘executive function’ of the brain, which has been mentioned, previously, determines which pieces of incoming information should be given attention to, depending on what the goals of the person are. This theory emerges from the positive incentive model of addiction. This bears great importance for people with addictions as their goals, especially during craving are impaired.
Studies have shown that attention towards drug-related stimuli increases with the duration of drug use and the development of dependence. This leads to increased action tendencies to get alcohol, increased impulsive decision making, and impaired inhibitory control overdrives and behavior. (Field) It was concluded in another study that ‘Because drug stimuli produce conditioned responses that may motivate drug-taking, biased attention toward these cues may play an important role in drug use and relapse following treatment.’ (Robbins) Various tools are present to investigate attentional bias but the most commonly used are the modified Stroop and the attentional probe tasks. There is uncertainty concerning if acute abstinence is associated with increased attentional bias and if the degree of addiction influences the degree of bias.
Implicit cognition
Delving into the intricacies of cognition also reveals that there are two sub-levels to it, the lower one dealing with a quick, inflexible, automatic process termed implicit cognition, and the higher explicit level which concerns slow, flexible actions that require thinking and judgment. In a way, it is a bit like Freud’s id and superego. An example of implicit cognition is the response towards an object that the subject is prejudiced towards. This response is automatic and instantaneous, involving the amygdala in the brain. The stronger the prejudice, the higher is the amplitude of response in the amygdala. Explicit processing can be demonstrated through mentalization, in which people can understand and predict the beliefs, intentions, and desires of others. However, it is little known if explicit processes build on implicit ones, or if they interact together—the explicit modulating the implicit. (Frith)
Both implicit and explicit processes are important in the development of addictive behavior. Implicit cognition is important to evaluate because it may predict individuals who are at a high risk of relapse that may not be screened for by using self-reporting. Knowledge of implicit functioning may lead to the development of interventions that target both levels of cognition rather than explicit alone, and therefore have better results. Also, modification of these interventions according to the individual may be possible through knowledge of implicit functions.
As such addiction is characterized by disinhibition and loss of control, even though intentions to restrain might be present. This influence on cognition may in turn be dependant on the level of intact executive functioning. A study done in the Netherlands regarding alcohol addiction showed that ‘Implicit positive-arousal cognitions predicted alcohol use after 1 month more strongly in students with lower levels of working memory capacity, whereas explicit positive-arousal cognitions predicted 1-month follow-up alcohol use more strongly in students with higher levels of working memory capacity. (Thrush) This has significance as it indicates that different interventions may be needed for different groups of people.
Details of these sublevels of cognition are helpful when intervention strategies are being designed. Those that target implicit function include attentional re-training, in which automatic responses are directly targeted and the patient may not be aware that an intervention is being received. These interventions result in the formation of new attentional responses and cognitive behaviors.
Conclusion
In conclusion, it can be said that addiction is a condition that can be looked upon as a chronic brain disease. Therefore combining cognitive behavioral therapy (CBT) with pharmacological interventions would not only make sense but has also been shown to be quite successful. CBT deals effectively with the patient’s feelings, thoughts, and behaviors, which are all dependent on cognition. A vital component of CBT centers is about identifying negative thoughts, which could lead to relapse or continued substance abuse and this helps in relapse prevention. Treating acute symptoms, like withdrawal anxiety and craving while ignoring the impairment in decision making and loss of self-control, leads only to frustration and relapses. These coping skills are essential to restore functionality and repair damage incurred due to addictive habits. When novel medications are paired with continued sobriety and motivation, then only can any meaningful healing result. Clinicians are finding that if addiction is looked at as a condition resulting from brain damage that impairs cognition, and not as a failure of morals, maximally effective treatment can be given to patients. (Urschel III)
References
Fama, R., et al. “Working and Episodic Memory in HIV Infection, Alcoholism, and Their Comorbidity: Baseline and 1-Year Follow-up Examinations.” Alcohol Clin Exp Res (2009).
Robbins, T. W., K. D. Ersche, and B. J. Everitt. “Drug Addiction and the Memory Systems of the Brain.” Ann N Y Acad Sci 1141 (2008): 1-21.
Carpenter, SIRI. “Cognition Is Central to Drug Addiction” Monitor on Psychology 32.5 (2001).
Field, M., T. Schoenmakers, and R. W. Wiers. “Cognitive Processes in Alcohol Binges: A Review and Research Agenda.” Curr Drug Abuse Rev 1.3 (2008): 263-79.
Robbins, S. J., and R. N. Ehrman. “The Role of Attentional Bias in Substance Abuse.” Behav Cogn Neurosci Rev 3.4 (2004): 243-60.
Frith, Chris D., and Uta Frith. “Implicit and Explicit Processes in Social Cognition.” 60.3 (2008): 503-10.
Thush, C., et al. “Interactions between Implicit and Explicit Cognition and Working Memory Capacity in the Prediction of Alcohol Use in at-Risk Adolescents.” Drug Alcohol Depend 94.1-3 (2008): 116-24.
III, Harold Urschel. “Approaching Addiction as a Chronic Brain Disease“. 2009. Psychology Today.