Alcohol Use in Early Adolescence may Alter Reward Motivation

The brain responds to rewarding stimuli by increasing the release of a neurotransmitter called dopamine. When we feel motivated, it is because our brain anticipates this dopamine reward.
The transition from early to mid-adolescence is associated with increased reward sensitivity and reward-seeking behavior, a consequence of normal brain development. This heightened sensitivity or prioritization of reward can be thought of as reflecting a greater motivation to obtain rewards. A new study, published in Alcoholism: Clinical and Experimental Research, has addressed whether drinking alcohol in early adolescence might impact the brain’s reward systems, by examining associations between alcohol initiation and subsequent changes in reward motivation while accounting for baseline scores. Differences between boys and girls were also evaluated.

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Cumulative Effects of Long Term Alcohol on Brain Function

Functional MRI (fMRI), a type of scan that measures brain activity, has enabled study of the impact of alcohol on brain function. This type of imaging allows brain activity to be assessed while participants are at rest, performing a simple task like tapping a finger, or doing a complex cognitive task like a memory task or decision-making. It works by detecting the change in blood flow that occurs when brain cells (or neurons) in different parts of the brain are activated. Blood flow provides the energy and oxygen needed for brain cells to activate, and it is this exchange of oxygen that is measured using fMRI and is reflected by brain blood flow. Complicated physics are involved in determining the profile of blood flow when a part of the brain is activated, and studies have shown that the time course of these changes – known as the hemodynamic response function (HRF) – is affected by acute alcohol consumption. However, the effects of heavy chronic (long-term) alcohol consumption on HRF

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