What we learned about the brain this week: anxiety and motivation

  • 04 Mar 2016
Armando Veve

Anxiety has many physiological side effects; increased heart rate, nausea, dizziness. Now a new study has added another side effect: changes in perception.

A study from the Weizmann Institute of Science, published in Current Biology, has found that people with anxiety were "less able to distinguish between neutral stimuli and stimuli associated with threat". This meant they actually heard a ringing tone differently to those who hadn't been diagnosed with anxiety.

This is because anxiety causes "plastic changes" in the brain that take time to wear off, even after an anxiety-inducing experience is over. "Anxiety traits can be completely normal, and even beneficial evolutionarily. Yet an emotional event, even minor sometimes, can induce brain changes that might lead to full-blown anxiety," said Rony Paz, who lead the study.

Another study this week found a biological basis to human motivations. In Science, a team from the University of Zurich found that the communication between different brain regions different depending on the motives that drove a particular behavioural choice.

This meant they could identify motives by observing the areas of the brain active during a particular behaviour, and were even able to identify different processes in those who were considered 'selfish' to those who were considered 'prosocial'.

Understanding this kind of process is complex, and the complexity increases as you go further down, to the cellular level. But a new study from Columbia University, and published in Cell, details a "powerful new approach" to identifying classes of neurons. This could, they say, help us understand the underlying circuits which underpin many brain processes. "What makes this work so foundational is that even with very limited data--such as the prevalence of these transcription factors combined with information on where the neurons were located--we could infer a detailed repertoire of cellular diversity," said Dr. Larry Abbott, senior author of the study. "Some of the most exciting work in neuroscience these days involves efforts to combine many different kinds of experimental measurements using a single unified statistical model--and these papers are one example of this," he said. "We're looking forward to further extending and generalising these methods and applying them in other parts of the nervous system."