AuthorTopic: Response repetition biases in human perceptual decisions are explained by activity decay in competit  (Read 177 times)

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James J Bonaiuto,1,* Archy de Berker,1 and Sven Bestmann1
Richard Ivry, Reviewing editor
Richard Ivry, University of California, Berkeley, United States;
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This article has been cited by other articles in PMC.
Associated Data

Data Citations

        Bonaiuto J, de Berker AO, Bestmann S. Data from: Neural hysteresis in competitive attractor models predicts changes in choice bias with non-invasive brain stimulationDryad Digital Repository. 2016 http://dx.doi.org/ 10.5061/dryad.r1072

Supplementary Materials

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Abstract

Animals and humans have a tendency to repeat recent choices, a phenomenon known as choice hysteresis. The mechanism for this choice bias remains unclear. Using an established, biophysically informed model of a competitive attractor network for decision making, we found that decaying tail activity from the previous trial caused choice hysteresis, especially during difficult trials, and accurately predicted human perceptual choices. In the model, choice variability could be directionally altered through amplification or dampening of post-trial activity decay through simulated depolarizing or hyperpolarizing network stimulation. An analogous intervention using transcranial direct current stimulation (tDCS) over left dorsolateral prefrontal cortex (dlPFC) yielded a close match between model predictions and experimental results: net soma depolarizing currents increased choice hysteresis, while hyperpolarizing currents suppressed it. Residual activity in competitive attractor networks within dlPFC may thus give rise to biases in perceptual choices, which can be directionally controlled through non-invasive brain stimulation.

DOI: http://dx.doi.org/10.7554/eLife.20047.001
Research Organism: Human
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eLife digest

When making decisions, people and other animals tend to repeat previous choices even if this is no longer the best course of action. This tendency is especially common when the choice is difficult to make. For example, when people are asked to decide whether groups of dots on a television screen are moving mostly to the left or the right, they often repeat their previous choice when the direction of motion is not clear.

Recordings of brain activity in animals suggest that once a choice is made, there is brain activity left over that influences the level of activity at the beginning of the following choice. If this leftover activity is stronger in the brain cells that represent the first choice, it might give this option a head start when another decision is made; this would provide one explanation as to why that same choice is repeated. However, this explanation had not been tested directly.

Bonaiuto et al. reasoned that if leftover activity is indeed the cause of choice repetition, directly manipulating this activity in the human brain should alter this tendency in a predictable way. First, computer-based simulations of circuits of brain cells were used to predict what the consequences of such manipulation would be. The model predicted that brain activity left over after a choice is made would indeed cause the choice to be repeated. Moreover, stimulating this virtual circuit did increase or decrease the tendency to repeat choices depending on the type of stimulation used.

Bonaiuto et al. went on to confirm that human volunteers who had been asked to complete the “moving dots” task did tend to repeat their choices. Next, the volunteers had a region of their brain, which is known to be important for making choices, stimulated using electrodes placed on their scalp (a non-invasive method of brain stimulation). Exactly as the computer simulations predicted, one form of stimulation made the individual more likely to repeat their previous choice, while another form of stimulation had the opposite effect.

These findings show that stimulating the brain via a non-invasive technique can shape the choices that people make in ways that can be predicted by a biologically realistic computer simulation of networks in the brain. The findings also support the idea that leftover activity following a choice might be the biological reason why people tend to go against evidence and repeat previous choices. This new knowledge could be exploited in future studies that try to understand and influence decision making in humans.

THEN THE STUDY in DETAILS FOLLOW...ABOUT 30 PAGES

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5243027/

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