TY - JOUR
T1 - Increased locus coeruleus tonic activity causes disengagement from a patch-foraging task
AU - Kane, Gary A.
AU - Vazey, Elena M.
AU - Wilson, Robert C.
AU - Shenhav, Amitai
AU - Daw, Nathaniel Douglass
AU - Aston-Jones, Gary
AU - Cohen, Jonathan D.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - High levels of locus coeruleus (LC) tonic activity are associated with distraction and poor performance within a task. Adaptive gain theory (AGT; Aston-Jones & Cohen, 2005) suggests that this may reflect an adaptive function of the LC, encouraging search for more remunerative opportunities in times of low utility. Here, we examine whether stimulating LC tonic activity using designer receptors (DREADDs) promotes searching for better opportunities in a patch-foraging task as the value of a patch diminishes. The task required rats to decide repeatedly whether to exploit an immediate but depleting reward within a patch or to incur the cost of a time delay to travel to a new, fuller patch. Similar to behavior associated with high LC tonic activity in other tasks, we found that stimulating LC tonic activity impaired task performance, resulting in reduced task participation and increased response times and omission rates. However, this was accompanied by a more specific, predicted effect: a significant tendency to leave patches earlier, which was best explained by an increase in decision noise rather than a systematic bias to leave earlier (i.e., at higher values). This effect is consistent with the hypothesis that high LC tonic activity favors disengagement from current behavior, and the pursuit of alternatives, by augmenting processing noise. These results provide direct causal evidence for the relationship between LC tonic activity and flexible task switching proposed by AGT.
AB - High levels of locus coeruleus (LC) tonic activity are associated with distraction and poor performance within a task. Adaptive gain theory (AGT; Aston-Jones & Cohen, 2005) suggests that this may reflect an adaptive function of the LC, encouraging search for more remunerative opportunities in times of low utility. Here, we examine whether stimulating LC tonic activity using designer receptors (DREADDs) promotes searching for better opportunities in a patch-foraging task as the value of a patch diminishes. The task required rats to decide repeatedly whether to exploit an immediate but depleting reward within a patch or to incur the cost of a time delay to travel to a new, fuller patch. Similar to behavior associated with high LC tonic activity in other tasks, we found that stimulating LC tonic activity impaired task performance, resulting in reduced task participation and increased response times and omission rates. However, this was accompanied by a more specific, predicted effect: a significant tendency to leave patches earlier, which was best explained by an increase in decision noise rather than a systematic bias to leave earlier (i.e., at higher values). This effect is consistent with the hypothesis that high LC tonic activity favors disengagement from current behavior, and the pursuit of alternatives, by augmenting processing noise. These results provide direct causal evidence for the relationship between LC tonic activity and flexible task switching proposed by AGT.
KW - Decision-making
KW - Foraging
KW - Locus coeruleus
KW - Norepinephrine
UR - http://www.scopus.com/inward/record.url?scp=85029177677&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029177677&partnerID=8YFLogxK
U2 - 10.3758/s13415-017-0531-y
DO - 10.3758/s13415-017-0531-y
M3 - Article
C2 - 28900892
AN - SCOPUS:85029177677
VL - 17
SP - 1073
EP - 1083
JO - Cognitive, Affective and Behavioral Neuroscience
JF - Cognitive, Affective and Behavioral Neuroscience
SN - 1530-7026
IS - 6
ER -