Robust Encoding of Spatial Information in Orbitofrontal Cortex and Striatum

Abstract

Knowing whether core reward regions carry information about the positions of relevant objects is crucial for adjudicating between choice models. One limitation of previous studies, including our own, is that spatial positions can be consistently differentially associated with rewards, and thus position can be confounded with attention, motor plans, or target identity. We circumvented these problems by using a task in which value-and thus choices-was determined solely by a frequently changing rule, which was randomized relative to spatial position on each trial. We presented offers asynchronously, which allowed us to control for reward expectation, spatial attention, and motor plans in our analyses. We find robust encoding of the spatial position of both offers and choices in two core reward regions, orbitofrontal Area 13 and ventral striatum, as well as in dorsal striatum of macaques. The trial-by-trial correlation in noise in encoding of position was associated with variation in choice, an effect known as choice probability correlation, suggesting that the spatial encoding is associated with choice and is not incidental to it. Spatial information and reward information are not carried by separate sets of neurons, although the two forms of information are temporally dissociable. These results highlight the ubiquity of multiplexed information in association cortex and argue against the idea that these ostensible reward regions serve as part of a pure value domain.

Economic Choice as an Untangling of Options into Actions

“…However, some recent studies, using more sensitive tasks or analysis methods, support the idea that there is selectivity for spatial position throughout core reward regions (Roesch et al, 2006; Strait et al, 2016; Tsujimoto et al, 2009; Yoo et al, 2018). This evidence was previously somewhat limited because of the possible confounds with attention or object identity (Padoa-Schioppa and Cai, 2011).…”

“…This evidence was previously somewhat limited because of the possible confounds with attention or object identity (Padoa-Schioppa and Cai, 2011). We recently performed a study of two core reward regions, orbitofrontal cortex (OFC) and ventral striatum (VS), that was designed to circumvent these problems (Yoo et al, 2018). Specifically, we used the asynchronous presentation of three choice options to control for attention and object identity in a variant of the Wisconsin Card Sorting Task (Sleezer and Hayden, 2016; Sleezer et al, 2016; Sleezer et al, 2017).…”

“…The motor function of dACC is strongly established (Morecraft and Van Hoesen, 1998; Paus, 2001). Likewise, the OFC is generally classified as earlier in the system, but has ostensible motor signals, albeit ones that are weaker than those observed in dACC (Roesch et al, 2006; Strait et al, 2016; Yoo et al, 2018). The gradual strengthening of motor signals presumably reflects two factors: the inclusion of new sources of motor-related information and the untangling of latent motor information present earlier.…”

“…Although any positional information is orthogonal to choice in current task, core reward regions encode this choice-orthogonal information. Figure modified from Yoo et al, 2018.…”

Exploratory noise governs both flexibility and spontaneous errors and is regulated by cocaine

“…Behavioral task. Specific details of this task have been reported previously (Sleezer and 648 Hayden, 2016; Sleezer et al, , 2017Yoo et al, 2018). Briefly, the present task was a 649 version of the CSST: an analogue of the WCST that was developed for use in nonhuman 650…”