Spatial and temporal distribution of visual information coding in lateral prefrontal cortex.

Mikiko Kadohisa,Mark J Buckley,Natasha Sigala,David Gaffan,Philippe Petrov,Makoto Kusunoki,John Duncan

doi:10.1111/ejn.12754

Abstract

Prefrontal neurons code many kinds of behaviourally relevant visual information. In behaving monkeys, we used a cued target detection task to address coding of objects, behavioural categories and spatial locations, examining the temporal evolution of neural activity across dorsal and ventral regions of the lateral prefrontal cortex (encompassing parts of areas 9, 46, 45A and 8A), and across the two cerebral hemispheres. Within each hemisphere there was little evidence for regional specialisation, with neurons in dorsal and ventral regions showing closely similar patterns of selectivity for objects, categories and locations. For a stimulus in either visual field, however, there was a strong and temporally specific difference in response in the two cerebral hemispheres. In the first part of the visual response (50–250 ms from stimulus onset), processing in each hemisphere was largely restricted to contralateral stimuli, with strong responses to such stimuli, and selectivity for both object and category. Later (300–500 ms), responses to ipsilateral stimuli also appeared, many cells now responding more strongly to ipsilateral than to contralateral stimuli, and many showing selectivity for category. Activity on error trials showed that late activity in both hemispheres reflected the animal's final decision. As information is processed towards a behavioural decision, its encoding spreads to encompass large, bilateral regions of prefrontal cortex.

Highlights

Recordings from the lateral prefrontal cortex (LPFC) of behaving monkeys show extensive coding of visual information (e.g. Watanabe, 1986; Miller et al, 1996)
Though cells were randomly selected across a large region of the LPFC, many showed significant coding of the location, object and category information required in the task
There was no evidence for more frequent object coding in the ventrolateral prefrontal cortex (VLPFC), or location coding in the dorsolateral prefrontal cortex (DLPFC)

Summary

Introduction

Recordings from the lateral prefrontal cortex (LPFC) of behaving monkeys show extensive coding of visual information (e.g. Watanabe, 1986; Miller et al, 1996). Recordings from the lateral prefrontal cortex (LPFC) of behaving monkeys show extensive coding of visual information Influential proposal held that ventrolateral prefrontal cortex (VLPFC) is specialised for coding of complex object information, while dorsolateral prefrontal cortex (DLPFC) processes spatial location Different regions of LPFC have different patterns of anatomical connectivity. Complex visual information is transmitted to the VLPFC from inferotemporal cortex (Ungerleider et al, 1989), while DLPFC has greater connectivity to parietal and motor regions (Rushworth, 2000). Widespread connections within frontal cortex, suggest extensive transmission of information between regions (Pucak et al, 1996). In line with widespread information exchange, many electrophysiological studies report substantial regional overlap for coding of different kinds of information In line with widespread information exchange, many electrophysiological studies report substantial regional overlap for coding of different kinds of information (e.g. Watanabe, 1986; White & Wise, 1999; Wallis et al, 2001), and single cells with complex patterns of joint selectivity for several stimulus features (Rao et al, 1997; Tsujimoto et al, 2012; Rigotti et al, 2013)

Methods

Results

Conclusion