Representation of Accumulating Evidence for a Decision in Two Parietal Areas

“The reported latencies are the times at which the ROC index significantly departed from 0.5 for at least 50 ms ( p 0.05; Hanley and McNeil, 1982).”

“Experimental control and stimulus presentation were achieved with either REX (Hays et al., 1982) in combination with the Psychophysics toolbox (Brainard, 1997) or with EXPO (developed by Peter Lennie, currently maintained by Rod Dotson, Center for Neural Science at New York University, New York,…”

“This is not the type of parallel processing that is often associated with neural networks (Rumelhart and McClelland, 1986) or computer systems but is instead a direct representation (Barlow, 1995) of a decision variable in the firing rates of neurons.”

“Such an accumulation of noisy evidence has been likened to a random walk or diffusion process (Ratcliff, 1978; Gold and Shadlen, 2002).”

“…occurs in circuits associated with provisional behavioral responses to stim- uli (Schall, 2001; Romo et al., 2004; Rorie and Newsome, 2005; Gold and Shadlen, 2007; Lemus et al., 2007; Andersen and Cui, 2009; Cisek and Kalaska, 2010; Hernández et al., 2010; Westendorff et al., 2010),…”

“We estimated the rate of this rise or decline by fitting lines to the response averages in the 150 ms epoch from the earliest point that these trends appear to emerge (see Materials and Methods).”

“…saccadic eye movements (Thier and Andersen, 1998), MIP neurons signal the spatial location of objects that are potential targets of reach movements (Mountcastle et al., 1975; Johnson et al., 1996; Snyder et al., 1997; Batista et al., 1999; Eskandar and Assad, 1999), as well as the outcome of…”

“We recorded from single neurons in areas LIP and MIP of two rhesus monkeys that were trained to judge the direction of motion of a dynamic random-dot display (Britten et al., 1992).”

“This task permits evaluation of delay-dependent (i.e. hippocampal) 17,21 and delay-independent (i.e. non-hippocampal) 22,23 memory processes under continuous low-dose isoflurane while simultaneously quantifying markers of arousal.”

“In addition, neither the spiking neural network nor the diffusion model specify the nature of the motor response, so the models can in principle apply equally to the initiation of saccadic eye movements, limb movements, or finger keypresses (Cisek et al., 2009; de Lafuente et al., 2015).”

“…Copyright © 2021 the authors the superior colliculus (SC) (Shadlen and Newsome, 1996, 2001; Kim and Shadlen, 1999; Horwitz and Newsome, 2001; Roitman and Shadlen, 2002; Ding and Gold, 2010, 2012; de Lafuente et al., 2015; Ding, 2015; Brody and Hanks, 2016; Yartsev et al., 2018).”

“While the LIP region accumulated evidence during both eye- and hand-movement trials, such modulations were specific for hand-movement trials in the MIP region (de Lafuente et al., 2015).”

“Neural signatures of evidence accumulation for perceptual and value computations have been found in associative and frontal cortical regions respectively (de Lafuente et al., 2015; Lin et al., 2020).”

“There is ample evidence that PPC neurons in non-human primates can respond to both saccades and arm movements, even in specialized areas such as the LIP and the parietal reach region (PRR) (de Lafuente, Jazayeri, & Shadlen, 2015; Snyder, Batista, & Andersen, 1997).”

“More recent analyses (De Lafuente et al., 2015) have looked at the population-level behaviors of LIP, specifically how they might vary depending on the kind of response that the monkey has to make.”

“To exploit these regularities, the brain must be able to measure time intervals between repetitive events (Buhusi and Meck 2005; de Lafuente, Jazayeri, and Shadlen 2015; Confais et al. 2012; Leon and Shadlen 2003), and use this timing information to anticipate future events (Goel and Buonomano…”

“…do not reflect a serial neural chain but arise from overlapping and intertwined neural processes (Cisek & Kalaska, 2005; Contemori et al., 2023; de Lafuente et al., 2015; Donner et al., 2009; Gold & Shadlen, 2003; Rogge et al., 2022; Roitman & Shadlen, 2002; Selen et al., 2012, 2023; Visser et…”

“…2015; Zhou et al., 2021), economists (de Hollander et al., 2020; Heng et al., 2020; Khaw et al., 2021; Prat-Carrabin & Woodford, 2022; Woodford, 2020) and neuroscientists (Donner et al., 2009; Kristan, 2008; Lafuente et al., 2015; O’Connell et al., 2018; Shadlen & Kiani, 2013) over several decades.”

“An important diagnostic signature of perceptual decision-making is the gradual accumulation of noise (5, 51) expected for most accumulation-to-bound decision models.”

“A salient result from this line of research is that the accumulation of sensory evidence for decisions is instantiated by neurons associated with motor planning (de Lafuente et al., 2015; Ding & Gold, 2010, 2012; Roitman & Shadlen, 2002).”

“The study of sensorimotor decision-making is currently enjoying an ever-increasing amount of attention across different species and levels of neuronal organization (Heekeren et al., 2008; de Lafuente et al., 2015; Hanks et al., 2015; Licata et al., 2017; O’Connell et al., 2018).”

“…explains decision-making under varied sensory contexts such as the perception of visual motion, and the discrimination of auditory and tactile stimuli (Brunton et al., 2013; Churchland et al., 2008; de Lafuente et al., 2015; Hernández-Pérez et al., 2020; Pinto et al., 2018; Ratcliff et al., 2016).”

“Neurons in these areas, such as in VIP, combine and align somatosensory and visual motion signals, allowing the visual analysis of approaching objects (Colby et al., 1993; Duhamel et al., 1998) potentially colliding with different body parts, face and head in particular.”

“To investigate flexible decision-making, a large body of studies examined the neural and behavioral basis of sensory based decisions 1–7 .”

“…using different effector modality such as arm reaching or finger pressing instead of saccadic eye movement in Shushruth et al. (2022) (Figure 5A, top); previous work (e.g. Lafuente et al., 2015) has shown than LIP neurons robustly encode decision variable regardless of reaches or saccades.”

“Similarly, models of animal behavior and perception describe sequential inference akin to navigation towards a ”decision boundary” [91, 31, 48, 56, 12, 22, 45, 71, 84, 85].”

“For instance, decision-variables are differentially implemented in the parietal cortex depending on whether a saccade or a reach task is the required response (De Lafuente et al., 2015).”

“One possibility is that evidence accumulation could be done by areas receiving the vlPFC inputs, such as in SC 31 or LIP 32,33 .”

“In contrast, MIP passed this test only for the reach task (de Lafuente et al., 2015, their Fig.”

“…tendency (Snyder et al., 1997; Calton et al., 2002; Cui and Andersen, 2007). de Lafuente et al. (2015) found that the discharge rate of neurons in both LIP and MIP was correlated with the amount of evidence accumulated over time to sup- port a particular choice (de Lafuente et al., 2015, their Fig.”

“…et al., 2008; Banks & Isham, 2009; Haynes, 2011; Bode et al., 2011; Fried et al., 2011; Moore, 2011; Harris, 2012; Soon et al., 2013; Nahmias et al. 2014; Salvaris & Haggard, 2014; de Lafuente et al., 2015; Perez et al., 2015; Hallett, 2007, 2016; Wisniewski et al., 2016; Frith & Haggard, 2018).”