The Dynamics of Functional Brain Networks: Integrated Network States during Cognitive Task Performance

Rapid variations in cortical state during wakefulness have a strong influence on neural and behavioural responses and are tightly coupled to changes in pupil size across species. However, the physiological processes linking cortical state and pupil variations are largely unknown. Here we demonstrate that these rapid variations, during both quiet waking and locomotion, are highly correlated with fluctuations in the activity of corticopetal noradrenergic and cholinergic projections. Rapid dilations of the pupil are tightly associated with phasic activity in noradrenergic axons, whereas longer-lasting dilations of the pupil, such as during locomotion, are accompanied by sustained activity in cholinergic axons. Thus, the pupil can be used to sensitively track the activity in multiple neuromodulatory transmitter systems as they control the state of the waking brain.

Pupil fluctuations track rapid changes in adrenergic and cholinergic activity in cortex.

ONE of the most remarkable examples of sudden and rapid development of a new scientific method and a new and extensive body of scientific fact is to be seen in the growth of the study of animal psychology during the last ten or a dozen years. As in the case of the general science of psychology, the change came with the introduction of experiment as the fundamental method of investigation, but the transition was accentuated by a craving for objectivity of results, which focussed the attention upon the objective performance or behaviour of the animal under examination, not only to the detriment, but even, in the case of many observers, to the complete neglect of speculation as to its psychical life. If the new psychology claimed to be a psychology without a soul, the new animal psychology threatened, and still threatens, to become an animal psychology without consciousness. Many investigators have indeed openly declared for this ideal-not denying the presence of consciousness, but regarding it as of no importance or value in an explanatory scientific system. Nevertheless signs are not wanting in the most recent work of a healthy reaction from this extreme view, based as much upon observed fact as upon a priori speculation. Animal Intelligence: Experimental Studies. By E. L. Thorndike. Pp. viii + 297. (New York: The Macmillan Co.; London: Macmillan and Co., Ltd., 1911.) Price 7s. net.

Animal Intelligence: Experimental Studies

https://cyberleninka.org/article/n/1450567.pdf

Beyond eye gaze: What else can eyetracking reveal about cognition and cognitive development?

Pupillometry research has experienced an enormous revival in the last two decades. Here we briefly review the surge of recent studies on task-evoked pupil dilation in the context of cognitive control tasks with the primary aim being to evaluate the feasibility of using pupil dilation as an index of effort exertion, rather than task demand or difficulty. Our review shows that across the three cognitive control domains of updating, switching, and inhibition, increases in task demands typically leads to increases in pupil dilation. Studies show a diverging pattern with respect to the relationship between pupil dilation and performance and we show how an effort account of pupil dilation can provide an explanation of these findings. We also discuss future directions to further corroborate this account in the context of recent theories on cognitive control and effort and their potential neurobiological substrates.

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Pupil dilation as an index of effort in cognitive control tasks: A review

Relationships between Pupil Diameter and Neuronal Activity in the Locus Coeruleus, Colliculi, and Cingulate Cortex.

The effects of the general opioid antagonist, naltrexone, on the acquisition and expression of flavor preferences conditioned by the sweet taste of fructose were examined. Food-restricted rats were trained over eight daily alternating one-bottle sessions (2 h) to drink an 8% fructose solution containing one novel flavor (CS+/F) and a less preferred 0.2% saccharin solution containing a different flavor (CS−/S). Four groups of rats were treated daily with either saline (control group) or naltrexone doses of 0.1, 1.0, or 5.0 mg/kg during training. Preferences were assessed in two-bottle tests with the CS+/S and CS−/S flavors presented in 0.2% saccharin solutions following saline injections. Naltrexone dose-dependently reduced fructose and saccharin intakes during training, confirming the drug's well-known suppressive effect on the intake of sweet solutions. Despite their reduced training intakes, the naltrexone groups displayed preferences for the CS+/S over the CS−/S (72–86%) that were similar to that of the control group (78%). The effect of naltrexone on the expression of the CS+/S flavor preference was evaluated by treating control rats with naltrexone (0.1–5 mg/kg) prior to CS+/S vs. CS−/S choice tests. The drug doses produced a dose-dependent reduction in CS+/S intake but did not significantly attenuate the CS+/S preference. These data are consistent with the relative inability of naltrexone to reduce flavor–flavor conditioning by sucrose in sham-feeding rats and flavor-nutrient conditioning in rats receiving intragastric sucrose infusions. In contrast, dopamine antagonists reduce both sucrose- and fructose-conditioned flavor preferences, which indicates the sensitivity of these conditioning paradigms to neuropharmacological manipulations. These data indicate that the endogenous opioid system, unlike the dopamine system, does not play a major role in either the acquisition or expression of flavor preference learning as measured in two-bottle choice tests.

Naltrexone does not prevent acquisition or expression of flavor preferences conditioned by fructose in rats.

The cingulate cortex contributes to complex, adaptive behaviors, but the exact nature of its contributions remains unresolved. Proposals from previous studies, including evaluating past actions or selecting future ones, have been difficult to distinguish in part because of an incomplete understanding of the task-relevant variables that are encoded by individual cingulate neurons. In this study, we recorded from individual neurons in parts of both the anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) in 2 male rhesus monkeys performing a saccadic reward task. The task required them to use adaptive, feedback-driven strategies to infer the spatial location of a rewarded saccade target in the presence of different forms of uncertainty. We found that task-relevant, spatially selective feedback signals were encoded by the activity of individual neurons in both brain regions, with stronger selectivity for spatial choice and reward-target signals in PCC and stronger selectivity for feedback in ACC. Moreover, neurons in both regions were sensitive to sequential effects of feedback that partly reflected sequential behavioral patterns. However, neither brain region exhibited systematic modulations by the blockwise conditions that governed the reliability of the trial-by-trial feedback and drove adaptive behavioral patterns. There was also little evidence that single-neuron responses in either brain region directly predicted the extent to which feedback and contextual information were used to inform choices on the subsequent trial. Thus, certain cingulate neurons encode diverse, evaluative signals needed for adaptive, feedback-driven decision-making, but those signals may be integrated elsewhere in the brain to guide actions.SIGNIFICANCE STATEMENT Effective decision-making in dynamic environments requires adapting to changes in feedback and context. The anterior and posterior cingulate cortex have been implicated in adaptive decision-making, but the exact nature of their respective roles remains unresolved. Here we compare patterns of task-driven activity of subsets of individual neurons from parts of the two brain regions in monkeys performing a saccadic task with dynamically changing reward locations. We find evidence for regional specializations in neural representations of choice and feedback, including task-relevant modulations of activity that could be used for performance monitoring. However, we find little evidence that these neural representations are used directly to adjust choice behavior, which thus likely requires integration of these signals elsewhere in the brain.

https://www.jneurosci.org/content/jneuro/39/34/6668.full.pdf

Individual Neurons in the Cingulate Cortex Encode Action Monitoring, Not Selection, during Adaptive Decision-Making

Long-term utility and complication profile of open craniotomy for biopsy in patients with idiopathic encephalitis.

Sensory perception often requires our brains to interpret ambiguous information relayed by our sensory organs to form categorical decisions about the world ([Gold and Shadlen, 2007][1]; [Kable and Glimcher, 2009][2]). An influential paradigm for studying this interpretation process, known as a

https://www.jneurosci.org/content/jneuro/35/27/9783.full.pdf

Yin Li

Papers

Relationships between Pupil Diameter and Neuronal Activity in the Locus Coeruleus, Colliculi, and Cingulate Cortex.

Naltrexone does not prevent acquisition or expression of flavor preferences conditioned by fructose in rats.

Individual Neurons in the Cingulate Cortex Encode Action Monitoring, Not Selection, during Adaptive Decision-Making

Long-term utility and complication profile of open craniotomy for biopsy in patients with idiopathic encephalitis.

Is There a General Role for the Monkey Oculomotor System in Perceptual Decision-Making?