Significance Statement: Grand neuroscience projects, such as connectomics, have a recurrent tendency to overpromise and underdeliver. Here I critically assess what is done in contrast with what is claimed about such endeavors, especially when the results are “horizontal” and the conclusions “vertical”, namely, when maps of one level (synaptic connections) are conflated with mappings between levels (neural function, animal behavior, cognitive processes). I argue that to suggest that connectomics will give us the mind of a mouse, a human or even a fly is theoretically flawed at many levels. Even if we, neuroscientists, do not take our metaphors literally, we should take them seriously.

In the article “Sleep Differentially Affects Early and Late Neuronal Responses to Sounds in Auditory and Perirhinal Cortices,” by Yaniv Sela, Aaron Joseph Krom, Lottem Bergman, Noa Regev, and Yuval Nir, which appeared on pages [2895–2905][1] of the April 1, 2020 issue, there was a labeling

In the article “The Hippocampal Film Editor: Sensitivity and Specificity to Event Boundaries in Continuous Experience,” by Aya Ben-Yakov and Richard N. Henson, which appeared on pages [10057–10068][1] of the November 21, 2018 issue, there was an error in the code used for analysis. Ben-Yakov

Impulsive decisions arise from preferring smaller but sooner rewards compared with larger but later rewards. How neural activity and attention to choice alternatives contribute to reward decisions during temporal discounting is not clear. Here we probed (1) attention to and (2) neural representation of delay and reward information in humans (both sexes) engaged in choices. We studied behavioral and frequency-specific dynamics supporting impulsive decisions on a fine-grained temporal scale using eye tracking and MEG recordings. In one condition, participants had to decide for themselves but pretended to decide for their best friend in a second prosocial condition, which required perspective taking. Hence, conditions varied in the value for themselves versus that pretending to choose for another person. Stronger impulsivity was reliably found across three independent groups for prosocial decisions. Eye tracking revealed a systematic shift of attention from the delay to the reward information and differences ...

Allelic variation in CHRNA3 , the gene encoding the α3 nicotinic acetylcholine receptor (nAChR) subunit, increases vulnerability to tobacco dependence and smoking-related diseases, but little is known about the role for α3-containing (α3*) nAChRs in regulating the addiction-related behavioral or physiological actions of nicotine. α3* nAChRs are densely expressed by medial habenula (mHb) neurons, which project almost exclusively to the interpeduncular nucleus (IPn) and are known to regulate nicotine avoidance behaviors. We found that Chrna3tm1.1Hwrt hypomorphic mice, which express constitutively low levels of α3* nAChRs, self-administer greater quantities of nicotine (0.4 mg kg−1 per infusion) than their wild-type littermates. Microinfusion of a lentivirus vector to express a short-hairpin RNA into the mHb or IPn to knock-down Chrna3 transcripts markedly increased nicotine self-administration behavior in rats (0.01–0.18 mg kg−1 per infusion). Using whole-cell recordings, we found that the α3β4* nAChR-select...

What happens in the brain when conscious awareness of the surrounding world fades? We manipulated consciousness in two experiments in a group of healthy males and measured brain activity with positron emission tomography. Measurements were made during wakefulness, escalating and constant levels of two anesthetic agents (experiment 1, n = 39), and during sleep-deprived wakefulness and non-rapid eye movement sleep (experiment 2, n = 37). In experiment 1, the subjects were randomized to receive either propofol or dexmedetomidine until unresponsiveness. In both experiments, forced awakenings were applied to achieve rapid recovery from an unresponsive to a responsive state, followed by immediate and detailed interviews of subjective experiences during the preceding unresponsive condition. Unresponsiveness rarely denoted unconsciousness, as the majority of the subjects had internally generated experiences. Unresponsive anesthetic states and verified sleep stages, where a subsequent report of mental content inclu...

Recent behavioral evidence implicates reward prediction errors (RPEs) as a key factor in the acquisition of episodic memory. Yet, important neural predictions related to the role of RPEs in episodic memory acquisition remain to be tested. Humans (both sexes) performed a novel variable-choice task where we experimentally manipulated RPEs and found support for key neural predictions with fMRI. Our results show that in line with previous behavioral observations, episodic memory accuracy increases with the magnitude of signed (i.e., better/worse-than-expected) RPEs (SRPEs). Neurally, we observe that SRPEs are encoded in the ventral striatum (VS). Crucially, we demonstrate through mediation analysis that activation in the VS mediates the experimental manipulation of SRPEs on episodic memory accuracy. In particular, SRPE-based responses in the VS (during learning) predict the strength of subsequent episodic memory (during recollection). Furthermore, functional connectivity between task-relevant processing areas ...

Covert spatial attention has a variety of effects on the responses of individual neurons. However, relatively little is known about the net effect of these changes on sensory population codes, even though perception ultimately depends on population activity. Here, we measured the EEG in human observers (male and female), and isolated stimulus-evoked activity that was phase-locked to the onset of attended and ignored visual stimuli. Using an encoding model, we reconstructed spatially selective population tuning functions from the pattern of stimulus-evoked activity across the scalp. Our EEG-based approach allowed us to measure very early visually evoked responses occurring ∼100 ms after stimulus onset. In Experiment 1, we found that covert attention increased the amplitude of spatially tuned population responses at this early stage of sensory processing. In Experiment 2, we parametrically varied stimulus contrast to test how this effect scaled with stimulus contrast. We found that the effect of attention on...

To accurately represent the world, the brain must distinguish between internally generated activity and activity evoked by external stimuli. When internal brain dynamics mimic stimulus-evoked activity patterns, phantom perception may occur ([Kenet et al., 2003][1]). One common form of phantom

Pamela J. Urrutia, Felipe Bodaleo, Daniel A. Bórquez, Yuta Homma, Victoria Rozes-Salvador, et al. (see pages [1636–1649][1]) Most cells have distinct subdomains with specialized functions. Epithelial cells, for example, have an apical domain, which typically faces a lumen, and a basolateral