Current and future goals are represented in opposite patterns in object-selective cortex
- Vrije Universiteit Amsterdam, Netherlands
Abstract
Adaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files and source code files have been provided for Figures 2,3,4, 5, S1,S2,S3 and the fMRI data is made available via the open science framework:""Current and Future Goals Are Represented in Opposite Patterns in Object-Selective Cortex."" Open Science Framework. May 31. osf.io/hcp47.For the newly added experiment 2, the data and scripts have also been provided.
-
Current and Future Goals Are Represented in Opposite Patterns in Object-Selective CortexOpen Science Framework, osf.io/hcp47.
Article and author information
Author details
Anouk Mariette van Loon
Johannes Jacobus Fahrenfort
Funding
European Research Council (615423)
- Christian N L Olivers
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Human subjects: Twenty-four healthy volunteers participated in Experiment 1 and twenty-five healthy volunteers participated in Experiment 2. The experiment was approved by the Ethical Committee of the Faculty of Social and Behavioral Sciences, University of Amsterdam and conformed to the Declaration of Helsinki. All subjects provided written informed consent and consent to publish.
Copyright
© 2018, van Loon et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,835
- views
-
- 453
- downloads
-
- 60
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Current and future goals are represented in opposite patterns in object-selective cortex
eLife 7:e38677.
https://doi.org/10.7554/eLife.38677
Further reading
-
- Neuroscience
At many vertebrate synapses, presynaptic functions are tuned by expression of different Cav2 channels. Most invertebrate genomes contain only one Cav2 gene. The Drosophila Cav2 homolog, cacophony (cac), induces synaptic vesicle release at presynaptic active zones (AZs). We hypothesize that Drosophila cac functional diversity is enhanced by two mutually exclusive exon pairs that are not conserved in vertebrates, one in the voltage sensor and one in the loop binding Caβ and Gβγ subunits. We find that alternative splicing in the voltage sensor affects channel activation voltage. Only the isoform with the higher activation voltage localizes to AZs at the glutamatergic Drosophila larval neuromuscular junction and is imperative for normal synapse function. By contrast, alternative splicing at the other alternative exon pair tunes multiple aspects of presynaptic function. While expression of one exon yields normal transmission, expression of the other reduces channel number in the AZ and thus release probability. This also abolishes presynaptic homeostatic plasticity. Moreover, reduced channel number affects short-term plasticity, which is rescued by increasing the external calcium concentration to match release probability to control. In sum, in Drosophila alternative splicing provides a mechanism to regulate different aspects of presynaptic functions with only one Cav2 gene.
-
- Neuroscience
Sleep loss increases AMPA-synaptic strength and number in the neocortex. However, this is only part of the synaptic sleep loss response. We report an increased AMPA/NMDA EPSC ratio in frontal-cortical pyramidal neurons of layers 2–3. Silent synapses are absent, decreasing the plastic potential to convert silent NMDA to active AMPA synapses. These sleep loss changes are recovered by sleep. Sleep genes are enriched for synaptic shaping cellular components controlling glutamate synapse phenotype, overlap with autism risk genes, and are primarily observed in excitatory pyramidal neurons projecting intra-telencephalically. These genes are enriched with genes controlled by the transcription factor, MEF2c, and its repressor, HDAC4. Sleep genes can thus provide a framework within which motor learning and training occur mediated by the sleep-dependent oscillation of glutamate-synaptic phenotypes.
