Reconstructions of Information in Visual Spatial Working Memory Degrade with Memory Load

• DOI: 10.1016/j.cub.2014.07.066
• Publication Date: 2014-09-05T13:19:28Z
• Authors: Thomas C. Sprague; Edward F. Ester; John T. Serences
• Keywords: Adult; Male; Agricultural and Biological Sciences(all); Biochemistry, Genetics and Molecular Biology(all); Magnetic Resonance Imaging; Frontal Lobe; Young Adult; 03 medical and health sciences; Memory, Short-Term; 0302 clinical medicine; Image Processing, Computer-Assisted; Visual Perception; Humans; Female; Photic Stimulation; Spatial Memory

Working memory (WM) enables the maintenance and manipulation of information relevant to behavioral goals. Variability in WM ability is strongly correlated with IQ [1Kane M.J. Engle R.W. The role prefrontal cortex working-memory capacity, executive attention, general fluid intelligence: an individual-differences perspective.Psychon. Bull. Rev. 2002; 9: 637-671Crossref PubMed Scopus (1571) Google Scholar], function impaired many neurological psychiatric disorders [2Park S. Holzman P.S. Schizophrenics show spatial working deficits.Arch. Gen. Psychiatry. 1992; 49: 975-982Crossref (799) Scholar, 3Luck S.J. Vogel E.K. Visual capacity: from psychophysics neurobiology individual differences.Trends Cogn. Sci. 2013; 17: 391-400Abstract Full Text PDF (622) suggesting that this system a core component higher cognition. storage thought be mediated by patterns activity neural populations selective for specific properties (e.g., color, orientation, location, motion direction) memoranda [4Serences J.T. Ester E.F. Awh E. Stimulus-specific delay human primary visual cortex.Psychol. 2009; 20: 207-214Crossref (507) 5Jerde T.A. Merriam E.P. Riggall A.C. Hedges J.H. Curtis C.E. Prioritized maps space frontoparietal cortex.J. Neurosci. 2012; 32: 17382-17390Crossref (135) 6Emrich S.M. Larocque J.J. Postle B.R. Distributed sensory reflect precision multiple items maintained short-term memory.J. 33: 6516-6523Crossref (223) 7Riggall relationship between elevated as measured functional magnetic resonance imaging.J. 12990-12998Crossref (233) 8Ester Anderson D.E. Serences A measure 25: 754-761Crossref (120) 9Harrison S.A. Tong F. Decoding reveals contents early areas.Nature. 458: 632-635Crossref (829) 10Christophel T.B. Hebart M.N. Haynes J.-D. parietal 12983-12989Crossref (183) 11Funahashi Bruce C.J. Goldman-Rakic Mnemonic coding monkey's dorsolateral Neurophysiol. 1989; 61: 331-349Crossref (1962) 12Pasternak T. Greenlee M.W. primate systems.Nat. 2005; 6: 97-107Crossref (494) 13Albers A.M. Kok P. Toni I. Dijkerman H.C. de Lange F.P. Shared representations mental imagery cortex.Curr. Biol. 23: 1427-1431Abstract (250) Scholar]. Accordingly, models propose differences amplitude these population responses should related performance [14Bays P.M. Noise accounts errors 2014; 34: 3632-3645Crossref (128) 15Ma W.J. Husain M. Bays Changing concepts memory.Nat. 347-356Crossref (633) Here, we used imaging image reconstruction technique based on encoding model [16Sprague T.C. Attention modulates priority occipital, frontal cortices.Nat. 16: 1879-1887Crossref (127) Scholar] visualize quantify population-level supported multivoxel activation within regions while participants precisely remembered location(s) zero, one, or two small stimuli. We successfully reconstructed images containing remembered—but not forgotten—locations parietal, using delay-period patterns. Critically, locations both decreased increasing load. These results suggest load conditions are changes fidelity large-scale response profiles distributed across areas cortex.