Seeing what is not there shows the costs of perceptual learning.

Perceptual learning is an improvement in one's sensory abilities after training and is thought to help us to better adapt to the sensory environment. Here, we show that perceptual learning also can lead to misperceptions, such that subjects actually perceive stimuli when none are physically presented. After learning, subjects not only showed enhanced performance when tested with the motion direction of the trained stimulus but also often reported seeing dots moving in the trained direction when no stimulus was displayed. We further show that these misperceptions are not attributable to a response bias. These results show that there are costs as well as benefits to perceptual learning and that performance enhancements for a specific feature also can be accompanied by misperceptions of the visual environment.

[1]  W. Schultz.  Multiple reward signals in the brain , 2000, Nature Reviews Neuroscience.

[2]  M. Kilgard,et al.  Cortical map reorganization enabled by nucleus basalis activity. , 1998, Science.

[3]  D. Hubel,et al.  Extent of recovery from the effects of visual deprivation in kittens. , 1965, Journal of neurophysiology.

[4]  E. Loftus,et al.  The Formation of False Memories , 1995 .

[5]  L. Squire,et al.  Stability of long temporal gradients of retrograde amnesia in mice. , 1987, Behavioral and neural biology.

[6]  S. Hochstein,et al.  Attentional control of early perceptual learning. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[7]  S. Treue,et al.  Attentional Modulation Strength in Cortical Area MT Depends on Stimulus Contrast , 2002, Neuron.

[8]  A. Arnsten,et al.  Catecholamine regulation of the prefrontal cortex , 1997, Journal of psychopharmacology.

[9]  Emad N Eskandar,et al.  Parietal activity and the perceived direction of ambiguous apparent motion , 2003, Nature Neuroscience.

[10]  J. Maunsell,et al.  Neuronal correlates of inferred motion in primate posterior parietal cortex , 1995, Nature.

[11]  H. Dinse,et al.  Pharmacological Modulation of Perceptual Learning and Associated Cortical Reorganization , 2003, Science.

[12]  John H. R. Maunsell,et al.  Coding of image contrast in central visual pathways of the macaque monkey , 1990, Vision Research.

[13]  T Poggio,et al.  Fast perceptual learning in visual hyperacuity. , 1991, Science.

[14]  J. Maunsell,et al.  The Effect of Perceptual Learning on Neuronal Responses in Monkey Visual Area V4 , 2004, The Journal of Neuroscience.

[15]  E. Gibson,et al.  Principles of Perceptual Learning and Development , 1973 .

[16]  C. Furmanski,et al.  Learning Strengthens the Response of Primary Visual Cortex to Simple Patterns , 2004, Current Biology.

[17]  J. Assad,et al.  Dissociation of visual, motor and predictive signals in parietal cortex during visual guidance , 1999, Nature Neuroscience.

[18]  Z Liu,et al.  Perceptual learning in motion discrimination that generalizes across motion directions. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[19]  G. Orban,et al.  Practising orientation identification improves orientation coding in V1 neurons , 2001, Nature.

[20]  Paul T. Sowden,et al.  Perceptual learning of the detection of features in X-ray images: a functional role for improvements in adults' visual sensitivity? , 2000, Journal of experimental psychology. Human perception and performance.

[21]  T. Poggio,et al.  Fast perceptual learning in hyperacuity , 1995, Vision Research.

[22]  M. Posner,et al.  The attention system of the human brain. , 1990, Annual review of neuroscience.

[23]  Z L Lu,et al.  Perceptual learning reflects external noise filtering and internal noise reduction through channel reweighting. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[24]  L. Vaina,et al.  Neural systems underlying learning and representation of global motion. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[25]  B. Moulden,et al.  The Standard Deviation of Luminance as a Metric for Contrast in Random-Dot Images , 1990, Perception.

[26]  David Marr,et al.  VISION A Computational Investigation into the Human Representation and Processing of Visual Information , 2009 .

[27]  T. Robbins,et al.  Distinct Changes in Cortical Acetylcholine and Noradrenaline Efflux during Contingent and Noncontingent Performance of a Visual Attentional Task , 2001, The Journal of Neuroscience.

[28]  Aaron R. Seitz,et al.  Psychophysics: Is subliminal learning really passive? , 2003, Nature.

[29]  Takeo Watanabe,et al.  Perceptual learning without perception , 2001, Nature.

[30]  S. Kosslyn,et al.  The role of area 17 in visual imagery: convergent evidence from PET and rTMS. , 1999, Science.

[31]  E. Bizzi,et al.  Neuronal Correlates of Motor Performance and Motor Learning in the Primary Motor Cortex of Monkeys Adapting to an External Force Field , 2001, Neuron.

[32]  C. Gilbert,et al.  The Neural Basis of Perceptual Learning , 2001, Neuron.

[33]  J. Kaas,et al.  The reorganization of somatosensory cortex following peripheral nerve damage in adult and developing mammals. , 1983, Annual review of neuroscience.

[34]  S. Grossberg.  How does a brain build a cognitive code , 1980 .

[35]  D. Wilkin,et al.  Neuron , 2001, Brain Research.

[36]  S. Zeki.  Functional organization of a visual area in the posterior bank of the superior temporal sulcus of the rhesus monkey , 1974, The Journal of physiology.

[37]  M. Lévesque.  Perception , 1986, The Yale Journal of Biology and Medicine.

[38]  M. Fahle,et al.  The role of visual field position in pattern–discrimination learning , 1997, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[39]  G. Orban,et al.  Human perceptual learning in identifying the oblique orientation: retinotopy, orientation specificity and monocularity. , 1995, The Journal of physiology.

[40]  Bruce D. McCandliss,et al.  Testing the Efficiency and Independence of Attentional Networks , 2002, Journal of Cognitive Neuroscience.

[41]  S. Hochstein,et al.  Task difficulty and the specificity of perceptual learning , 1997, Nature.

[42]  Elizabeth F. Loftus,et al.  Warning: Even memory for faces may be contagious , 1980 .

[43]  E. Gibson.  Principles of Perceptual Learning and Development , 1969 .

[44]  M. Fahle,et al.  Effects of biased feedback on learning and deciding in a vernier discrimination task , 1999, Vision Research.

[45]  C. Gilbert,et al.  Perceptual learning of spatial localization: specificity for orientation, position, and context. , 1997, Journal of neurophysiology.

[46]  M. Chun,et al.  Contextual cueing of visual attention , 2022 .

[47]  E. Loftus,et al.  Changing beliefs and memories through dream interpretation , 1999 .

[48]  José E. Náñez,et al.  Greater plasticity in lower-level than higher-level visual motion processing in a passive perceptual learning task , 2002, Nature Neuroscience.

[49]  C. Gilbert,et al.  Perceptual learning and top-down influences in primary visual cortex , 2004, Nature Neuroscience.

[50]  Alvaro Pascual-Leone,et al.  Transcranial magnetic stimulation and neuroplasticity , 1998, Neuropsychologia.

[51]  H. Barlow.  Vision: A computational investigation into the human representation and processing of visual information: David Marr. San Francisco: W. H. Freeman, 1982. pp. xvi + 397 , 1983 .

[52]  D. Hubel,et al.  Effects of monocular deprivation in kittens , 1964, Naunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie.

[53]  K. H. Britten,et al.  Neuronal plasticity that underlies improvement in perceptual performance. , 1994, Science.

[54]  D Sagi,et al.  Where practice makes perfect in texture discrimination: evidence for primary visual cortex plasticity. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[55]  M. Merzenich,et al.  Cortical remodelling induced by activity of ventral tegmental dopamine neurons , 2001, Nature.

[56]  Edward F Chang,et al.  Temporal plasticity in the primary auditory cortex induced by operant perceptual learning , 2004, Nature Neuroscience.

[57]  A. Fiorentini,et al.  Perceptual learning specific for orientation and spatial frequency , 1980, Nature.

[58]  R Sekuler,et al.  Adaptive processing of visual motion. , 1981, Journal of experimental psychology. Human perception and performance.

[59]  P. Maquet,et al.  Neural correlates of perceptual learning: A functional MRI study of visual texture discrimination , 2002, Proceedings of the National Academy of Sciences of the United States of America.