Perceptual learning

…change during adult categorization learning remains debated. Some studies suggest that neural responses of visual areas change with training, e.g., during perceptual learning. Others propose that behavioral changes are readily explained by adjustments in the readout of information by downstream frontoparietal regions, with sensory regions remaining largely unchanged. Here, we investigated changes in neural representations in macaque visual areas V4 and IT during the learning of novel catego

The mammalian striatum is critically involved in perceptual decision-making, where disrupted dopamine transmission leads to perceptual disturbances such as hallucinations. The precise mechanism by which striatal dopamine contributes to perceptual decisions is not known. We investigated this by developing a circuit model in which perceptual learning and value learning are implemented in parallel corticostriatal loops to inform action selection. Previous models of corticostriatal plasticity have focused primarily on how reward prediction errors signaled by dopamine enable value learning in the v

Organisms continually tune their perceptual systems to the features they encounter in their environment. We have studied how this experience reorganizes the synaptic connectivity of neurons in the olfactory (piriform) cortex of the mouse. We developed an approach to measure synaptic connectivity in vivo, training a deep convolutional network to reliably identify monosynaptic connections from the spike-time cross-correlograms of 4.4 million single-unit pairs. This revealed that excitatory piriform neurons that respond similarly to each other are more likely to be connected. We asked whether thi

The adult human brain shows remarkable plasticity following perceptual learning, resulting in improved visual sensitivity. However, such improvements in visual perception commonly require extensive practice and hours of training. Therefore, an ongoing challenge has been to improve the efficiency of such prolonged repetition-based learning. Here we aimed to uncover whether improving the efficiency of repetition-based learning with brief memory reactivations engages distinct neural mechanisms. To address this question, human participants encoded a visual discrimination task. Then, three sessions

The brain and its inherent functions can be modified by various forms of learning. Learning-induced changes are seen even in basic perceptual functions. In particular, repeated training in a perceptual task can lead to a significant improvement in the trained task—a phenomenon known as perceptual learning. There has been a long-standing debate about the mechanisms of perceptual learning. In this talk, I will present results from our series of electrophysiological studies. These studies have consistently shown that perceptual learning is mediated by concerted changes in both perceptual and cogn

Perceptual learning has been associated with altered sensory cortical representations in trained animals relative to naive ones. While there is substantial variability across animals in the degree of behavioral learning and the associated changes in neural representations, we lack an account of how experiences during learning may drive these differences. Here we address this question in the context of an auditory learning task, by combining experiments and computational modeling. Mice were progressively trained to classify tones as a single, center frequency or non-center by licking left or ri

Training subjects to discriminate fine details of stimuli can improve perceptual capabilities, a phenomenon known as perceptual learning (PL). Experiments have discovered intriguing psychophysical findings despite the simple stimuli (e.g., Gabor patches) and training procedures (e.g., 2AFC task) involved. Finding explanations for these learning effects could shed light on sensory plasticity in adulthood and constraints in sensory processing. A profound feature of (visual) PL is its slow learning speed, which can take days of training and hundreds or thousands of trials for the performance to s

Perceptual learning (PL) is defined as long-term performance improvement on a perceptual task as a result of perceptual experience (Sasaki, Nanez& Watanabe, 2011, Nat Rev Neurosci, 2011). We first found that PL occurs for task-irrelevant and subthreshold features and that pairing task-irrelevant features with rewards is the key to form task-irrelevant PL (TIPL) (Watanabe, Nanez & Sasaki, Nature, 2001; Watanabe et al, 2002, Nature Neuroscience; Seitz & Watanabe, Nature, 2003; Seitz, Kim & Watanabe, 2009, Neuron; Shibata et al, 2011, Science). These results suggest that PL occurs as a result of

Single neurons in visual cortex provide unreliable measurements of visual features due to their high trial-to-trial variability. It is not known if this “noise” extends its effects over large neural populations to impair the global encoding of stimuli. We recorded simultaneously from ∼20,000 neurons in mouse primary visual cortex (V1) and found that the neural populations had discrimination thresholds of ∼0.34° in an orientation decoding task. These thresholds were nearly 100 times smaller than those reported behaviourally in mice. The discrepancy between neural and behavioural discrimination